Gas Turbine

NONRESIDENT TRAINING COURSE

Gas Turbine Systems Technician (Electrical) 3/Gas Turbine Systems Technician (Mechanical) 3, Volume 2NAVEDTRA 14114

DISTRIBUTION STATEMENT A: Approved for public release; distribution is unlimited.

SUMMARY OFGAS TURBINE SYSTEMS TECHNICIAN

(ELECTRICAL) 3/GAS TURBINE SYSTEMSTECHNICIAN (MECHANICAL) 3

TRAINING MANUALS

VOLUME 1

Gas Turbine Systems Technician (Electrical) 3/Gas Turbine SystemsTechnician (Mechanical) 3, Volume 1, NAVEDTRA 14113, covers informa-tion on the ratings, administration and programs, tools and test equipment,electrical theory and mechanical theory, piping systems and their components,support and auxiliary equipment, the power train, the controllable pitchsystems, and engineering electrical systems and their maintenance procedures.

VOLUME 2

Gas Turbine Systems Technician (Electrical) 3/Gas Turbine SystemsTechnician (Mechanical) 3, Volume 2, NAVEDTRA 14114, contains infor-mation on the basic fundamentals of gas turbines, the LM2500 gas turbine,the Allison 501-K17 gas turbine generator, engineering systems, electric plantoperation, and the control consoles for the CG-, DD-, and FFG-classships.

PREFACE

By enrolling in this self-study course, you have demonstrated a desire to improve yourself and the Navy. Remember, however, this self-study course is only one part of the total Navy training program. Practical experience, schools, selected reading, and your desire to succeed are also necessary to successfully round out a fully meaningful training program.

COURSE OVERVIEW: This course is designed to assist enlisted personnel in the advancement to GSE Third Class Petty Officer/GSM Third Class Petty Officer. In completing this course you will demonstrate a knowledge of course materials by correctly answering questions on the following topics: gas turbine fundamentals, the LM2500 gas turbine engine, ship’s service gas turbine generator sets, engineering auxiliary and support systems, PACC and PLCC for DD- and CG-class ships, PCC and LOP for FFG-class ships, machinery control system for DDG-class ships, electrical plant operation, and auxiliary equipment and consoles.

THE COURSE: This self-study course is organized into subject matter areas, each containing learning objectives to help you determine what you should learn along with text and illustrations to help you understand the information. The subject matter reflects day-to-day requirements and experiences of personnel in the rating or skill area. It also reflects guidance provided by Enlisted Community Managers (ECMs) and other senior personnel, technical references, instructions, etc., and either the occupational or naval standards, which are listed in the Manual of Navy Enlisted Manpower Personnel Classifications and Occupational Standards, NAVPERS 18068.

THE QUESTIONS: The questions that appear in this course are designed to help you understand the material in the text.

VALUE: In completing this course, you will improve your military and professional knowledge. Importantly, it can also help you study for the Navy-wide advancement in rate examination. If you are studying and discover a reference in the text to another publication for further information, look it up.

1991 Edition Prepared by GSCS Bradford E. Edwards and

GSEC(SW) Anthony T. Askew

Published by NAVAL EDUCATION AND TRAINING

PROFESSIONAL DEVELOPMENT AND TECHNOLOGY CENTER

NAVSUP Logistics Tracking Number0504-LP-026-7800

CONTENTS

CHAPTER

1. Gas Turbine Engine Fundamentals . . . . . . . . . . . . . . . . . .

2. LM2500 Gas Turbine Engine . . . . . . . . . . . . . . . . . . . . . . .

3. Ship’s Service Gas Turbine Generator Sets . . . . . . . . . . .

4. Engineering Auxiliary and Support Systems . . . . . . . . . .

5. PACC and PLCC for DD- and CG-class Ships . . . . . . .

6. PCC and LOP for FFG-class Ships . . . . . . . . . . . . . . . . .

7. Machinery Control System . . . . . . . . . . . . . . . . . . . . . . . .

8. Electrical Plant Operation. . . . . . . . . . . . . . . . . . . . . . . . . .

9. Auxiliary Equipment and Consoles . . . . . . . . . . . . . . . . . .

APPENDIX

I. Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

II. Abbreviations and Acronyms . . . . . . . . . . . . . . . . . . . . . . .

Page

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AII-1

INDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . INDEX-1

CHAPTER 1

GAS TURBINE ENGINE FUNDAMENTALS

This chapter will help you understand thehistory and development of gas turbine engines(GTEs). It will help you become familiar with thebasic concepts used by GTE designers, followdiscussions of how the Brayton cycle describes thethermodynamic processes in a GTE, and learnhow various conditions and design limitationsaffect GTE performance. How a GTE developsand uses hot gases under pressure is alsothoroughly discussed in this chapter. After readingthis chapter, you should have the basic knowledgeto be able to describe the principal componentsof GTEs and their construction, the GTE auxiliarysystems, and also be familiar with the nomen-clature related to GTEs and GTE technology. Amore in-depth coverage of the individual systemsand components for the General Electric LM2500GTE will be discussed in chapter 2 of thisTRAMAN. To refresh your memory about thedifferent laws and principles discussed in thischapter, refer to NAVEDTRA 10563, volume 1,chapter 4.

the reaction principle (Newton’s third law) existedin early history. However, practical applicationof the reaction principle. occurred only recently.This delay is due to the slow progress of technicalachievement in engineering, fuels, and metallurgy(the science of metals).

Hero, a scientist in Alexandria, Egypt, wholived between the first and third centuries A.D.,described what is considered to be the first jetengine (the aeolipile). This device (fig. 1-1) ismentioned in sources dating back as far as 250B.C., and many sources credit Hero as theinventor.

History records several examples of otherscientists using the principle of expanding gasesto perform work. Among these were inventions

HISTORY AND BACKGROUND

Until recent years, GTE technology and jetengine technology have overlapped a great deal.The same people have worked in both fields, andthe same sciences have been applied to both typesof engines. In the past, the jet engine has beenused more as a part of aviation. The GTE hasbeen used for electric generation, ship propulsion,and even experimental automobile propulsion.Many operational turbine power plants use aderivative of an aircraft jet engine as a gasgenerator (GG). When used as such, the enginemust be modified by the addition of a powerturbine (PT) and reduction gearing to completethe plant.

In nature, the squid was using jet propulsionlong before scientists thought of it. Examples of Figure 1-1.—Hero’s aeolipile.

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Figure 1-2.—da Vinci’s chimney jack.

Figure 1-3.—Branca’s jet turbine.

of Leonardo da Vinci (around 1500 A.D.) (fig.1-2) and Giovanni Branca (in 1629) (fig. 1-3).

In the 1680s Sir Isaac Newton described thelaws of motion (discussed in GSE3/GSM3,volume 1, chapter 4). All devices that use thetheory of jet propulsion are based on these laws.Newton’s steam wagon is an example of the reac-tion principle (fig. 1-4).

In 1791 John Barber, an Englishman, sub-mitted the first patent for a design that used thethermodynamic cycle of the modern GTE. Thisdesign was also suggested for jet propulsion.

TWENTIETH-CENTURYDEVELOPMENT

The patented application for the GTE as weknow it today was submitted in 1930 by another

Figure 1-4.—Newton’s steam wagon.

Englishman, Sir Frank Whittle. His patent wasfor a jet aircraft engine. Whittle used his ownideas along with the contributions of otherscientists. After several failures, he came up witha working GTE.

American Development

The United States did not go into the GTEfield until 1941. General Electric was thenawarded a contract to build an American versionof the British-designed Whittle aircraft engine.The engine and airframe were both built in 1 year.The first jet aircraft was flown in this country inOctober 1942.

In late 1941 Westinghouse Corporation wasawarded a contract to design and build the firstall-American GTE. Their engineers designedthe first axial-flow compressor and annularcombustion chamber. Both of these ideas, withminor changes, are the basis for most modern gasturbines in use today.

Marine Gas Turbine Engine

Using a GTE to propel a ship goes back to1937 when a Pescara free piston gas engine wasused experimentally with a GTE. The free pistonengine, or gasifier (fig. 1-5), is a form of dieselengine. It uses air cushions instead of a crankshaftto return the pistons. It was an effective producerof pressurized gases. The German navy used it intheir submarines during World War II as an aircompressor. In 1953 the French placed in servicetwo small vessels powered by a free pistonengine/GTE combination. In 1957 the liberty shipWilliam Patterson went into service on atransatlantic run. It had six free piston enginesdriving two turbines.

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Figure 1-5.—Free piston engine.

At that time applications of the use of a rotarygasifier to drive a main propulsion turbine wereused. The gasifier (used as a compressor) wasusually an aircraft jet engine or turboprop frontend. In 1947 the Motor Gun Boat 2009 of theBritish navy used a 2500-hp GTE. In 1951 thetanker Auris, in an experimental application,replaced one of four diesel engines with a1200-hp GTE. In 1956 the gas turbine ship JohnSergeant had a very efficient installation. It gavea fuel consumption rate of 0.523 pounds perhp/hr. The efficiency was largely due to use ofa regenerator, which recovered heat from theexhaust gases.

By the late 1950s the marine GTE wasbecoming widely used, mostly by Europeannavies. All the applications used a dual mainpropulsion system, combining the gas turbineplant with another conventional form ofpropulsion machinery. The GTE was used forhigh-speed operation. The conventional plant wasused for cruising. The most common arrange-ments were the combined diesel and gas(CODAG) or the combined diesel or gas(CODOG) systems. Diesel engines give goodcruising range and reliability, but they have adisadvantage when used in antisubmarine warfare.Their low-frequency sounds travel great distancesthrough water. This makes them easily detectedby passive sonar. Steam turbines have beencombined to reduce low-frequency sound in thecombined steam and gas (COSAG) configurationlike those used on the British County classdestroyers. The COSAG configuration requiresmore personnel to operate. Also they do not havethe long range of the diesel combinations.Another configuration that has been successfulis the combined gas or gas (COGOG), such asused on the British 42. These ships use the4,500-hp Tyne GTE for cruising and the Rolls

Royce Olympus, a 28,000-hp engine, for high-speed situations.

The U.S. Navy entered the marine gas turbinefield with the Asheville class patrol gunboats.These ships have the CODOG configuration withtwo diesel engines for cruising and a GeneralElectric LM1500 GTE for high-speed operations.The Navy has now designed and is buildingdestroyers, frigates, cruisers, hovercraft, andpatrol hydrofoils that are entirely propelled byGTEs. This is a result of the reliability andefficiency of the new GTE designs.

ADVANTAGES ANDDISADVANTAGES

The GTE, when compared to other types ofengines, offers many advantages. Its greatest assetis its high power-to-weight ratio. This has madeit, in the forms of turboprop or turbojet engines,the preferred engine for aircraft. Compared to thegasoline piston engine, the GTE operates oncheaper and safer fuels. The relatively vibration-free operation of the GTE, compared withreciprocating engines, has made it even moredesirable in aircraft. Less vibration reduces strainon the airframe. In a warship, the lack of low-frequency vibration of GTEs makes thempreferable to diesel engines because there is lessnoise for a submarine to pick up at long range.Modern production techniques have made GTEsmore economical in terms of horsepower-per-dollar on initial installation. Their increasingreliability makes them a cost-effective alternativeto steam turbine or diesel engine installation. Interms of fuel economy, modern marine GTEs cancompete with diesel engines and they may evenbe superior to boiler/steam turbine plants that areoperating on distillate fuel.

The GTEs do have a few disadvantages. Sincethey are high-performance engines, many partsare under high stress. Improper maintenance andlack of attention to details of the maintenanceprocedures will impair engine performance andmay lead to engine failure. A pencil mark on acompressor turbine blade can cause failure of thepart. Most GTE propulsion control systems arevery complex and require the monitoring ofnumerous operating conditions and parameters.The control systems must react quickly to turbineoperating conditions to avoid casualties to theequipment. In shipboard installations specialsoundproofing is necessary because GTEs producehigh-pitched noises that can damage the humanear. The turbine takes in large quantities of air

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that may contain substances or objects that canharm it. Also, the large amount of air used bya GTE requires large intake and exhaust ducting,which takes up much valuable space on a smallship. This adds to the complexity of theinstallation and makes access for maintenancemore difficult.

From a tactical standpoint, the GTE has twomajor drawbacks. The first is the large amountof exhaust heat produced by the engines. Mostcurrent antiship missiles are heat-seekers.Therefore, the infrared (IR) signature of a GTEis an easy target. Countermeasures, such asexhaust gas cooling and IR decoys, have beendeveloped to reduce this problem.

The second tactical disadvantage is the require-ment for depot maintenance and repair of majorcasualties. On the whole, the turbines are toocomplex to overhaul in place. They must beremoved and replaced by rebuilt engines if anymajor casualties occur. However, this problem isreduced by the design of the system. A GTE ona frigate, cruiser, or destroyer can be changed outin about 4 days if crane service and a replacementengine are available. A GTE on a hovercraft canbe changed out in 8 hours. Gas turbine ships canoperate or be repaired to the same standards astheir steam- or diesel-driven counterparts.

FUTURE TRENDS

As improved materials and designs permitoperation at higher combustion temperatures andpressures, GTE efficiency will increase. Even now,GTE main propulsion plants offer fuel economyand installation costs comparable to dieselengines. Initial costs are lower than equivalentsteam plants that burn distillate fuels. Theseimprovements have made GTEs the best choicefor nonnuclear propulsion of naval ships up to,and including, an underway replenishment shipin size.

At present, marine GTEs use derivatives ofaircraft jet engines for GGs. These are slightlymodified for use in a marine environment,particularly in respect to corrosion resistance. Asmarine GTEs become more widely used, specificdesigns for ships may evolve. These compressorsmay be heavier and bulkier than aircraft enginesand take advantage of regenerators to permitgreater efficiency.

The high power-to-weight ratios of GTEspermit the development of high-performancecraft, such as the hovercraft and the hydrofoil,the patrol combatant missile the patrol

combatant (PG), and the landing craft, aircushion (LCAC). These crafts are capable of highspeed, can carry formidable weapons systems, andare being seen in increasing numbers in our fleet.In civilian versions, hydrofoils have served formany years to transport people on many of theworld’s waterways. Hovercraft are being usedmore and more as carriers of people. They arecapable of speeds up to 100 knots. If beachgradients are not too steep, they can reach pointsinland over virtually any type of terrain.

GAS TURBINE ENGINE THEORY

Two elements are required for properoperation of a GTE. One is expressed byNewton’s third law (action/reaction). The otheris the convergent-divergent process (or Bernoulli’sprinciple). Convergent means coming closertogether, as the inner walls of a tube that isnarrowing. Divergent means moving away fromeach other, as the inner walls of a tube that flaresoutward. The venturi of an automobile carburetoris a common example of Bernoulli’s principle andthe convergent-divergent process. Before wediscuss GTE construction and design, we willdiscuss a little more on cycles and theory.

THEORETICAL CYCLES

A cycle is a process that begins with certainconditions, progresses through a series ofadditional conditions, and returns to the originalconditions. The basic GTE cycle is named for theBoston engineer, George Brayton, who proposedit in the late nineteenth century.

The Brayton cycle is one in which combustionoccurs at constant pressure. In GTEs, specificcomponents are designed to perform eachfunction of the cycle separately. These functionsare intake, compression, combustion, expansion,and exhaust. Refer to figure 1-6 as we explain theBrayton cycle graphically.

Intake—At point A, air enters the inlet atatmospheric pressure and ambient temperature.

Compression—As the air passes throughthe compressor, it increases in pressure andtemperature and decreases in volume (line A-B).

Combustion—At point B, combustionoccurs at constant pressure while the addition ofheat causes a sharp increase in volume (line B-C).

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Figure 1-6.—The Brayton cycle.

Expansion —The gases at constant pressureand increased volume enter the turbine andexpand through it. As the gases pass through theturbine rotor, the rotor turns kinetic energy intomechanical energy. The expanding size of thepassages causes further increase in volume and asharp decrease in pressure and temperature (lineC-D).

Exhaust—The gases are released throughthe stack with a large drop in volume and atconstant pressure (line D-A).

The cycle is continuous and repetitive in aGTE. The functions occur simultaneously through-out the system.

OPEN, SEMICLOSED, ANDCLOSED CYCLES

Most internal-combustion engines operate onan open engine cycle. This means the workingfluid is taken in, used, and discarded. The GTEsyou will encounter in the Navy operate on theopen cycle. In the open cycle all the working fluidpasses through the engine only once. The opencycle offers the advantages of simplicity and lightweight.

Some GTEs operate on a semiclosed cycle.They use a regenerator, such as used on the JohnSergeant. The regenerator simply transfers theheat from the turbine exhaust gas to thecompressor discharge gas before that gas hasenergy externally supplied (ahead of thecombustor).

The third classification of cycles is the closedcycle, in which energy is added externally. The

closed cycle has been called the “natural” cyclefor the GTE because it allows use of any fuel,including nuclear, as an energy source. The typicalship’s steam plant is an example of a closed cyclesystem.

BASIC GTE OPERATION THEORY

The following is a description of a practicaldemonstration of how a GTE operates. Refer tofigure 1-7 as you read the description.

A balloon full of air (view A) does nothingunless the trapped air is released. When the airis released, it escapes rearward, causing theballoon to move forward (Newton’s third law)(view B).

If you could devise a way to keep the balloonconstantly full of air, it would continue to moveforward (view C) as long as the air is allowed toescape from it.

If you place a fan or pinwheel in theescaping airstream, the pressure energy andvelocity energy will cause the fan to rotate.Then you can use the escaping air to do work(view D).

Now, if you replace the balloon with a firmlymounted tube or container and keep it filled withair from a fan located in the air opening anddriven by an external source, you could use thedischarge air to turn a fan at the rear to do work(view E).

If you add fuel and allow combustion tooccur (view F), the volume of air and the velocitywith which it passes over the exhaust fan aregreatly increased (Charles’s law). The horsepowerthe fan will produce is also increased. Thecontinuous pressure created by the inlet fan, orcompressor, prevents the hot gases from goingforward.

Now, if you attach a shaft to the compressorand extend it back to a turbine wheel, you havea simple GTE (view G). It can supply power torun its own compressor and still provide enoughpower to do useful work. It could drive agenerator or propel a ship.

By comparing view H with view G, you cansee that a GTE is very similar to the balloon

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Figure 1-7.—Practical demonstration of GTE operations.

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discussed earlier. A review of the gas turbineprocess is detailed as follows:

1. Air is taken in through the air inlet duct bythe compressor. There it is raised in pressure anddischarged into the combustion chamber (orcombustor).

2. Fuel is admitted into the combustionchamber by the fuel nozzle(s). The fuel-airmixture is ignited by an igniter(s) (not shown) andcombustion occurs.

3. The hot and rapidly expanding gases aredirected aft through the turbine rotor assembly.There, thermal and kinetic energy are convertedinto mechanical energy. The gases are thendirected out through the exhaust duct.

CONVERGENT-DIVERGENT PROCESS

Several pressure, volume, and velocity changesoccur within a GTE during operation. Theconvergent-divergent process is an application ofBernoulli’s principle. (If a fluid flowing througha tube reaches a constriction or narrowing of thetube, the velocity of the fluid flowing through theconstriction increases and the pressure decreases.The opposite is true when the fluid leaves theconstriction; velocity decreases and pressureincreases.) Boyle’s law and Charles’s law(discussed in NAVEDTRA 10563, volume 1,chapter 4) also come into play during thisprocess. Refer to figure 1-8 as we apply these lawsto the GTE.

Air is drawn into the front of the compressor.The rotor is so constructed that the area decreasestoward the rear. This tapered construction givesa convergent area (area A).

Between each rotating stage is a stationarystage or stator. The stator partially converts highvelocity to pressure and directs the air to the nextset of rotating blades.

Because of its high rotational speed and theaerodynamic shape of its blades, the rotorincreases the velocity of the air. Each pair of rotorand stator blades constitutes a pressure stage.Both a pressure increase and a reduction involume occurs at each stage (Boyle).

This process continues at each stage until theair charge enters the diffuser (area B). There isa short area in the diffuser where no furtherchanges take place. As the air charge approachesthe end of the diffuser, you will notice that theopening flares (diverges) outward. At this point,the air loses velocity and increases in volume andpressure. The velocity energy has become pressureenergy, while pressure through the diffuser hasremained constant. The reverse of Bernoulli’sprinciple and Boyle’s law has taken place. Thecompressor continuously forcing more air throughthis section at a constant rate maintains constantpressure. Once the air is in the combustor,combustion takes place at constant pressure. Aftercombustion there is a large increase in the volumeof the air and combustion gases (Charles’s law).

The combustion gases go rearward to area C.This occurs partially by velocity imparted by the

Figure 1-8.—Convergent-divergent process.

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compressor and partially because area C is a lowerpressure area. The end of area C is the turbinenozzle section. Here you will find a decrease inpressure and an increase in velocity. The high-velocity, high-temperature, low-pressure (LP)gases are directed through the inlet nozzle to thefirst stage of the turbine rotor (area D). The high-velocity, high-temperature gases cause the rotorto rotate by transferring velocity energy andthermal energy to the turbine blades. Area D isa divergent area. Between each rotating turbinestage is a static stage or nozzle. The nozzlesperform the same function as the stators in thecompressor.

A turbine nozzle is a stator ring with a seriesof vanes. The vanes direct the combustion gasesuniformly and at the proper angle to the turbineblades. The passages between the vanes aredesigned as diverging nozzles. Each succeedingstage imparts velocity to the gases as theypass through the nozzle. Each nozzle convertsheat and pressure energy into velocity energy bycontrolling the expansion of the gas.

Each stage of the turbine is larger than thepreceding one. The drop in pressure is quite rapid;consequently, each stage must be larger to use theenergy of a lower pressure, lower temperature,and larger volume of gas.

Atmospheric air is raised in pressure andvelocity and lowered in volume in area A by thecompressor. Each stage can only compress airabout 1.2 times. In the turbine rotor (area D), thegases give up thermal and pressure energy and

increase in volume through three stages. (If thisdid not happen rapidly, back pressure from areaD would cause area C to become choked.) Thegases in the combustor would back up into thecompressor. There they would disrupt airflow andcause a condition known as surge, or compressorstall. This condition can destroy an engine in amatter of seconds. Surge will be explained laterin our discussion of axial-flow compressors.

The gases from the last turbine stage enterthe exhaust duct where they are sent to theatmosphere. The leading portion of the exhaustduct is part of a divergent area. Further divergencereduces the pressure and increases the volume ofthe warm gases and aids in lowering the velocity.The exhaust gases enter the atmosphere at orslightly above atmospheric pressure. This dependson the length and size of the exhaust duct.

Refer to figure 1-6 and compare the graph andthe actual operation of the cycle. Air enters theintake at constant pressure (point A). It iscompressed as it passes through the compressor(line A-B in fig. 1-6 and area A in fig. 1-8).Between the end of area B and the beginning ofarea C in figure 1-8, combustion occurs andvolume increases (fig. 1-6, line B-C). As the gasespass through area D (fig. 1-8), the gases expandwith a drop in pressure and an increase in volume(fig. 1-6, line C-D). The gases are discharged tothe atmosphere through the exhaust duct atconstant pressure (fig. 1-6, line D-A and fig. 1-8,exhaust). At this point, you should have the basicknowledge of how a simple gas turbine works.

Figure 1-9.—GTE pressure-temperature-volume relationship.

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ADIABATIC COMPRESSION

In an adiabatic stage change, no transfer ofheat to or from the system occurs during theprocess. Theoretically, in the ideal GTE,the air enters the compressor and is compressedadiabatically. In many real processes, adiabaticchanges can occur when the process is performedrapidly. Since heat transfer is relatively slow, anyrapidly performed process can approach anadiabatic state. Compression and expansion ofworking fluids are often achieved almostadiabatically. This is the case in todays’s GTEs.

Figure 1-9 is a schematic representation of astationary simple GTE. It uses two graphs to showthe pressure-temperature-volume relationships atvarious process states. The major components ofthe GTE are the compressor for the process from1 to 2, the combustor for the process from 2 to3, and the turbine for the process from 3 to 4.The heat rejection process from 4 to 1, whichcompletes the cycle, is carried out by exhaustingthe hot gas and allowing it to mix with theatmosphere.

In an initial simplified analysis, the com-pressor is taken to include the inlet nozzle andducting and any exit diffuser leading to thecombustor. Thus, for the compressor inletcondition (point 1), the air being drawn fromthe surroundings has zero velocity, ambienttemperature, and ambient pressure. For the exitcondition (point 4), the air has zero velocity atsome elevated pressure and temperature that aremeasured. View A of figure 1-9 depicts a pressure-temperature graph for a simple GTE, while viewB depicts a pressure-volume graph. The distancebetween adjacent numbers on each of thediagrams represents an event of the combustioncycle. A combustion cycle includes compressionof air, burning of the compressed air and fuelmixture, expansion of gases, and removal ofgases. By comparing the numerical points on bothgraphs (point 1 to 2 on view A with point 1 to2 on view B), you can get a better understandingof the pressure-temperature-volume relationshipof a simple GTE.

During operation the work produced by thecompressor turbine rotor is almost the sameamount as the work required by the compressor.The mass flow available to the compressorturbine is about the same as the mass flow handledby the compressor. This allows the heat ofcompression to be about the same value as theheat of expansion. Allowances are made for

factors such as bleed air, pressure of fuel added,and heat loss to turbine parts.

As the high-temperature, high-pressure (HP)gases enter the turbine section, they expandrapidly. Relatively little change in the temperatureof the gases occurs. The net power available fromthe turbine is the difference between the turbine-developed power and the power required tooperate the compressor.

FACTORS AFFECTINGENGINE PERFORMANCE

Many factors, such as aerodynamics andthermodynamics, have a direct effect on efficientGTE performance. In this chapter we will discussonly two common factors, the effect of ambienttemperatures and the effect of compressorcleanliness. As a gas turbine technician, you willbe concerned with these in your daily operationof the GTE.

Effect of Ambient Temperature

In discussions of temperature effects on GTEs,you will often hear the term Navy standard day.This term refers to a theoretical condition seldomduplicated except in some permanent testsituations and is used only as a reference orstandard. A standard day is indicated by thefollowing conditions at sea level: barometricpressure—29.92 Hg, humidity (water vaporpressure)—0.00 Hg, and temperature—59°F.Operation of engines above or below 50°F willproportionally affect engine power output by asmuch as 15 or 20 percent.

The power and efficiency of a GTE areaffected by both outside and inside variables. Airhas volume that is directly affected by itstemperature. As the temperature decreases, thevolume of air for a given mass decreases and itsdensity increases. Consequently, the mass weightof the air increases, causing the engine to operatemore efficiently. This happens because less energyis needed to achieve the same compression at thecombustion chambers. Also, cooler air causeslower burning temperatures. The resultingtemperatures extend turbine life. For example, apropulsion GTE is operating at 100 percent GGspeed with 100 percent PT speed. The ambient(external air) temperature is 70°F. If thetemperature were increased to 120°F, the volumeof air required would increase. The mass weightwould decrease. Since the amount of fuel addedis limited by the inlet temperature the turbine will

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withstand, the mass weight flow cannot beachieved; the result is a loss of net power availablefor work. The plant may be able to produce only90 to 95 percent of its rated horsepower.

On the other hand, if the ambient temperaturewere to drop to 0°F, the volume of air (mass)required would decrease. However, the massweight would increase. Since the mass weight isincreased and heat transfer is better at higherpressure, less fuel is needed to increase volume.This situation produces quite an efficient powerplant. It has a GG speed of 85 to 90 percent anda PT speed of 100 percent. In a constant speedengine, the differences in temperature will showup on exhaust gas temperature. In some cases, itwill show up on the load the engine will pull. Forinstance, on a hot day of 120°F, the engine ona 300-kW generator set may be able to pull only275 kW. This is due to limitations on exhaust orturbine inlet temperature. On a day with 0°Fambient temperature, the same engine will pull300 kW. It can have an exhaust or turbine inlettemperature that is more than 100°F, lower thanaverage. Here again, less fuel is needed to increasevolume and a greater mass weight flow. In turn,the plant is more efficient.

Effect of Compressor Cleanliness

Another factor that will have a great effect onperformance is the condition of the compressor.A clean compressor is essential to efficiencyand reliability. During operation at sea, thecompressor takes in a high volume of salt-contaminated air. Salt buildup is relatively slowin the compressor and will occur more on thestator vanes and the compressor case than onrotating parts. Centrifugal force tends to sling saltcontaminants off the rotor blades.

Any oil ingested into the engine coats thecompressor with a film and will rapidly increasecontamination of the compressor. The film trapsany dust and other foreign matter suspended inthe air. The dust and dirt absorb more oil, whichtraps more dirt, and so forth. If left unattended,the buildup of contamination (either oil or salt)will lead to a choking of the compressor and arestricted airflow. This restricted airflow willrequire the main fuel to schedule more fuel toproduce an equivalent horsepower. The combus-tion gas temperatures will rise until loss ofpower, and damage to the turbine may result.Contamination, if not controlled, can induce asurge condition in the compressor during enginestart. It will also reduce the life of the compressor

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and turbine blading through corrosion of theengine parts.

TYPES OF GAS TURBINE ENGINES

The different types of GTEs all use the samebasic principles already discussed. A GTE isclassified by its construction (the type ofcompressor, combustor, or shaft system used).The compressor may be either centrifugal oraxial type. The combustor may be annular, can-annular, or can type. The type of shaft used ona GTE may be either single shaft, split shaft, ortwin spool. These classifications will be discussedin the following paragraphs.

CLASSIFICATION BYCOMPRESSOR TYPE

The compressor takes in atmospheric air andcompresses it to a pressure of several atmospheres.A GTE may be classified by compressor type,based on the direction of the flow of air throughthe compressor. The two principal types ofcompressors are the centrifugal flow and theaxial flow. The centrifugal-flow compressor drawsin air at the center or eye of the impeller andaccelerates it around and outward. In the axial-flow compressor, the air is compressed whilecontinuing its original direction of flow (parallelto the axis of the compressor rotor).

Centrifugal Compressor

The centrifugal compressor is usually locatedbetween the accessory section and the combustionsection. The basic compressor section consists ofan impeller, diffuser, and compressor manifold.The diffuser is bolted to the manifold. Often theentire assembly is referred to as the diffuser. Forease of understanding, we will discuss each unitseparately.

The impeller may be either single entry or dualentry (fig. 1-10). The main differences betweenthe single-entry and dual-entry impeller are thesize of the impeller and the ducting arrangement.The single-entry impeller permits convenientducting directly to the inlet vanes. The dual-entryimpeller uses a more complicated ducting to reachthe rear side of the compressor. Single-entryimpellers are slightly more efficient in receivingair, but they must be of greater diameter toprovide sufficient airflow. This increases theoverall diameter of the engine.

Figure 1-10.—Centrifugal compressors. A. Single entry.B. Dual entry.

Dual-entry impellers are smaller in diameterand rotate at higher speeds to ensure a sufficientairflow. Most modern GTEs use the dual-entrycompressor to reduce engine diameter. Becausethe air must enter the engine at almost right anglesto the engine axis, a plenum chamber is requiredfor dual-entry compressors. The air mustsurround the compressor at a positive pressurebefore entering the compressor to ensure anundisturbed flow.

PRINCIPLES OF OPERATION.—The com-pressor draws in the air at the hub of the impellerand accelerates it radially by centrifugal forcethrough the impeller. It leaves the impeller at ahigh velocity and a low pressure and flowsthrough the diffuser (fig. 1-10, view A). Thediffuser converts the high-velocity, LP air to low-velocity, HP air. The compressor manifold divertsthe flow of air from the diffuser (an integral partof the manifold) into the combustion chambers.

CONSTRUCTION.—In a centrifugal com-pressor the manifold has one outlet port for eachcombustion chamber. The outlet ports are boltedto an outlet elbow on the manifold (fig. 1-10,view A). The outlet ports ensure that the sameamount of air is delivered to each combustionchamber. Each outlet port elbow contains fromtwo to four turning vanes to change the airflowfrom radial to axial flow and to reduce airpressure losses by presenting a smooth turningsurface.

The impeller is usually made from a forgedaluminum alloy that is heat-treated, machined,and smoothed for minimum flow restriction andturbulence. Some types of impellers are madefrom a single forging, while in other types theinducer vanes are separate pieces that are weldedin place.

Centrifugal compressors may achieve effi-ciencies of 80 to 84 percent at pressure ratios of2.5:1 to 4:1 and efficiencies of 76 to 81 percentat pressure ratios of 4:1 to 10:1.

Some advantages of centrifugal compressorsare as follows:

Rugged, simple in design

Relatively light in weight

Develop high-pressure ratio per stage

Some disadvantages of centrifugal compressorsare as follows:

Large frontal area

Lower efficiency than axial-flowcompressors

Difficulty in using two or more stages dueto the air loss that occurs between stagesand seals

Axial-Flow Compressors

The purpose of the axial compressor is thesame as the centrifugal compressor. They both

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Figure 1-11.—Components of an axial-flow compressor.A. Rotor. B. Stator.

take in ambient air and increase its velocity andpressure. The air is then discharged through thediffuser into the combustion chamber.

The two main elements of an axial-flowcompressor are the rotor and the stator (fig. 1-11).The rotor has fixed blades which force the airrearward much like an aircraft propeller. Behindeach rotor is a stator which directs the airrearward to the next rotor. Each consecutive pairof rotor and stator blades constitutes a pressurestage.

The action of the rotor at each stage increasescompression and velocity of the air and directsit rearward. By virtue of this increased velocity,energy is transferred from the compressor to theair in the form of velocity energy. The stators ateach stage act as diffusers, partially convertingthis high velocity to pressure.

The number of stages required in a compressoris determined by the amount of air and totalpressure rise required by the GTE. The greaterthe number of stages, the higher the compressionratio. Most present-day engines have 8 to 16stages.

COMPRESSOR CONSTRUCTION.—Therotor and stators are enclosed in the compressorcase. Today’s GTEs use a case that is horizontallydivided into upper and lower halves. The halvesare bolted together with fitted bolts and dowelpins located at various points for casing align-ment. This ensures proper casing half alignment.Other assemblies can then be bolted to either endof the compressor case.

On some older design engines, the case is aone-piece cylinder open on both ends. The one-piece compressor case is simpler to manufacture,but any repair or detailed inspection of thecompressor rotor requires engine removal anddelivery to a shop. At the shop it is disassembledfor inspection or repair of the rotor or stator. On

Figure 1-12.—Compressor rotors. A. Drum type. B. Disktype.

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engines with the split case, either the upper orlower case can be removed, allowing the engineto remain in place for maintenance andinspection.

The compressor case is usually made ofaluminum or steel. The material used will dependon the engine manufacturer, the weight require-ments of the engine, and the accessories attachedto the case. The compressor case may haveexternal connections made as part of the case.These connections are normally used as bleed airports to aid in the prevention of stalls duringstarting and acceleration or at low-speedoperation.

Figure 1-13.—Rotor blades.

The two main types of axial compressor rotorsare the drum type and the disk type.

Drum Type.—The drum-type rotor (fig. 1-12,view A) consists of rings that are flanged to fitone against the other. The entire assembly maythen be held together by through bolts (oftencalled tie bolts). The drum is one diameter overits full length. The blades and stators vary intheir radial length from the front to the rearof the assembly. The compressor case tapersaccordingly. This type of construction is satisfac-tory for low-speed compressors where centrifugalstresses are low.

Disk Type.—The disk-type rotor (fig. 1-12,view B) consists of a series of disks of increasingdiameter which are machined from forgings andshrunk fit over a steel shaft. Another method ofrotor construction is to machine the disks andshaft from a single aluminum forging and boltsteel stub shafts on the front and rear of theassembly. The stub shafts provide bearingsupport surfaces and splines for joining theturbine shaft. The blades decrease in length fromentry to discharge. This is due to a progressivereduction in the annular working space (drum tocasing) toward the rear. The working spacedecreases because the rotor disk diameterincreases. The disk-type rotors are used almostexclusively in all present-day, high-speed engines.

COMPRESSOR BLADING.—Each stage ofan axial compressor has a set of rotor and statorblades. Stator blades may also be referred to asvanes. The construction of these blades isimportant to efficient operation of a GTE.

Rotor Blades.—The rotor blades are usuallymade of aluminum, titanium, or stainless orsemistainless steel. Methods of attaching theblades in the rotor disk rims vary. They arecommonly fitted into the disks by either the bulbor the fir-tree type of roots (fig. 1-13, views A andB). The blades are then locked with grub-screws,lockwires, pins, or keys.

Compressor blade tips are reduced by cutouts,which are referred to as blade profiles. Somemanufacturers use a ring (usually called a shroud)that acts as a spacer for the stators. The shroudcan also act as a wear surface when the blade tipscome into contact with the ring. This rubbing ofblade tips maintains the close tolerances necessaryto maintain the efficiency of the compressor andthe profiles prevent serious damage to the bladeor housing.

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Figure 1-14.—Blade with squealer tip.

Another method of maintaining minimumclearance is to metal-spray the case and stators.Thin squealer tips on the blades and vanes (fig.1-14) contact the sprayed material. The abrasiveaction of the blade tip cuts into the sprayedmaterial, thus obtaining minimum clearance.

The primary causes of rubbing are anexcessively loose blade or a malfunction of acompressor support bearing. This causes thecompressor rotor to drop.

Large compressors have loose-fitting bladeson the first several stages. These move duringacceleration to minimize vibration while passingthrough critical speed ranges. Once up to speed,centrifugal force locks the blades in place and littleor no movement occurs. Movement of the bladesalso occurs during rundown. On a clean enginesome of the blades may have as much as 1/4-inchradial movement, which can cause a tinklingsound during rundown.

Large compressor rotors have long blades onthe first stage. They have a wing tip on the bladefaces called a midspan platform (fig. 1-15). Theplatform gives some radial support to the bladesduring acceleration. This midpoint support isneeded because of the length and amount ofmovement of the blades.

Stators.—The stator vanes project radiallytoward the rotor axis and fit closely on either sideof each stage of the rotor. The function of thestators is twofold: (1) they receive air from theair inlet duct or from each preceding stage of therotor and deliver the air to the next stage or tocombustors at a workable velocity and pressure;(2) they control the direction of air to each rotorstage to obtain the maximum compressor bladeefficiency. The stator vanes are made of alloyswith corrosion- and erosion-resistant qualities.Frequently, the vanes are shrouded by a band ofsuitable material to simplify the fasteningproblem. The outer shrouds are secured to theinner wall of the compressor case by radialretaining screws.

Some manufacturers machine a slot in theouter shrouds and run a long, thin key the lengthof the compressor case. The key is held in placeby retaining screws to prevent the stators fromturning within the case. This method is used whena one-piece compressor case is slid over thecompressor and stator assembly.

Each pair of vanes in a stator acts as adiffuser. They use the divergent principle: theoutlet of the vane area is larger than the inlet. Inthis diverging area, the high-velocity, LP air fromthe preceding rotor stage is converted to a low-velocity, HP airflow and directed at the properangle to the next rotor stage. The next rotor stagewill restore the air velocity that was lost becauseof the pressure rise. The next stator will give afurther pressure rise. This process continues foreach stage in the compressor.

A pressure rise of about 1.2 times thepreceding stage is about as much as a single stagecan handle. Higher pressure rises result in higherdiffusion rates with excessive turning angles. Thiscauses excessive air instability and low efficiency.

Preceding the first stage compressor blades isa row of vanes known as inlet guide vanes (IGVs).The function of the IGVs varies somewhat,depending on the size of the engine and the air-inlet construction. On smaller engines the airinlet is not totally in line with the firststage of the rotor. The IGVs straighten theairflow and direct it to the first-stage rotor.On large engines the IGVs are variable andmove with the variable stators. The variableIGVs on large engines direct the airflow atthe proper angle to reduce drag on the first-stage

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Figure 1-15.—Large engine compressor rotor with midspan platforms.

rotor. Variable IGVs achieve the same purposesas variable stator vanes (VSVs).

Some GTEs have moveable, or variable,stators. The position of the variable stators isdetermined by compressor inlet temperature (CIT)and engine power requirements. They are movedby mechanical linkages that are connected to,and controlled by, the fuel-control governor.Variable stators have two purposes. First, they are

positioned at various angles, depending oncompressor speed, to ensure the proper angle ofattack of the air in the compressor blades.Varying the stator angle helps to maintainmaximum compressor efficiency over the operatingspeed range of the engine. This is important invariable-speed engines, such as those used formain propulsion, Second, the variable statorson large engines greatly reduce incidences of

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Figure 1-16.—Compressor surge.

compressor surge. Surge (fig. 1-16) results whenthe airflow stalls across the compressor blades;that is, air is not smoothly compressed into thecombustion and turbine section. Stalling mayoccur over a few blades or a section of somestages. If enough flow is interrupted, pressuremay surge back through the compressor. Thisoccurrence can be minor or very severe withdamage to the turbine resulting. If severedisturbance occurs, all the air in the combustormay be used for combustion instead of only theprimary air. This would result in a lack ofcooling air (secondary) that may cause extremetemperatures which burn the combustor andturbine section. We will discuss primary andsecondary air systems later in this chapter.

combustion chamber consists of a casing, aperforated inner shell, a fuel nozzle, and a devicefor initial ignition (igniter). The number ofcombustion chambers used in a GTE varieswidely; as few as one and as many as16 combustion chambers have been used in oneGTE. The combustion chamber is the mostefficient component of a GTE. The three typesof combustion chambers are the (1) can,(2) annular, and (3) can-annular. The can-typechamber is used primarily on engines that havea centrifugal compressor. The annular and can-annular types are used on axial-flow compressors.

Can Chamber

By a change in the angle of the stators and useof bleed valves, smooth airflow through thecompressor is ensured.

Constant-speed engines, such as those used todrive generators, normally do not use variablestators. They are designed to operate at100 percent rpm all the time. Proper fuelscheduling and use of bleed air valves are usedto reduce the probability of compressor surge inthese engines.

The can-type combustion chamber hasindividual liners and cases mounted around theaxis of the engine. Each chamber (fig. 1-17)contains a fuel nozzle. This arrangement makesremoving a chamber easy, but it is a bulkyarrangement and makes a structurally weakengine. The outer casing is welded to a ring thatdirects the gases into the turbine nozzle. Each ofthe casings is linked to the others with a shorttube. This arrangement ensures that combustionoccurs in all the burners during engine start.Inside each of these tubes is a flame tube that joinsan adjacent inner liner.

CLASSIFICATION BY COMBUSTIONCHAMBER DESIGN Annular Chamber

The combustion chamber is the component The annular-type combustion chamber isin which the fuel-air mixture is burned. The probably one of the most popular combustion

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Figure 1-17.—Can-type combustion chamber.

Figure 1-18.—Annular-type combustion chamber.

systems in use. The construction consists ofa housing and liner the same as the can type (fig.1-18).

The difference between the two is in the liner.On large engines, the liner consists of an undividedcircular shroud extending all the way around theoutside of the turbine shaft housing. A large one-piece combustor case covers the liner and isattached at the turbine section and diffusersection.

The dome of the liner has small slots andholes to admit primary air. They also imparta swirling motion for better atomization offuel. There are holes in the dome for the fuelnozzles to extend through into the combustionarea. The inner and outer liners form thecombustion space. The outer liner keeps flamefrom contacting the combustor case. The innerliner prevents flame from contacting the turbineshaft housing.

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Figure 1-19.—Can-annular type of combustion chamber.

Large holes and slots are located along theliners. They (1) admit some cooling air into thecombustion space to help cool the hot gases toa safe level, (2) center the flame, and (3) admitthe balance of air for combustion.

The annular-type combustion chamber is avery efficient system that minimizes bulk and canbe used most effectively in limited space. Thereare some disadvantages. On some engines, theliners are one piece and cannot be removedwithout engine disassembly. Also, engines that usea one-piece combustor dome must be disassembledto remove the dome.

Can-Annular Chamber

The can-annular type of combustion chambercombines some of the features of both the canand the annular burners. The can-annular typeof chamber design is a result of the split-spoolcompressor concept. Problems were encounteredwith a long shaft and with one shaft within theother. Because of these problems, a chamber wasdesigned to perform all the necessary functions.

In the can-annular type of chamber, individualcans are placed inside an annular case. The cansare essentially individual combustion chambers(fig. 1-19) with concentric rings of perforatedholes to admit air for cooling. On some modelseach can has a round perforated tube that runsdown the middle of the can. The tube carriesadditional air, which enters the can through theperforations to provide more air for combustionand cooling. The effect is to permit moreburning per inch of can length than couldotherwise be done.

Fuel nozzle arrangement varies from onenozzle in each can to several nozzles around theperimeter of each can. The cans have an inherentresistance to buckling because of their smalldiameter. Each can has two holes that are oppositeeach other near the forward end of the can. Onehole has a collar called a flame tube. When thecans are assembled in the annular case, these holesand their collars form open tubes. The tubes arebetween adjacent cans so a flame passes from onecan to the next during engine starting.

Figure 1-20.—Single-shaft engine.

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Figure 1-21.—Split-shaft engine.

The short length of the can-annular type ofchamber provides minimal pressure drop of thegases between the compressor outlet and the flamearea. The relatively cool air in the annular outercan reduces the high temperatures of the innercans. This air blanket keeps the outer shell of thecombustion section cooler. Maintenance on theburners is simple. You can remove and inspectany number of burners just by sliding the caseback.

CLASSIFICATION BYTYPE OF SHAFTING

Several types of GTE shafts are used. Theseare single shaft, split shaft, and twin spool. Ofthese, the single shaft and split shaft are the mostcommon in use in naval vessels. The twin-spool

-shaft is currently used for marine military applica-tion only on the U.S. Coast Guard Hamilton classcutters, which use the Pratt-Whitney FT-4 twin-spool GTE.

In current U.S. Navy service, the single-shaftengine is used primarily for driving ship’s servicegenerators. The split-shaft engine is used for mainpropulsion, as a variety of speed ranges isencountered.

Figure 1-20 is a block diagram of a single-shaftGTE. In the engine shown, the power output shaft

is connected directly to the same turbine rotor thatdrives the compressor. Usually, a speed decreaseror reduction gear is located between the rotor andthe power output shaft. A mechanical connectionstill exists throughout the engine.

In the split-shaft engine (fig. 1-21), nomechanical connection exists between the GGturbine and the PT. In this type of engine, theoutput speed is varied by variation of thegenerator speed. Also, under certain conditions,the GG can run at a reduced rpm and still providemaximum PT rpm. The reduced rpm greatlyimproves fuel economy and also extends the lifeof the GG turbine. The starting torque requiredis lowered because the PT, reduction gears, andoutput shaft are stationary until the GG reachesapproximate idle speed. Another feature of themultishaft marine propulsion plant is the GGrotates only one way. One design (clockwiserotation or counterclockwise rotation) of the GGcan be used on either shaft and still allow the PTto rotate either way. This is done by changing thePT wheel and nozzles. The arrangement shownin figure 1-21 is typical for propulsion GTEsaboard today’s ships.

The twin-spool type of GTE is sometimesreferred to as a multistage GTE. It has twoseparate compressors and two separate turbine

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rotors. They are referred to as LP compressor andturbine rotor and HP compressor and turbinerotor (fig. 1-22). The LP compressor and turbineare connected by a shaft. The shaft runs throughthe hollow shaft that connects the HP turbine tothe HP compressor. The starter drives the HPassembly during engine start. The PT functionsthe same as in the split-shaft engine. A largervolume of air can be handled as compared to asingle- or split-shaft engine. The increase in overalldimensions and complexity makes the engine lessdesirable for ship’s propulsion than the split-shaftengine, as this type of engine has more movingparts.

TURBINE ASSEMBLIES

The GTEs are not normally classified byturbine type. However, we will discuss turbinesnow so you will have knowledge of theirconstruction before we describe the GeneralElectric LM2500 GTE in the next chapter.

I n t h e o r y , d e s i g n , a n d o p e r a t i n gcharacteristics, the turbines used in GTEs aresimilar to those used in steam plants. The GTEdiffers from the steam turbine chiefly in (1) thetype of blading material used, (2) the meansprovided for cooling the turbine shaft bearings,and (3) the lower ratio of blade length to wheeldiameter.

The designations GG and PT are used todifferentiate between the turbines. The GG

Figure 1-22.—Twin-spool engine.

turbine powers the GG and accessories. The PTpowers the ship’s propeller through the reductiongear and shafting. Refer to figures 1-21 and 1-22as we discuss these turbines.

Gas Generator Turbine

The turbine that drives the compressor of aGTE is located aft of the combustion chamberoutlet. The turbine consists of two basic elements,the stator or nozzle, and the rotor. A cutawayview of a stator element is shown in figure 1-23;a rotor element is shown in figure 1-24.

TURBINE STATORS.—The stator elementof the turbine section is known by a variety ofnames. The most common are turbine nozzlevanes and turbine guide vanes. In this text,turbine stators are usually referred to as nozzles.The turbine nozzle vanes are located directly aftof the combustion chambers and immediatelyforward of, and between, the turbine wheels.

Turbine nozzles have a twofold function.First, the nozzles prepare the mass flow forharnessing of power through the turbine rotor.This occurs after the combustion chamber hasintroduced the heat energy into the mass airflowand delivered it evenly to the nozzles. Thestationary vanes of the turbine nozzles arecontoured and set at a certain angle. The spacesbetween the vanes form several small nozzles thatdischarge the gas as extremely high-speed jets. The

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Figure 1-24.—Turbine rotor elements.

Figure 1-23.—Cutaway view of a turbine stator.

nozzle converts a varying portion of the heat andpressure energy to velocity energy. The velocityenergy can then be converted to mechanical energythrough the rotor blades.

The turbine nozzle functions to deflect thegases to a specific angle in the direction ofturbine wheel rotation. The gas flow from thenozzle must enter the turbine blade passagewaywhile it is still rotating, making it essentialto aim the gas in the general direction of turbinerotation.

The turbine nozzle assembly has an innershroud and an outer shroud between whichare fixed the nozzle vanes. The number ofvanes varies with different types and sizesof engines. Figure 1-25 shows typical turbinenozzle assemblies.

Figure 1-25.—Turbine nozzle assemblies. A. Loose-fittingvanes. B. Welded vanes.

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All turbine nozzles must be constructed toallow for thermal expansion, because rapidtemperature variances could cause distortion orwarping of the metal components. Thermalexpansion of turbine nozzles is allowed by one ofseveral construction methods.

In one method the vanes are assembled looselyin the supporting inner and outer shrouds (fig.1-25, view A). Each of the vanes fits into acontoured slot in the shrouds. The slots conformwith the airfoil shape of the vanes. These slotsare slightly larger than the vane to give a loosefit. For further support the inner and outershrouds are encased by an inner and an outersupport ring. This adds strength and rigidity tothe turbine nozzle. These supports also permitremoval of the nozzle vanes as a unit; otherwise,the vanes could fall out of the shrouds as theshrouds are removed.

Another method to allow for thermal expansionis to fit the vanes into inner and outer shrouds.In this method the vanes are welded or rivetedinto position (fig. 1-25, view B). Either theinner or the outer shroud ring is cut intosegments to provide for thermal expansion. Thesaw cuts dividing the segments will allow enoughexpansion to prevent stress and warping of thevanes.

The basic types of construction of nozzles arethe same for all types of turbines. The turbinenozzles are made of high-strength steel towithstand the direct impact of the hot, HP, high-velocity gases from the combustor. The nozzlevanes must also resist erosion from the high-velocity gases passing over them.

If the inlet gas temperature could be increasedby about 750°F, almost a 100 percent increase inspecific horsepower could be achieved. Nozzlescan not stand up for long to these highertemperatures. Many different methods of in-creasing nozzle endurance have been tried overthe years. One method that was tried was tocoat the nozzle with ceramic. Higher temperatureswere achieved, but the different expansion ratesof the steel and the ceramic caused the coatingto break away after several hours of operation.Experiments are still being conducted, even so faras to use an entirely ceramic nozzle.

Another means of withstanding high tempera-tures is to use newly developed alloys. However,the extreme costs of the alloys prohibit commer-cial production of such nozzles. Still anothermethod, in wide use today in large engines, is touse air-cooled nozzle vanes. Compressor bleed airis fed through passages to the turbine, where it

Figure 1-26.—First-stage GG turbine nozzle cooling.

is directed to the nozzle. The air cools both theturbine (discussed later) and the nozzle. Thenozzle may also be cooled by air admitted fromthe outer perimeter of the nozzle ring. The methodof getting the air in is determined by themanufacturer.

The nozzle vanes are made with many smallholes or slots on the leading and trailing edges(fig. 1-26). Air is forced into the nozzle and outthrough the slots and holes. The vane is cooledas the air passes through. The air is dischargedinto the hot gas stream, passing through theremainder of the turbine section and out theexhaust duct.

Figure 1-27 shows temperature comparisonsof a nornair-cooled vane and an air-cooled vane.Cooling air is used primarily in the HP turbinesection and not in the LP section. By the time thegases reach the LP turbine section, the tempera-ture of the gases is at an acceptable level. In theLP turbine section, metals in current use will lastfor a long time.

TURBINE ROTORS.—The rotor element ofthe turbine consists of a shaft and bladed wheel(s).The wheel(s) is attached to the main powertransmitting shaft of the GTE. The jets ofcombustion gas leaving the vanes of the statorelement act upon the turbine blades, making themrotate. The turbine wheel can rotate in a speedrange of about 3,600 to 42,000 rpm. These highrotational speeds impose severe centrifugal loadson the turbine wheel. At the same time, the hightemperatures (1050° to 2300°F) result in alowering of the strength of the material. Theengine speed and temperature must be controlledto keep turbine operation within safe limits.

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Figure 1-27.—Cooling comparisons between a nonair-cooled vane and an air-cooled vane.

The turbine wheel is a dynamically balancedunit consisting of blades attached to a rotatingdisk. The disk in turn is attached to the rotor shaftof the engine. When in an unbladed form, werefer to this section of the unit as the turbine disk.The portion of the unit consisting of the turbineblades is called the turbine wheel. The disk actsas an anchoring component for the turbine blades.This enables the blades to transmit to the rotorshaft the energy they extract from the exhaustgases.

The disk rim is exposed to the hot gasespassing through the blades and absorbs con-siderable heat from these gases. In addition,because the rim also absorbs heat from theturbine blades by conduction, the disk rimtemperatures are higher than the temperatures ofthe remote inner portion of the disk. As a resultof these temperature gradients, thermal stressesare added to the stresses caused by rotation.

Various means are provided to relieve thesestresses. One way is to incorporate an auxiliaryfan, which is usually rotor-shaft driven,somewhere ahead of the disk. This will forcecooling air back into the face of the disk. Anothermethod of relieving the thermal stresses of the diskis by the method of blade installation. By notchingthe disk rims to conform with the blade rootdesign, the disk is made able to retain the turbineblades. This space provided by the notches allowsfor thermal expansion of the disk.

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The turbine shaft is usually made from low-alloy steel. It must be capable of absorbing hightorque loads, such as exerted when a heavy axial-flow compressor is started. The methods ofconnecting the shaft to the turbine disk vary. Onemethod used is welding. The shaft is welded tothe disk, which has a butt or protrusion providedfor the joint. Another method is by bolting. Thismethod requires that the shaft have a hub thatmatches a machined surface on the disk face. Thebolts then are inserted through holes in the shafthub. They are anchored in tapped holes in thedisk. Of the two methods, the latter is morecommon.

The turbine shaft must have some means forjoining the compressor rotor hub. This is usuallyaccomplished by a splined cut on the forward endof the shaft. The spline fits into a coupling devicebetween the compressor and the turbine shafts.If a coupling is not used, the splined end of theturbine shaft fits into a splined recess in thecompressor rotor hub. The centrifugal compressorengines use the splined coupling arrangementalmost exclusively. Axial compressor engines mayuse either of these methods.

Various ways of attaching turbine blades arein use today. Some ways are similar to the waycompressor blades are attached. The mostsatisfactory method used is the fir-tree design

Figure 1-28.—Turbine blade with fir-tree design and tab lockmethod of blade retention.

Figure 1-29.—Riveting method of turbine blade retention.

shown in figure 1-28. The blades are retained intheir respective grooves by a variety of methods.Some of the more common methods are pinning,locking tabs, riveting, and retaining rings. Figure1-29 shows a typical turbine wheel using rivetingfor blade retention.

Turbine blades may be either forged or cast,depending on the metal they are made of.Turbine blades are usually machined fromindividual forgings. Various materials are used inthe forging. Speed and operating temperatures areimportant factors in deciding what materials gointo the turbine blades.

Large engines use an air-cooled bladingarrangement on the GG turbine (fig. 1-30).Compressor discharge air is constantly fedthrough passages along the forward turbine shaftbetween a spacer and the shaft. A thermal shielddirects the cooling air along the face of the diskto cool the disk. The shield is between the first-and second-stage turbine wheels. The air is thendirected through slots in the fir-tree portion ofthe disk, into slots in the blade fir-tree. The airthen goes up through holes in the blades to coolthe blades (fig. 1-31).

Cooling of the turbine wheel and bladesreduces thermal stresses on the rotating members.The turbine nozzles are also air-cooled. Bycooling the stationary and rotating parts of theturbine section, higher turbine inlet temperaturesare permissible. The higher temperatures allow formore power, a more efficient engine, and longerengine life.

Figure 1-30.—GG turbine rotor cooling airflow.

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Figure 1-31.—GG turbine rotor blade cooling.

Power Turbines

The PT (fig. 1-32) is a multistage turbinelocated behind the GG turbine. The two turbineshave no mechanical connection between them.The PT is connected to a reduction gear througha clutch mechanism. Either a controllablereversible pitch (CRP) propeller or a reverse gearis used to change the direction of the ship.

Power turbines are used to extract theremaining energy from the hot combustion gases.They extract this energy in the following threeways, depending upon engine application:

1. The aircraft power turbine is designed sothe turbine extracts only enough energy from thegases to run the compressor and accessories.

2. In the solid-wheel turbine (used primarilyin small GTEs), as much energy as possible isextracted from the gases to turn the turbine. Theturbine provides power for the compressor,accessories, and the airplane propeller or theship’s generator. These engines are designed torun at 100 percent specified rpm all the time. Thelocation of the mechanical connection between theturbine wheel and the reduction gear on thecompressor front shaft depends on the design ofthe installation. Normally, a ship’s servicegenerator cannot be disconnected from its GTEexcept by disassembly. This setup is used forgenerators to prevent slippage between the engineand the generator.

Figure 1-32.—Typical power turbine.

3. Marine propulsion engines use a combina-tion of the previously mentioned two turbinetypes. The GG has a single- or multiple-stage HProtor that drives the compressor and accessoriesand an LP turbine to transmit power to the ship’spropeller via the reduction gear and shafting.

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Some ships that have two sets of engines usecounterrotating PTs. For example, PTs on onemain propeller shaft rotate clockwise while thePTs on the other shaft rotate counterclockwise.The GG rotates in the same direction for both setsof engines. The blade angle of the wheel and thenozzles in the PT section determine the directionalrotation of the PT. On large ships where differentlength propeller shafts are permitted, the engine(s)can be mounted to the other end of the reductiongear. This allows for counterrotation of thepropellers without changing PT rotation.

You can control the output speed of the PTby varying the GG speed. Since only a portionof the energy is used to drive the compressor,the plant can be operated very efficiently.For example, on a cold day you can have100 percent power turbine rpm with 80 to90 percent gas generator rpm. The operatingtemperature variables discussed earlier in thischapter account for this situation.

The PT is constructed much like the GGturbine. The main differences are (I) the absenceof vane and blade cooling air and (2) inter-locking shroud tips on the PT blades to reducevibration. Honeycomb shrouds in the turbine casemate with the blade shrouds to provide a gas seal.They also protect the case from the high-temperature gas. Two popular methods of bladeretention are the bulb and the dovetail. Thesemethods were discussed earlier in this chapter.

MAIN BEARINGS

The main bearings have the critical functionof supporting the main engine rotor. For the mostpart, the number of bearings necessary forproper engine support is decided by the length andweight of the engine rotor. The length and weightare directly affected by the type of compressorused in the engine. Naturally a split-spool axialcompressor will require more support than asimple centrifugal compressor engine. Theminimum number of bearings required will bethree, while some of the later models of split-spoolaxial compressor engines will require six or more.

While some engines use sleeve bearings, theGTE rotors are usually supported by either ballor roller bearings. In general, ball or rollerantifriction bearings are preferred for thefollowing reasons:

They offer little rotational resistance.

They facilitate precision alignment ofrotating elements.

They are relatively inexpensive.

They may be easily replaced.

They can withstand high momentaryoverloads.

They are simple to cool, lubricate, andmaintain.

They can accommodate both radial andaxial loads.

They are relatively resistant to elevatedtemperatures.

The main disadvantages of ball or rollerantifriction bearings are their vulnerability toforeign matter damage and their tendency to failwithout appreciable warning.

Usually the bearings are positioned on thecompressor or turbine shaft to absorb any axial(thrust) loads or radial loads. The ball bearingsare designed to absorb the thrust loads, and theroller bearings are used to support the radial loadsbecause they present a larger working surface.

The elements of a typical ball or rollerbearing assembly include a bearing supporthousing, which must be strongly constructed andsupported to carry the radial and axial loads ofthe rapidly rotating rotor. The bearing housingusually contains oil seals to prevent the oil fromleaking from its normal path of flow. The housingalso delivers lube oil to the bearing, usuallythrough spray nozzles.

On modern engines, the bearing is mountedin a sump. The bearing sump has a line throughwhich the lube oil is scavenged back to the sump.The bearing sump is also vented to prevent eithera pressure or vacuum. The vent goes either to theatmosphere or to an air-oil separator.

GAS TURBINE ENGINEAUXILIARY SYSTEMS

Up to this point, we have pointed out thephysical features and functions of a typical GTE.In this section we will point out the basics of therequired auxiliary systems being used on mostGTEs of today’s Navy. The systems are notdiscussed in any order of importance. We will giveyou a broad overview of the systems, whichinclude the air systems, the fuel oil system, theaccessory drive system, the lubrication system, thestarting systems, and the spark igniter system.

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AIR SYSTEMS

Air is used for many different functions onthe GTE. The terms primary airflow andsecondary airflow designate the major systems.Figure 1-33 (At the end of this chapter)shows the LM2500 GTE airflow. See page 1-34 foran overall view and pages 1-35 through 1-37 for details.Althoughthe following discussion on air systems isgeneric, we are using the LM2500 system discussedin chapter 2 as our example. For a betterunderstanding of primary airflow and secondaryairflow, use this figure in conjunction with thefollowing discussion. You should also use thisfigure when studying the bleed air system inchapter 2 of this manual.Primary Airflow

The GG compressor draws air from the ship’sinlet plenum. After being compressed, the primaryair enters the combustion section, where some ofit is mixed with fuel, and the mixture is burned.The remainder of the primary air is used forcentering the flame in the combustor andcooling some parts of the GG turbine. Theprimary air becomes part of the hot combustiongases. Some of the energy in the hot combustiongas is used to turn the GG turbine rotor, whichis coupled to, and turns, the compressor rotor.Upon leaving the GG turbine section, the gas

passes into the PT section. Most of the remainingenergy is extracted by the PT rotor, which drivesthe high-speed, flexible-coupling shaft. The shaftprovides the power for the ship’s drive system.The gas exits from the PT through the turbine rearframe and passes into the exhaust duct and outthrough the ship’s exhaust.

Secondary Airflow

Secondary air is the source of bearing pressureseal air and bleed air for cooling. Bleed air hasnumerous other uses. We will not attempt todescribe them all because each type of engine hasits own peculiarities.

Secondary air is taken from the compressorahead of the combusiton stage. Secondary airis bled from various pressure stages on thecompressor due to different pressure requirementsat different points in the engine. Occasionally itis bled from the combustor outer case. The airis fed internally through passages to bearingcavities and seals, and it also cools the GGturbine and nozzles. On some engines the air ispiped externally to seals where shafts extendoutside a housing, such as a reduction gear.

Seal air is used in the GTE air seals, which areof two types: labyrinth/honeycomb, used in thesump and turbine areas, and fishmouth, used inthe combustor and turbine midframe (fig. 1-34).

Figure 1-34.—Typical air seals.

1-27

The labyrinth/honeycomb seal combines arotating seal having a serrated surface with astationary seal having a honeycomb surface. Theserrations cut into the honeycomb to maintainclose tolerances over a large temperature range.The fishmouth seals are sheet metal, circular,stationary, interlocking seals used to preventexcessive leakage of hot combustion gas from theprimary airflow.

FUEL OIL SYSTEM

The fuel oil system has a number of functions.Primarily, it provides filtered, pressurized, andaccurately metered fuel for combustion. Whiledoing this, it controls the power output of the GG,which in turn determines the amount of powerdelivered by the engine from the PT. Additionally,the fuel system may provide pressurized fuel asa hydraulic medium to actuate the fuel controls.In some engines it controls the angle of thevariable compressor stator vanes.

All fuel systems are not alike, but they allhave certain elements in common. For example,they must have a fuel pump, a fuel control, apressurizing valve or its equivalent, a fuelmanifold, and fuel nozzles or vaporizers. Thefuel pump capacity is great enough to performany required hydraulic functions in addition toproviding combustion fuel. Excess fuel is bypassedin the fuel control and returned to the LP sideof the pump. Pressure in excess of the capabilityof this bypass is dumped by a relief valve in thepump assembly. The fuel pump and fuel controlare usually assembled together and mounted onthe gearbox.

ACCESSORY DRIVE SYSTEM

A popular misconception exists that the GTEhas only one moving part because the turbine andthe compressor are on the same rotating shaft.This is not true. A GTE requires a starting device(which is usually a moving part), some kind ofcontrol mechanism, and power takeoffs to driveother components, such as the lube oil and fuelpumps. The accessory drive section of the GTEtakes care of these various accessory functions.The primary function of the accessory drivesection is to provide space for the mounting ofthe accessories required for the operation andcontrol of the engine. The accessory drive sectionalso serves as an oil reservoir and/or sump andhouses the accessory drive gears and reductiongears.

1-28

The gear train of the accessory drive is drivenby the engine rotor through an accessory driveshaft coupling. The reduction gearing within thecase provides suitable drive speeds for each engineaccessory or component. Because the operatingrpm of the rotor is so high, the accessoryreduction gear ratios are relatively high. Theaccessory drives are supported by ball bearingsassembled in the mounting bores of the accessorycase.

Accessories provided in the accessory drivesection include the fuel control, with itsgoverning device; the HP fuel oil pump or pumps;the oil sump; the oil pressure and scavengingpump or pumps; the auxiliary fuel pump; and astarter. Additional accessories, which may beincluded in the accessory drive section or whichmay be provided elsewhere, include a starting fuelpump, a hydraulic oil pump, a generator, an air-oil separator, and a tachometer. Most of theseaccessories are essential for the operation andcontrol of any GTE. The particular combinationand arrangement and location of engine-drivenaccessories depend on the use for which the GTEis designed.

The three common locations for the accessorydrive section are on the side of the air inlethousing, under the compressor front frame, orunder the compressor rear frame. One manu-facturer of a generator engine used by theU.S. Navy had the reduction gear attached to theforward end of the compressor and the accessoriesmounted to the reduction gear.

LUBRICATION SYSTEM

The GTE lubrication system is designed tosupply bearings and gears with clean lube oil atthe desired pressures and temperatures. In someinstallations, the lubrication system also furnishesoil to various hydraulic systems. Heat absorbedby the lube oil is transferred to the coolingmedium in a lube oil cooler.

The lubrication system shown in figure 1-35is the dry-sump type, with a common oil supplyfrom an externally mounted oil tank. The systemincludes the oil tank, the lube oil pressure pump,the scavenging pumps, the oil cooler, oil filters,the pressure-regulating valve, and filter and coolerbypass valves.

All bearings and gears in the engine andaccessory drives are lubricated and cooled by thelubrication system. The lube oil supplied to eachbearing in a GTE is specifically controlled by acalibrated orifice which provides the proper flow

Figure 1-35.—Lubrication system schematic (typical).

of lube oil to the bearing at all engine speeds. Thisis sometimes known as a calibrated oil system.Since lube oil is supplied to the various parts ofthe system under pressure, provision is made toprevent the oil from leaking into unwanted areas,such as the compressors and turbines. This isusually accomplished by use of lip-type seals,labyrinth oil seals, or carbon ring pneumatic oilseals. We will discuss these seals in detail later inthis section.

The lubrication system provides the GTEbearings, gears, and splines with adequate cooloil to prevent excessive friction and heat. Oil

nozzles direct the oil onto the bearings, the gears,and the splines. Separate scavenge elements in thelube and scavenge pump remove oil from thesumps and the transfer gearbox (accessory drive).The scavenged oil is returned to the lube storageand conditioning assembly where it is filtered,cooled, and stored. Scavenge oil is filtered by aduplex filter mounted on the lube storage tank.

Lubrication System Subsystems

The lubrication system is usually divided intothree subsystems identified as lube supply, lube

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scavenge, and sump vent. We will discuss thesesubsystems and their components in chapter 2.

Oil Seals

Three types of oil seals are common to theGTEs, the lip-type seal, the labyrinth/windback,and the carbon ring.

LIP-TYPE SEAL.—The lip-type seal (fig.1-36) is used to prevent leakage in one directiononly. A metal frame is covered with a syntheticmaterial, usually neoprene. The neoprene issomewhat smaller than the shaft. The elasticityof the neoprene will allow the shaft to slidethrough the seal. The seal is molded with a lip toretain a spring around the center. The spring keepsa snug fit around the shaft. The construction ofthe lip-type seal allows for some very slightmisalignment and for axial movement of the

Figure 1-36.—Lip-type seal.

Figure 1-37.—Labyrinth/windback seal.

1-30

shaft. The lip seals are used where relatively lowspeeds and temperatures are encountered.

Two disadvantages of the lip-type seals arethat (1) they will seal against only little or no fluidpressure, and (2) they are easily damaged. A burron the shaft or dirt can tear the seal and causeleakage.

LABYRINTH/WINDBACK SEAL.—Thelabyrinth/windback seals (fig. 1-37) combine arotating seal having oil slingers and a serratedsurface with a stationary seal having windbackthreads and a smooth rub surface. The oil slingersthrow oil into the windback threads, which directthe oil back to the sump area. The serrations cutgrooves into the smooth surface of the stationaryseal to maintain close tolerances throughout alarge temperature range. This seal allows a smallamount of seal pressurization air to leak into thesump, thereby preventing oil leakage.

CARBON RING SEAL.—The carbon seal(fig. 1-38) has a stationary, spring-loaded, carbonsealing ring and a rotating, highly polished steelmating ring. It prevents oil in the gearbox fromleaking past the drive shafts of the starter, fuelpump, and auxiliary drive pad.

Another form of the carbon seal is also in use.The carbon rings are not spring-loaded. Theymove freely around the shaft and seal axiallyagainst the housing. When the engine is up tospeed, the rings center themselves radially in thehousing. Compressor bleed air is forced between

the carbon rings. The air pressure is forced outalong the shaft in both directions. The pressureprevents oil from entering the compressor orturbine and combustion gases from reaching thebearings. The main disadvantage of this seal isminor oil leakage that occurs during start-up andrun down as the oil pump moves oil before enoughairflow prevents leakage. However, the leakageis so slight that the engine normally will reach itsdesignated overhaul hours of operation before oilaccumulation will have any effects.

STARTING SYSTEMS

The GTEs use a starter to turn the compressorat sufficient speed to initiate and sustaincombustion. Both the compressor and the GGturbine must spin. In starting dual axial-flowcompressor engines, the starter needs to rotateonly the HP compressor. The starter’s firstrequirement is to accelerate the compressor toprovide enough airflow and pressure to supportcombustion in the burners.

Once fuel has been introduced and the enginehas fired, the starter must continue to acceleratethe compressor above the self-sustaining speed ofthe engine. The starter must provide enoughtorque to overcome rotor inertia and the frictionand air loads of the engine.

Figure 1-39 shows a typical starting sequencefor a GTE. When the starter has accelerated thecompressor enough to establish airflow through

Figure 1-38.—Carbon ring seal. Figure 1-39.—Typical starting sequence for a GTE.

1-31

the engine, the ignition is turned on and the fuelvalves are opened. The sequence of the startingprocedure is important. At the time the fuel/airmixture is ignited, enough airflow must passthrough the engine to support combustion.

After the engine has reached its self-sustainingor self-accelerating speed, the starter can bedeactivated. If the starter is cut off below theself-sustaining speed, the engine may deceleratebecause it doesn’t have enough energy toovercome its own friction and operating losses.It may also suffer a “hung start” in which it idlesat a speed so low that it is unable to accelerateenough to obtain proper operating parameters.A hung-start engine will overheat because of alack of cooling air. The starter must continue toboost engine speed well above self-sustainingspeed to avoid hot or hung (false) starts, or acombination of both. In a hot start, the enginelights off, but because of a lack of adequatecooling and combustion air, the exhaust gastemperature exceeds the allowable limit for theengine.

At the proper points in the starting sequence,the starter and, usually, the ignition system willcut off. The higher the rpm before the starter cutsout, the shorter will be the total time required forthe engine to attain idle rpm. This is because theengine and the starter are working together.

All GTE starters must be able to produceenough torque to start the engine properly. TheGTEs must reach a certain minimum idle rate fora start to be satisfactory. This requires thetorque characteristics of an acceptable starter toexceed by a good margin the amount of torqueneeded to overcome friction.

The GTEs use three basic types of startersand starter systems—electric, hydraulic, andpneumatic. Pneumatic (air-turbine) starters arethe most commonly used on all except smallerengines, which generally use electric starters. Somemarine GTE installations use hydraulic starters.

Another type of starter system is the airimpingement system. Bleed air from another GTEis used directly in the HP turbine assembly torotate the GG. Due to the volume of air required,the air impingement system is used primarily instarting aircraft engines and will not be coveredin any further detail. We will describe thepneumatic starter system in chapter 2 of thisTRAMAN.

1-32

Figure 1-40.—Spark igniter.

SPARK IGNITER SYSTEM

Once adequate airflow has been establishedthrough the combustion area, fuel can be injectedand the spark igniters start the burning process.The spark igniters are high-voltage electrical sparkproducers powered from the ignition excitercircuits.

The ignition exciter derives its input powerfrom the ship’s service 60-Hz, 115-volt electricalsystem. Its function is to produce a high-energyspark at the spark igniter in the engine. This mustbe accomplished with a high degree of reliability

under widely varying conditions. These includeinternal pressure, humidity, temperature,vaporization, and carbon deposits on the sparkigniter. To accomplish this, the capacitordischarges a spark of very high energy (about100,000 watts). This concentration of maximumenergy in minimum time achieves an optimumspark for ignition purposes. This spark is capableof blasting carbon deposits and vaporizingglobules of fuel.

Spark igniters are of several types. Someresemble common automobile spark plugs. Themore common annular gap types are shown infigure 1-40. Since they do not operate continually,they are usually durable and reliable, requiringonly occasional cleaning to remove carbon fromthe tip and ceramic barrel.

SUMMARY

In this chapter you have learned aboutthe principles and construction of GTEs. Wehave discussed the evolution of the GTE, thetheory of operation, classifications of thedifferent types of engines, and their subsystemcomponents. Many other publications areavailable that discuss GTE construction indepth. This chapter was provided to give youthe basis on which to expand your knowledgeof marine GTEs. You may not feel youunderstand the temperature-pressure relation-ships in a simple GTE at this point. If so,you should review the sections of this chapterrelated to theory before continuing on to thematerial that follows.

1-33

Figu

re l

-33.

—L

M25

00 G

TE

air

flow

1-34

Figure l-33A.—LM2500 GTE airflow.

1-35

Figure l-33B.—LM2500 GTE airflow—Continued..

l -36

Figure l-33C.—LM2500 GTE airflow—Continued.

1-37

CHAPTER 2

LM2500 GAS TURBINE ENGINE

As a gas turbine technician, you need to knowthe basic construction and function of the mainpropulsion power plant on your ship. TheLM2500 GTE has been selected as the power plantfor the CG-, DD-, FFG-, and AOE-6-classships. The greater your understanding of theconstruction of the engine, the better you will beable to operate and maintain the engine.

In chapter 1 of this TRAMAN you learned thebasic theory of how a GTE operates and thevariety of engine types available. In this chapterwe will discuss the LM2500 GTE in particularsince this engine is the one you will most oftenwork on. We will occasionally point out somesimilarities between the LM2500 GTE and the

Allison 501-K17 GTE, which is covered in detailin chapter 3 of this TRAMAN.

The LM2500 GTE is manufactured by theGeneral Electric Company and is a marineversion of the engine used in a variety of aircraft.It is the main propulsion plant for many gasturbine-powered ships. The engine is rated atapproximately 20,000 brake horsepower; it hasa power turbine speed (Np t) of 3,600 rpm on theCG-, DD-, and FFG-class ships and 3,253rpm on the ship.

The gas turbine equipment is composed of abase enclosure assembly and a gas turbineassembly. The gas turbine assembly (fig. 2-1) hasa GG, a PT, a high-speed flexible coupling shaft,

Figure 2-1.—Gas turbine assembly.

2-1

Figure 2-2.—Gas turbine assembly (exploded view).

inlet and exhaust components, and a lube oilstorage and conditioning assembly (LOSCA).

The primary function of the GTE is togenerate power and to transmit it through a high-speed flexible coupling shaft to the ship’sreduction gearbox and propeller shafting.

NOTE: Figure 2-2 provides an exploded viewof the LM2500 GTE. Refer to it during your studyof the construction of this engine. The sectionsthat follow describe the various components ofthe GTE.

BASE/ENCLOSURE ASSEMBLY

The base/enclosure assembly (fig. 2-3)provides a thermally and acoustically insulated

structure for the gas turbine assembly andconnections for electrical, fire-extinguishing, air,and liquid services.

The base/enclosure assembly has an enclosure(about 26 feet long, 8 feet high, and 9 feet wide),a shock-mounted base, a GTE mounting system,an intake and exhaust system, a fire detection andextinguishing system, an enclosure heater, alighting system, and a GTE water wash system.The base/enclosure assembly is maintained in theinstalled position as a permanent part of the ship.This is opposed to the GTE assembly, which canbe removed for major repair, overhaul, or replace-ment. Module doors provide access for routinemaintenance. The number and location of themodule doors varies on the different class ships.Removable side panels are installed on allmodules.

2-2

Figure 2-3.—Base/enclosure assembly.

2-3

Figure 2-4.—LM2500 GTE base frame and shock mounts (exploded view).

BASE ASSEMBLY

The base assembly (fig. 2-4) has a fabricatedsteel frame of steel double I-beams to provide astable platform for the GTE. It contains suitablemounts and links to secure the GTE. Thirty-twoshock mounts under the base secure the entirebase/enclosure assembly to the ship’s foundation.The shock mounts have two stacks of springwashers aligned above, and attached to, a resilientneoprene shock mount. They weaken shock loadsby absorbing most of the abrupt up and downmovements of the ship’s foundation. The basealso provides for connection of electrical, air,carbon dioxide (CO2) or Halon, and liquidservices. This area is known as the basepenetration plate. More detailed descriptions ofthe functions of the components that enter theenclosure are provided throughout this chapter.

The GTE and the exhaust duct are attachedto the base by 11 supports (fig. 2-5) that securethe GTE vertically, laterally, and axially. Thesupport to the base attachment points are shimmedto align the GTE. The forward end of the GTEis supported by a large yoke and two supportsattached at the compressor front frame (pointsA and G on fig. 2-5). The aft end is attached byfour supports—three on the right side and one onthe left (shown on fig. 2-5 at points B, C, and F).The exhaust duct is secured by two supports (pointE) on each side and one support (point D) anda thrust pin (point H) underneath. Figure 2-5 alsoshows an exploded view of each support pointcorresponding to its position on the baseassembly.

NOTE: All GTE and enclosure references toleft, right, front (forward), rear (aft), and clock

2-4

Figure 2-5.—Gas turbine assembly mounting.

positions apply when viewing the GTE from therear (exhaust end) looking forward.

ENCLOSURE

Refer to figure 2-3 as we discuss the enclosure.It is a soundproof, fire-resistant housing in whichthe GTE operates. The enclosure providesthermal and acoustical insulation, inlet andexhaust ducting, and a controlled environment forthe GTE. Flexible coupling joints are provided atthe air inlet and exhaust ducts which allow a flowpath/interface between the enclosure and theship’s ducting. The enclosure is of double-wallconstruction. (NOTE: For personnel safety,testing was conducted to ensure the enclosure is

explosionproof and fireproof. The inner wall isconstructed of perforated metal and can withstanda temperature of 2000°F for 15 minutes.) Withventilation air being supplied to the enclosure, thetemperature of the outer wall normally does notexceed 150°F. The right and left propulsion GTEmodules are functionally identical. The onlydifference between the enclosures of the differentclass ships is their access to the engine.

Lighting

Enclosure illumination is provided by nineexplosionproof light fixtures—eight on theceiling and one on the base. With the exceptionof the CGs module illumination is the

2-5

Figure 2-6.—Block diagram and an exploded view of a UV flame detector.

same on each class. The lights are turned on witha rotary switch mounted on the exterior wall ofthe enclosure near the port side access door. Theswitch has four positions: off, base light, ceilinglights, and base and ceiling lights. The CGs andhave two additional explosionproof lightfixtures in the intake plenum. These two lights canbe turned on and off by a push-button switchmounted on the front of the module adjacent tothe inlet plenum observation window.

Heater

The heater is ceiling mounted in the enclosure.It maintains the air temperature above 60°F whenthe GTE is not operating to ensure suitable fuelviscosity is maintained for engine starting. Theheater is an electrically powered (440-volt ac,3-phase) and thermostatically controlled, forced-air, 8-kilowatt space heater and blower motor.The thermostat cuts on the heater at 60° to 70°F

2-6

Figure 2-7.—Signal conditioner block diagram and typical signal conditioner unit.

and shuts it off when inlet air temperature reaches85° to 95°F. The thermostat turns on the blowermotor at 125°F and secures it at 145°F.

FIRE DETECTION ANDEXTINGUISHING SYSTEMS

All LM2500 GTE modules have some methodfor detecting and extinguishing a fire in theenclosure. The sensors used to detect a fire areidentical on all classes. The detection system hasthree ultraviolet (UV) flame detectors, a flamedetector signal conditioner, and two resistancetemperature elements (RTEs) used as temperatureswitches. The use of these sensors and the fire-extinguishing systems vary with ship classes.

Figure 2-6 shows a block diagram and anexploded view of a UV flame detector. Thisdetector senses the presence of fire in the enclosureand generates a photoelectric signal. This signal

is transmitted to the signal conditioner to alert theoperator of fire in the module. On the LM2500GTE of the twin-shaft ships and on the Allison501-K17, it also activates the fire stop sequenceand releases fire-extinguishing agents to extinguishthe fire.

The signal conditioner (fig. 2-7) is containedin a metal box. The box is attached to theunderside of the base enclosure on the LM2500GTE. On the Allison 501-K17 GTE, the unit islocated in the alarm terminal box on the generatorend of the base. Identical detector cards (onefor each UV sensor) are located in the signalconditioner. The detector card amplifies, rectifies,and filters the current pulses from the UVsensor. This provides an output voltage levelproportional to the UV light level at the UVsensor. The signal conditioner processes theinput from the UV flame detector and completesthe alarm control circuitry outside of the gas

2-7

Figure 2-8.—Fire system temperature switches and manualswitches.

turbine module (GTM), which results in the alarmindication.

The two temperature switches are mounted onthe enclosure ceiling and generate an alarm signalif the temperature reaches a preset level (fig. 2-8).The output of the RTEs, which generate a firesignal only, is an input to the free standingelectronic enclosure (FSEE).

CG-, DD-, and Class Ships

Since we discussed the components of the firedetection system in the previous section, we willnot discuss them here. The alarm system also hasa manual fire alarm push button (shown infig. 2-8) besides the electrical signal generatedby either the temperature switch or the flamedetector signal conditioner. The extinguishingsystem has two CO2 discharge nozzles. Whenmanually activated, the CO2 fire-extinguishingagent is discharged into the enclosure. It also hasan extinguish release/inhibit switch and a CO2release/inhibit switch mounted to the outside ofthe enclosure, next to the side access door.

Figure 2-9.—CG, DD, and fire stop sequence flowchart.

Two CO2 discharge nozzles are located insidethe enclosure. They are mounted on the crossbeamunder the compressor front frame. One is forinitial discharge (primary) and the other forextended discharge (secondary). The fire extinguishrelease/inhibit switch is mounted above the firealarm push button. It is a two-position switch(ACTIVE/INACTIVE). When in the INACTIVEposition, this switch prevents discharge of the CO2extinguishing agent.

Figure 2-9 is a signal flow chart of the firestop sequence. Fire is sensed by the flamedetectors or temperature switches. The firemay also be discovered by watch station personnelwho would operate the manual CO2 releaseswitch. In either situation, the sequence ofevents are the same after the fire is discovered.Electrical contacts close to activate the fire-extinguishing system and the following concurrentactions occur:

1. The fire alarm signal sounds.

2. The system conducts a self-check to see ifbattle override has been selected at thepropulsion local control console (PLCC)or the propulsion auxiliary control console(PACC) or if the module cooling systemhas failed. Either event will terminate thefire stop sequence.

3. The GTE fuel shutdown valves close,shutting down the GTE.

4. The fuel supply to the GTM is shut off inthe ship’s service system.

2-8

Figure 2-10.—FFG fire system block diagram.

5. The module cooling air fan is shut down.6. The module vent damper is closed.7. The bleed air valve is closed.8. The enclosure lights flash (only if lights

were previously on).9. After a delay of 20 seconds, the initial CO2

discharge occurs.

To prevent CO2 discharge, position the releaseinhibit switch to the INACTIVE position duringthe 20-second time delay. The initial dischargedelivers 150 pounds of CO2 at a rate of 50 lb/min.If required, the extended CO2 discharge ismanually activated. The extended dischargedelivers 200 pounds of CO2 at the rate of10 lb/min.

FFG-Class Ship

Like the other ship classes already discussed,the fire detection system of the FFG-class ship hasthree flame detectors, a flame detector signalconditioner, and two temperature switches. Themanual alarm system has a fire alarm pushbutton. The extinguishing system has a singleHalon discharge nozzle, connecting tubing, andan extinguish release inhibit switch.

The UV flame detectors of the FFG-class shipare identical to the type on the other class ofGTE-powered ships, but provide only analarm. The RTE fire sensor will also sound thatsame alarm, indicating a fire is present.

The manual fire alarm push button is mountedon the outside of the enclosure, next to the sideaccess door. When activated, a contact closuresignal is provided to the ship’s system which

sounds an alarm at the propulsion controlconsole (PCC) to notify the engineering officerof the watch (EOOW). Fire may also be sensedby the flame detectors (fig. 2-10) or either of thetwo temperature switches may detect enclosuretemperature above preset limits.

The Halon discharge nozzle is located insidethe enclosure. It is mounted on the underside ofthe crossbeam under the compressor front frame.This one nozzle provides both initial (primary) andstandby (reserve) Halon discharge. The fireextinguish inhibit switch is mounted above the firealarm push button on the outside of the module.When in the ACTIVE position, this switch willallow automatic or manual discharge of theHalon. When in the INACTIVE position, thisswitch provides a signal to the ship’s system thatis used to prevent discharge of the Halon,However, this switch does not override manualactivation locally.

You can extinguish a fire in either enclosureby filling the enclosure with Halon. The PCC hasa FLAME DET ALARM/HALON FLOOD pushbutton for each enclosure. To prevent anenclosure from being flooded with Halon whilepersonnel are inside, place the fire extinguishinhibit switch in the INACTIVE position.

Activation of the FLAME DET ALARM/HALON FLOOD switch on the PCC will providethe initial Halon discharge of 60 pounds at a rateof 1.45 lb/sec. An additional 60 pounds, with thesame rate of discharge, is available on standby(manually activated).

AIR INTAKE SYSTEM

The air intake system for the LM2500 GTEprovides the large quantity of air with a minimumpressure drop that is needed for proper engineoperation. The design of the ducting varies withthe ship class. However, the function of thesystems are the same. The intake system reducesthe flow distortion, pressure drop, and saltingestion. The intake system also provides ductsilencing, a supply of cooling air, anti-icingprotection, and mounting for moisture separationpads, and allows for engine removal by a systemof rails on the duct walls. Blow-in doors locatedon the ship’s upper level protect the GTE fromair starvation if inlet blockage occurs.

2-9

Figure 2-11.—GTE air inlet and exhaust.

Figure 2-11 shows the air inlet and exhaustcomponents of a GTE. We will discuss the exhaustsystem after we describe the intake system.

The intake section of the enclosure iscomposed of five parts:

1. A primary inlet flexible joint, whichconnects the ship’s ducting with the enclosure. Ithas an upper and lower flange and a fiber-filledflexible boot.

2. A barrier wall, which has four stainless steelpanels bolted together. It prevents exhaust andventilation air from being drawn into the intake.It has a removable access hatch for maintenance/operator personnel access to the inlet plenum.

3. A wire mesh inlet screen (foreign objectdamage (FOD) screen), which is bolted to thebarrier wall and prevents foreign objects fromentering the engine.

4. An inlet duct, which is bell-shaped andattached to the front frame of the compressor.The duct, or bellmouth, smoothes the airflowentering the turbine. A flexible seal is attachedbetween the inlet duct and the barrier wall.

5. A dome-shaped faring, called the center-body, which is attached to the compressor frontframe hub to aid in smoothing the airflow.

CG, DD, AND INLETDUCT SYSTEMS

The inlet duct systems for the CG-, DD-class ships are very similar. The majordifference is the sand separators used on thes h i p s . S i n c e o n l y t h e f o u r 9 9 3class ships have the sand separators installed, wewill not discuss this unique feature.

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Overall Flow Description

Refer to figure 2-12 while you are studying thissection on the inlet duct systems. It shows the CG,DD, (minus the sand separators) intakeduct system. Intake air enters the main ductthrough the demisters (moisture separators)located in the sides of the high hat inlet. The airflows down the main duct and passes throughsilencers located about midway down the duct.It then flows through a flexible coupling into theengine inlet plenum. Cooling air taken off themain duct ahead of the silencers flows throughthe cooling duct, cooling duct silencers, andcooling air fan. It then enters the engine enclosurethrough a vent damper. The air circulates aroundthe engine and exits the enclosure through theexhaust plenum. If the moisture separation systembecomes blocked, the blow-in doors automaticallyopen to supply the engine with combustion andcooling air. Under these conditions, no demistingprotection exists.

High Hat Assembly

The high hat assembly (fig. 2-13) is locatedon the 04 level of the ship. It houses all thecomponents of the moisture separation system.

Figure 2-12.—CG, DD, intake duct system.MOISTURE SEPARATION SYSTEM.—

The moisture separation system includes the

Figure 2-13.—High hat assembly.

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inlet louvers and the demister panels. The inletlouvers are arranged in sections. They are locatedin the sides of the high hat assembly. The designand arrangement of the louvers aresuch that theywill shed sea spray. The louvers are electricallyheated to prevent icing. These heaterstype and are located on the back of the louversurface. The heaters are controlled from theengine control consoles. The demisters are thetwo-stage, mesh-pad type and are mountedvertically behind the louvers. Water, separatedfrom the inlet air as it passes through thedemisters, is collected in scuppers and drainedoverboard. The demisters will remove 70 percentof the particles that are 1.7 to 5 microns in sizeand 90 percent of the particles that are 5 micronsand larger.

BLOW-IN DOORS.—The blow-in doors arelocated just below the inlet louver Thenfunction is to bypass the moisture seperationsystem. They provide an unrestricted inlet airflowto the engines if the moisture separation systembecomes blocked. They are designed to open bysolenoid-operated latch mechanisms, and willopen if the inlet airflow becomes too restrictedfor normal engine operation.

On the DD-class ships, a controlleris located in each engine room to provide formanual or automatic operation of the doors. Thisis done by a selector switch and a push button onthe controller door. On the CG-class ship thiscontroller is in the helo hangar. The push buttonon the CG-class is located on the high hatassembly. In manual operation, you can only openthe doors by depressing the push button. Inautomatic operation the doors open by operationof a pressure switch. The switch operates on lowduct pressure. This pressure switch also providesa DUCT PRESSURE LOW signal to propulsionauxiliary machinery control equipment (PAMCE)and propulsion local control equipment (PLOE).The pressure switch operates when duct pressurefalls below 8 inches of water. If the doors open,the doors must be manually reset closed.

Ducting

See figure 2-12 as we discuss the ducting. Itallows the air to travel from the high hat assemblyto the inlet of the compressor. The componentsof the ducting include the silencers, the anti-icingpiping, the cooling air duct, and the engineremoval system.

SILENCERS. —The main engine intake ductsilencers are located about halfway clown the duct.The silencers are vertical vane assembliesconstructed of sound-deadening material. Theintake ducts are encased in perforated stainlesssteel sheet. The vane assemblies are arranged inmodules which are removable to aid in theremoval of the GTEs through the intake duct.

ANTI-ICING SYSTEM.—This system pre-vents the formation of ice in the intake duct.High-temperature bleed air from the GTEs ispiped to a manifold. This manifold is locatedinside the duct between the cooling air extractionport and the silencers. From the manifold thebleed air is discharged into the inlet airstream. Thebleed air is mixed with the inlet air, raising thetemperature enough to prevent the formation ofice. When enabled from the PAMCE or thePLOE, an electromechanical control systemregulates bleed air flow to maintain the inlet airtemperature at about 38°F. This prevents theformation of ice. A temperature sensor in thestack provides an ANTI-ICING INSUFFICIENTsignal. This alarm activates when the anti-icingsystem has been enabled and the temperaturedrops below 36°F.

COOLING AIR DUCT.—Main engine coolingair is extracted from the main intake duct. It istaken at a point between the blow-in doors andthe main duct silencers. It is then ducted to theengine enclosure. The cooling air duct containsa silencer and a cooling air fan. The coolingsystem will be discussed in more depth later in thischapter.

ENGINE REMOVAL SYSTEM.—Sometimesa main propulsion GTE must be removed fromthe ship for maintenance/overhaul. At the timeof engine removal, a set of channel-shapedmaintenance rails is installed in the engineenclosure. These are put adjacent to each side ofthe engine. A set of rollers, which fit into therails, is attached to each side of the engine. Theremovable maintenance rails extend into theenclosure inlet plenum. They then turn 90 degrees,from horizontal to vertical attitude. They matewith permanently installed rails that extend upthe intake duct. In the FFG-class ship, the uptakerails must be installed each time the engine isremoved. The engine is removed through theintake duct. In the inlet plenum, three sets ofmaintenance rails interface with three sets ofpermanently installed rails in the ship’s intake

2-12

Figure 2-14.—FFG air intake system.

duct. The permanently installed rails extendthrough the high hat section. These serve to guidethe engine as it is lifted vertically from the ship.

Removal of the engine is accomplished in twooperations due to space constraints. The GG isseparated from the PT while still in the enclosure.Then it is removed from the ship, followed byremoval of the PT.

FFG INLET DUCT SYSTEM

Refer to figure 2-14 as we discuss the FFGinlet duct system. The GTE uptake spaces andintake system house three separate ducting systemsper GTE. They are for combustion air, modulecooling air, and exhaust gas elimination.Atmospheric air for the combustion and coolingair ducting normally enters through the intakeplenums. These are located on each side of theship’s structure. The air is then carried throughducting to the GTMs in the engine room below.Ducting connections to the GTMs are made viaexpansion joints on top of each GTM. Thecombustion air intake ducts also provide theaccess for removal and replacement of the engineGG and PT sections.

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Besides the ducting, the GTE uptake andintake system includes moisture separatorassemblies, emergency inlet doors, and cooling airfans (not shown). Also included are cooling airbypass dampers and provisions for anti-icingupstream and downstream of the moistureseparators (not shown).

Demister Panels

The demister panels (or moisture separators)are of knit wire mesh construction mounted in asupporting frame. They remove moisture dropletscontaining sea salt and prevent other foreignobjects from entering the intake and cooling airducts. In operation, the moisture droplets adhereto the wire mesh while the air passes through. Themoisture droplets coalesce into larger drops andfall free of the airstream. They then drain intotroughs which are piped to the plumbing drainssystem. Each combustion air intake duct has eightdemister panels. Each cooling air intake duct hasfour panels.

Blow-In Doors

Emergency inlet (blow-in) doors are providedin the combustion air and cooling air ducts to each

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engine. One emergency inlet door is locatedbetween the uptake space and each combustionand cooling air duct. If the moisture separatorsstart to ice or are partially blocked for any reason,the emergency inlet doors will open, These openautomatically to provide inlet air from the uptakespace and permit continued limited power engineoperation. The doors are pneumatically operated,electrically actuated, and automatically controlledby differential pressure switches. Each combustionair emergency inlet door opens automatically ata differential pressure of 9.0 inches of water(in. H2O). The cooling air emergency inlet doorsopen automatically at 3.75 to 4.25 in. H2O differentialpressure. You can actuate each door manuallyusing the air solenoid override at the doorcontrol panel. If a loss of air pressure occurs, youcan open or close the doors manually using awrench at the door assembly.

Anti-Icing System

An anti-icing system uses bleed air from theGTE. It is used to prevent the formation of icein the intake system. Anti-icing nozzles are locatedupstream and downstream of the moistureseparators.

The system has a sensor located in the inletducting and a signal conditioner. Icing conditionsexist when the ambient air temperature is below41°F and humidity above 70 percent. The signalconditioner transmits a signal to the anti-icingsystem when these conditions occur. This signalprovides an alarm indication at the controlconsole and provides an enable signal forinitiation of the anti-icing system.

Bleed air from each GG is piped to itsassociated intake system for anti-icing purposes.The piping to each intake system contains a250/38 psig regulating valve to reduce the bleedair pressure. The bleed air supplied to the intakesystem provides anti-icing air for the moistureseparators, the GG bellmouth, and the enclosurecooling fan. Bleed air also supplies the coolingair bypass damper and the enclosure cooling airdamper.

The anti-icing pressure regulating valve isactuated from either the PCC or the localoperating panel (LOP). Valve status indication isprovided at both control stations.

Intake Monitoring and Control

Outside air temperature is sensed by aresistance temperature detector (RTD). It is

mounted in each intake plenum upstream of themoisture separators. The temperature is displayedon the PCC demand display and on an edgewisemeter on the LOP. The temperature signal isused by the propulsion control system (PCS)for gas turbine enclosure ventilation damperlogic. It is also used for automatic GTE powercorrection when operating in programmed control.A differential pressure sensor measures thepressure difference between the intake duct andoutside atmospheric pressure. If the differentialpressure exceeds 7.5 in. H2O, the combustion airintake LP alarm is activated on the PCC in thecentral control station (CCS). This parameter canalso be demand displayed on the PCC.

EXHAUST SYSTEMS

The exhaust system (see fig. 2-11) routes theengine exhaust gases to the atmosphere. It isdesigned to prevent re-ingestion of exhaust gasesinto the intakes and to minimize heating oftopside equipment. This system also minimizes thesound and the heat sensing of the ship by hostilevessels and aircraft. Re-ingestion of the exhaustgases is prevented by having the exhaust stackhigher than the air inlet ducts. Sound level isreduced by exhaust duct wall insulation. On someship classes a silencer is installed to assist in noisereduction. The exhaust gas temperature is reducedwhen the module cooling air combines with thehot engine gases as they leave the GTM. Exhaustgas temperature may be further reduced by an IRsuppression system.

The exhaust duct is attached to the base andturbine. An inner deflector is bolted to theturbine rear frame hub and protects thehigh-speed flexible coupling shaft from theexhaust gases. An outer cone is bolted tothe turbine rear frame outer flange to directexhaust gases smoothly into the duct. Theexhaust extension differs in construction betweenthe FFG- and the CG-, and DD-classships, but serves the same purpose. On theFFG-class ship the exhaust extension is boltedto the exhaust duct through which the enginegases enter the exhaust duct. It creates aneductor effect which allows for enclosureventilation air to exit through the spacebetween the extension and the flexible joint.The primary exhaust flexible joint connects theship’s ducting to the enclosure.

Figure 2-15.—DD exhaust duct systems.

DD AND CG EXHAUSTDUCT SYSTEMS

These ship classes have replaced the outmoted IRsuppression system with the boundary layer infared suppression system (BLISS), figure 2-17. Figure 2-15shows a cross-sectional view of the DD exhaust ductsystem.

Silencers

A single vane type of silencer is located in thecenter of the exhaust duct. It has sound-deadeningmaterial encased in perforated stainless steel sheet.This material, along with the duct wall insulation,reduces the sound level enough to meet acceptableairborne noise requirements.

Eductors

Figure 2-16 is a cross-sectional view of aneductor. The exhaust eductors are located at thetop of each propulsion engine exhaust duct. It ispositioned so the gas flow from the exhaustnozzle will draw outside air into the exhaust stream toreduce exhaust gas temperature.

2-15

Figure 2-16.—DD and DDG exhaust eductor.

It is positioned so the gas flow fromthe exhaust nozzles will draw outside air intothe exhaust stream. It also draws IR suppressionspray into the exhaust as it enters the mixingtube.

Figure 2-17.—CG exhaust eductor.

FFG EXHAUST DUCT SYSTEM

The FFG exhaust (uptake) system (fig. 2-18)conducts the GTE combustion exhaust gases andthe enclosure exhaust air to the atmosphere.The exhaust trunk extends from the exhaustexpansion joint at the enclosure, up throughthe ship. It terminates in the atmosphere abovethe top of the stack. The enclosure coolingair exhaust is drawn into the exhaust trunkthrough an eductor effect, explained previously.An RTE is mounted in the exhaust trunk. Itprovides a signal to the propulsion control systemfor the demand display of the exhaust temperatureat the PCC.

Figure 2-18.—FFG exhaust system.

2-16

MODULE COOLING SYSTEMS

Navy GTEs are not rated for operation inambient temperatures above 130°F. A modulecooling system must be used to prevent moduletemperatures from exceeding 130°F. The LM2500GTE module uses a combination of fan-forcedventilating air and exhaust gas eduction to coolthe GTM (fig. 2-19). The location and operationof the cooling fan system differ among shipclasses, but the ducting is connected to a flexiblejoint common to all enclosures. Cooling air istaken into the cooling duct and pressurized bythe fan. It is then discharged at the electro-pneumatically controlled ventilation damper onthe top of the module. This vent damper also willisolate the enclosure in case of fire or when theengine is secured. Once the air enters the module,a natural swirling effect takes place around theengine. The cooling air moves to the back of themodule where it is removed by the exhausteductor. A temperature monitor is located on theenclosure ceiling just forward of the exit area. Thismonitor provides an alarm indication to thecontrol consoles if the enclosure temperatureexceeds a set limit. Although the cooling systemsof the different class ships perform the samefunction, they are constructed differently. Thefollowing sections of this chapter describe thesedifferences.

Figure 2-19.—Gas turbine module cooling.

CG, DD, COOLING SYSTEM

In this system, main engine cooling air isextracted from the main intake duct at a pointbetween the blow-in doors and the main ductsilencers. It is then ducted to the engine enclosure.The cooling air duct contains a silencer and acooling air fan (see fig. 2-12). The silencer has adouble-walled cylinder. The cooling is activatedeither manually or automatically from the PACC andthe PLCC (automatically from the Shaft Control Unit(SCU) on the DDG-51 class); the cooling system must be runningfor engine operation.The space between is filled with sound-deadening material. Suspended in the center ofthe cylinder is a torpedo-shaped baffle. It is madeof perforated stainless steel sheet filled withsound-deadening material. The silencer forms asection of the cooling air duct. The cooling airfan is located in the duct between the engineenclosure and the silencer. The fan is rated at 80hp and 17,000 cubic feet per minute (ft3/min) airflow.

From the cooling fan, the air is ducted to theengine enclosure. It enters the enclosure througha ceiling-mounted vent damper. Then it circulatesaround the engine. The air exits the enclosurethrough the exhaust plenum. The cooling isactivated either manually or automatically fromthe PACC or the PLCC and must be running forengine operation. The vent dampers are electro-pneumatically operated. They use air from the

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Figure 2-20.—FFG cooling system.

ship’s service air system (SSAS). The ventdampers are operable either automatically ormanually from the PACC or the PLCC.

FFG COOLING SYSTEM

In this system, the cooling air ducts to eachengine are made up of two parallel sections (fig.2-20). One section contains a cooling air fan andthe other a cooling air bypass damper. The twosections join together before connecting to theGTM. At low engine power the cooling air fanin one leg supplies cooling air to the GTM. Thisacts to close the bypass damper in the other leg.As the engine power level passes 3,000 shafthorsepower (shp), the engine exhaust eductorcreates enough draft for the bypass damper toopen. Both parallel legs then permit cooling airto enter the GTM. The cooling air fan is shut offautomatically at an engine power level of 3,000shp by the PCS.

The PCS provides the control and statusindications for the cooling air fans at the PCCand the LOP. Both locations have controls formanually starting the fans. They also haveautomatic control of the fans after the GTE hasbeen started. The fan local motor controllerprovides the only controls for stopping the fanin the manual mode. The cooling air bypassdampers have position switches that show thestatus of the bypass damper at the PCC.

GAS TURBINE ENGINE ASSEMBLY

The LM2500 GTE is an axial-flow, split-shaftGTE with an annular-type combustion chamber.The gas turbine assembly aboard ship has a GG,a PT, a high-speed flexible coupling shaft,and inlet and exhaust components. The GG iscomposed of a FOD screen, a bellmouth, a16-stage variable geometry compressor, anannular combustor, a two-stage high-pressure(HP) turbine, an accessory drive system, controls,and accessories. The accessory gearbox (AGB) ismounted on the GG. The PT is aerodynamicallylinked to the GG and is composed of a six-stagelow-pressure (LP) turbine rotor, a low-pressureturbine stator, and a turbine rear frame. The high-speed flexible coupling shaft is connected to thepower-turbine rotor and provides shaft powerto the ship’s drive system. The GTE inletcomponents consist of the inlet duct and thecenterbody (see fig. 2-2). The GTE exhaustcomponents consist of the exhaust duct, the outercone, and the inner deflector (see fig. 2-11).

GAS GENERATOR ASSEMBLY

In this section we will individually describe theGG assembly components and their functions.These components are the FOD screen, bellmouthand bulletnose, compressor, combustor, HPturbine, and accessory drive.

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Figure 2-21.—LM2500 GTE inlet (FOD screen, centerbody(bulletnose), and bellmouth).

FOD Screen

The FOD screen, or air inlet screen (fig. 2-21),is mounted on the module barrier wall. Thepurpose of this screen is to prevent foreignobjects larger than 1/4 inch from entering theengine.

The screen will also prevent items fromentering the engine if the blow-in doors open.

After major work, major intake cleaning, oranytime the ship is coming out of a shipyardenvironment, a special screen is used. It is a nylonscreen that attaches over the metal FOD screen.The nylon screen will catch particles much smallerthan the metal screen will. You must be carefulnot to exceed specified throttle limitationswhen using the nylon screen. Exceeding throttlelimitations could starve the engine for air andcause a compressor stall. NAVSEA issues specificinstructions for use of the nylon FOD screen.

Bellmouth and Bulletnose

The bellmouth and bulletnose (centerbody)(see fig. 2-21) are mounted on the forward endof the compressor front frame. These componentsare used to direct air from the inlet plenum to thecompressor. The surfaces of the two componentshave a smooth coat to reduce the turbulence ofthe airflow into the engine. The bellmouth alsocontains the water wash manifold. The water washmanifold is used to inject fresh water and/or acleaning solution into the engine. This is donewhen the engine is being motored. This procedureis for maintenance purposes to clean depositsfrom the compressor. The water wash manifoldis supplied by a common water wash system pipedas a ship’s system.

Compressor Section

The LM2500 GTE compressor (fig. 2-22) is a16-stage, HP ratio, axial-flow design. Major

Figure 2-22.—LM2500 GTE compressor components.

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Figure 2-23.—Compressor front frame.

components are the compressor front frame, acompressor stator, a compressor rotor, and thecompressor rear frame. The primary purpose ofthe compressor section is to compress air forcombustion. A secondary purpose of thecompressor section is to provide air for enginecooling, sump seal pressurization, and bleed airfor ship’s service use.

Air is drawn in through the front frame. Thenit passes through successive stages of compressorrotor blades and compressor stator vanes. The airis compressed as it passes from stage to stage.After passing through 16 stages, the air has beencompressed in the ratio of about 16 to 1. The

inlet guide vanes (IGVs) and first six stages ofstator vanes are variable; their angular positionis varied as a function of GG speed andcompressor inlet temperature (CIT) by hydraulicfuel pressure from the main fuel control(MFC). This provides stall-free operation of thecompressor throughout a wide range of speed andinlet temperature. Because these blades are ableto be set at different angles, the term variablegeometry applies to this compressor.

FRONT FRAME.—The compressor frontframe (fig. 2-23) provides the forward attachmentpoint for the GTE, supports the forward end of

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Figure 2-24.—Compressor rotor.

the compressor section, and forms a flow pathfor compressor inlet air. Five struts (see strutpositions, fig. 2-23) between the hub and the outercase provide passages for lube oil, scavenge oil,seal pressurization air, and a vent for the A-sumpcomponents. The bearings of the engine arenumbered 3 through 7. The No. 3 bearing, whichsupports the forward end of the compressor rotorand the inlet gearbox, are located in the A sump.The compressor inlet total pressure (Pt2) probeand CIT sensor (not shown) are mounted in theouter case. The No. 3 strut (6 o’clock position)houses the radial drive shaft which transferspower from the inlet gearbox to the transfergearbox (TGB) mounted on the bottom of theframe.

ROTOR.—The compressor rotor (fig. 2-24)is a spool/disk structure with circumferentialdovetails. The use of spools makes it possiblefor several stages of blades to be carried on asingle piece of rotor structure. The seven majorstructural elements and three main bolted jointsare as follows:

The first-stage disk, the second-stage disk(with integral front stub shaft), and the 3- through

9-spool stage are joined by a single bolted jointat stage 2.

The 3- through 9-spool stage, the stage10 disk, and the 11- through 13-spool stage arebolted at the stage 10 joint.

The 11- through 13-spool (with its integralrear shaft) and the cantilevered 14- through16-spool connect in a single bolted joint at stage13.

An air duct, supported by the front and rearshafts, routes stage 8 air aft through the centerof the rotor for pressurization of the B-sump seals.Close vane-to-rotor spool and blade-to-statorcasing clearances are obtained with metal spray-rub coating. Thin squealer tips on the blades andvanes contact the sprayed material and abrasiveaction on the tips prevents excessive rub whileobtaining minimum clearance. The first-stageblades have midspan platforms to reduce bladetip vibration.

STATOR.—The compressor stator has foursections bolted together. The top and bottomcases are manufactured in matched sets. For

2-21

Figure 2-25.—Compressor stator.

clarity, figure 2-25 shows only the top twosections and the major components of thecompressor stator. The front casing containsthe IGVs and stages 1 through 11. The IGVs andthe first six stages are variable to providestall-free operation. The variable vanes areactuated by a pair of master levers (one on eachside). The aft end of the master levers areattached to pivot posts at about the 10th stageon each side of the casing. Each of the lever’sforward ends is positioned by a hydraulic actuatorwhich uses fuel oil as the actuating medium. Theoperation of the IGVs and variable stator vanes(VSVs) are covered later in this chapter. Theremaining vanes are stationary. The rear casingcontains the 12th through the 16th stages, whichare also stationary.

Three bleed manifolds are welded to the statorcasings. Eighth-stage air, used for sump sealpressurization and cooling, is extracted frominside the annulus area at the tips of the holloweighth-stage vanes. Ninth-stage air, used forPT cooling, PT forward seal pressurization, andPT balance piston cavity pressurization, isextracted from between the ninth-stage vanesthrough holes in the vane bases. Thirteenth-stageair, used for cooling the second-stage HP turbinenozzle, is extracted from between the thirteenth-stage vanes through holes in the vane bases.

REAR FRAME.—The compressor rear frame(fig. 2-26) has an outer case, a hub containingthe B sump, and 10 struts attaching the hub tothe outer case. The outer case supports the

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Figure 2-26.—Compressor rear frame.

combustor, the fuel manifold, 30 fuel nozzles,2 spark igniters, and the first-stage HP turbinenozzle support. To provide the ship’s bleedair system with compressor discharge air, aninternal manifold within the frame extractsair upstream of the combustion area androutes it through struts 3, 4, 8, and 9.Compressor discharge air is also used forcooling the HP internal structures and theHP stage 1 and stage 2 blades. This willbe addressed in more detail later. Six bore-scope ports, located in the case just forwardof the mid flange, permit inspection of the

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combustor, fuel nozzles, and the first-stageturbine nozzle.

Two borescope ports are provided in the aftportion of the case for inspection of the turbineblades and nozzles. The B sump contains the No.4R and 4B bearings (R or no letter = roller,B = ball). The 4B bearing is the thrust bearing forthe HP rotor system. The frame struts providepassage for lube oil, scavenge oil, sump vent, sealleakage (air leakage past the compressor dischargepressure (CDP) seals), and customer bleed air formasker, prairie, anti-icing, and engine startingservices. The rear frame supports the aft end of

Figure 2-27.—LM2500 GTE combustor.

the compressor stator by the frame’s forwardflange, the aft end of the compressor rotor bythe No. 4R and 4B bearings, and the forwardend of the HP turbine rotor by the 4R and 4Bbearings.

Combustor Section

The LM2500 GTE combustor (fig. 2-27) is anannular type and has four major componentsriveted together-the cowl (diffuser) assembly, thedome, the inner liner, and the outer liner.

The cowl assembly and the compressor rearframe serve as a diffuser and distributor forthe compressor discharge air. They furnishuniform airflow to the combustor throughout alarge operating range. This provides uniformcombustion and even-temperature distribution atthe turbine. The combustor is mounted in thecompressor rear frame on 10 equally spacedmounting pins in the forward (low temperature)section of the cowl assembly. These pins providepositive axial and radial location and assurecentering of the cowl assembly in the diffuserpassage. The mounting hardware is enclosedwithin the compressor rear frame struts so it willnot affect airflow. Strength and stability of thecowl ring section are provided with a trussstructure. The structure has 40 box sectionswelded to the cowl walls. The box sections alsoserve as aerodynamic diffuser elements. The cowlassembly leading edge fits within and around thecompressor rear frame struts. This arrangementprovides a short overall combustor systemlength.

Figure 2-28.—HP turbine.

Thirty vortex-inducing axial swirl cups in thedome (one at each fuel nozzle tip) provide flamestabilization and mixing of the fuel and air. Theinterior surface of the dome is protected from thehigh temperature of combustion by a cooling-airfilm of the 16th-stage air. Accumulation ofcarbon on the fuel nozzle tips is minimized byventuri-shaped spools attached to the swirler.

The combustor liners are a series of over-lapping rings joined by resistance-welded andbrazed joints. They are protected from the highcombustion heat by circumferential film cooling.Primary combustion and cooling air entersthrough closely spaced holes in each ring. Theseholes help to center the flame and admit thebalance of the combustion air. Dilution holes onthe outer and inner liners provide additionalmixing to lower the gas temperature at theturbine inlet. Combustor/turbine nozzle air sealsat the aft end of the liners prevent excessive airleakage and also provide for thermal growth.

About 30 percent of the total airflow is usedin the combustion process. To understand this,you need to know that the ideal fuel/air ratio forcombustion is about 15 to 1 (15 parts of air to1 part of fuel). The rated airflow of the LM2500GTE is 123 lb/sec or 442,800 lb/hour. At ratedpower, the engine burns about 9,000 pounds offuel per hour. At the ideal fuel/air ratio of15 to 1, only 135,000 pounds of air per hour, isrequired (30.5 percent of 442,800).

The remaining 70 percent of the airflow is usedfor cooling, seal pressurization, and ship’sservice use. This breaks down to 5.5 percent(maximum) used for ship’s service and about 0.5percent for seal pressurization. The rest is usedfor cooling, the majority of which reenters themass flow cycle.

2-24

Figure 2-29.—HP turbine rotor.

High-Pressure Turbine Section

The HP turbine section (fig. 2-28) has an HPturbine rotor, the first- and second-stage turbinenozzle assemblies, and the turbine mid frame. Theturbine rotor extracts energy from the gas streamto drive the compressor rotor. The turbine rotoris mechanically coupled with the compressorrotor. The turbine nozzles direct the hot gas fromthe combustor onto the rotor blades at the bestangle and velocity.

The turbine nozzles are contained in andsupported by the compressor rear frame. Theturbine mid frame, besides supporting the aft endof the turbine rotor, also supports the front endof the PT and contains the transition duct. Thegas flows throughout this duct from the HPturbine section into the PT.

ROTOR.—The HP turbine rotor (fig. 2-29)has a conical forward shaft, two disks with bladesand retainers, a conical rotor spacer, a thermalshield, and a rear shaft. The front end of theturbine rotor is supported at the compressor rotorrear shaft by the No. 4 bearings. The rear of therotor is supported by the No. 5 bearing in theturbine mid frame (C sump).

Energy extracted from the hot combustiongases is transmitted to the compressor rotorthrough the turbine rotor forward shaft. Two airseals are on the forward end of the forward shaft.The front seal helps prevent CDP air from enter-ing the sump. The other seal maintains CDP inthe plenum formed by the rotor and combustor.This plenum is a balance chamber that providesa corrective force that minimizes the thrust loadon the No. 4B bearing.

High-Pressure Turbine Rotor Cooling.—TheHP turbine rotor is cooled by a continuous flow ofcompressor discharge air. This air passes throughholes in the first-stage nozzle support and in theforward turbine shaft. The air cools the inside ofthe rotor and both disks before passing between thedovetails and out to the blades. Figure 2-30 showsthe airflow path for HP turbine rotor cooling.

Figure 2-30.—HP turbine rotor cooling.

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Figure 2-31.—HP turbine rotor blade cooling.

High-Pressure Turbine Blade Cooling.—Both leading edge circuit provides internal convectionstages of HP turbine blades are cooled by cooling by airflow through the labyrinth and outcompressor discharge air (fig. 2-31). This air through the leading edge nose and gill holes.flows through the dovetail and through blade Convection cooling of the trailing edge is providedshanks into the blades. First-stage blades are by air flowing through the trailing edge exitcooled by internal convection and external film holes. Second-stage blades are cooled bycooling. The convection cooling of the center area convection, with all the cooling air dischargedis done through a labyrinth within the blade. The at the blade tips.

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FIRST-STAGE NOZZLE ASSEMBLY.—The first-stage nozzle assembly has the nozzlesupport, the nozzles, the inner seal, the outer seal,and baffles (fig. 2-32). The nozzles are coated toimprove erosion and oxidation resistance. Theyare bolted to the first-stage nozzle support andreceive axial support from the second-stagenozzle support. The nozzle assembly has 32 nozzlesegments, each segment has two vanes. The vanesare cast and then welded into pairs (segments) todecrease the number of gas leakage paths. The

first-stage nozzles are cooled by air from thecompressor’s 16th stage. The first-stage nozzlesupport forms the inner flow path wall from thecompressor rear frame to the nozzle segments.Additionally, it supports the nozzle segments. Itis bolted to the aft end of the pressure balanceseal support.

SECOND-STAGE NOZZLE ASSEMBLY.—The major parts of the second-stage nozzleassembly (fig. 2-33) are the nozzles, the nozzle

Figure 2-32.—First-stage HP turbine nozzle.

Figure 2-33.—Second-stage HP turbine nozzle.

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support, the stage 1 and stage 2 turbine shrouds,and the interstage seal. The nozzle supportis a conical section with a flange that isbolted between the flanges of the compressorrear frame and the turbine mid frame. Thesupport provides for the mounting of the nozzles,the cooling air feeder tubes, and the stage 1and stage 2 turbine shrouds. The nozzles arecast and then coated to improve erosion andoxidation resistance. The vanes (two per nozzle)direct the gas stream onto the second-stageturbine blades. The inner ends of the nozzlesform a mounting circle for the interstage sealattachment. The turbine shrouds form a portionof the outer aerodynamic flow path through theturbine. They are located radially in line withthe turbine blades and form a pressure sealto prevent excessive gas leakage over the bladetips. The first stage has 24 shroud segments; thesecond stage has 11 shroud segments. The inter-stage seal is composed of six segments bolted tothe nozzles. Its purpose is to minimize gas leakagebetween the second-stage nozzle and the turbinerotor. The sealing surface is honeycomb and hasfour steps for maximum sealing. Since thehoneycomb cools more rapidly than the fourrotating sealing teeth, the honeycomb is pre-grooved to prevent contact under rapid oremergency shutdown conditions. The second-stage nozzle is air-cooled by convection. Thenozzle vane center area and leading edge arecooled by 13th-stage air which enters throughcooling air tubes. Some of the air is dischargedthrough holes in the trailing edge; the remainderflows out through the bottom of the vanes andis used to cool the interstage seals and turbineblade shanks.

MID FRAME.—The turbine mid frame(fig. 2-34) supports two areas. It supports the aftend of the HP turbine rotor (No. 5 bearing); andthe forward end of the PT rotor (No. 6 bearing).It is bolted between the aft flange of thecompressor rear frame and the forward flange ofthe PT stator. The frame provides smoothdiffuser flow passage for HP turbine exhaust gasinto the PT. The frame hub is an open, drum-shaped, one-piece casting with flanges to supportthe C-sump housing, stationary seals, inner linersupport, and PT first-stage nozzle support. TheC sump contains the No. 5 and No. 6 bearings.Eight struts connect the hub to the outer case. Thestruts provide passage for C-sump lubrication andscavenge oil, cooling air, sump vent, and sealdrain services.

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Figure 2-34.—Turbine mid frame.

The frame has ports for the HP turbineexhaust thermocouples and pressure probes (notshown). These ports also provide access forborescope inspection of the PT inlet area. The PTfirst-stage nozzle assembly is part of the frame.

Figure 2-35.—Accessory drive section. A. Accessory gearbox. B. Aft view of accessory gearbox.

The frame liner assembly has an inner and anouter liner held together with airfoil-shaped strutfairings butt-welded to both liners. This assemblyguides the gas flow and shields the mainstructure from high temperature. The PT first-stage nozzle assembly is part of the turbine midframe assembly. This assembly has 14 segmentswith 6 vanes each. The inner end is bolted to thenozzle support; the outer end is secured betweenthe mid frame aft flange and the PT statorforward flange.

Accessory Drive Section

The accessory drive section (fig. 2-35) has aninlet gearbox in the hub of the front frame, aradial drive shaft inside the 6 o’clock strut of thefront frame, and a TGB bolted underneath thefront frame. The fuel pump and MFC, the

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pneumatic starter, and the lube and scavengepump are mounted on the aft side of the TGB.It also provides mounting for the GG speedpickup. An air/oil separator on the front is a partof the gearbox.

Power to drive the accessories is extractedfrom the compressor rotor through a large-diameter hollow shaft which is spline-connectedto the rotor front shaft. A set of bevel gears inthe inlet gearbox transfers this power to the radialdrive shaft. The radial drive shaft transmits thepower to another set of bevel gears in the forwardsection of the TGB. Each bevel gear is supportedby a duplex ball bearing and a roller bearing. Ashort horizontal drive shaft transmits the powerto the accessory drive adapters in the TGB.

TRANSFER GEARBOX.—The TGB shownin figure 2-35, view A, has a two-piece aluminum

casing, an air/oil separator, gears, bearings,seals, oil nozzles, and accessory adapters. Theaccessories are the fuel pump, main fuel control(MFC), lube and scavenge pump, air/oilseparator, and starter. All except the air/oilseparator are mounted on the aft section (fig.2-35, view B). The aft section of the TGB isthe AGB. An access cover in the bottom of thecasing allows easy removal and installation ofthe radial drive shaft. Also, an access cover is onthe manual drive pad. This feature allows accessto the jacking gears, which you can use tomanually jack the engine over for maintenance.

The “plug-in” gear concept is used on allaccessory adapters and idler gears in the aftsection. This concept permits an entire gear,bearing, seal, and adapter assembly to be removedand replaced without disassembling the gearbox.Each spur gear is supported by a casing-mountedroller bearing on one end and an adapter-mountedball bearing on the other end. The accessory drivespur gears are internally splined. Internal tubesand oil nozzles provide lubrication of the gearsand bearings. Gearbox carbon-face seals areretained from the outside of the gearbox. You canreplace them without disassembly of the gearbox.The TGB is assembled as a single unit and boltedto the engine externally. This feature allows youto replace the entire unit without removing theengine from the enclosure.

INLET GEAR BOX.—The inlet gearboxassembly (fig. 2-36) has a cast aluminum casing,

Figure 2-36.—Inlet gearbox.

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a shaft, a pair of bevel gears, bearings, and oiljets (not shown). Two duplex ball bearings anda roller bearing are mounted in the casing. Thecasing is bolted inside the front frame hub andhas internal oil passages and jets to providelubrication for the gears and bearings. The shaft,which rotates on a horizontal axis, is splined atthe aft end to mate with the second-stage disk ofthe compressor rotor. The forward end of theshaft mounts the upper bevel gear and issupported by a duplex ball bearing. The lowerbevel gear rotates on a vertical axis. It is supportedat its upper end by a roller bearing and at its lowerend by a duplex ball bearing. The lower end isalso splined to mate with the radial drive shaft.

RADIAL DRIVE SHAFT.—The radial driveshaft, a hollow shaft externally splined on eachend, mates with the bevel gears in the inlet andtransfer gearboxes. Its function is to transmitpower from the inlet gearbox to the forwardsection (bevel gearbox) of the TGB. The shaft con-tains a shear section (for overtorque protection)to prevent damage to the accessory drive system.

POWER TURBINE/LOW-PRESSURESECTION

The PT is used to extract the remaining energyfrom the hot gas. This energy is used to powerthe ship for propulsion. The PT section (fig. 2-37)has a six-stage LP turbine rotor, a turbine stator,and a rear frame. The PT is a separate unit from

Figure 2-37.—LM2500 GTE power turbine.

Figure 2-38.—LP turbine rotor and stator.

the GG. If the GG must be changed out, it issimply unbolted from the PT and removed. If PTreplacement is required, the GG must be removedalso.

first three stages of blades are coated for corrosionprotection.

Stator

Rotor

The PT rotor (fig. 2-38) has six disks withintegral disk spacers bolted together to form therotor spool. Blades of all six stages containinterlocking tip shrouds for low vibration levelsand are retained in the disks by dovetails.Replaceable rotating seals, secured between thedisk spacers, mate with stationary seals toprevent excessive gas leakage between stages. The

The PT stator, also shown in figure 2-38, hastwo casing halves (only the lower half is shown),the stage 2 through 6 turbine nozzles, and sixstages of blade shrouds. The first-stage nozzle ispart of the turbine mid frame. Honeycombshrouds, mounted in casing channels, mate withthe shrouded blade tips to provide close-clearanceseals. These stationary interstage seals areattached to the inner ends of the nozzle vanes tomaintain low leakage between stages. Insulation

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Figure 2-39.—PT rear frame.

is installed between nozzle shrouds and casing toprotect the casing from the high temperature ofthe gas stream.

Rear Frame

The PT rear frame (fig. 2-39) has an outercasing, eight equally spaced radial struts, and asingle-piece cast-steel hub. It forms the PT exhaustflow path and supports the aft end of the PT. Italso supports the forward end of the high-speedflexible-coupling shaft. The turbine rear framehub supports the inner deflector of the exhaustsystem. It also has a bearing housing for the No.7B and No. 7R bearings. The No. 7B bearing isthe thrust bearing for the PT. The hub and the

bearing housings have flanges to which air andoil seals are attached to form the D sump. Theframe casing supports the outer cone of theexhaust system and provides attaching points forthe GTE rear supports. The struts provide passagefor lubrication and scavenge oil, C- and D-sumpseal pressurization air, D-sump vent, cooling air,and PT balance piston air services. The two PTspeed pickups also pass through the struts (No.3 and No. 7).

HIGH-SPEED FLEXIBLECOUPLING SHAFT

The high-speed flexible-coupling shaft has aforward adapter, which mates with the PT, two

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flexible couplings, a distance piece, and an aftadapter, which mates with the reduction gearhigh-speed pinion. The forward and aft adaptersare connected to the distance piece by theflexible couplings. The flexible couplings allowfor axial and radial deflection between the GTEand the ship’s drive system during operation.Inside the aft adapter and the aft flexiblecoupling is an axial damper system which has acylinder and piston assembly. The damperassembly prevents excessive cycling of theflexible couplings. Antideflection rings restrictradial deflection of the couplings during shockloads.

ENGINE SYSTEMS

Engine control systems were discussed brieflyin chapter 1 of this TRAMAN. They consist ofthe start air system, the fuel and speed-governingsystem, the synthetic lube oil system, the ignition

system, the water wash system, and the bleed airsystem. In this section, we will present a moredetailed description of these systems for theLM2500 GTE.

START AIR SYSTEM

The start air system provides compressed airto rotate the engine starter through the accessorydrive. The starter rotates the GG for starting,motoring, and water washing. The system useseither engine bleed air or HP air on the CG-, DD-,class ships. The FFG-class ships use HPair as the primary start system and diesel-drivenstart air compressors (SACs) and engine bleed airas secondary start air systems.

The start air system (fig. 2-40) has a pneumaticturbine starter and a starter (air regulating) valve.The starter is mounted on the aft side of the TGB(AGB). The starter valve is line-mounted behindthe starter. The starter drives the GG through thegearbox during the start cycle. It drives it untilthe GG reaches or exceeds self-sustaining speed.

Figure 2-40.—LM2500 GTE start air system.

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Starter

The starter has an inlet assembly, a turbineassembly, and reduction gearing. It also includesa cutout switch, an overrunning clutch, and asplined output shaft. The turbine is a single-stage,axial-flow type. The reduction gearing is acompound planetary system with a rotating ringgear. The overrunning clutch is a pawl andratchet type. This provides positive engagementduring starting and overrunning when driven bythe GG. The cutout switch is normally closed. Itis actuated by a centrifugal governor whichtrips open the switch. This also illuminates aSTARTER CUTOUT indicator light at thepropulsion consoles. The output shaft has a shearsection to prevent overtorque damage. The starteroperating air pressure is 35 to 41 psig for startingand 21 ± 1 psig for water washing. Air to thestarter is piped from the starter air regulatingvalve. The starter exhausts directly into themodule enclosure.

Starter Air Valve

The starter valve is a normally closed pneu-matic regulator and shutoff valve. It has ableed-on regulator, a solenoid switch, and apneumatic switch. It also incorporates a checkvalve, an actuator, and a butterfly valve. Air fromthe ship’s start air system is supplied through aninlet fitting on the enclosure base to the startervalve at 0 to 75 psig. When 28-volt dc power issupplied to the solenoid from the FSEE, the valveopens. It regulates discharge air pressure (to thestarter) at 35 to 41 psig at a flow rate of 0 to3.5 lb/sec.

Regulation is accomplished by the balancebetween the pneumatic actuator and a torsionspring on the butterfly. When the 28-volt dc signalis removed, the butterfly is closed by thepneumatic actuator and the torsion spring. Valveposition is displayed by a mechanical positionindicator at the valve. The valve position switchprovides a valve position signal to the propulsionconsole.

FUEL AND SPEED-GOVERNINGSYSTEM

The fuel and speed-governing system regulatesand distributes fuel to the combustion section ofthe GG to control gas generator speed (NGG ). ThePT speed is not directly controlled, but isestablished by the gas stream energy level

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produced by the GG. The PT overspeedprotection is provided by an electronic overspeedswitch that is located in the FSEE via signals fromthe two PT speed pickups. The fuel used by theLM2500 GTE is supplied by the fuel servicesystem. For more information on your ship’s fuelsystem, refer to the Engineering OperationalSequencing System (EOSS).

The fuel system of the LM2500 GTE hasseveral components. These components are thefuel pump and filter, MFC, a pressurizing valve,two fuel shutdown valves, a purge valve, the fuelmanifold and shroud, and 30 fuel nozzles. Alsoincluded are the CIT sensor, the VSVs, the VSVactuators, and the power lever angle (PLA) rotaryactuator. We will discuss these componentsindividually and explain how they relate to thesystem. Refer to figure 2-41, which shows theLM2500 GTE fuel system flow path, to help youfollow our discussion.

Fuel Pump and Filter

The fuel pump has two pumping elements, acentrifugal boost element (1) and an HP gearelement (2). It provides mounting pads and flangeports for the fuel filter and the MFC. This featurereduces the amount of external piping required.The pump also provides a drive shaft for theMFC. This eliminates the need for a separate TGBdrive pad.

To assure an adequate supply of fuel for GTEoperation, the fuel pump has a higher flowcapacity than the GTE uses. Within the MFC thepump discharge is divided into metered flow andbypass flow. This division maintains a presetpressure drop across the metering valve by use ofa bypass valve. Bypass fuel is ported to the HPelement inlet screen (3) of the fuel pump. If anabnormal condition occurs that causes pumpoutlet pressure to become too high, a relief valve(4) in the pump bypasses fuel back to the HPelement inlet screen (3).

Fuel from the ship’s supply enters the pumpthrough the fuel inlet port and is boostedin pressure by the centrifugal boost element (1),discharging into a circumferential scroll, The flowpasses through the strainer element (3) which hasan integral bypass; it then passes into the HPpositive displacement gear element (2). Thecombination of pumping elements is designed toprovide improved fuel pump features so normaloperation can be sustained without external boostpumps. The pump incorporates an HP relief valve(4). This valve cracks at or above 1,350 pounds

Figure 2-41.—LM2500 GTE fuel system. A. Cross-sectional view of the fuel pump. B. Fuel system block diagram,

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Figure 2-42.—Main fuel control.

per square inch absolute (psia); it reseats at orabove 1,325 psia. These features protect the pumpand downstream components against excessivesystem pressures.

The fuel filter (5) is an HP filter mounted on The MFC schedules the VSVs as a functionthe fuel pump and flange-ported to eliminate of GG speed and CIT. Actual position of theexternal piping. The head houses a bypass relief VSVs is sensed by the control via a positionvalve (6); the bowl houses the filter element. The feedback cable. One end of the feedback cablefilter element is rated at 46 microns nominal is connected to the left master lever arm. Theand 74 microns absolute. It prevents larger other end is connected to the feedback lever oncontaminants from being carried into the MFC. the MFC.

High-pressure fuel flows from the fuel pumpthrough the flange port and enters the filter bowl.The fuel then flows from the outside of the filterelement to the center, up into the head, out theflange return port, and back into the fuel pump.There, it is routed to the MFC. If the filterbecomes clogged, the bypass relief valve opens at35 pounds per square inch differential (psid).From the MFC the fuel goes to the fuel shutdownvalves, the purge valve, the fuel manifold, andfinally the fuel nozzles.

Pressurizing Valve

The pressurizing valve pressurizes the fuelsystem. It ensures adequate fuel control servosupply pressure and VSV actuation pressure.These pressures are essential for proper fuel andstator vane scheduling during GG operation at lowfuel flow levels. The valve is a fuel pressure-operated, piston-type valve. The piston is held onits seat (closed) by spring force and fuel pressure(reference pressure) from the MFC. Servopressure is 110 to 275 psig. The MFC dischargefuel (metered fuel for combustion) enters thepressurizing valve at the opposite side of thepiston. When MFC discharge pressure is 80 to 130

Main Fuel Control

The MFC (fig. 2-42) is basically a speedgovernor which senses NGG and power lever

position; it adjusts the fuel flow to maintain thedesired speed set by the power lever. The MFCis a hydromechanical device which operates by useof fuel-operated servo valves. The MFC has twoprimary functions. One is to control GG speed(schedules acceleration fuel flow and decelerationfuel flow). The other controls stator vane angle(for stall-free, optimum performance over theoperating range of the GTE).

The MFC controls GG speed as a function ofpower lever position. The power level is setelectrically by a signal from the FSEE. Movementof the power lever changes speed demand. Aflyweight governor senses GG speed. This adjuststhe fuel flow as necessary to maintain the speedset by the power lever. Three fuel schedulesare established by the control: acceleration,deceleration, and minimum fuel schedules. Theacceleration schedule limits fuel flow necessaryfor acceleration to prevent overtemperature andstall. The deceleration schedule limits the rate offuel flow decrease to prevent combustionflameout during deceleration. The minimum fuelschedule limits fuel flow for starting to preventovertemperature. The MFC senses CIT, CDP,and NGG, which biases the fuel schedules as afunction of atmospheric and engine operatingconditions.

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Figure 2-43.—Fuel shutdown valve.

psig greater than reference pressure, the valveopens. The upstream pressure (including servosupply and stator actuation) is 190 psig or greaterbefore the pressurizing valve opens. This isadequate for proper operation.

Fuel Shutdown Valves

The two fuel shutdown valves (fig. 2-43) arepilot-valve actuated and electrically controlled.The valves are piped hydraulically in series. Theyare electrically operated in parallel by control logicduring an automatic sequence. The consoleoperator can also operate them at the LOP, thePCC, or the PACC during a manual stop. Bothvalves must be energized to port metered fuel tothe GG fuel manifold. De-energizing either valvewill bypass the fuel back to the pump inlet.Normally, both valves are de-energized to shutdown the engine. The second valve acts as abackup and will bypass fuel if the first should failto function. You can operate the two valvesindependently from the LOP as a maintenancecheck.

Each shutdown valve has a pilot pressure bleedrelief valve to prevent backflow through the valveduring GTE motoring. A check valve which hasa 2 psid cracking pressure is located in the bypassport of the No. 2 shutdown valve to prevent fuel

backflow into the No. 2 valve from the No. 1valve bypass line.

Purge Valve

The purge valve operates electrically. It is anormally-closed, on-off valve used to drain low-temperature fuel from the system before a GTEstart. It is spring-loaded to the closed position;a solenoid opens the valve when it is energized.About 3 gallons of fuel are drained from thesystem during purging.

Fuel Manifold System

The fuel manifold system is shrouded. (Themanifold and the manifold-to-fuel nozzle con-nector tubes are tubes within a tube assembly.)If a fuel leak develops in the manifold system,the leakage collects inside the shroud. It is thendrained through a drain line to a telltale drainunder the enclosure base. Next it goes to acollection tank. Fuel leakage inside the enclosurefrom the manifold system is prevented and firehazard is minimized by this system design.

Fuel Nozzles

The LM2500 GTE uses 30 fuel nozzles toadmit fuel to the combustor. The fuel nozzle

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Figure 2-44.—Fuel nozzle.

(fig. 2-44) is a dual-orifice, swirl atomizerwith an internal flow divider. The fuel nozzlesproduce the desired spray pattern over the fullrange of fuel flow. Fuel enters the nozzlethrough a single tube, flows through a 117-micronscreen, and then the flow divider. When thenozzle is pressurized, primary fuel flows througha drilled passage and tube assembly in thenozzle shank. It then flows through the primaryspin chamber and into the combustor. Whenfuel pressure to the nozzle rises to 330 to 350 psig,the flow divider opens and introduces secondaryfuel flow. The secondary fuel flows throughthe flow divider, through a passage in thenozzle shank, into the secondary spin chamber,and mixes with the primary flow as it entersthe combustor. An air shroud (swirl cup)around the nozzle tip scoops a small quantity ofair from the main airstream to cool the nozzletip. This retards the buildup of carbon depositson its face.

Compressor Inlet Temperature Sensor

The CIT sensor has a constant-volume, gas-filled probe and a metering valve. This sensorcontrols or meters fuel across an orifice. It ismounted at the 8 o’clock position in thecompressor front frame. The sensing probeprojects through the frame into the airstream.Since the temperature sensing probe has aconstant volume, the gas pressure inside theprobe is equal to the temperature. This pressureis connected to a sensing bellows, which, inturn, is connected to the metering valve. Fuelfrom the MFC enters the CIT sensor. There it ismetered by the metering valve proportional to thetemperature at the sensing probe. It is then usedas a scheduling parameter by the MFC.

Variable Stator Vanes

The VSVs are positioned by two hydraulicactuators operated by fuel pressure from the

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MFC. The MFC has a variable vane scheduling,3-dimensional (3-D) cam which is positioned byNGG and CIT signals; it has a variable vanefeedback mechanism which receives a vaneposition signal from a linkage connected tothe VSV master lever; it also has a variablevane pilot valve positioned as a result of thecomparison of the scheduling cam positionand the feedback signal. Changes in enginespeed rotate the scheduling cam; changes inCIT reposition the cam. Movement of the camrepositions the pilot valve. The pilot valveports HP fuel (pump discharge pressure) toeither the rod end (closing) or head end(opening) of the vane actuators; it ventsthe other end to bypass pressure. The variablevane actuating linkage mechanically transmitsthe actuator movement to the variable vanesand IGVs. A flexible cable is attached to thelinkage. It transmits a feedback signal to theMFC. The feedback mechanism in the MFCrepositions the pilot valve to terminate theactuator signal when the vanes reach the scheduledposition.

Variable Stator Vane Actuators

The VSV actuators (fig. 2-45) are single-ended,uncushioned hydraulic cylinders which are drivenin either direction by HP fuel. The piston strokeis controlled by internal stops. The two actuatorsare mounted tangentially on the compressor stator

forward flange at the 3 o’clock and 9 o’clockpositions. They are connected to the VSVsthrough master lever arms and actuation rings.The MFC schedules HP fuel to either thehead-end port (opens VSVs) or the rod-endport (closes VSVs). Control parameters sensedby the MFC to schedule variable vane angleare NGG, CIT, and stator vane angle via afeedback cable. The feedback cable is connectedon one end to the left master lever armand on the other end to the MFC.

Power Lever Angle Rotary Actuator

The PLA rotary actuator is an electro-mechanical device that interfaces the PLAactuator electronics in the FSEE with the MFCof the GTE. It moves the internal componentsof the MFC to control fuel flow to the engine.It has a dc servomotor, a reducing gear, aslide potentiometer, a tachometer generator,mechanical linkage, and an electrical line filter.The PLA actuator is mounted on the fuel pump;it is connected to the fuel control power leverthrough a mechanical linkage. It is electricallyconnected to the FSEE.

Signals from the PLA actuator electronics,located in the FSEE, are converted by a servo-mechanism into mechanical action that positionsthe fuel-control power lever. Feedback of PLAand rate of change are sent to the FSEE. A

Figure 2-45.—VSV actuator, cross-sectional view.

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positive mechanical rig feature allows locking ofthe PLA actuator output lever at a position of113.5° ± 1°. This rig point is used in conjunctionwith a corresponding rig point on the fuelcontrol. Its purpose is to establish mechanicalsynchronization between the PLA actuator andthe fuel control.

SYNTHETIC LUBE OIL SYSTEM

The synthetic lube oil system providesthe GTE bearings, gears, and splines withadequate cool oil to prevent excessive frictionand heat. The synthetic lube oil used in thisapplication is MIL-L-23699. It is a dry sumpsystem. It is divided into three subsystems withthree functions identified as lube supply, lubescavenge, and sump vent.

The lube supply subsystem provides oil to thebearings. It contains the supply element of thelube and scavenge pump, the supply duplex filter,the supply check valve, and the C- and D-sumpsupply check valves. The lube scavenge subsystemremoves the oil from the sumps. It contains thescavenge elements of the lube and scavenge pump.Oil from this pump goes to the LOSCA. Thecomponents of the LOSCA are the scavenge oilfilter, the scavenge oil check valve, the oil cooler,and the oil tank. The third subsystem ventsexcessive air pressure to the atmosphere. Itcontains piping to the atmosphere, piping to theair/oil separator, and the air/oil separator. Figure2-46 is a block diagram of the lube oil system.Please refer to this figure to help you understandthe following paragraphs as we describe thesystem’s components and the lube oil flowpath.

Figure 2-46.—Lube oil system block diagram.

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Lube Oil System Components

In this section we will describe the lube oilsystem components in the order of lube oil flow,from the LOSCA through the system and backto the LOSCA.

signal when the oil level is too high or too low.An oil level sensor on the FFG-class ship monitorsoil level from within the tank and transmits acontinuous electrical signal for remote readoutof lube oil level. The oil tank is consideredfull when oil is visible at the 24-gallon sightglass.

OIL TANK.—The oil tank is an integral Instrumentation valves, a filter differentialpart of the LOSCA. The early configuration of pressure transducer, a filter differential pressurecast construction on the DD-class ship contains gauge, a level sensor, and an oil temperaturesix sight glasses (view ports) for visual detection switch are mounted on the tank. A gravity fill capof oil level in the tank. Starting with the is installed on the tank cover fill port. The fill portsecond glass from the bottom, they are spaced has a strainer to prevent foreign material fromat 5-gallon intervals. On the later configuration entering the tank. Baffles are located in theof fabricated construction (fig. 2-47), three bottom of the tank to minimize oil sloshing. Asight glasses are provided for low level, 19-gallon deaerator is inside the tank at the scavenge inletlevel, and full level positions. An oil level (which separates air from the scavenge oil). Youswitch on the DD-class ship monitors oil level can drain the oil tank by positioning a leverfrom within the tank and transmits an electrical located in the assembly base.

Figure 2-47.—LOSCA.

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Figure 2-48.—Lube and scavenge pump.

LUBE AND SCAVENGE PUMP.—The lubeand scavenge pump (fig. 2-48) is a six-element,positive-displacement vane pump. Each elementhas a wire mesh strainer. One element is used forlube supply and five are used for lube scavenging.

The lube supply element supplies oil to theseven main bearings that support the GG assemblyand the PT assembly. These bearings are locatedin the sumps as follows:

Bearing No. 3R in the A sump

Bearings No. 4R and 4B in the B sump

Bearings No. 5R and 6R in the C sump

Bearings No. 7B and 7R in the D sump

Scavenge oil enters the pump through the fivescavenge oil ports, passes through an inlet screenin each port, and enters the scavenge elements.The outputs of the five scavenge elements areconnected inside the pump and discharge througha common scavenge discharge port. This scavengedischarge is routed to the duplex filter mountedon the lube storage and conditioning assembly oiltank.

The five scavenge elements of the lube andscavenge pump scavenge oil from the B, C, andD sumps and from the TGB and AGB (A sump).There are five RTDs located in the scavenge oil

system lines in the immediate vicinity of the pump.They sense oil temperatures for the A, B, C, andD sumps and for the TGB; they also provide asignal to the off-engine electronic controls.

LUBE SUPPLY FILTER.—The lube supplyfilter (fig. 2-49) is a duplex filter assembly withprovision for manual selection of either element.It is mounted on the outboard rail of the enginesubframe. It is the same type that is used for thescavenge oil filter. Oil to the GTE enters theinlet port, flows through the selected element(outside to inside), and exits through the filteroutlet port. A bypass (relief) valve in the filteropens to allow oil to bypass the filter if the filterbecomes clogged. To make a filter selection, raisethe spring-loaded locking pin, move the selectorhandle until it is in front of the element NOTbeing used, and release the locking pin. Makecertain you engage the pin in the locking slot. Adrain plug in the bottom of each filter bowlpermits oil to be drained from the element beforeit is removed for cleaning.

LUBE SUPPLY CHECK VALVE.—Thelube supply check valve is on the downstreamside of the supply filter. It prevents oil inthe tank from draining into the sumps whenthe GTE is shut down. It opens and flowsat a rate of 20 gpm with a maximum differentialpressure of 15 psid.

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Figure 2-49.—Lube supply filter.

C- AND D-SUMP CHECK VALVE.—Thischeck valve is in the lube supply line to the C andD sumps. It isolates the C and D sumps from theGG lube oil system when an external lube supplyand scavenge system is used for the PT. Both theC- and D-sump oil supply lines and scavenge lineshave fittings to connect an external lube systemfor the PT. During normal engine operation, thelube oil pump supplies lube oil to the C and Dsumps. The check valve opens at 2 psid.

SCAVENGE OIL FILTER.—The duplexscavenge oil filter differs from the lube supplyfilter only in its mounting position. The scavengefilter is located on and is part of the LOSCA. Seefigure 2-47.

SCAVENGE OIL CHECK VALVE.—Thecheck valve is between the scavenge filter and theoil cooler (heat exchanger). It prevents oil in thescavenge lines from draining back into the sumpsand gearbox while the engine is shut down. Itfunctions the same as the lube supply check valve.

OIL COOLER.—The oil cooler is a shell-tubeassembly (see fig. 2-47). The coolant is mainreduction gear (MRG) lube oil (2190 TEP). The

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coolant passes from the MRG lube oil coolerthrough temperature control valves and throughthe inside of the tubes. The synthetic lube oilpasses around the outside of the tubes. The oilis discharged from the oil cooler back to the oiltank. To gain direct access to the inside of thecoolant tubes for cleaning, remove the end domes.

AIR/OIL SEPARATOR.—The air/oilseparator has a fabricated sheet metal impellerwith a cast aluminum housing. It preventsexcessive oil loss from venting oil vapor over-board. All sumps are vented to the air/oilseparator. The sump air is vented to the exhaustduct after passing through the separator. Oil iscollected on the inside of the impeller as the oil-laden sump air passes through the separator.Small holes in the segments of the impeller allowthe collected oil to be discharged to the separatorouter housing. Vanes on the housing wall areused to collect and direct the oil to the separatoroutlet where it is returned to the gearbox. Toprevent oil and oil vapors from escaping past theend of the impeller, the separator has twolabyrinth seals, with the cavity between thetwo seals pressurized with eighth-stage ejectorair.

Figure 2-50.—Bearing sump.

Lube Oil Flow

Lube oil is gravity fed from the oil tank in theLOSCA through the ship’s piping to an inletfitting in the enclosure base. It is then fed to theinlet of the supply element of the lube andscavenge pump. From the supply element of thepump, the oil passes through the supply duplexfilter. It then goes through a check valve andinto a supply manifold. From the supplymanifold, the oil is distributed to the foursumps and the TGB. Each end of the sump hasa labyrinth/windback oil seal and a labyrinth airseal (fig. 2-50). This is to prevent oil leakage fromthe sumps. The cavity between the two seals ispressurized by eighth-stage air ejectors. Thepressure in the cavity is always greater than thepressure inside the sump. Air flowing from thecavity, across the oil seal, prevents oil fromleaking across the seal.

The scavenge oil is drawn in from the sumpsand TGB by the five scavenge elements of thepump. It passes through the pump, through an

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outlet fitting on the enclosure base, and is returnedto the LOSCA.

At the LOSCA the oil passes through thescavenge filters to the scavenge check valve.The oil then goes through the oil cooler where itis cooled by the MRG (2190 TEP) lube oil. Thecooled oil is then routed to the oil tank for storageand deaerating.

IGNITION SYSTEM

The ignition system provides ignition to startcombustion in the engine. It has ignition excitersand two spark igniters located in the combustor.The system is actuated by an electronic signalduring the engine start sequence. It is generatedeither manually by the operator or by theelectronic timing controls. The engine must reacha speed of 1,200 rpm prior to ignition; then, ifperforming a manual start, you must energize theigniters before opening the fuel valves. Whenyou start the engine in the automatic mode, thefuel valves will not open unless the igniters arealready functioning. This prevents excess fuel

from entering the combustion chamber andcausing excessive start temperatures. The ignitersare secured by an electronic signal at 4,500 rpm.By this time combustion has occurred and theengine has reached self-sustaining speed.

Ignition Exciters

The ignition exciters are the capacitordischarge type. They are located on the right sideof the front frame. They are attached to specialmounts that absorb shock and vibration. Theexciters operate on 115-volt ac, 60-Hz input. Thepower is transformed, rectified, and dischargedin the form of capacitor discharge energy pulses.It then flows through the coaxial shielded leadsto the spark igniters.

When the starting switch is closed, shipboard60-Hz power is applied to the exciter circuits. Theexciter has input, rectifier, discharge, and outputcircuits. The input circuit includes a filter thatprevents feedback of radio-frequency interference(RFI) (generated within the exciter). The filter alsoprevents introduction of electromagnetic inter-ference (EMI) (generated externally). The inputcircuit also includes a power transformer thatprovides step-up voltage for the rectifier circuit.The full-wave rectifier circuit includes diodes thatrectify the high-voltage ac. This circuit alsoincludes capacitors that are arranged in a voltagedoubler configuration. Tank capacitors store thedc voltage developed in the rectifier circuit. Theystore this voltage until the potential developedreaches the breakdown point of spark gaps in thedischarge circuit. The discharge circuit containsthe spark gaps, high-frequency (HF) capacitor,resistors, and HF transformer. When the spark

gaps break down, a current (caused by a partialdischarge of the tank capacitors) through the HFtransformer and in conjunction with the HFcapacitor causes a series resonant condition toexist. It also causes HF oscillations to occur inthe output circuit. These HF oscillations causeionization of a recessed spark gap of the igniterplug. A low-resistance path now exists for totaldischarge of the tank capacitor, producing a high-energy spark used to ignite the fuel within thecombustor. The spark rate is determined by thetotal rectifier circuit resistance. This controls theresistive capacitive (RC) time constant in thecharging circuit.

Spark Igniters

The spark igniters (fig. 2-51) are the surfacegap type. They have internal passages for aircooling and air vents. These passages prevent theaccumulation of carbon in interior passages. Theigniter has a seating flange with attached coppergaskets for sealing purposes. Grooves in the outersurface of the tip and axial holes cool the outerand inner electrodes with compressor bleed air.

The surface gap will ionize at 8,500 volts whendry and 15,000 volts when wet. A discharge of2 joules of energy exists across the gap.

CAUTION

This energy level is lethal. You shouldnever contact the output from the sparkexciter, the leads, or the igniter. You mustuse a grounding probe to ground the ignitionsystem when maintenance is performed.

Figure 2-51.—Spark igniter.

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Ignition Leads

The ignition leads are low-loss connectionsbetween the ignition exciters and the sparkigniters. They are coaxial leads with metallicshielding that incorporates copper inner braid,sealed flexible conduit, and nickel outer braid.

WATER WASH SYSTEM

The purpose of the water wash system is toremove contaminants from the inlet and com-pressor sections. The system has a waterwash/rinse supply tank and piping attached to theoutside of the base enclosure. A flexible hose isattached from the inside base enclosure floor tothe GG inlet duct at the 6 o’clock position. Theinlet duct is made with an internal passageway ormanifold which distributes water wash fluid tooutlet spray orifices. The outlet spray orifices ejectthe water wash fluid into the airstream flowingthrough the inlet duct.

BLEED AIR SYSTEM

Air extracted from the compressor for cooling,seal pressurization, pressure balance to reducerotor thrust loads, and ship’s service (secondary)air is called bleed air. For this application, air isbled from the 8th, 9th, 13th, and 16th stages. Only16th-stage air (known as CDP) is used for theship’s bleed air system. Refer to figure 1-33(At the end of chapter 1), which shows theLM2500 GTE airflow, to help you understand thefollowing discussion.

Eighth-Stage Air

Eighth-stage air is bled from the compressorthrough hollow eighth-stage stator vanes into an

external manifold. From the manifold, the air ispiped forward and aft to ejector nozzles. Eachejector contains a venturi through which theeighth-stage air passes; it draws enclosure airinto the ejector. This air mixes with the eighth-stage air, reduces the downstream pressure andtemperature, and increases the volume. Air fromthe forward ejector is piped into the front framehub; there it pressurizes and cools the A sump.Some of the A-sump air passes through holes inthe compressor rotor front shaft, through therotor air duct, and through holes in the rotor aftshaft; there it pressurizes and cools the B sump.Air from the rear ejector is piped into the turbinerear frame hub; it is used to pressurize and coolthe D sump. Part of the air entering the D sumpbleeds into the flexible-coupling shaft tunnel forcooling and passes out the aft end of the exhaustduct. Some of the D-sump air passes throughholes in the PT aft shaft, rotor air tube, and holesin the rotor front shaft; there it pressurizes andcools the C sump.

Ninth-Stage Air

Ninth-stage air is bled from the compressorthrough holes in the ninth-stage vane bases andcompressor casing into an external manifold.There it is piped to the turbine mid frame andturbine rear frame. Air enters the turbine midframe through all the struts. Some of the airexits through holes in the frame hub to cool theframe inner liner. The rest of the air enters tubesin the C-sump air seals; after it crosses these seals,the air passes through and cools the PT rotor. Itthen exits into the PT exhaust gas. The air to theturbine rear frame enters the frame through struts2 and 8. It passes into an area between the

Figure 2-52.—Balance piston principle.

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forward air seals. At this point it is called balancepiston air.

Balance Piston Air

On the LM2500 GTE, balance piston air (orpressure balance air) is ninth-stage air that is bledinto a balance chamber to reduce the aft loadingon the No. 7B bearing. This air applies force tothe face of a rotor disk in the direction oppositethe thrust load to reduce the axial load appliedto the thrust bearing by the rotor thrust. Thisincreases the thrust-bearing life. The balancepiston principle is shown in figure 2-52.

Thirteenth-Stage Air

Thirteenth-stage air is bled from the com-pressor through holes in the thirteenth-stage vanebases and compressor casing into an externalmanifold. The air is piped through the compressorrear frame casing and into the HP turbineshrouds. The air then flows through and cools thesecond-stage turbine nozzle. Some of the airexits through nozzle-trailing edge holes. Theremaining air is used for cooling the interstageseal, the aft side of the first-stage blade shanks,and the front side of the second-stage shanks.

Sixteenth-Stage Air

Sixteenth-stage compressor discharge bleed airis bled through holes in the inner wall of thecompressor rear frame and out through Nos. 3,4, 8, and 9 frame struts. It is then piped to thebleed air valve. The bleed air valve operateselectrically to provide air to the ship’s bleed airsystem. High-pressure turbine rotor and bladecooling air is extracted internally through theaft stationary air seal and holes in the forwardend of the rotor front shaft. The remainingcompressor discharge bleed air is used forcooling the combustion liner and first-stage HPturbine nozzle vanes.

ENGINE INSTRUMENTATION

The GT assembly is instrumented with sensorsthat provide for remote monitoring of the engine,module, and LOSCA. Temperature, vibration,and speed sensors give an electrical output signaldirectly. However, pressure sensors use base-mounted transducers to convert a pressure level

to a corresponding electric signal. The sensorinformation is transmitted to the controls, eitherdirectly or through the FSEE. The controls usethe sensor information for GTE monitoring,alarming, and control sequencing. A majority ofthese sensors, along with their location/function,are described in the following paragraphs.

Compressor Inlet Total Pressure (Pt 2)—Pressure is sensed by a total pressure probemounted in the compressor front frame at the 12o’clock position. Pressure is piped to a transducermounted on the bottom of the enclosure base. Theelectrical output signal from the transducer is sentto the FSEE signal conditioner and torquecomputer electronics. Output signals from theFSEE are sent to the controls.

Power Turbine Inlet Total Pressure(Pt 5 . 4)—Pressure is sensed by five total pressureprobes located circumferentially in the turbine midframe. Pressure is piped to a transducer mountedon the bottom of the enclosure base. Theelectrical output signal from the transducer issent to the FSEE signal conditioner and torquecomputer electronics. An output signal from theFSEE is sent to the controls.

Compressor Inlet Temperature (T2)—Temperature is sensed by a platinum RTDpenetrating the enclosure inlet barrier wall at thelower left corner. The signal from the RTD issent to the FSEE signal conditioner and torquecomputer electronics. An output signal from theFSEE is sent to the controls.

NOTE: Only Pt 2, P5 . 4, and T2 (which aretorque computer inputs) are signal conditionedin the FSEE. Signals from the following instru-mentation go to the controls where they are signalconditioned and used for monitoring, control,alarm, and shutdown as noted.

Power Turbine Speed (Np t)—Npt is sensedby two magnetic pickups in the turbine rear frame.The signal from the magnetic pickups is sent tothe controls to the FSEE signal conditioner andtorque computer electronics, The controls use thesignal for PT speed meter displays and PToverspeed alarm generation.

Gas Generator Speed (N GG )—Gasgenerator speed is sensed by a single magneticpickup located on the top left side of the aft TGB(AGB).

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Gas Turbine Vibration—Vibration issensed by two velocity pickups. One pickup ismounted on the compressor rear frame forwardflange at the 12 o’clock position; one is mountedon the turbine rear frame forward flange at the12 o’clock position.

Fuel inlet temperature—Temperature issensed by a platinum RTD installed in the fuelinlet line inside the gas turbine enclosure.

Compressor discharge static pressure(Ps3)—Pressure is sensed from a pressure tap onthe Ps3 sensing line to the MFC and is piped toa base-mounted transducer.

Power turbine inlet gas temperature(T5.4)—Temperature is sensed by 11 dual-elementchromel-alumel thermocouples installed cir-cumferentially in the turbine mid frame. They areelectrically paralleled to produce a singleoutput signal.

Fuel manifold pressure—Pressure is sensedfrom a pressure tap on the fuel manifolddownstream from the No. 2 fuel shutdown valve.The pressure is piped to a base-mountedtransducer.

Enclosure cooling air out temperature—Temperature is sensed by a platinum RTDmounted on the enclosure ceiling on the centerlineand just forward of the exit area.

Fuel pump filter differential pressure—Pressure is sensed from two pressure taps in thefuel pump body at the filter inlet and dischargeports. Pressure is piped to a base-mountedtransducer and a base-mounted gauge.

MFC power lever position—A 0.5 to10-volt dc signal from the PLA actuator positionfeedback potentiometer is sent to the FSEE.

Lube supply pressure (pump discharge)—Pressure is sensed from a tap on the supplymanifold downstream from the supply checkvalve. Pressure is piped to a base-mountedtransducer.

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Lube supply filter differential pressure—Pressure is sensed from taps in the filter head atthe inlet and discharge ports. Pressure is pipedto a base-mounted transducer and a base-mountedgauge.

Lube scavenge fil ter differentialpressure—Pressure is sensed from taps in the filterhead and piped to a transducer. Both filter andtransducer are mounted on the LOSCA.

Lube scavenge temperature—A-, B-, C-,and D-sump and the AGB-sump temperaturesare sensed by platinum RTDs installed ineach scavenge line near the inlet ports of thepump.

Lube scavenge pressure—The pressure issensed by a transducer in the lube scavenge returnline near the LOSCA.

Lube cooler outlet temperature—Temper-ature is sensed by a platinum RTD installed in thecooler discharge line at the LOSCA storage-tankinlet port.

FREE STANDINGELECTRONIC ENCLOSURE

The FSEE is the major electrical interface tothe LM2500 GTE. It is a metal cabinet locatedoutside of the gas turbine enclosure that containsmost of the electronics necessary for control ofthe propulsion turbines. Each FSEE controls twoLM2500 GTEs. Therefore, there will be one FSEEper engine room.

Since the FSEEs are similar on all ship classes,we will discuss the basic FSEE, pointing out thedifferences as necessary. The major differencesare the input power supply and the start/stopsequencer (on the FFG class). Another differenceis the use of an acceleration limiting circuit in theFSEE of all classes but the FFG class.

The start/stop sequencer in the FFG-classFSEE provides for independent manual andautomatic remote control of startup, operation,and shutdown of the GTE. The system alsomonitors various parameters to ensure safe GTEoperation. The same capabilities are provided foron the CG-, and DD-class ships, but froma separate system called the engineering controland surveillance system (ECSS). In the followingdiscussion, we concern ourselves with theoperation of the FSEE which, with the exceptionsalready discussed above, are similar to all classes.The FSEEs used on the CG-, and DD-classships (fig. 2-53) have fewer components. This isbecause the start/stop sequencing on these shipsis done in the PLCC. Only one circuit card rackis used; it holds the circuit cards for both GTs.

Figure 2-53.—FSEE on the CG-, DD-class ships.

One common card, the M card, is used by bothGTs on these classes but is not used on FFGFSEEs. The FSEE on the FFG-class ship (fig.2-54) has two card racks (one per engine) and twopower supplies.

The FSEE circuitry is divided into twoidentical sections—one for each turbine. Theelectronic circuitry is in the form of pull-outcards and a power supply rack; the cards may bereferred to as either printed-circuit boards (PCBs)or printed-wiring boards (PWBs). Functionally,the electronics for either turbine can be dividedinto five subsystems: signal conditioning circuitry,torque computer, overspeed switch control, powersupply, and the PLA actuator electronics. The

Figure 2-54.—FSEE on the FFG-class ship.

FSEE also generates some signals (uplink) fordisplay on the GTE control consoles.

SIGNAL CONDITIONINGELECTRONICS

The signal conditioning electronics arecontained on one PWB—the E card. Fivetransducer signals and one internal signal areprocessed in these circuits. These are Pt 2, Pt 5 . 4 ,T2 , and two Npt speed signals (one from each PTspeed pickup). Four of these signals are providedas inputs to the torque computer. In addition, fivesignals are buffered and transmitted uplink to theGTE control console. Two pressure signals, Pt 2and Pt5.4 are received in the form of 4 to 20

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milliamp signals. They are converted to 0- to5-volt signals for the torque computer. They arealso processed into 0- to 10-volt signals forexternal use. The only temperature signalprocessed by the FSEE is T2 . This signal comesfrom a platinum RTD. The electronics changesthe RTD signal to a 0- to 5-volt and a 0- to 10-voltsignal for the torque computer and uplink,respectively.

A dual tachometer system is mounted on thePT. This has a spur gear with 83 teeth whichrotate past two sensors. The output of eachsensor is a pulse train whose frequency isdirectly proportional to the speed of theturbine. The purpose for the two-speed signals isreliability. One is the normal (channel A) signal,the other (channel B) is a backup in case the firstfails. The speed signal is converted to voltagesproportional to speed for purposes of torquecomputer monitoring.

TORQUE COMPUTER

The torque computer is a special-purposecomputer used to calculate engine torque. It hasseven PCBs (PWBs) whose only function is tocalculate the torque output of the PT. Fiveinputs are necessary to the computer for thecalculations. Four are 0- to 5-volt analog inputsfrom the signal conditioning circuitry—Pt 2,Pt 5 . 4, T2 , and Np t. The fifth is a discrete(ON/OFF) input to indicate whether bleed air isbeing diverted from the GG. If the bleed air valveis open (ON), it will affect the efficiency of theengine and the torque output.

The torque computer is similar to manygeneral-purpose computers of this size. Thecomputer performs internal calculations andcompares them to internally stored data tables.From the tables, selected values are taken to beused in further calculations to determine the finalvalue of torque. The torque calculated is accurateto within 3,000 ft-lb.

When the turbine is at idle, the computeroutput is a torque value of about 5,000 ft-lb. Thisset point is the basic value used to allow theelectronics to operate accurately over a broadrange of operating conditions.

The output of the torque computer is a 0- to5-volt signal, which is the input to the PLA

actuator electronics and a 0- to 10-volt signal foruplink and display. Torque range is 5,000 to50,000 ft-lb. The computer also calculateshorsepower as a function of PT speed andtorque for shipboard monitoring.

OVERSPEED SWITCH CONTROL

The overspeed switch control circuits functionto shut down the engine if a PT overspeed, PTunderspeed, or a loss of control power to thecontrol circuits occurs. Two PCBs (PWBs) (theD cards) of identical type are required per enginefor overspeed protection. Speed signal channelsA and B go to their own respective D cards. Eachcard receives its signal from its own speed pickupand controls both fuel valves. (Remember, thereare two fuel solenoid valves piped in series,but wired in parallel.) This allows for twoindependent speed channels and two independentoverspeed trips. The outputs of the overspeedswitch circuits are overspeed voltages, loss-of-speed signal voltages, and a voltage for the fuelshutdown valves. The following two test functionsare provided:

1. Overspeed test function. Each board hasa test generator with an output frequency abovethe highest PT speed to ensure a proper test. Whenyou depress the test button, the overspeedindicator on the GTE control console lights andthe fuel shutdown valves de-energize (close).

2. Speed limit test function. When youdepress the speed limit test push button, theelectronics lowers the speed limit to 75 percentof the normal speed limit and permits testingthe speed limit circuitry without overspeedingthe PT.

If the PT speed signals should become dis-connected or lost (Np t <100 rpm), the overspeedswitch opens. Both signals must be lost before thefuel shutdown valves actuate.

To start the GTE, a method of bypassing theloss of speed signal (Np t <100 rpm) shutoff isprovided. With the throttle position at a nominal30 degrees or below, a signal is generated thatcauses the loss of speed-signal function to bebypassed. The throttle must remain below 30degrees until the PT exceeds 100 rpm. The signalloss bypass function is deactivated whenever thethrottle is above a nominal 30 degrees.

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Figure 2-55.—Simplified FFG FSEE power distribution.

POWER SUPPLY

The two different models of the FSEE use twodifferent power distribution sets. A majordifference between the two model FSEEs is thatthe FFG FSEE uses a 115-volt ac input and onlydistributes power, while the other model FSEEgenerates all FSEE voltages from a 28-volt dcinput. The following is a basic overview of thepower distribution of the two different FSEEs.For a detailed functional description of theseFSEEs, refer to Volume 1, Part 1, of the LM2500Technical Manual, S9234-AD-MMO-010.

FFG FSEE Power Distribution

The power requirements for the FFG FSEE(fig. 2-55) are supplied by the ship power supplies.It requires +5 volt dc, +15 volt dc, –15 voltdc, +24 volt dc, + 28 volt dc, and +115 volt acinputs to operate the various GTE systems. Power

is routed through the FSEE via interconnectingcables. The dc power is routed to dc powerdistribution assemblies A3 and A4. The A3 andA4 assemblies are identical and distribute all dcpower for the FSEE circuits. The A3 assemblydistributes dc power to circuit card moduleassembly Al for the 1A GTE, and the A4assembly distributes dc power to circuit cardmodule assembly A2 for the 1B GTE.

The 115-volt, 60-Hz ac power is routed toac power distributor assembly A5. The A5assembly filters and distributes the ac power tothe flame detectors, ice detectors, and ignitionexciters of both engines.

CG, DD, and FSEEPower Distribution

This model FSEE also has the power circuitryfor two GTEs. The power requirements for allthe FSEE equipment are supplied by a 28-volt

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Figure 2-56.—Simplified CG, and DD FSEE power distribution.

dc power bus to power supply set assembly A2 redundant power supplies feed engine A and(fig. 2-56). High-frequency line noise on the three engine B and are controlled by separate rotarypower inputs are filtered by line filters FL1, FL2, switches, S1 and S2 (not shown), in the powerand FL3. The A2 assembly distributes power to supply set. The engine A and engine B PWBs inthe circuit card module assembly Al and has the Al assembly are supplied by separate +28 voltdual redundant power supplies. Each pair of dc and regulated +5, +15, and – 15 dc voltages.

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All the voltages, except for the 24-volt dctransducer (xdcr) power, are distributed directlyfrom the A2 assembly. The 24-volt dc powersource for the PT2 and PT5.4 pressure transducersfor both engines are distributed from the Alassembly.

PLA ACTUATOR ELECTRONICS

The main functions of this subsystem areto condition the command signal, compare itto the feedbacks from the actuator, and providethe signal to drive the PLA actuator to thecommanded position. In conjunction withthe main functions, this subsystem providesmonitoring of certain system parameters for theprotection of the GTE and power train. The PLAactuator electronics are identical in both modelFSEEs. The major difference between theactuator electronics of both models is location.In the FSEE on the CG-, and DD-classships, the PLA actuator electronics are locatedin the A2 power supply set. In the FSEE on theFFG-class ships, they are located in the A3 andA4 dc power distribution assemblies.

The PLA electronics are composed of threePCBs (PWBs) per engine in the FSEE. These arethe A, B, and C cards. The PLA actuator sendstwo signals back to the electronics. They areposition feedback (potentiometer) and ratefeedback (tachometer). Besides the commandsignal, these two signals provide most of theinformation necessary for the electronics to placethe MFC at the correct position.

The potentiometer receives its referencevoltages from the PLA actuator electronics. Thepotentiometer slider takes a voltage proportionateto the actuator position from the potentiometer;this voltage signal is connected to the controlcircuit. The voltage signal is used to compare withthe command signal and to generate an uplinksignal representative of actuator position. Also,the position feedback is used within an idleposition detection circuit; this circuit detects whenthe MFC is within 2 degrees of the normal idleposition and generates an uplink signal to indicatewhen the MFC is at idle.

Rate feedback is developed by the tachometerattached to the motor shaft. The purpose of therate feedback is to control the response of thePLA actuator during changes of MFC leverposition. When a large difference exists betweenthe commanded position and the actual positionof the PLA actuator, the drive signal to theservomotor is large. A large drive signal causes

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rapid acceleration of the motor, which could allowthe motor to overshoot the desired PLA actuatorposition. Tachometer feedback reduces thisproblem. If the feedback signal was not present,the desired position would be passed. This wouldforce the system to backtrack by turning themotor in the other direction; it would eventuallyseesaw past the desired position a number of timesbefore it settled at the correct position. Thetachometer feedback anticipates the overshootingof the correct position and acts as a brakingsystem for the motor. This is the same functionthat a compensating system in a hydraulicgovernor provides.

Slider Potentiometer

The slider potentiometer provides a positionfeedback signal, which is proportional to theposition of the PLA actuator shaft and MFClever. It is a linear nonwire-wound variableresistance whose potentiometer slider position iscontrolled by the actuator output shaft. Two gearsbetween the output shaft and the potentiometerincrease the potentiometer’s range of rotationalmovement by a factor of 2.27. The normaloperating range of the actuator is about 100degrees and the potentiometer 227 degrees. Thepotentiometer reference voltages are suppliedfrom electronics in the FSEE.

Servomotor

The dc servomotor is driven by the PLAactuator drive signal from the PLA actuatorelectronics. The drive signal is developed by theelectronics in the FSEE. It is amplified andconnected through the fail-to-idle relay. Themotor’s direction of rotation is determined by thepolarity of the drive signal; its velocity isproportional to the drive signal amplitude. Foran input range of – 23 to +23 volts, the motoroutput shaft speed range is 0 to 900 rpm in eitherdirection. The PLA actuator is reduced by a gearratio of 55.64 to 1. This allows a speed range of0° to 16 rpm (0 to 96°/second). It is also capableof running into mechanical stops at full voltageand velocity and remain stalled without damageto the motor.

Tachometer

The tachometer is a dc generator that isdirectly coupled to the motor shaft and outputsa dc voltage proportional to the motor speed. The

Figure 2-57.—PLA drive and fail-to-idle circuit.

polarity of the signal is dependent on the shaft’sdirection of rotation. The tachometer outputrange is 0 to 2.7 volts dc nominal for a shaftinput of 0 to 840 rpm.

PLA Actuator Drive

The PLA actuator drive and fail-to-idlecircuit (fig. 2-57) provides the power to drive theactuator motor. It also provides the fail-to-idlesignal that drives the motor during FSEEmalfunctions.

In normal operation, the output of summationamplifier No. 2 is amplified by the poweramplifier in the power distribution assembly.The output of this amplifier is sent throughthe fail-to-idle relay. This signal, in turn,is sent to the PLA actuator. A fail-to-idlesignal is sent to the relay from either thefail or command loss detector (discussedunder the system fail protection topic). Ifthis occurs, the amplifier output is disconnectedby the gate; a 28-volt dc signal is insertedto drive the motor. The polarity of thissignal is such that it drives the PLA to theidle stop.

Protective Functions

The protective functions of the PLA actuatorelectronics are torque limit control, speed limitcontrol, acceleration limit control, PLA commandrate limit control, and system fail protection.

TORQUE LIMIT CONTROL.—The PLAactuator contains the circuitry that monitors foran overtorque condition. Torque is calculated foreither one or two engines in the operation on theFFGs or split plant or full power on the CG-,and DD-class ships. If the torque signalreceived from the torque computer exceeds thelimit, the limiting circuit goes into action todrive the MFC back, thereby reducing the torqueoutput of the turbine(s).

SPEED LIMIT CONTROL.—The speed limitcontrol circuitry starts limiting when turbine speedreaches 3,672 rpm. The purpose of the speed limitcontrol is to keep the turbine speed below 3,852rpm. The circuit receives a speed signal from thesignal conditioning card. This signal goes throughan anticipation (to anticipate speed) amplifier; thisamplifier detects the rate of increase of the speed(acceleration). This acceleration signal and thespeed signal together are compared to a limit

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Figure 2-58.—Gas turbine simplified control loops.

voltage. If that voltage is exceeded, the speedlimiting circuit goes into action to limit the PTspeed or acceleration.

ACCELERATION LIMIT CONTROL.—Aseparate circuit also receives the PT speed signalwhere the rate of speed change (acceleration) ismonitored. If the acceleration exceeds 332rpm/second, this circuit lowers the PLA actuatordrive signal to lower the PT acceleration.

PLA COMMAND RATE LIMIT CON-TROL.—The position of the MFC lever isproportionally’controlled by the command signal.The rate of change of the lever position isnormally limited to predetermined increasing anddecreasing rates by the command rate limiter.

SYSTEM FAIL PROTECTION.—The PLAactuator generates two signals when certainabnormal conditions are detected. One is anuplink signal to indicate a system failure; the otherenergizes the fail-to-idle relay to open the path

of the PLA actuator’s drive signal and inserts afixed voltage to drive the MFC to idle.

If the command signal exceeds a maximumof +12 volts dc or falls below a minimum of +0.3volt dc, a command loss condition exists. Boththe fail-to-idle relay energizing voltage and thesystem fail signal are generated.

A malfunction is considered to exist if theunamplified drive signal to the rotary actuatorexceeds +2.7 volts or below –2.7 volts for1 second or longer. Again both the fail-to-idlerelay energizing voltage and the system fail signalare generated.

If the MFC is at idle and an overtorquecondition exists or if either of the 15-volt powersupplies fail, a system fail signal is generated.

PLA Actuator Theory of Operation

In the following discussion, please refer tofigure 2-58 to help you trace the command signalfrom the throttle to the MFC.

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The command signal is developed by anoperator at a throttle. When it reaches the PLAelectronics, it first goes through a command ratelimiting circuit. This circuit does not let thecommand signal (into summation amplifier No.1) exceed a rate of change of 2.1 volts(22.5°)/second increasing or 9.0 volts(89°)/second decreasing. At summation amplifierNo. 1, the command signal is compared to theposition feedback signal. The difference is calledthe position error signal.

The position error signal is passed through thecontrolled limited attenuator. Here the signal ispassed unchanged or is attenuated (decreased inamplitude). Whether attenuation occurs or notdepends on the limit discrete signal. This signalis generated from within the limit loops when thetorque or speed limit is exceeded. The attenuatorattenuates the position error signal when the limitdiscrete signal is present. The attenuation of theposition error signal lowers its effect on the PLAactuator.

NOTE: When the torque or speed limits areexceeded, the limit discrete and the analog limitingsignals are simultaneously generated. The limitdiscrete signal lets the analog signal have moreeffect by diminishing the drive signal beforethe analog limiting signal is added to it atsummation point No. 2.

The position error signal out of the attenuator,the speed (PLA actuator rate) feedback, and theanalog limiting signal from the limit loops is addedinto summation point No. 2. There they arealgebraically summed to generate the unamplifieddrive signal for the servomotor. The tachometerfeedback signal lowers the drive signal wheneverthe PLA actuator moves fast. When the PLAactuator is moving slowly, the tachometerfeedback is low and its effect is minimal on thedrive signal.

The analog limiting signal is generated in thelimiting electronics when the torque, speed,acceleration, or PLA actuator rate limit isreached. This signal is proportional to the amountof PT torque, speed, acceleration, or PLAactuator rate present over their respective limit.It drives the MFC in the direction necessary toremove the PT from the limit condition.

The corrected drive signal is sent through apower amplifier where it is amplified by a gainof 20. The signal then goes through the fail-to-idle relay to the servomotor. The fail-to-idle relayconnects the drive signal to the PLA actuator

through normally closed contacts; it may gate afixed voltage, through normally open contacts,to drive the PLA actuator to idle if one of theconditions discussed previously exists.

The limiting functions of the PLA actuatorelectronics have a passive role during normaloperation of the PT. Only when a limit is exceededor, as in the case of speed limiting, seems like itis going to be exceeded, do the limiting circuitsbecome active.

The inputs to the limiting circuits are PT speedand PT torque. The speed signal comes from oneof two PT speed transducers through a signalconditioning circuit. The torque signal iscalculated by the torque computer in the FSEE.

If more than one event (overspeed or over-torque) occurs simultaneously, the analog signalsfrom the speed acceleration and torque limitingcircuits are brought to the same point. At thispoint, the largest of the signals gates tosummation point No. 2 in the control loops. Theanalog signal from the rate limit can be appliedto summation point No. 2 regardless of otherinputs.

The operation of the control circuits in thePLA actuator electronics can be altered by thebattle override function. During testing andemergency operation of the ship, authorizedpersonnel can activate this function at thecontrol consoles. In the battle override mode, thefail-to-idle relay will not operate. This willprevent the PLA being forced to idle. The analoglimit signal used by the limit loops to lower PLAactuator position is inhibited. ( NOTE: Depressingthe engine synchronizing switch located within theFSEE will activate battle override as long as theswitch is depressed.)

FSEE CIRCUITRY TESTS

The electronics within the FSEE covers variousinternal tests to check if circuits are workingproperly. The tests are for the torque computer,the speed limit circuit, and the overspeed switch.These tests only test the FSEE circuitry. For a totalsystem test, refer to the applicable maintenancerequirement card (MRC) of the PlannedMaintenance System (PMS).

Torque computer test. On this test, thetorque computer uses several fixed parametervalues to calculate a torque value. If the valueexceeds the reference set point, an indicator lighton the control console signals that the torque testpassed.

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Speed limit test. This test lowers the speedlimit loop reference voltage by 25 percent. To testthis loop using the turbines, the PT would onlyhave to be run to 75 percent of real limit point.(NOTE: Follow the PMS procedure to test speedlimiting.)

Overspeed test. Four push buttons arelocated in the FSEE, one each for channels A andB on each turbine. When you depress a pushbutton for testing the circuit, a frequencygenerator in each PWB introduces a signalsimulating a high-speed signal. This signal causesthe fuel valves to close and the overspeed lightto illuminate.

START/STOP SEQUENCER

The start/stop sequencer is installed in theFSEE on FFG-class ships. It provides signalconditioning, monitoring, and logic circuitsrequired for safe GT starting and stopping. Ninecircuit cards are used for this feature. Three cards(the X, Y, and Z cards) are signal conditioners.Four of the cards are logic cards (the AB, AD,AE, and AC cards). The other two cards are atransmitter card (AA) and a thermocoupleamplifier card (V).

The start/stop sequencer provides the follow-ing functions:

Signal conditioning of gas turbineparameters

Monitoring of vital parameters

Sensing out-of-limits instrumentationsignals

Signal conditioning output status signals

Initiating automatic control signals

Receiving and processing operator com-mands

The start sequencer has three sequence modesavailable. These modes are auto, manual, andauxiliary (or test). In the auto mode, whencommanded by a signal from the PCC, anautomatic start-up of the GTE can be performed.This auto start sequence using a programmed timesequence monitors and controls the enginestarting. Parameters monitored include NGG ,T5.4, fuel manifold pressure, and lube oil supply

pressure. If these parameters are not within limitduring start-up, the sequencer will initiate animmediate automatic shutdown.

In the manual mode, an operator is requiredto initiate the starter on, fuel on, and ignition oncommands. When the sequencer receives a manualstart command, it provides the time sequence andengine parameters for the operator’s information.The conditions that would cause shutdowns in theautomatic mode provide only an alarm in themanual mode.

In the auxiliary (or test) mode, an operatorcan test the engine start components withoutactivating the fuel and ignition at the same time.In this mode, the operator can check the fuelsystem without causing a start of the engine. Theoperator does this by manually motoring anengine, and at 1,200 rpm, energizing the fuelvalves. Then the operator checks the operationof the fuel system components. This is done bythe operator monitoring the fuel supplytemperature, pressure, fuel flow, and fuelmanifold pressure. In this way, the operatorchecks the operation of the fuel pump, MFC, andfuel shutoff valves. The operator checks the fuelshutdown valves upon completion of the test byde-energizing the valves. A fuel valve test modealso allows you to test the valves to ensureproper operation of the valves. Also, you can testthe ignition system using the auxiliary mode. Theignition test will cause the igniters to be on as longas you depress the igniter push button.

SUMMARY

In this chapter and the previous one, wediscussed how the LM2500 GTE is constructedand the function of its various parts. We describedthe operations of its many systems, including theflow of air into the combustion section, the mixof fuel and air, and how the fuel system andignitor system cause combustion. We describedthe operation of the lube oil system and lookedat a description of its function and how the engineis controlled electronically by the FSEE. Webriefly covered the control systems for thedifferent class ships. We discussed the ECSS andstart/stop sequencer control.

We will describe the actual start, operation,and stopping of the LM2500 GTE in chapters 6,

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7, and 8 of this manual. After reading this chapter You should now be familiar enough with theand chapters 6, 7, and 8, you will be able to engine and its operational systems to be able tounderstand how the overall engine operation is follow instructions concerning basic maintenancecontrolled from the engine room or from a procedures and understand the importance of thecentral control point aboard ship. numerous parameters that control the engine.

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CHAPTER 3

SHIP’S SERVICE GAS TURBINEGENERATOR SETS

Until now our discussion has centered on thepropulsion uses of GTEs. This means we havecovered only part of the job tasks of GSs. On thelarger gas turbine ships, such as the DD,and CG classes, GSs must maintain the ship’sservice gas turbine generator sets (SSGTGSs).These ships use four different gas turbinegenerator sets (GTGSs). The model 104 is foundon the DD-class ships, the model 119 onships, and the model 139 on CG-class ships.The model 170 GTGS is found only on the USSPaul F. Foster (DD-964). It is very similar to themodel 104. Except for the 51 class ships,all of the GTGSs use the Allison 501-K17 GTEas a prime mover. The 51 class ship usesthe Allison 501-K34, a modified version of theK17. In this chapter we refer to the Allison501-K17 (K34) as the GTE, the engine, or theprime mover. Although the engine is the same onall sets, many differences exist between the units.Models 104 and 170 GTGSs are 2000-kW GTGSs;models 119 and 139 are 2500-kW GTGSs. Models104, 119, and 170 have solid-state local operatingcontrol panels (LOCOPs) that use analog meters;the model 139 incorporates a digital LOCOP withlight-emitting diodes (LEDs) used to displayoperating parameters. Models 119 and 139 use abrushless exciter that replaces the brushes and sliprings found on the 104 and 170. Many otherdifferences exist between these GTGSs. We willdiscuss most of these in detail in this chapter.Model 170 incorporates features from each of theother three models. It will not be discussedseparately in this chapter.

Normally the GTGS is not attended while itis in operation. It is controlled either at theswitchboard (SWBD) or the electric plant controlconsole (EPCC). The EPCC operators are thewatches that monitor the electric plant. They areresponsible for taking action to prevent loss ofthe electrical load during a generator casualty.Neither control station can monitor all theparameters of the operating GTGS. For thisreason, a monitor who makes hourly rounds of

the equipment is usually required to logparameters not otherwise observed. Most oftenthese monitors are GSs in the junior paygrades(E-5 and below). You will need to be able toquickly identify any impending casualty to theGTGS to prevent loss of the ship’s electricalpower. To do this, you must first understand howthe set is constructed, how its systems function,and how to operate it.

After reading this chapter and completing theassociated nonresident training course (NRTC),you should be ready to begin qualification as anengine-room equipment monitor and as an EPCCoperator. You should also be able to identify anddescribe a majority of the GTE and generatorcomponents. You should be able to understandthe operations of the various engine systems andthe generator control and monitoring equipment.You should understand the procedures forstarting, stopping, and motoring a gas turbinegenerator (GTG) locally or from the SWBD. Youshould also be able to understand frequency andvoltage control functions.

The EOSS gives you the correct procedures foroperating this vital piece of machinery. Alwaysuse the EOSS when actually operating anyengineering equipment. Using the EOSS willprevent you from missing any steps/proceduresthat could result in damage to a valuable pieceof ship’s equipment.

NOTE: Directions in this chapter relate to anobserver standing at the exhaust end of the GTGSlooking toward the generator (aft lookingforward).

GENERAL DESCRIPTION OF THEGENERATOR SET

Ship’s service electric power is provided bythree 2500-kW GTGSs on the CG-class ships. Onthe DD-class ships, ship’s serviceelectric power is provided by three 2000-kW

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GTGSs except the USS Paul F. Foster. This ship Under normal operating conditions, any twohas a fourth GTGS (model 170), which is a generators can supply the entire ship’s demand.modified model 104. For detailed information on The third GTGS can be set up in auto-standby.this GTGS, refer to NAVSEA technical manual, It will then come on the line automatically in caseDescription, Operation and Installation, Model either on-line GTGS fails.104 Gas Turbine Generator Set, S9234-BC- The No. 1 GTGS and the No. 2 GTGS areMMO-010, change B. located in the No. 1 and No. 2 engine rooms,

Figure 3-1.—Model 104 GTGS.

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respectively, on the second platform level. Theyare located opposite the main engines. The No.3 GTGS is located in the No. 3 generator roomat the first platform level. This arrangementseparates each GTGS by at least three watertightbulkheads. This reduces the change of total lossof electric power because of battle damage. Figure3-1 shows the equipment layout of a GTGS. Referto the numbers listed in parentheses after eachdescription to locate the component in figure3-1.

Each GTGS is a module consisting of a GTE,a reduction gear assembly, and a generator. Theseare all mounted on a common base with asso-ciated engine controls and monitoring devices.Each GTGS is about 25 feet long, 7 feet wide, and9 feet high. The GTE and reduction gear assemblyare housed in an acoustical enclosure (1). Eachgenerator has a remotely mounted generatorcontrol unit (2). The lube oil cooler (3) for eachgas turbine/reduction gear system is mountedunder the module base.

The GTGSs can be started and monitoredlocally at the LOCOP (4) mounted on the genera-tor housing or remotely from the SWBD or EPCCin CCS. The LOCOP contains the electronic con-trols that sequence and monitor the operation ofthe GTE. Control of generator voltage, fre-quency, and the generator circuit breaker isavailable at either the EPCC or the SWBD.

Each GTGS has its own seawater coolingsystem and lube oil system (5). The module iscooled by air supplied from the intake systemthrough an electric fan. Two fans are used on theC G c l a s s e s . T h e m o d u l e r e c e i v e sstarting air from the bleed (low-pressure) (6) andhigh-pressure (7) air systems, signal air from theship’s service air system (SSAS), cooling andemergency cooling water from the seawater servicesystem, fuel from the engine room’s fuel oil (FO)service system, carbon dioxide (CO2) from thefire extinguishing system, and gas turbinecleaning/rinsing solution from the water washsystem. Figure 3-2 shows the interrelations of

Figure 3-2.—GTGS interrelation with ship’s systems.

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these systems to the GTGS. These and otherservices interface connections are made at themodule (fig. 3-3).

GAS TURBINE GENERATOR SETMODULE COMPONENTS AND

SYSTEMS

The module components and systems supportthe operation of the engine, reduction gear, andgenerator. These components and systems includethe base, the enclosure, the cooling air flow andtemperature monitoring systems, the water washsystem, the fire detection and extinguishingsystem, the intake and exhaust systems, the GTGSfire detection and CO2 system, and the seawaterservice system.

BASE

The GTGS base is a steel frame attached tothe ship’s structure through 5000-pound capacity,shock/vibration isolating mounts. Twelve mountsare used for the model 104 GTGS; fourteen areused for the models 119 and 139 GTGSs. The base

supports the entire GTGS system except for thesetwo components. They are the generator exciter/voltage regulator unit (including the electronicgovernor) and an externally mounted oil coolerfor the GTE and the reduction gear lube oilsystems.

ENCLOSURE

The engine and the reduction gear assemblyare housed in an acoustical enclosure (fig. 3-4).The enclosure reduces the noise level within themachinery space and ducts cooling air for theGTE. Barrier walls and the air inlet plenum withinthe enclosure separate the engine compartmentfrom the reduction gear compartment.

Blow-In and Blow-Out Panels

Figure 3-4 shows the blow-in and blow-outpanels on the enclosure. They prevent damage tothe GTGS due to high or low external pressure.The panels are spring-loaded in the closedposition. The blow-in panel is located in the leftwall of the enclosure. It is near the aft end and

Figure 3-3.—GTGS ship’s system interface connections.

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Figure 3-4.—GTGS enclosure-left side view.

just above the base. The blow-out panel is locatedin the enclosure roof panel on the left side. It isforward of the cooling air inlet silencer.

Module Cooling Air Flow andTemperature Monitoring

Cooling air is extracted from the GTEcombustion air intake duct and flows through alouvered cooling air modulator on the model 104.Then it flows through an axial fan (two on CGs)a n d a f i r e d a m p e r . I t i s d u c t e d i n t othe enclosure, entering the enclosure through asilencer mounted on the aft (exhaust) end of theenclosure roof. Ceiling-mounted baffles in theenclosure direct the cooling air to the forward(compressor) end of the engine enclosure. The aircirculates around the engine and exits through agap between the engine exhaust nozzle and the

exhaust. The flow of exhaust gas past this gappulls the cooling air out of the enclosure and intothe uptake. The cooling fan(s) is only activatedif this natural flow is not enough to keep theenclosure air temperature below 195°F.

DD MODULE TEMPERATURE MONI-TORING. —Two temperature switches, athermostat, and an RTD are associated with thecooling air system. These components are alllocated inside the acoustical enclosure. One switchcontrols the cooling air fan, turning the fan onwhen the air temperature in the enclosure is 195°Fand off when it is 175°F. The second switchactivates the ENCLOSURE TEMP HIGH alarmindicator at the electric plant control equipment(EPCE). It also activates the summary alarm atthe associated switchboard. The alarms areactivated when the enclosure temperature reaches

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200°F. The RTD provides a continuous enclosuretemperature signal to both the LOCOP andpropulsion and auxiliary machinery informationsystem equipment (PAMISE). The signal in thePAMISE is used for data logging and the demanddisplay indicators (DDIs). The thermostat controlsthe operation of the louvered cooling airmodulator.

CG CLASS MODULE TEMPERATUREMONITORING.—Two temperature switches, athermostat, a manual rotary selector switch, andan RTD are associated with the cooling air system.The manual rotary selector switch is located onthe LOCOP. It is a four-position switch: FAN A,FAN B, MANUAL, and OFF. When the selectorswitch is positioned on FAN A or FAN B, thisselects the lead fan. The temperature switcheswork with the rotary switch to determine whichis the lead fan or for manual operation. With therotary switch in the FAN A position, fan A willact as lead fan. When the GTG is started, fan Awill start at an enclosure temperature of 170°F.

If the temperature continues to rise, standby fanB will start at 190°F. It will continue to run untilthe temperature drops to 180°F. When you securethe GTG, the lead fan will continue to run untilthe temperature drops to a point below 140°F.

When the LOCOP switch is positioned onMANUAL, you can select a fan by using theLOCOP push-button indicators. The fan selectedwill operate until it is stopped manually.

The RTD on the model 139 operates like theRTD on the model 104 except that the RTD inthe enclosure provides a temperature signal to theEPCC that activates the ENCLOSURE TEMPHIGH alarm indicator at the EPCC.

WATER WASH SYSTEM

Figure 3-5 shows the components of the waterwash system and the CO2 system. The CO2 systemis discussed later in this chapter. The water washsystem is used to clean the compressor section ofthe GTE. Two spray nozzles spray chemicalcleaner or fresh water into the engine inlet while

Figure 3-5.—GTGS water wash and CO2 systems.

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the engine is motoring. The nozzles are mountedin the forward wall of the inlet plenum. Exceptfor the spray nozzles and the solenoid-operatedsignal air valve (not shown) located under themodule, all components of the water wash systemare ship’s systems.

FIRE DETECTION ANDEXTINGUISHING SYSTEMS

Figure 3-5 also shows the fire detection andextinguishing system. This system has two UVflame detectors, a signal conditioner (not shown),and four CO2 discharge nozzles. The flamedetectors are mounted on the engine side of theinlet plenum wall. The CO2 discharge nozzles are

mounted in pairs above and below the air inlethousing. Each pair has one primary and onesecondary discharge nozzle. The CO2 is piped tothe module from the primary and secondary CO2tank banks. When the flame detector detects afire, an electrical signal from the vent fancontroller activates the primary CO2 system. Iffailure of the primary system occurs, or theprimary is not enough to extinguish the fire, thesecondary system can be manually activated at themodule or outside the space.

INTAKE, COOLING, AND EXHAUSTSYSTEMS

The intake, cooling, and exhaust systems (fig.3-6) provide the flow path for combustion and

Figure 3-6.—GTGS intake, cooling, and exhaust systems.

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cooling air to and from the GTE. The inletsystems have inlet louvers, demisters, blow-indoors, silencers, cooling airflow modulators, fans,and a fire damper. The exhaust systems containsilencers and IR suppression systems. The exhaustgas is routed through waste heat boilers (WHBs)before entering the exhaust stack.

Intake Duct

The intake ducts are rectangular structuresattached to the enclosure by a flexible rubberboot. Both combustion and cooling air entersthrough a common duct, but separate beforeentering the enclosure. The ducts for the No. 1and No. 2 engines are located on the inboard sideof the exhaust stacks. Air enters the ducts throughlouvers mounted in the side of the stack. It flowsthrough mesh pad demisters and silencers into themodule inlet plenum and into the engine inlet. Thecooling air splits off just before the flexible booton top of the inlet plenum. It is routed to the aftend of the enclosure through another flexibleboot.

The intake air plenum for the No. 3 GTGSis located on the 01 level, starboard side, aft ofthe missile launcher area. Air enters a verticalbellmouth and flows into the No. 3 generator.This plenum serves as a green water trap. It allowsany large quantities of water to drain through slotsin the deck combing. The air then flows throughdemisters into the No. 3 generator intake room.The bulkhead between these two compartmentshas the blow-in doors. Combustion and coolingair flow through separate ducts from the intakeroom to the module.

LOUVERS.—The intake duct inlets for theNo. 1 and No. 2 engines have louvers similar tothe main engine inlet louvers. Like the mainengine louvers, they are designed and arrangedto shed sea spray. Because of the vertical flow inletdesign, the No. 3 engine duct inlet has no louvers.

DEMISTERS. —The demisters are mesh pads.They are similar to those in the main engine inlet.They are arranged vertically behind the louvers.Moisture separated from the air collects inscuppers under the demisters and is drainedoverboard.

BLOW-IN DOORS.—A single blow-in dooris located in each inlet below the demisters. Theirpurpose is to bypass the demisters if they becomeclogged. This permits enough combustion and

cooling airflow to the engine for normaloperation. A controller provides for manual orautomatic operation by a selector switch on thecontroller door. When in manual, you can use apush button to energize a solenoid and release theblow-in door. When in automatic, the solenoidis energized by action of a pressure switch. Thisswitch is set to operate at about 8 inches of water(in.H2O) differential pressure. Indication andalarm of DUCT PRESS LO are given at thepropulsion local operating equipment (PLOE) andthe propulsion and auxiliary machinery controlequipment (PAMCE) consoles. Once open, thedoors must be closed manually.

SILENCERS. —The vane-type silencers havesound-deadening material encased in a perforated,stainless steel sheet. They are mounted verticallyin the duct between the demisters and the coolingair duct.

ANTI-ICING.—The anti-icing system issimilar to that in the main engine inlet ducts. Hotbleed air from the engine is discharged into theinlet duct. There it mixes with the inlet air andraises the temperature above the freezing point.Bleed air flow is regulated as a function ofupstream temperature versus a fixed temperature.This maintains an inlet temperature of about 38°Fwhen anti-icing is selected. This temperature isenough to prevent the formation of ice. It alsomelts any ice, sleet, or snow entrained in the air.

Module Cooling System

The module cooling system has a duct, a flowmodulator, an axial fan (two fans on the model139), a fire damper, an air silencer, and a ceiling-mounted baffle within the module.

FLOW MODULATOR.—The flowmodulator is located in the cooling duct betweenthe engine intake duct and the fan. It controls theflow of air to the module enclosure based on theenclosure air temperature. When the enclosuretemperature increases to 180°F, the high-temperature set point contacts of the module-mounted thermostat will close. This causes theflow modulator motor to rotate the modulatingblade-type vanes to the full-open position. Whenthe enclosure temperature decreases to 170°F, thelow-temperature set point contacts will close. Thiscauses the flow modulator motor to rotate themodulating vanes back to the half-open position.The modulator is not used on the model 139GTGS.

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COOLING FAN(S).—The fan(s) is located inthe cooling air duct between the flow modulatorand the fire damper. The fan(s) draws air fromthe intake duct through the flow modulator. Itblows the air through the fire damper to themodule enclosure. The air enters the modulethrough the silencer. It passes across the ceiling-mounted baffle within the enclosure and thencirculates around the engine. It exits through agap between the engine exhaust nozzle and theexhaust eductor where it mixes with the engineexhaust.

COOLING FAN CONTROLLER.—The fancontroller has a circuit to cycle the fan on and offautomatically based on the enclosure temperature.It also has circuitry to perform a GTGS systemfire stop, which is described later in this chapter.It is provided with a NORMAL/ALTERNATEpower supply selector switch. The NORMALsource for the controller is the generator bus; theALTERNATE source is one of the other SWBDs.The fan will cycle on when a temperature switchwithin the module enclosure senses a temperatureof 175°F. It cycles off when the temperaturedecreases to 160°F. The model 139 also cycles onand off based on the enclosure temperature. Thisfunction is controlled by the LOCOP; however,no separate fan controller is used.

FIRE DAMPER.—The fire damper is locatedin the cooling air duct between the fan and moduleenclosure. It closes off the flow of cooling air tothe module when a fire is present within themodule. During normal operation, the firedamper is in the full-open position. A fire detectedby either of the two UV detectors within theenclosure will cause the fire stop circuit within thefan controller to close a set of contacts. Thisenergizes the fire damper motor and rotates thedamper to the closed position. The fire damperis reset manually.

Exhaust Duct System

The exhaust ducts are round, insulated,stainless steel structures. Each duct has a silencerand an IR suppression system. The model 139 usesa BLISS-type IR suppression system similar to theones used on the CG main engines. Because oftheir smaller size and lower gas flow rate, theydo not require eductors as do the main exhaustducts. The exhaust ducts from the No. 1 and No.2 engines run parallel to the main engine ductsin the exhaust stacks. The duct from the No. 3

Figure 3-7.—No. 3 exhaust configuration.

engine (fig. 3-7) traverses the ship and dischargesfrom the aft, port side on the 01 level. Becauseof the location of the No. 3 exhaust, a seawatertrap is provided to trap and drain this wateroverboard.

SILENCERS. —The silencers have sound-deadening material. They are encased in aperforated stainless steel sheet cylinder. This issuspended in the center of the exhaust duct. Thisunit with the duct wall insulation provides therequired sound reduction to meet airborne noiserequirements.

BOUDARY LAYER INFRARED SUPPRESSION.—The purpose of the IR suppression system is to reduce theexhaust gas temperature before it is dischargedto the atmosphere. This minimizes heat sensingof the ship by other vessels and aircraft.

GREEN WATER TRAP.—Figure 3-7 showsthe location of the green water (seawater) trap.Because of the low location of the No. 3 engineexhaust duct exit relative to sea level, green watercan enter the duct exit during high sea states. Tostop the seawater from flowing down through theexhaust system, a tank is located in the duct nearthe exit. Any water that enters the duct is trappedin the tank and drained overboard.

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GTGS FIRE STOP AND CO2SYSTEM

Two UV detectors are used to sense a firecondition in the engine enclosure. Only the engineenclosure is protected by the installed CO2 system.The UV sensors and signal conditioners used onthe GTGS are similar to the type used on theLM2500 GTE. The two sensors are mounted inthe enclosure near the compressor inlet. The signalconditioners are mounted in the alarm terminalbox located on the generator end of the base. Thefire stop logic is controlled by the module coolingfan controller.

Model 104 Fire Stop Logic

When a fire is detected by the UV sensors inthe module of the model 104 GTGS, a signal issent to the fire shutdown relays. The followingactions then occur:

1.

2.

3.

4.

A 5-second delay occurs. This prevents anystray signals from causing a fire stop. Thefire condition must exist for these 5seconds.

After the 5-second delay, the followingactions occur:

a.b.c.d.e.

f.

Primary CO2 is released.A stop command is sent to the LOCOP.The module fire damper is closed.The cooling fan is stopped.Ship’s service LP air is ported to the5th- and 10th-stage bleed air valves tokeep them closed.Fire alarms are activated at the damagecontrol console (DCC), EPCC, and thesummary alarm at the SWBD.

The stop command to the LOCOP closesthe fuel valve. When the GTGS rpm dropsbelow 12,780 rpm, the 14th-stage bleed airvalve closes.

Door interlocks are provided to preventCO2 discharge if the engine section moduledoors are open.

Model 139 Fire Stop Logic

The model 139 fire stop is also controlled bythe cooling fan controller. The fire stop sequence

is different from that on the model 104. Thefollowing actions occur if a fire is detected by theUV sensors:

1. The cooling fan(s) stop(s), if running.

2. A 20-second delay is activated if the firesignal remains for 1.5 seconds or longer.

3. After 20 seconds the following actionsoccur:

a. A stop command is sent to the LOCOP.b. Ship’s service LP air is ported to the

5th- and 10th-stage bleed air valves tokeep them closed.

c. The fire dampers are closed.d. Primary CO2 is released.e. Fire alarms are activated at the DCC,

EPCC, and the SWBD.

4. The LOCOP stop command closes theengine fuel valve. When the engine dropsto 12,780 rpm, the 14th-stage bleed airvalve closes.

CO2 System

The primary CO2 system has two 50-poundCO2 cylinders (one master and one slave), twopressure switches, and two high-volume, low-velocity nozzles. The CO2 cylinders are mountedin racks adjacent to the module. The pressureswitches are located in the piping system. One isoutside and the other is inside the enclosure. Thenozzles are mounted on the air intake assembly.Figure 3-5 shows the CO2 system components andtheir location on the GTGS.

Normally, the primary bank is activated byfire stop logic. You can also activate the primarybank manually at the bank or remotely from thepull box. When the two pressure switches areactivated by CO2 pressure in the header, a CO2release alarm is initiated locally and at the DCC.The summary alarm at the SWBD is alsoactivated. Once started, CO2 discharge cannot bestopped. The primary discharge occurs at the rateof 200 lb/min until the primary cylinders areexhausted.

The secondary system has three 50-pound CO2cylinders (one master and two slave) and two high-volume, low-velocity nozzles. These are connectedby a common piping system. The secondary bank

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must be released manually at the bank. Thesecondary system is not equipped with monitorsor alarms. Once released, CO2 discharge cannotbe stopped. The secondary discharge is at the rateof 67 lb/min.

SEAWATER SERVICE SYSTEM

Each GTGS has an independent seawaterservice system for the lube oil coolers andgenerator air cooler. Power for the pumps is takenfrom the generator side of the main circuitbreaker. Thus, the electric pumps start automa-tically as the generator’s voltage exceeds excitationvoltage. Figure 3-8 is a flow diagram of this servicesystem. A solenoid-operated pilot valve auto-matically opens the diaphragm-actuated,hydraulically operated stop valve when LPcontacts close in the pressure switch in the normalservice line. Cooling water is drawn from the seachest. It flows through a strainer and then thegenerator air cooler and lube oil cooler. It passesthrough the reduction gear/engine lube oil cooler.The seawater flow requirements are different for

the three coolers. Therefore, each unit has abypass valve to adjust the amount of seawaterflowing through the cooler. This amount isbased on the temperature of the oil or air beingcooled.

If the electric pump system fails, emergencycooling water is supplied by the ship’s seawaterservice system. This is accomplished by activationof the pressure switch that senses pump dischargepressure. If the GTGS is running and pumpdischarge pressure drops below the pressure switchset point, the solenoid-operated pilot valve willenergize, opening the diaphragm-actuated stopvalve and circulating the emergency seawatersupply through the coolers. Seawater is dischargedoverboard through an emergency stop valve.

GTE ASSEMBLY

The Allison 501-K17 is a single-shaft, axial-flow GTE. It has a 14-stage axial-flowcompressor, a can-annular combustor, and a4-stage axial-flow turbine directly coupled to the

Figure 3-8.—Generator seawater service system.

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compressor (fig. 3-9). The GTE drives thegenerator through a reduction gear. The reductiongear is mounted in front of the GTE. It isconnected to the compressor front shaft by apower take-off (PTO) shaft assembly. The GTEis mounted on a suspension system at itsapproximate center of gravity. It is adjusted sominimum stress is placed on the bolted flangesof the PTO housing. Engine to reduction gearmisalignment is, therefore, minimized whenmovement occurs because of shock or thermalgrowth changes. The direction of rotation of theengine is counterclockwise when viewed from theexhaust end.

In this section we will describe the Allison501-K17 air intake system; the compressor,combustor, and turbine section; and the accessorydrive section.

AIR INTAKE

The air intake has a one-piece cast aluminuminlet housing. This forms the airflow path to thecompressor. Figure 3-10 shows the air inlethousing, the compressor IGV assembly, and thecompressor front frame assembly. The housinghas an outer case, a center hub, and eight strutsconnecting the hub to the outer case. The hubcontains the compressor front bearing. Thissupports the forward end of the compressor rotor,the bearing labyrinth seal, and the bevel gears.The bottom strut contains the radial drive shaft.The shaft transfers power from the compressorrotor to the AGB, which is used to drive theaccessories. The outer case has a pad on thebottom that provides the mounting for the AGB.The turbine breather is mounted on the top. The

Figure 3-9.—Allison 501-K17 GTE. A. Overall view. B. Cutaway view.

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Figure 3-10.—Air inlet housing, IGV assembly, and compressor front frame assembly.

3-13

Figure 3-11.—Allison 501-K17 compressor. A. Stator. B. Rotor.

3-14

Figure 3-12.—Allison 501-K17 diffuser and 14th-stage stator vane assembly.

housing also has passages for directing anti-icing air to the strut leading edges and theIGV assembly. This assembly is located inthe after side of the inlet housing. However,in this application, engine anti-icing is no longerused.

COMPRESSOR SECTION

The compressor section has a compressorstator (fig. 3-11, view A), a compressor rotor (fig.3-11, view B), and a diffuser (fig. 3-12). The airinlet housing described in the preceding paragraphis also part of the compressor section. Thecompressor case is made up of four sections boltedtogetber along horizontal split lines. The casecontains the 14 stages of stator vanes and the exit

guide vanes. The rotor is made up of 14 individualwheels. The wheels contain the 14 stages of bladesand are pressed and bolted together as oneassembly.

The diffuser is of welded steel construction.It is used to slow the compressor discharge airbefore entering the combustor. The diffusersupports the compressor rear bearing/thrustbearing, the compressor seal (two-stage)stationary members, and six fuel nozzles. Itprovides three bleed air extraction ports to whicha manifold is attached. This allows bleed airextraction (up to 10 percent of total engineairflow) to the ship’s bleed air system. Bleed airis also extracted for use in keeping the 5th- and10th-stage bleed valves closed during normaloperation.

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COMBUSTION SECTION

The combustion section has six individualcombustion chambers (burner cans) (fig. 3-13).They are equally spaced in an annulus formed bya one-piece outer casing and a two-piece innercasing. Six crossover tubes connect the burnercans. These provide flame dispersal duringstarting. The burner cans are held by the fuelnozzles, spark igniters (two chambers), and linersupports (four chambers). The burner cans are ofwelded construction.

The outer casing encloses the burner cans andprovides the supporting structure between thediffuser and turbine. The casing has two drainvalves to drain unburned fuel after shutdown orafter a false start. They may be called eitherburner drain valves (model 104) or combustordrain valves (model 139). These valves open whencombustion pressure drops below 1 to 5 psig. Theyclose above 2 to 5 psig on increasing pressure.

The two-piece inner casing has an inner casingand inner casing liner. These are separated by anair space and bolted together at the front. Theinner casing liner has a bellows to take up thermalexpansion and contraction. It is bolted to the

turbine inlet casing at the rear. The aft end of theinner casing is bolted to the turbine inlet casing.The front end is supported by a sleeve in thediffuser.

About 25 percent of the compressor dischargeair entering the combustion section passes to theburner cans. Combustion takes place in the sixcombustion liners. Air initially enters the linersthrough vanes at the front of the liners that swirlthe airflow. The swirling air mixes with the fuelsprayed into the liners by the fuel nozzles. Themixture is ignited during start by the spark igniterslocated in two of the liners (these are describedlater in this chapter). After a start, a steady flameis established by the constant addition of fuel andair.

Holes along the body of the liners allowcooling air to enter the liners. This air providesa buffer between the liner and the hot flames. Tworeverse flow baffles ensure the liners direct airfrom some of the cooling air holes toward thefront of each liner. This cools the forward portionof the liners and provides additional turbulence(for better combustion) of the fuel and airmixture. The hot gases produced in the liners existthrough a transition section into the turbine.

Figure 3-13.—Allision 501-K17 combustion section.

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TURBINE SECTION

The turbine section (fig. 3-14) has severalparts: the turbine inlet casing and front bearingsupport, turbine rotor, turbine vanes (not shown)and rear labyrinth seals, turbine vane casing,turbine rear bearing support, and the turbine rearscavenge pump.

The turbine inlet casing and front bearingsupport house the first-stage vanes, the frontturbine roller bearing, 18 turbine inlet temperature

front bearing support is bolted to the inlethousing.

The second-, third-, and fourth-stage vanes aremounted in the vane casing. The vane casing isa one-piece structure bolted between the aft flangeof the inlet casing and the forward flange of theturbine rear bearing support.

The turbine rear bearing support contains therear roller bearing. It also provides the sump forthe rear bearing scavenge oil and mounting for

thermocouples, and the front labyrinth seal. The the turbine rear scavenge oil pump.

Figure 3-14.—Allison 501-K17 turbine section.

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The turbine rotor has four wheels containingthe turbine blades and is supported at each endby roller bearings. The turbine rotor extractsenergy from the hot exhaust gas. It converts thisenergy into shaft horsepower to drive the com-pressor through a coupling shaft that runs throughthe combustion chamber inner casing liner as-sembly and the generator through the PTO shaftand reduction gear. This is different from theLM2500 GTE. It uses one turbine to drive its com-pressor and a separate turbine to drive its load.

pump, governor actuator, and external scavengeoil pump. Pads on the front face are for the speed-sensitive valve, main oil pump, and oil filter (thisrequires no gearing). The components themselvesare discussed later in this chapter. The accessorydrive is driven by the compressor rotor extensionshaft. This is accomplished by bevel gears thatdrive a radial drive shaft, located in the inlet hous-ing. The radial drive shaft is splined into one bevelgear through the bottommost strut of the inlethousing. A pinion on the other end of the shaftdrives the gears in the accessory drive housing.

ACCESSORY DRIVE SECTION

The accessory drive housing (fig. 3-15) pro- ENGINE SYSTEMS

vides mounting pads on the front and rear faces. As previously mentioned, the model 104 andThe pads on the rear face are for the fuel the model 139 both use the same GTE. However,

Figure 3-15.—Allison 501-K17 accessory drive housing.

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some differences exist in the support systems ofeach model. In this section we will describe thesesystems and point out their differences. We willdescribe the ignition system, the bleed air system,the engine fuel system, the reduction gear/enginelube oil system, and the air start system.

IGNITION SYSTEM

The ignition system is identical for the twotypes of GTGSs. The ignition system (fig. 3-16)has an ignition exciter, two high-tension leads, andtwo spark igniters. The system operates on + 28volts dc. However, proper operation can beobtained over a range of + 14 to + 28 volts dc( f o r M O D 1 3 9 , + 2 2 t o + 2 8 V d c ) .Power is supplied to the system through anelectronic speed switch actuated relay. Thisenergizes the system at 2200 rpm and de-energizesat 8400 rpm during the starting cycle.

Ignition Exciter

The ignition exciter is a sealed unit mountedon the right side of the compressor. It is a high-voltage, capacitor-discharge type of exciter. It iscapable of firing two spark igniters at the sametime.

Spark Igniters

The two spark igniters are mounted in theouter combustion case. One extends into the No.2 can and the other into the No. 5 can. The ignitersreceive the electrical output from the ignitionexciter. They discharge this electrical energyduring starting to ignite the fuel-air mixture in thecombustion cans. Two high-voltage leads connectthe spark igniters to the ignition exciter.

Figure 3-16.—Ignition system components.

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BLEED AIR SYSTEM

The bleed air system (fig. 3-17) on themodel 104 and model 139 are nearly identical.The major difference is found in the 14th-stagebleed air valve. A fast-acting 14th-stage bleedair valve is used on the model 139. Thisallows the engine to respond quickly to transientload conditions brought about by failure ofone of two GTGSs operated in parallel. ThisGTGS loss is partially compensated for bythe quick closing (in about 150 to 200 milli-seconds) of the 14th-stage bleed air valveon the surviving GTGS. The quick-closingfeature is controlled by the externally mountedturbine overtemperature protection system(TOPS). This system is not covered in thischapter.

The bleed air system consists of twoindependent systems—the 14th-stage system andthe 5th- and 10th-stage system. The 5th- and 10th-stage bleed air system unloads the compressorduring starts. This reduces the possibility ofcompressor surge during the starting cycle. The14th-stage bleed air system extracts air from thecompressor for the ship’s bleed air system.Airflow up to 2.37 lb/sec at 55 to 60 psig maybe extracted. This is about 8 percent ofcompressor airflow.

Fourteenth-Stage Bleed Air

Fourteenth-stage compressor discharge air isextracted from ports on the compressor diffuser.A manifold surrounds the diffuser to collect thedischarge air. This air is piped through a bleed

Figure 3-17.—Allison 501-K17 bleed air system.

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air control valve and into the ship’s bleed airsystem. The control valve receives signals fromthe LOCOP for operation. If the TIT reaches1870°F, the bleed air control valve will close tomaximize the amount of cooling air to the turbineand maintain the TIT in the range of 1850°F to1870°F. A manual switch, 14TH-STAGEBLEED, is located on the LOCOP. It allows youto enable the bleed air control circuit. When thisswitch is in the ON position, the bleed valve willopen at 12,780 rpm. It is then fully automatic withrespect to TIT. The 14th-stage bleed air valve willalso close when the engine speed drops below12,780 rpm.

The model 139 LOCOP bleed air selectorswitch also has a remote position. When theswitch is placed in remote, the control of the 14th-stage bleed air valve is transferred to a controlpanel in CCS.

Fifth- and Tenth-Stage Bleed Air

This system has eight pneumatically operatedbleed air valves, a speed-sensitive valve, a filter,and a three-way, solenoid-operated valve. Fourbleed air valves are mounted on each of the 5th-stage and the 10th-stage bleed manifolds. Thesevalves are piston-type valves, with 5th- and 10th-stage air pressure on the inboard side of the valve.Either atmospheric pressure or 14th-stage airpressure is routed to the outboard side.

The speed-sensitive valve is engine driven. Itis mounted on the left forward side of the AGB.The valve has three ports. One port receives 14th-stage air via a pipe from the diffuser. A secondport is piped to the outboard side of the 5th- and10th-stage bleed air valves. The third port isvented to the atmosphere. During operation atengine speeds below 12,780 rpm, a pilot valve inthe speed-sensitive valve blocks 14th-stage air.This allows the outboard side of the 5th- and 10th-stage bleed air valves to be vented to theatmosphere (through the third port on the speed-sensitive valve). Since 5th- and 10th-stage airpressure is greater than atmospheric pressure, thevalves open and vent air from the compressor. Atengine speeds above 12,780 rpm, the pilot valvecloses the vent port. This allows 14th-stage air tobe ported to the outboard side of the 5th- and10th-stage bleed air valves. Since 14th-stage airpressure is greater than 5th- and 10th-stage airpressure, the valves close and bleed air is stopped.

The filter is located in the 14th-stage air linefrom the diffuser to the speed-sensitive valve. Itprevents contaminants in the air from cloggingthe valve.

The solenoid valve is located in the linebetween the speed-sensitive valve and the bleedair valves. When activated, it routes ship’s serviceair to hold the 5th- and 10th-stage bleed air valvesclosed. It is used during a fire stop or while theengine is water washed.

ENGINE FUEL SYSTEM

The fuel system meters and distributes fuel tothe engine. This system is used to maintain aconstant generator rotor speed under varying loadconditions. Components of the fuel system areboth engine mounted and off-engine mounted.

The engine-mounted components on themodel 104 GTGS (fig. 3-18) include the followingparts: a dual-element fuel pump (1), an LP fuelfilter (2), an HP fuel filter (3), a pressure reliefvalve (4), a liquid fuel valve (LFV) (5), anelectrohydraulic (electric) governor (EG) actuator(6), a fuel shutoff valve (7), a manifold drain valve(8), fuel nozzles (9), and burner/combustor drainvalves (10).

Off-engine mounted components of the model104 are a temperature-biased compressor inlettemperature (CIT)/compressor discharge pressure(CDP) sensor (11), the governor control unit(GCU) (not shown), and a start temperature limitcontrol valve (12). The model 104 uses theWoodward 2301 governor control system.

The model 139 fuel system (fig. 3-19) is slightlydifferent from the model 104 fuel system. Bothmodels incorporate an engine-mounted fueldivider (1), two manifold drain valves (onemanifold drain valve on the model 104) (2), dual-entry fuel nozzles (3), and two fuel manifolds (4).Refer to your ship’s technical manuals for thesystem used on your ship.

The governor system on the model 139 is theWoodward 9900-302 governor control system. Forthis adaption the engine is fitted with an electricalCIT sensor, mounted in the air inlet housing, amagnetic speed pickup, and a LFV-mountedlinear variable displacement transformer (LVDT)(5).

Model 104 Fuel System Flow Path

The following paragraph describes the fuelflow path through the fuel system of the model104. Refer to figure 3-18 as we describe theoperation.

Fuel from a gravity feed tank enters theenclosure through an external emergency shutoffvalve and flows into the inlet of the fuel pump.

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It passes through the pump boost element,through the LP filter, and into the HP elements.From the pump’s HP elements, the fuel passesthrough the HP filter and into the LFV. Meteredfuel from the LFV passes through the fuel shutoffvalve. It then flows through the flow divider andinto the fuel manifolds and fuel nozzles. It isdischarged into the combustion chambers by thefuel nozzles. The fuel pump delivers more fuelthan is required. So the LFV bypasses the excessfuel back to the inlet side of the pump’s HPelements.

Model 139 Fuel System Flow Path

Fuel system operation of the model 139 issimilar to the model 104 (refer to fig. 3-19). Afterthe fuel shutoff valve, the fuel goes to the fueldivider. Some of the fuel goes directly to the pilotmanifold. At 150 psig, fuel is also diverted to themain fuel manifold. Two manifold drain valvesare also used to drain both manifolds at shut-down. Remember, some model 104 units havebeen modified to use this flow divider and dual-entry fuel nozzles.

Fuel Pump

To help you understand the following dis-cussion of the various fuel system components,

refer to figure 3-20 and the flow diagrams of themodel 104 and model 139 fuel systems. The fuelpump is an engine-driven, dual-element pump. Itis mounted on the aft right side of the AGB. Theboost element has an impeller-type centrifugalpump and bypass valve. The HP element has adual-element (primary and secondary) gear-typepump.

In operation, fuel enters the boost pump andthen flows externally through the LP filter. It thenreturns to the HP elements through passages inthe HP filter assembly. (It is not actually goingthrough the filter element at this point.) Thebypass valve (not shown) opens only if the boostpump fails. This allows fuel to flow directly tothe HP filters through the LP filter. Fuel normallyflows in series through the primary and secondaryelements of the two HP elements. However, thetwo HP elements. However, the two elements areplaced in parallel from about 2200 to 8400 rpmby a solenoid-operated paralleling valve. The valveis located in the fuel pump assembly. From theHP element of the pump, fuel flows throughinternal passages to the HP filter.

Low-Pressure Filter

The LP filter is a paper cartridge type. It islocated in the fuel line between the boost pump

Figure 3-20.—Fuel system components-bottom view of engine.

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outlet and the HP element inlet. Relief valves areincorporated in the filter head to bypass the fuelif the filter becomes clogged. The LP filter inletand outlet pressures are shown on the enginegauge panel.

High-Pressure Filter

The HP filter assembly is mounted on thebottom of the fuel pump. It has a filter, bypassvalve, two check valves, and a solenoid-operatedparalleling valve. The filter is a 33-micron disktype. It is removable for servicing. The bypassvalve opens to permit continuous flow if the filterbecomes clogged. If one HP gear element fails,the check valves permit engine operation from theother element.

Pressure Relief Valve

The pressure relief valve is closed duringnormal engine operation. If the pump dischargepressure reaches 500 ± 10 psig above the bypassline pressure, the relief valve opens. This permitsexcess fuel to return to the pump inlet.

Model 104 Liquid Fuel Valve

The LFV is mounted on the left, lower sideof the engine. It is mechanically and hydraulicallyconnected to the EG actuator. The hydraulicconnection is through the CIT/CDP sensor andthe start temperature limit control valve. The LFVhas a metering valve, an acceleration limiter, anda bypass valve. It meters the required fuel for allengine operating conditions. The EG actuatorlinkage and the acceleration limiter (internal partof the fuel valve) control the metering valveposition. This, in turn, allows control of the fuelflow.

The acceleration limiter schedules fuel flowduring start as a function of CIT and CDP.During start and rapid acceleration, the limiteroverrides the governor input. This preventscompressor surge (stall) and excessive TIT. Thelimiter linkage (internal) is actuated by servo oilpressure from the EG actuator. This is regulatedby the CIT/CDP sensor.

To accurately meter fuel flow, you have tomaintain a constant pressure drop across themetering valve. This is done when the bypass valveopens and returns excess fuel from the pumpoutlet to the pump inlet.

Model 139 Liquid Fuel Valve

Like the model 104, the model 139 LFV ismounted on the left side of the engine. It ismechanically connected to the EG actuator. It hasa fuel metering valve and a fuel valve position

sensor. It meters the required fuel for all engineoperating conditions.

The LFV is directly controlled by the governoractuator. During start and running of the engine,the LFV is positioned by the governor to limit theamount of fuel to the fuel nozzles. The governorcontrol circuit receives inputs of engine speed,CIT, fuel valve position, and TIT. The CDPpressure is provided to the LFV directly. Thecontrol circuit sets the LFV through the governoractuator. This provides the proper amount of fuelto the engine for all engine power and accelerationsettings.

The fuel valve position sensor is an LVDT.It is mechanically linked to the LFV meteringsleeve and senses fuel valve position. The linkagemoves the sleeve to the actuator. As it does this,the amount of excitation voltage at the LVDToutput is changed. The output of the LVDT isproportional to the position of the fuel meteringsleeve. A comparator compares inputs from theelectronic control unit (ECU) and the LVDT. Thisis done to correctly position the fuel valve.

Excess fuel from the pump is returned to thesecondary pump suction by the bypass valve. Likethe model 104 LFV, this is done to maintainconstant pressure at the metering valve.

Electrohydraulic Governor Actuator

The EG actuator is engine driven. It ismounted on the left side of the AGB. Its outputshaft is mechanically linked to the LFV. It receivessignals from the EG control box and positions theLFV. The LFV, in turn, meters fuel to the engine.The governor actuator incorporates normalcontrol by the EG system and backup control bya centrifugal governor. Each is independently ableto position the output shaft to maintain enginespeed.

An integral oil pump provides servo oilpressure for governor operation as well as otherfunctions. Engine lube oil pressure from the AGBis supplied to the actuator pump through anexternal line. During normal operation, an outputsignal from the EG control box produces a forceon an armature magnet. The magnet is attachedto a pilot valve plunger and moves the plungerup or down. The pilot valve plunger directs servooil pressure to change the position of the outputshaft. If the electrical signal to the governoractuator is interrupted, it may attempt tooverspeed the engine. If this happens, the pilotvalve plunger and terminal shaft will be positionedtoward the maximum fuel flow position. Whenthe engine speed exceeds a preset limit (about14,300 rpm), the centrifugal governor will assume

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control of the engine. Flyweights, opposed byspring force, position the pilot valve plunger asa function of engine speed. The pilot valve plungerdirects servo oil pressure to position the outputshaft. The centrifugal governor is set to regulateengine speed at 480 to 580 engine rpm above thenormal EG operating speed. It has been factoryadjusted between 14,300 to 14,400 rpm. Thisequals between 62 and 62.5 Hz generator output.

Compressor Inlet Temperature/Compressor Discharge Pressure Sensor

The CIT/CDP sensor (fig. 3-18, item 11)senses both CIT and CDP. It regulates servo oilfrom the EG to the acceleration limiter in the LFVin relation to CIT and CDP. The accelerationlimiter, in turn, schedules fuel flow as a functionof servo oil pressure. During the start cycle (above2200 rpm) and during rapid accelerations, theacceleration limiter overrides the input from theEG. This limits the maximum fuel flow andprevents compressor stall and/or excessive TIT.Below 2200 rpm, the regulated oil pressure fromthe CIT/CDP sensor is blocked by the starttemperature limit control valve. This assures theturbine starts on the minimum fuel flow atlightoff. The CIT/CDP sensor is mounted on theinlet air plenum. The temperature sensing elementprotrudes into the inlet airstream.

Fuel Shutoff Valve

The fuel shutoff valve is a normally closed,solenoid-operated valve. It is located in the linebetween the LFV and the fuel manifold. All fuelto the fuel nozzles must pass through this valve.During the start cycle, the valve is opened(energized) by the electronic speed switch circuitat 2200 rpm. The valve is closed (de-energized)by the control circuits to shut down the engine.

Models 104 and 139 Flow Divider,Fuel Manifold, and Fuel Nozzles

Fuel flow from the fuel shutoff valve isdirected to the manifolds by a flow divider. Thedivider has an internal pressure-actuated valve.During start-up, the flow divider allows fuel tobe supplied to only the pilot manifold. When fuelpressure reaches about 150 psig, the valve opens.This allows fuel to be supplied to the mainmanifold.

Two fuel manifolds, pilot and main, supplyfuel to the six fuel nozzles. Both manifolds areTeflon-lined hoses with braided steel armor. Eachmanifold is fitted with a solenoid-operated drainvalve at its low point. The pilot manifold receivesfuel from the flow divider during start-up and

normal operation. It distributes the fuel to thepilot connection on each of the nozzles. After fuelpressure to the flow divider reaches about 150psig, fuel is supplied to the main connection ofeach fuel nozzle. The six nozzles are positionedto extend into their respective combustion liners.Fuel from the pilot manifold flows through thecenter hole in the tip of each nozzle. This formsa spray pattern in the combustion liner. Mainmanifold fuel is supplied to the holes in theperiphery of the nozzle tip. From there it issprayed into the combustion liner and mixed withcompressor air for combustion.

Fuel Manifold Drain Valve

The fuel manifold drain valves are spring-loaded, normally closed, solenoid-operated valveslocated at the bottom of the manifold (figs. 3-18and 3-19). They drain fuel from the manifolds tothe waste oil drain tank during coastdown. Thevalves are open (energized) only during the2-minute period determined by the coastdowntimer. On the model 139 these valves arealso open any time the engine is below 2200rpm.

Start Limit Control Valve

The start limit control valve is a normallyopen, three-way, solenoid-operated valve. It islocated in the regulated servo oil supply linebetween the CIT/CDP sensor and the LFV (fig.3-18, item 12). Below 2200 rpm in the start cycle,the valve is energized. This blocks the regulatedoil supply and ports the oil from the accelerationlimiter (part of the liquid fuel valve) to drain. Thiscauses the fuel valve to remain against the mini-mum fuel flow stop until the engine reaches 2200rpm. Between 2,200 and 12,780 rpm, the valve isnormally de-energized (open). However, if TITexceeds 1500°F, the valve is intermittently energized/de-energized until temperature drops below 1500°F.Above 12,780 rpm, the valve is electrically lockedout of the system (de-energized).

LUBE OIL SYSTEM

The lube oil systems on the model 104 andmodel 139 are almost identical. The enginereceives synthetic lube oil (MIL-L-23699) from theGTGS reduction gear lube oil system.

The engine and reduction gear lube systemsshare a common supply tank, filter, and cooler.The supply tank is the reduction gear sump,while the filter is base mounted inside thereduction gear section of the enclosure. Theoil cooler is mounted remotely under the module.Please follow figure 3-21 to help you understand

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the following discussion on oil flow through thesystem.

The engine lube oil system is an LP, dry sumpsystem. It consists of a combination lube supplyand scavenge pump (1), an external scavengepump (2), a turbine scavenge pump (3), pressure-regulating valves (4), an oil filter and check valve(5), a filter bypass valve (6), and a scavengepressure relief valve (7).

In operation, oil from the reduction gear sump(supply tank) is picked up by the reduction gearlube oil pump. It then flows through the supplyfilter and the oil cooler. Oil from the coolersupplies both the reduction gear and engine lubeoil systems. Oil to the engine flows through apressure regulating valve and into the inlet of theengine supply pump. From the engine supplypump, the oil flows through a filter and checkvalve. It then flows through drilled and coredpassages and internal and external lines to areasof the engine needing lubrication.

Scavenge oil is collected by the scavengeelement of the main lube and scavenge pump, theexternal scavenge pump, and the turbine scavengepump. Oil from the turbine scavenge pump flowsthrough drilled passages and internal lines to theAGB. There it is picked up by the scavengeelement of the main pump. Flow from the externalscavenge pump joins the flow from the mainscavenge pump (through external lines) and isreturned to the reduction gear sump. Themagnetic drain plugs (not shown) are on thebottom of the AGB and the discharge of the mainscavenge pump. These collect any steel particlesin the oil.

Main Pressure and Scavenge OilPump

The main pressure (supply) and scavenge oilpump assembly is mounted on the front of theAGB. It has two gear-type pumps, one for thesupply system and one for the scavenge system.It also has a pressure-regulating valve. Oil ispumped by the pressure (supply) element of thepump to the following components: the com-pressor extension shaft bearing, the PTO shaftmid-bearing, the AGB, the four main bearings ofthe engine, and the EG actuator.

The scavenge element picks up scavenge oil inthe AGB. The oil is gravity drained from thecompressor extension shaft bearing and thecompressor front bearing. The scavenge elementreturns the scavenge oil, along with the oil fromother scavenge pumps, to the reduction gear

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sump. An indicating type of magnetic plug islocated in the scavenge side of the pump.

Oil Filter

An oil filter is mounted on the front of theAGB. It has a pleated-type element andincorporates a Teflon-seated, poppet-type checkvalve. This valve prevents oil from draining outof the engine when the engine is shut down. Abypass valve, located in the AGB front cover,opens at a specific pressure differential. Thisbypasses the filter if it becomes clogged.

External Scavenge Pump

The external scavenge pump is a three-gear,dual-element pump. It is mounted on the aft sideof the AGB. It scavenges the oil from thecompressor rear bearing sump and from theturbine forward bearing sump. The oil from thepump is combined with the scavenge oil from themain scavenge pump. It is then returned to thereduction gear sump.

Turbine Scavenge Pump

The turbine scavenge pump is a gear-typepump. It is mounted in the rear turbine bearingsupport assembly. A splined coupling drives thepump from the turbine-to-compressor tie bolt.The pump scavenges oil from the turbine rearbearing and returns it to the accessory drivehousing. It is covered by a thermal insulationblanket and the exhaust inner cone.

Vent System

The air inlet housing cavity and AGB arevented. This is through an external line from theAGB to a breather mounted on top of the air inlethousing. Air used to send the compressor rearbearing sump is vented through the two horizontalstruts of the compressor diffuser. The combustorinner casing is vented to atmosphere through twohorizontal struts in the turbine inlet casing. Thecombustion inner casing liner provides a passagefor venting along the shaft. This flows throughholes in the turbine coupling shaft. From thereit flows to and pressurizes the turbine rear bearinglabyrinth seal at the rear face of the turbinefourth-stage wheel, finally entering the exhaustgas stream.

AIR START SYSTEM

The engine air start system (fig. 3-22) has anair turbine starter, a starter exhaust system, andtwo independent air supply systems. Each systemhas its own control valve. Air from the LP starterair control valve enters the starter inlet througha 3-inch line. Air from the HP starter air controlvalve enters the inlet through a 1 1/2-inch line.Exhaust air from the starter is discharged througha 6-inch line into the engine module cooling airduct downstream of the fire damper.

Low-Pressure Air Start System

Air from the ship’s bleed air system enters thestarter LP air control valve. The control valve isa normally closed, solenoid-operated regulatingvalve. It regulates airflow to the starter at 45 psig.

High-Pressure Air Start System

Air from the HP air flasks enters the starterHP control valve. The control valve is a normally

closed, solenoid-operated regulating valve. Itregulates airflow to the starter to 450 ± 50psig. A bypass line with an orifice and a pilot valveprovides for smooth engagement of the starterteeth. An HP start signal will cause the pilot valveto open. This allows air to flow through the orificeto the starter at less than 50 psig to engage thestarter teeth. After about one-quarter second, thepilot valve will cause the air control valve to open.Full pressure is then applied to the starter forrotation. A manual needle bypass valve isprovided for manual HP starting.

Air Starter Motor

The Bendix air turbine starter is mountedon the generator side of the reduction gearhigh-speed input shaft. It is directly coupledto the engine through the reduction gear high-speed pinion and PTO shaft during the startcycle.

Figure 3-22.—GTGS air start system.

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GTGS REDUCTION GEAR ANDLUBE OIL SYSTEM

The reduction gears used to couple the engineto the generator on the four models of GTGSsare identical. The reduction gear is a single-reduction, single-helical gear type of speedreducer. The reduction ratio is 7.678 to 1. Thegear is an over-under, vertically offset, parallelshaft design. It uses a three-piece housing splithorizontally at the center lines of the high-speedshaft and the low-speed shaft. The gear elementsare supported in sleeve bearings. The starter ismounted on the gear case and drives the high-speed shaft. The oil pump is located on the engineside of the low-speed shaft. The reduction gearis coupled to the generator by a diaphragm-typeflexible coupling.

Refer to figure 3-21 to help you understandthe following discussion of the reduction gear’slube oil system. The lube oil system is a wet sump,force-feed system. The sump has a capacity of 60gallons. It is an integral part of the reduction gearassembly. It also serves as the supply tank for theGTE lube oil system. Oil from the sump is pickedup by the reduction gear supply pump (8). Thepump is rated at 40 gpm at 1800 rpm. From thepump, the oil passes through a 25-micron base-mounted filter (9) and through a remotelymounted oil cooler (10). It is then distributed tothe reduction gear, PTO assembly, and the engine.

Pressure at this point is regulated at 25 psig byexcess flow returning to the reduction gear sump.Oil to the engine and PTO assembly is regulatedto 15 psig.

Oil to the PTO assembly is directed by a nozzleonto the shaft coupling. It is then returned bygravity to the sump. The shaft mid-bearing islubricated by a spray nozzle on the front of thecompressor extension shaft housing. Oil to thereduction gear assembly, 30 gpm at 25 psig,lubricates the reduction gears and bearings. Itreturns by gravity to the sump.

POWER TAKE-OFF ASSEMBLY

The PTO assembly (fig. 3-23) has a PTOshaft, shaft adapter, tapered coupling, mid-bearing assembly, housing, and speed sensorpickup. The assembly transmits the torqueproduced by the engine to the reduction gear. Italso provides the means to measure the enginespeed using a magnetic pickup mounted on thehousing over the shaft exciter wheel teeth.

POWER TAKE-OFF SHAFT ANDADAPTER

The PTO shaft is a solid steel shaft. It is boltedto the shaft adapter at the forward end and splinedto the compressor extension shaft at the aft end.

Figure 3-23.—PTO assembly.

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Forty equally spaced teeth are machined on theflange at the forward end of the shaft. Theseprovide excitation for the speed sensor.

HOUSING

The housing encloses the shaft, supports theforward end of the engine, and contains the mid-bearing assembly. The housing also provides themounting for the speed sensor assembly and anoil nozzle that lubricates the splines of the taperedcoupling and shaft adapter. The mid-bearingassembly prevents the shaft from whipping.

ENGINE INSTRUMENTATION

Besides the instruments that measure pressureand temperature of the engine’s support systemsand enclosure, several sensors monitor the engineitself. These are the thermocouples, vibrationsensor, and magnetic speed pickup.

The thermocouples are wired in parallel toprovide an average TIT signal. This is amplifiedby the turbine speed temperature box in theLOCOP. This signal provides TIT indication andinput to engine emergency shutdown functions.The speed temperature box uses the magneticspeed pickup signal for speed sensing and controlduring start. An alarm and automatic shutdownare provided for overspeed or underspeed. Thespeed temp box also transmits a speed andtemperature signal for remote display of enginespeed and temperature on the DDIs.

THERMOCOUPLE

Eighteen dual-element, Chromel-Alumel ther-mocouple probes are mounted on the turbine inletcasing. The probes extend into the outlet of thecombustion liners at the turbine inlet. Each of theprobe elements is independent of the other,thereby providing two independent samplingcircuits. The thermocouple probe housing leadingedges are air cooled to prolong probe life. Toaccomplish this, cooling air enters the probe cavityleading edge through a hole below the probeshoulder. It flows through the probe and isdischarged through two small openings in thebottom of the probe.

A thermocouple harness assembly has a rightand a left section. It is enclosed in channels thatare rigidly mounted on the turbine inlet caseforward flange. The harness incorporates separateleads for each thermocouple probe. A terminal

block serves as the junction for two thermocoupleharnesses and the amplifier leads. It has eightterminal connections and four terminals for eachof the two harnesses.

VIBRATION TRANSDUCER

Engine vibration is measured by a displace-ment type of vibration transducer. It is mountedon the turbine rear bearing support at the 12o’clock position. It provides a signal to a meteron the LOCOP.

SPEED PICKUP

Engine speed is measured by a magneticpickup. This is mounted in the PTO shaft housingover the shaft exciter teeth. Passage of the exciterteeth under the magnetic pickup produceselectrical impulses. These impulses are used by thespeed temp box for speed sensing. This, in turn,is used for start sequencing, over- and underspeedprotection, and speed monitoring.

SPEED GOVERNING SYSTEM

The Allison 501-K17 is a constant speedengine. It is designed to maintain a speed (13,821engine rpm) that will output a steady 60 Hz fromthe generator. Dependable 60-Hz power isrequired to keep electronic equipment and motorsoperating properly. The Allison 501-K17 uses anEG to maintain this constant speed. Two differentelectronic control systems are used on the GTGSs.Most model 104 GTGSs use the Woodward 2301control system. The model 139 GTGS and somemodel 104 GTGSs use the Woodward 9900-302control system. Both model GTGSs use theWoodward EGB-2P electrohydraulic actuator.

Both systems normally operate on the EG. TheEG will maintain the frequency set by theoperator. Once the frequency is set and the loadis balanced between GTGSs in parallel, thegovernor system will maintain the set frequencyand load balance.

If failure of the EG control occurs, amechanical flyweight governor will regulate theengine speed. The mechanical governor is set ata slightly higher speed than the EG. It willmaintain a frequency of about 62 Hz. Thismechanical governor prevents overspeed of theengine during an EG failure. It is set by a screwadjustment on the EG.

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OPERATING MODES

The governor system of both the model 104and the model 139 have two basic operatingmodes, NORMAL (isochronous) and DROOP.

Isochronous Mode

This mode provides constant speed operation,regardless of load. When generators are operatedin parallel and in the isochronous mode, thegovernor system maintains a constant speed. Italso controls the load division between paralleledgenerators. The isochronous mode is selectedwhen the EPCC selector or the SWBD selectoris in the NORMAL position. The load sharingfunction is automatically enabled when agenerator operating in the NORMAL mode isparalleled with another generator.

Droop Mode

In this mode, the governor system stillregulates engine speed, but the speed will decreaseslightly with an increase in load. Sometimes thegenerator is paralleled with a constant frequencybus (such as shore power) while in the droopmode. In this case, the governor cannot controlspeed since it is held constant by the busfrequency. Instead, it will control the load carriedby the generator. In this way, the droop modeprovides load control of a generator paralleledwith shore power. It also can unload a generatorparalleled with another GTGS without disturbingsystem frequency. When the selector is in theDROOP position, droop mode is selected at theEPCC or the SWBD.

MODEL 104 GOVERNOR SYSTEM

The engine speed governor on the model 104GTGS is the Woodward 2301 electrohydrauliccontrol system. It has a backup centrifugalgovernor override. Three major componentswithin the system are a motor-operatedpotentiometer, an ECU, and an EG actuator. Themotor-operated potentiometer is located at theECU. The ECU is mounted in the GCU. Theprimary function of the GCU is to providegenerator field excitation and voltage control ineither the automatic or manual mode. The GCUis a solid-state electronic package. It processesinput commands and feedback signals to generatea signal to position the engine-mounted EGactuator. The actuator positions its output shaft

in response to the control signal. This shaftcontrols the engine’s LFV through a mechanicallinkage. If the engine speed increases to a presetlimit because of a failure in the electronic control,then the centrifugal governor section of theactuator will automatically assume control of theoutput shaft. Engine speed will then be controlledat a point slightly above the normal operatingspeed.

Motor-Operated Potentiometer

The operating point of the governor is set bythe motor-operated potentiometer. The individualfrequency adjust controls at the EPCC or theSWBD are used to adjust the potentiometer.These controls adjust the position of the motor-operated potentiometer to a higher or lowerposition. If generators are operated in parallelfrom the EPCC, with the system frequencycontrols enabled, the motor-operated potenti-ometer returns to a calibrated 60-Hz position. Youcan make adjustments by using the SYSTEMFREQUENCY ADJUST control at the EPCC.This control will position a master frequencytrimmer in the EPCC. It sends equal adjust signalsdirectly to each generator’s ECU. The frequencyof the bus can be changed without disturbing theload balance between operating units. Duringautomatic paralleling operations, the APD willadjust the oncoming generator for synchroniza-tion. This adjust signal is also a direct input intothe ECU. It is in effect only during automaticparalleling conditioning. Figure 3-24 is a governorinterface diagram.

Electronic Control Unit

The ECU of the Woodward 2301 governorsystem is modular in design. It is composed ofthe motor-operated potentiometer, the masterfrequency trimmer, the APD, an amplifier, thefuel control actuator, two power supplies, anaccessory box, two filters, and a load sensor. Thefollowing paragraphs describe the function ofthese subunits and are keyed to figure 3-25, afunctional diagram of the Woodward 2301governor.

The motor-operated potentiometer (1) suppliesa reference to the amplifier. When the electricplant operates in the manual, manual permissive,or droop mode, frequency adjust commands willcause the motor to rotate in the raise or lowerdirection. This changes the reference corre-spondingly. When operating in the automatic

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Figure 3-24.—Woodward 2301 governor interface diagram.

Figure 3-25.—Woodward 2301 governor functional diagram.

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mode, the motor automatically drives to andremains at 60 Hz. This position is established bythe motor’s limit switches. External adjustmentsto the governor system are done by additionalinputs to the amplifier. These inputs come fromeither the master frequency trimmer (2) or theAPD (3). The master frequency trimmer in theEPCC provides frequency control to any two orall three generators when operating in parallel oneither the model 104 or the model 139 GTGS. Youmay use the EPCC panel SYSTEM FREQRAISE/LOWER switch to demand a change offrequency for the paralleled units. This controlinputs 115 volts ac into a reversible motorizedpotentiometer assembly. The potentiometeroutput is a dc signal. Its amplitude is proportionalto the correction demanded in the generatoroutput frequency. The polarity dictates thedirection of change.

The summing amplifier (4) provides thecurrent to the fuel control actuator (5). Thiscurrent is varied in response to the inputs to theamplifier. This includes the reference, frequencyfeedback, and load sensing. Input changesbecause of load, speed, or reference cause theamplifier current to reposition the actuator outputshaft. This increases or decreases fuel flow.Amplifier current then stabilizes at a new settingthat satisfies all inputs. The amplifier is reverseacting. That is, the larger the input (error signal),the smaller the output current to the actuator. Theactuator output shaft is designed to work so adecrease in current causes it to drive the LFVtoward the maximum fuel position. If theamplifier fails and the current goes to zero, theactuator will be positioned in the maximum fuelposition. (The centrifugal governor assumescontrol if engine speed increases to the presetlimit.)

The PMA input to the control unit providesvoltage for the two power supplies (6) and afrequency feedback signal to the frequency sensor(7). One power supply feeds the amplifier; thesecond provides power for the motor-operatedpotentiometer. The frequency sensor converts thePMA output (8) (about 120 volts ac at 420 Hz)to a proportional dc voltage. This is used for thefrequency feedback input to the amplifier.

The load sensor module (9) controls loadsharing in parallel isochronous operation. It isused to generate the droop characteristics duringdroop operation. Power generated by thegenerator is measured by transformers. Theysupply voltage to a bridge circuit. For loadsharing, the bridges of each paralleled generator

are connected so an unbalance because of unevenloads causes an input to each governor amplifier.This forces proportional fuel adjustments untilthe loads are balanced between the two units. Thisalso balances the bridge circuits. The amplifierinput is again returned to algebraic zero volts dc.Sudden shifts in load demand cause pulses to bedeveloped in the load sensor. This upsets thealgebraic zero voltage of the governor amplifier.This results in quicker response to load changes.Polarity of the pulse is also sensed to determinethe direction of load changes.

During droop mode some of the load sensoroutput opposes the action of the amplifier speedreference. The input to the amplifier will bedecreased by an amount proportional to load,resulting in droop.

If the generator is not paralleled with anothersource, this droop will result in a decrease infrequency. The decrease is proportional to theincrease in load. If the generator is paralleled withan infinite bus (such as shore power), droopprovides load control. When paralleled with aninfinite bus, the speed of the engine is heldconstant by the bus. The governor system, in thissituation, cannot control speed. Any attempt toincrease or decrease speed will only result in anincrease or decrease in load. Without the droopcharacteristics, the governor system wouldattempt to adjust the frequency to satisfy thereference exactly causing the load to increasebeyond generator capacity or decrease until theflow of power reverses. The droop input,however, will modify the speed reference. Thegovernor will reach a stable operating point eventhough the frequency does not match the re-ference. This operating point is set by the speedreference and droop input (since frequency isconstant). It determines the load on the generator.Under this condition, the load on the generatorwill remain constant for any reference setting.

Electrohydraulic Governor Actuator

The EG actuator is engine driven and ismounted on the left side of the AGB. Theactuators output shaft is mechanically linked tothe LFV. The actuator receives signals from theGCU and positions the LFV, which, in turn,meters fuel flow to the engine. The actuatorincorporates normal (electronic) control by theGCU and backup (mechanical) control by acentrifugal governor. Both systems are indepen-dently capable of positioning the actuator outputshaft.

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The mechanical centrifugal governor systembacks up the ECU of the Woodward governorsystem. The centrifugal governor speeder springdevice takes over control if the ECU fails and theengine speed increases due to the actuatorpositioning itself for full-speed failure mode. Itis set for about 62 Hz (depending on load) or theequivalent speed of about 14,300 rpm. This is 480rpm above the 60-Hz speed of 13,821 rpm. Thecentrifugal governor is part of the EG actuatorassembly.

MODEL 139 GOVERNOR SYSTEM

The engine speed governor on the model 139GTGS is the Woodward 9900-302 electrohydrauliccontrol system. It also uses a backup centrifugalgovernor override. There are eight componentswithin the system. These components are shownon figure 3-26, an interface diagram of theWoodward 9900-302 governor. They are anelectronic fuel control (1), an LFV with an LVDT(2), an EGB-2P actuator (3), an Allison speed andtemperature module (4), a CIT sensor (5), amagnetic speed pickup (6), a speed phase

matching (SPM) synchronizer (7), and a masterfrequency trimmer (8). Following is a list of theseeight components and a brief description of theirfunctions. The items are keyed to figure 3-26.

1. The electronic fuel control regulates fuelduring turbine lightoff, acceleration, and60-Hz power generation. It monitors speed,TIT, and liquid fuel valve position.

2. The LFV with the LVDT meters the fuelto the engine.

3. The EGB-2P actuator positions the LFVfeeding the valve position back to the fuelcontrol through the LVDT.

4. The Allison speed and temperature module

5.

6.

monitors the TIT and engine speed. Itsupplies signals to the electronic fuelcontrol. This is for the start fuel scheduleand for maximum temperature control.The CIT sensor monitors the ambient airtemperature. It applies the signal to thespeed correction and accelerationtemperature reference circuits.The magnetic pickup senses turbinespeed as an ac pulse signal with a

Figure 3-26.—Woodward 9900-302 governor interface diagram.

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frequency proportional to the speed of theturbine.

7. The SPM synchronizer compares the phaseof the generator with that of the bus. If anerror is sensed, a signal is applied to thefuel control unit. Then the generator phaseangle will be brought in phase with the bus.

8. The master frequency trimmer is used whenthe turbine is in load sharing. It changespower system frequency without changingthe load division between engines.

Governor Control Unit

The GCU supplies field excitation to itsassociated GTGS. Except for the remotelymounted selector switches, the GCU componentsare mounted in the GCU cabinet. Each cabinetcontains the redundant voltage regulator systemswith associated relays, transformers, motor-operated potentiometers, selector switchindicating lights, a reset button, and the governorcontrol assembly.

Electronic Fuel Control Unit

The electronic fuel control unit is a modular’solid-state electronic package. The nine majormodules are the load sensor, isolation, speedreference, speed channel, power supply, fuellimiter, temperature channel, final driver, andmotherboard modules. These modules are foundin the governor box in the GCU. Figure 3-27 isa functional diagram of the governor controlsystem. It shows the three major control functionsseparated by broken lines. These functions arespeed control, temperature control, and fuelmetering.

The following paragraphs describe theoperation of the electronic fuel control to theboard level. The module titles are descriptive oftheir major function.

LOAD SENSOR MODULE.—This moduleuses inputs from the generator voltage and CTs.Each phase is monitored for current and voltageby potential transformers and CTs to determinethe actual load. Each CT develops a voltage acrossa burden resistor, proportional to generatorcurrent. The signal representing the load on thethree phases is summed in the load sensor.

The current in all three phases is corrected forpower factor and summed in the load sensormodule. This provides a signal proportional to theload on the bus. A load gain potentiometer is

located within the load sensor. It determines thepercentage of the load that this generator handlesin a load sharing situation with other generators.

The droop potentiometer within the loadsensor determines the percentage of speed change.This is used when the turbine generator isoperating in droop mode. The effect of operatingin droop mode is a decrease in speed setting foran increase in load. A portion of the load gainvoltage is applied to the speed channel as a droopsignal.

When the turbine is in isochronous mode, theload pulse amplifier provides a speed errorcorrection signal in advance of the normal speederror signal. This improves the short-termtransient response of the controller. The outputof the load pulse amplifier is applied to the speedcontrol summing point in droop mode. It isapplied to the load matching circuit in isochronousmode.

In the load sharing mode, a bridge within theload matching circuit is connected in parallel withthe bridges in other controls. When the load onthe generator varies, an error signal is generatedby the load matching circuit. This adjusts the loadcarried by the generator. An LED indicator showsthe selection of isochronous or load sharingmodes.

ISOLATION MODULE.—The isolationmodule provides buffering of the governor masterfrequency trimmer and governor SPM syn-chronizer signals. Also, the discrete logic signalsfor the overspeed test, reset to 60 Hz, raise, lower,isochronous, and load sharing control arebuffered through isolators on this module.

SPEED REFERENCE MODULE.—Thespeed reference module generates the dc referencesignal used by the speed control module. Thereference values are selected by inputs from theSWBD or the EPCC. When the command is madeto change frequency, a digital counter within thespeed reference starts to count. It counts in anincreasing or decreasing direction toward the newreference level. The counting process continuesas long as the input command to change frequencyis present. It continues until the new referencelevel is reached. The output of the counter isapplied to a DAC. The converter changes thedigital output of the counter to the output analogspeed reference voltage. The speed referencemodule indicators show when it is at the reset,lower, or upper limits. They also show when theyare moving.

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SPEED CHANNEL MODULE.—The speedchannel module maintains turbine speed at thevalue selected by the operator. A magnetic pickupunit (MPU) provides an ac signal that isproportional to turbine speed. The frequencysensor circuits convert the MPU signal to aproportional dc turbine speed signal. The speedcontrol compares the actual turbine speed signalwith the reference signal. The speed controlamplifiers then generate a voltage signal tomaintain or correct turbine speed. The speedcontrol loop has the following inputs:

Master frequency trimmer

Synchronizer

Frequency sensor

Speed reference signal

Load sensor

These speed error signals are input to thesumming point. The stability amplifier applies thesummed signal to the speed control gain amplifier.

The control amplifiers provide proper tran-sient response of the turbine. The stabilityamplifiers control the time required to recoverfrom a transient. The gain amplifiers control theamplitude of the transient. Correct adjustment isachieved when the time and off speed are bothminimized without turbine instability.

The output for the speed control circuit isapplied to the low-signal select (LSS) bus. TheLSS bus has diode inputs from the speed, tem-perature, LSS bus maximum limit clamp, and thefuel filter control amplifiers. The bus allows thelowest signal input to dominate the bus. Theoutput of the LSS bus is applied to the input ofthe high-signal select (HSS) bus. A speed controlfeedback signal is used so the control amplifiercan anticipate control of the LSS bus. Thisprovides for smooth transition between controlchannels without excessive overshoot.

POWER SUPPLY MODULE.—The powersupply module provides isolated dc power for thecontrol circuits. The power supply converts +28volts dc to +12 volts dc and +R and –R precisionreference voltages for use by the control circuits.The +12 volt dc and -12 volt dc voltages powerthe control electronics. The +R and –R voltagesare reference voltages where precise voltages arerequired. The dc voltages are distributed to the

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modules by the motherboard . Dur ingmaintenance on the governor system, a jumperwire must be used between two designated testpoints. This enables the LEDs on the circuit cardsto illuminate.

FUEL LIMITER MODULE.—The fuellimiter module contains the circuits requiredduring turbine start and acceleration. The startfuel schedule circuit controls the fuel flow to theturbine during start. It monitors three signals fromthe turbine—first TIT, second CIT, and third N1(speed voltage). The combination of the CIT andN1 inputs produces corrected speed. Correctedspeed is the voltage from the speed frequencysensor corrected by the CIT temperature. Speedcorrection results in increased fuel as CITdecreases. Start fuel is decreased as a function ofTIT.

The output from the start fuel schedule isapplied to the HSS bus. The HSS bus is acomparator circuit. It allows the highest signalapplied to the bus to pass. The other input to theHSS bus is the fuel limiter circuit. The fuel limiterlimits the maximum amount of fuel to the turbineas a function of speed. At rated or isochronousspeed, fuel is limited by the mechanical stop onthe fuel valve. When turbine speed is in the low-speed range, the fuel limiter signal is less than thestart fuel schedule. So the fuel limiter signal is notselected by the HSS bus. The output from the HSSbus is applied to the fuel limiter amplifier. Thisamplifier then drives the LSS bus when its voltageis less than the speed or temperature controlinputs. The fuel limit mode LED illuminates whenthe fuel limiter module is controlling fuel.

The fuel limiter module has a decelerationlimiter circuit. The deceleration limiter controlsthe minimum fuel flow to the turbine. If fuel isdecreased too rapidly, a flameout will occur.During a start, the output of the LSS bus is high-signal selected. It has a fixed voltage when theengine speed is below 8400 rpm. This voltagelimiter prevents the fuel valve from reaching theminimum fuel flow stop during start.

The acceleration temperature reference voltageincreases as the turbine speed increases duringacceleration. A CIT bias sets the reference loweras the ambient temperature decreases. An8400-rpm speed switch and a start/run latch areused to select the temperature channel operatingreference. Below 8400 rpm, the latch is set to thestart mode. This selects the accelerationtemperature reference and start TIT LED. Whenthe speed switch is above 8400 rpm and speed

control has been achieved, the start/run latch isset to run. The run indicator LED lights up.

TEMPERATURE CHANNEL MODULE.—The temperature channel prevents turbinetemperature from exceeding safe operating limits.A signal proportional to TIT is compared withthe start or run temperature reference. Theamplifier generates a voltage signal output to theLSS bus to limit TIT.

The temperature control amplifiers operatesimilar to the speed control amplifiers. Separatestart and run LEDs are provided. Theycompensate for the longer thermocouple reactiontime at low turbine speeds. This lag is due to lowairflow at low speeds.

A start fuel schedule supplies enough fuel forTIT to reach the acceleration temperature range.When the turbine reaches the acceleration range,the temperature control requires less fuel than thefuel limiter. The LSS bus then selects thetemperature control for the rest of turbineacceleration.

When the turbine reaches isochronous or ratedspeed (60 Hz), the speed control takes controlfrom TIT control. Then the start/run referenceswitches to run limit. TIT is a function of loadon the turbine. If load is increased until TITequals the TIT reference, the temperature controlwill maintain TIT at that level. In droop modeor when paralleled with other units, the generatorload will be maintained at a level to produce theset TIT. When no other source is available to carrythe excess load, the temperature control willreduce speed.

FINAL DRIVER MODULE.—The finaldriver module generates current to position theactuator as required by the controlling channel.An oscillator generates an excitation voltage forthe LVDT located on the LFV. As mentionedbefore, the LVDT is mechanically linked to thefuel valve metering sleeve, It senses the fuel valveposition. This sleeve is moved through the actionof the actuator. As it moves, the excitation voltagetransmitted to the LVDT output is changed. Theoutput of the LVDT is proportional to theposition of the fuel metering sleeve. A de-modulator in the final driver changes the LVDTfeedback signal to a dc voltage. This voltage isproportional to the sleeve position on the fuelvalve. The final driver amplifier compares theinput from the control circuits with the LVDTvoltage. Then it correctly positions the fuel valve.The final driver and actuator are reverse acting.

The less current supplied to the actuator, thegreater the fuel supplied to the turbine.

MOTHERBOARD MODULE.—The mother-board’s primary function is to interconnect theeight daughter boards with each other and the J1,J2, and J3 receptacles. The motherboard also hasthe power drive transistor for the actuator. Thistransistor is mounted on a heat sink that isconnected to the chassis.

ALTERNATING CURRENTGENERATOR AND VOLTAGE

REGULATOR

As stated earlier in this chapter, two differentac generators are powered by the Allison 501-K17engine. The model 104 GTGS is a 2000-kW,3200-amp unit, while the model 139 GTGS is a2500-kW, 4000-amp unit. Each generator outputs450-volt, 60-Hz, 3-phase ac at a 0.8 power factorwith an 1800 rpm input. Each unit is a totallyenclosed, salient-pole, two-bearing generator.Each unit has an air cooler mounted above it tocool the generator. An independent lube oilsystem using 2190 TEP lube oil provideslubrication for the generator bearings.

GENERATOR ASSEMBLY

The model 104 and the model 139 generatorassemblies both have eight major components.However, only seven of these components areidentical on both generators. The identicalcomponents are as follows:

The stator assembly of four-pole, four-circuit delta connection

The rotor assembly with four salientpoles

The front and rear end bracket assemblies

The front and rear bearing assemblies

The permanent magnet alternator (PMA)and lube oil pump assembly

The air cooler assembly

The stator terminal/connection box.

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The unique components of each generator area slip ring and brush assembly on the model 104and a brushless exciter assembly on the model 139.This is because the model 104 is a brush-typegenerator and the model 139 is a brushless-typegenerator

Generator Lube Oil System

The generator lube oil system (fig. 3-28) isindependent of the gas turbine/reduction gearlube oil system. The generator lube oil system uses2190 TEP mineral oil. It force-feeds the twobearings with a flow of 3 gpm at 12 to 15 psigpressure. Oil is taken from the sump tank in theGTGS base by a pump mounted on the PMAshaft. The oil is passed through a 25-micron filterand the base-mounted cooler before reaching thesleeve bearings. Gravity flow through sight flowindicators return the oil to the sump.

The model 104 generator lube oil system mustbe manually prelubed only if the GTE hasremained idle for 5 days or more. On the model139 an installed prelube pump is provided for theinitial lubrication to the generator upon each start-up.

Generator Space Heater

Electric heater elements are mounted at thebottom of the generator. They prevent thecondensation of moisture when the generator issecured or on standby. Four 120-volt, 250-watt,tubular, finned heaters are mounted crosswiseunder the stator. They are spaced to distributeheat along the length of the stator. A heatercontrol switch with an indicator lamp is mountedon the control section of the SWBD. An interlockon the generator circuit breaker automaticallydisconnects the space heaters when the breakeris closed.

Figure 3-28.—Generator lube oil system.

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Generator Temperature Monitoring

Nine copper RTDs are embedded in thegenerator stator winding slots. The three-wire leadof each RTD is brought to an internal terminalboard. A rotary selector switch and a temperatureindicator are mounted on the LOCOP formonitoring six stator winding temperatures. Thethree remaining RTDs serve as spares.

A tip-sensitive RTD is embedded in the babbittof each generator bearing. A terminal assembly,connector, and straight plug are provided for eachRTD. A rotary selector switch and temperatureindicator, mounted on the LOCOP, selects andmonitors the two bearing temperatures. Bothstator and generator bearing RTD outputs are

signal conditioned at the LOCOP. They aretransmitted to the ECSS for monitoring.

VOLTAGE REGULATION

The model 104 and the model 139 use differentvoltage regulators. The major components of thevoltage regulators are mounted in the generatoror in the GCU. The GCU is mounted in the samearea as the SWBD.

Model 104 Voltage Regulation

The following four items are the majorcomponents of the model 104 voltage regulator(fig. 3-29):

1. Static exciter/voltage regulator assemblydeck mounted near the associated SWBD

Figure 3-29.—Model 104 voltage regulator functional diagram.

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2. Field rectifier assembly mounted in thegenerator enclosure air path

3. Motor-driven rheostat mounted on theassociated SWBD for manual voltagecontrol

4. Mode select rotary switch mounted on theassociated SWBD

The GCU provides generator field excitationat 100 amperes at 150 volts dc at full load. Voltagecontrol is in automatic or manual modes.

GENERATOR FIELD EXCITATION.—Excitation power for the generator field issupplied by the generator output. It is controlledby a 3-phase magnetic amplifier. Different valuesof dc flowing in a control winding providedifferent levels of saturation in the magneticamplifier. This controls the output of the magneticamplifier to the generator field.

Another source of field excitation comes fromthree CTs. This is rectified by a 3-phase, full-wavebridge in the field rectifier assembly. Since thesource of field excitation for the magneticamplifier comes from the generator output, ashort circuit on the system will cause the voltageto collapse. This results in a loss of excitationvoltage. The excitation source from the CTs cansupply enough excitation to the generator fieldunder short circuit conditions to keep thegenerator output at a minimum 320 percent ofrated current. In this way the overcurrent devicescan sense the short circuit. They can trip thegenerator breaker to clear the fault.

On initial start-up of the generator, themagnetic amplifier has little or no excitationvoltage. To assure that the generator voltage willbuild up, another source of excitation must beused. Excitation is supplied by the PMA on thegenerator shaft extension. It is rectified througha 3-phase, full-wave bridge. The output voltageof this excitation source is less than the normaloutput of the magnetic amplifier at 450-voltgenerator output. It is automatically removed bya blocking diode once the magnetic amplifieroutput takes over. This function is called fieldflashing.

Under manual operation (fig. 3-30, view A),the source of control current for the magnetic

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amplifier is an internal power supply. You canadjust the control current from the SWBD by theMANUAL MODE VOLT ADJ knob or theGEN VOLTAGE RAISE-LOWER switch (withthe VOLT REG MODE switch in the MANposition). With the EPCC in manual control,the control current may also be varied throughthe VOLT LOWER-OFF-RAISE switch at theEPCC.

In automatic operation (fig. 3-30, view B), thevoltage regulator output supplies control currentto the magnetic amplifier fields. An internalmotor-driven rheostat sets the required voltage.Control for this motor is from the SWBD for localoperation and from the EPCC for remoteoperation.

VOLTAGE REGULATOR.—The voltageregulator in auto operation compares generatorvoltage with a reference voltage to provide anerror signal (fig. 3-30, view B). This error signalis amplified and applied to the magnetic amplifiercontrol winding. This changes the output of themagnetic amplifier. This, in turn, provides fieldcurrent to set the output voltage of the generator.The reference voltage is adjustable through themotor-driven rheostat in the static exciter/voltageregulator assembly.

A line current signal is brought in fromthe three paralleling CTs to the field forcingrectifier. This provides two functions in automaticmode.

1. When an individual generator is on line,this current signal acts to compensate for loadchanges. When load increases, this signal will callfor an increase in excitation. This relieves thevoltage regulator of having to make the entirecorrection with its error signal. This loadcompensation increases the accuracy of voltageregulation.

2. When two generators are operating inparallel, their voltages are equal. Therefore, anyadjustments in the excitation of individualmachines can only change the power factor ofboth machines. This creates circulating reactivecurrents between machines. In this case, thecurrent signal brought in from the paralleling CTwill help regulate the division of reactive linecurrent. This reduces circulating current betweenmachines.

Figure 3-30.—Model 104 voltage regulation. A. Manual mode. B. Automatic mode.

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Model 139 Voltage Regulation

The major components of the model 139voltage regulator (fig. 3-31) consist of thefollowing:

1. Two voltage regulator assemblies (normaland standby), mounted in the GCUenclosure

2. Motor-operated rheostat for auto voltageregulation, mounted in the GCU enclosure

3. Brushless exciter assembly, mounted on thegenerator

4. Permanent magnet alternator (PMA),mounted on the generator

5. Auto voltage control RAISE/LOWERswitch, mounted in associated SWBD

6. Motor-driven variac for manual voltageadjustment, mounted in the associatedSWBD

7. Mode select

The GCU provides brushless exciter fieldexcitation and voltage control in the automaticcontrol modes.

Figure 3-31 .—Model 139 voltage regulator functional diagram.

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GENERATOR FIELD EXCITATION.—Main generator field excitation is supplied by abrushless exciter assembly. The brushless exciterassembly has three main parts: stator, rotor, andrectifier assembly. The rotor and rectifierassembly are attached to the generator shaft. Theyturn inside the stator that is attached to thegenerator frame. The operation of the exciter issimilar to that of any ac generator. The exceptionis that the rotor and stator functions have beenreversed. When dc is passed through the exciterfield winding, lines of magnetic flux are createdthat pass through the air gap. This creates a3-phase ac output from the rotor. This 3-phaseac is rectified to dc by the rectifier assembly. Itis then conducted through the generator field. Anadvantage of using this brushless exciter over thebrush slip ring type of generator is the greatlyreduced maintenance.

VOLTAGE REGULATOR.—Two solid-statevoltage regulators (normal and standby) controlthe exciter field in normal automatic operation(fig. 3-32). Indicator lights on the face of the GCUdepict which regulator is in use. Overvoltage relays

are provided to automatically switch regulatorsif a regulator fails. This prevents an overvoltagecondition. An indicating light on the face of theGCU will illuminate when a regulator fails. ARESET push button is provided on the face ofthe GCU. When depressed, it will return controlto the (normal) regulator. It also extinguishes theregulator failed light. Manual or automaticcontrol may be selected at the SWBD by theVOLT REG MODE-OFF/AUTO/MANUALcontrol. The regulators receive their power fromthe generator output through potentialtransformers. Thus, on initial start-up of thegenerator in automatic mode, the voltageregulator will have little or no excitation voltage.To assure that the generator voltage will build up,excitation is obtained from the PMA. A relayinternal to the regulator will divert power fromthe PMA to the generator field until voltage hasrisen about 340 volts (75 percent of rated). Then,the relay will switch excitation control over to theregulator.

The source of regulator power is the generatoroutput. Therefore, a short circuit on the systemwill cause the voltage to collapse. This results in

Figure 3-32.—Model 139 voltage regulator.

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a loss of excitation voltage. If a short circuitoccurs, a relay internal to the regulator willtransfer excitation from the regulator to the PMA.This is done if the voltage drops below 225 volts.This will allow the generator to supply enoughcurrent to activate overcurrent devices. It will alsotrip the generator breaker to clear the fault.

In manual operation, the generator excitationis controlled by the motor-operated variacmounted in the SWBD. Power is received fromthe PMA. It is scaled by the variac, then rectifiedand conducted to the exciter field. You can makeadjustments at the SWBD by turning the manualmode volt adjuster knob (with the VOLT REGMODE switch in the MAN position). When in themanual mode, you may make voltage adjustmentsfrom the EPCC. Operation of the voltageLOWER/RAISE control on the EPCC activatesthe motor-operated variac. In the manual mode,generator voltage will decrease with load unlessfield excitation is increased. Thus when operatingin the manual mode, observe generator operationcarefully.

In automatic operation (fig. 3-32), the voltageregulator output supplies control current to theexciter fields. The GCU internal motor-drivenrheostat sets the required voltage. Control of thismotor is from the SWBD voltage raise/lowercontrol for local operation and the EPCC forremote operation. When in automatic, theMASTER VOLTAGE ADJ located on the EPCCwill also operate the motor-operated rheostat inthe GCU. It changes the reference for the voltageregulator. This command will be parallel to theGCUs. It will raise or lower the reference to allregulators.

A line current signal is brought in from theparalleling CT. It provides two functions inautomatic mode.

1. When two generators are operating inparallel, their voltages are equal.Therefore, any adjustments in theexcitation of individual machines can onlychange the power factor of both machines.This creates circulating reactive currentsbetween machines. In this case, the currentsignal brought in from the paralleling CTwill help regulate the division of reactiveline current. This reduces circulatingcurrent between machines.

2. When two generators are operating inparallel and in droop mode, the reactivecurrent signal will produce a fixed droopin the voltage output of a generator. If an

individual generator takes on an increasedshare of reactive current, its voltage willdroop more. This, in turn, will tend totransfer some of that reactive current to theother machine. If both machines haveequal voltage droop, they will tend to sharereactive currents at various loads. Thevoltage droop is not self-regulating.

LOCAL OPERATING CONTROLPANEL

The LOCOP is the major operator interfacewith the GTGS. It has the controls and indicatorsnecessary to start, stop, motor, and monitor theGTGS operation. The LOCOP is also theinterface with the ECSS which provides controlof each GTGS at the EPCC. Many of theindicators available at the GTGS LOCOP are notavailable at the EPCC. This feature requirespersonnel to monitor the LOCOP during GTGSoperation. Usually this monitor is a junior GS.For this reason, you should know and becomevery familiar with the material in this section.

Two LOCOPs are used to control the twodifferent GTGS models. Their construction is verydifferent. They are made by two differentmanufacturers. Even though they are verydifferent, they provide the engine and the operatoralmost identical signals and data. Their maindifference lies in the method in which their dataand signals are provided.

MODEL 104 LOCOP

The model 104 LOCOP (fig. 3-33, view A) iscontained in a cabinet mounted on the generatorend of the module. On the outside of the cabinetdoors are the controls and indicators for localGTGS operation. Inside the cabinet are theelectronic components of the system (view B).Among these components are the logic cards (orPCBs), the 28-volt dc power line filter, powersupplies, relays, fuses, and the temperature andspeed control unit. Both 115 volts ac and 28 voltsdc are required for the operation of the equip-ment. The 115-volt ac circuits are protected bythe F1 and F2 fuses. The control elements of thesystem are powered by 28 volts dc from theSWBD. The 28-volt dc electronic circuits aresupplied through a power line filter, the F3 fuse,and the dc power switch. The ignition exciter issupplied through the F4 fuse and the contacts ofa relay operated from the logic circuits.

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Figure 3-33.—Model 104 LOCOP. A. External view. B. Internal view.

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The SWBD 28-volt dc supply uses a bank of15 amp-hr lead-acid batteries for backup. Thisbattery bank allows starting of a GTGS when theship is without 450-volt ac power.

The model 104 LOCOP electronics alsoinclude the turbine start/stop sequencing and theturbine temperature and speed control, which isenclosed in its own box.

Turbine Start/Stop Sequencing

The turbine start/stop sequencing has sevenlogic card assemblies. Each logic card assemblyperforms a specific function. The functions ofthese logic cards are as follows:

Relay or solenoid drivers energize relaysor solenoids in response to a signal froma logic unit. They are used because therelay and solenoid coils require morecurrent than can be supplied directly froma logic unit.

Contact buffers minimize the effect ofcontact bounce (due to the operation of apush button or relay contacts) on a logicinput.

The RTD signal conditioners convertgenerator stator, air, lube oil, and bearingtemperature to signals for local and remotemonitoring.

The RTD temperature/pressure signalconditioner converts engine enclosuretemperature and lube oil header pressureto signals for local and remote monitoring.

A set point card (1850°F to 1870°F)converts the TIT signal from the speedtemperature control unit for control of the14th stage bleed air valve.

The vibration signal conditioner is a specialcard. It is used to convert the signal froma vibration pickup unit to a signal for localand remote monitoring and alarm whenvibration of the turbine occurs.

The remaining cards are logic cards forcontrol, alarm, and alarm control.

Turbine Temperature and SpeedControl Box

The turbine temperature and speed controlbox (fig. 3-33, view B) is a combination electronicspeed switch and temperature amplifier. The boxreceives a speed signal from a magnetic pickupon the PTO shaft and a temperature signal fromthe turbine inlet thermocouples. These signalsposition control relays in four speed channels andfive temperature channels within the box. Theyalso provide signals for local and remotemonitoring of speed and TIT. In combinationwith logic circuitry described in the last section,the four speed channels and five temperaturechannels provide the functions as described in thefollowing paragraphs.

2200 RPM SPEED CHANNEL.—Energizes(opens) the fuel shutdown valve and opens the fuelenrichment valve if fuel enrichment has beenselected. The fuel enrichment valve will be closedagain when the fuel manifold pressure reaches 50psig. The 2200 rpm speed channel also providesthese functions:

Energizes the ignition system.

Closes the fuel manifold drain valve.

Energizes the fuel pump paralleling valvesolenoid (closed) to place the fuel pumpHP primary and secondary elements inparallel operation.

Positions the start limit control valve toprovide normal acceleration fuel flow.However, the valve circuit remains armed,permitting the valve position to be con-trolled by the 1500°F temperature channel.

Arms the fail-to-fire circuit, providing anautomatic shutdown through the 600°Ftemperature channel if 600°F TIT is notreached within 10 seconds.

8400 RPM SPEED CHANNEL.—Providesthe following functions:

Positions the paralleling valve to place thefuel pump in series operation.

De-energizes the ignition system.

Provides starter cutoff.

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12,780 RPM SPEED CHANNEL—Providesthe following functions:

Inhibits the start temperature limit valvecontrol circuit to permit TIT to increaseabove 1525°F.

Inhibits the start overtemperatureshutdown circuit to permit TIT to increaseabove 1600°F.

Arms the engine underspeed alarm circuitto enable an alarm to sound if the speeddrops below 12,780 rpm after being at12,780 rpm for more than 2 seconds.

15,800 RPM SPEED CHANNEL—Providesengine overspeed protection. If engine speedexceeds 15,800 rpm, an automatic shutdown isinitiated.

600°F TEMPERATURE CHANNEL—Provides automatic shutdown if 600°F TIT is notreached within 10 seconds after reaching 2200rpm. It also de-activates the fail-to-fire circuitwhen 600°F TIT is obtained.

1500°F TEMPERATURE CHANNEL—Activates the start temperature limit valve controlcircuit if 1500°F TIT is reached before the turbinereaches 12,780 rpm. The circuit intermittentlyenergizes the start temperature limit control valvesolenoid through a pulse timer. This reducesacceleration fuel flow, and thereby reduces TITbelow 1500°F.

1600°F TEMPERATURE CHANNEL—Initiates an automatic shutdown if 1600°F TITis reached below 12,780 rpm.

1880°F TEMPERATURE CHANNEL—Causes an alarm to sound if 1880°F TIT isreached.

1945°F TEMPERATURE CHANNEL—Starts an automatic shutdown if 1945°F TIT isreached above 12,780 rpm.

MODEL 139 GTGS LOCOP

The model 139 LOCOP provides start/stopsequencing for the GTGS, monitoring and alarmsfor critical turbine and generator parameters,signal conditioning for panel meters, andtransmission of selected data to the ECSS.

The LOCOP (fig. 3-34, view A) is a cabinetmounted on the generator end of the module. Onthe outside of the cabinet doors are the controlsand indicators for local GTGS operation. Insidethe cabinet (view B) are the electronic componentsof the system. Among these components areprinted circuit cards, voltage regulators, a ± 12volt dc converter module, a relay assembly, anda temperature and speed control unit. The controlelements of the system are powered by 28 voltsdc from the SWBD. The SWBD 28-volt dc supplyhas a bank of 15 amp-hr lead-calcium batteriesfor backup. This battery bank allows starting ofa GTGS when the ship is without 450-volt acpower.

The model 139 LOCOP is a computercontrolled digital system. It uses a centralmicroprocessor to control and monitor the GTGS.The LOCOP has the necessary power supplies topower all logic and switching level voltages.

The LOCOP system power supply printedcircuit card and associated heat sink are mountedon the left side of the LOCOP cabinet. The powersupply has the following components:

1. A dc-dc converter that supplies ± 5 voltsdc and ± 15 volts dc

2. A switching power supply that supplies± 12 volts dc and ± 10 volts dc

3. A switching power supply that supplies ± 5volts dc

The audible alarm system has a printed circuitcard where six different audible signals areelectronically generated and any one of the six areprogrammably selected. The selected signal is thenamplified by the alarm amplifier assembly. Theamount of amplification is adjustable to fit theenvironment. The printed circuit card is mountedin the card rack. The alarm amplifier assemblyand speaker are mounted externally on the rightside of the LOCOP cabinet.

For general description purposes, we havegrouped the LOCOP electronics into theirassociated tasks.

CPU, MEMORY, AND I/O INTERFACE—Comprise two microprocessors in the systemcomputer control. The central processing unit(CPU) card has the microprocessor. The memorycard has the system control program and datastorage memory space. The I/O interface cardprovides the link between the computer controland the outside world. The LOCOP has twocomputer control systems for faster, more

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Figure 3-34.—Model 139 LOCOP. A. External view. B. Internal view.

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efficient control of the GTGS and for backuppurposes.

BUS CONTROLLER—Generates thesystem’s real time clocks and the synchroni-zation signals. These are required to allowthe two computer control systems to operatetogether.

I/O MEMORY—Contains the data storagememory space. It is independent of the computercontrol memory. This memory may be used byeither computer control system where data needsto be shared between them.

CONTACT BUFFER—Monitors 16 inputs tointerpret a switch closure. Electronics are includedto interrupt the microprocessor so the special taskrequested by the switch can be handled. The cardmay be programmed to accept normally open orclosed contacts. It will interrupt the micro-processor on both transmissions of the switch.Each LOCOP system has two contact buffercards.

SWITCH BUFFER—Monitors 8 inputs tointerpret a switch closure. It differs from thecontact buffer by interrupting the microprocessorsonly upon initial closure. The switch release is notbuffered. Each LOCOP system has two switchbuffer cards.

LAMP DRIVER—Contains 8 output drivercircuits used to illuminate the visual indicators onthe LOCOP front panel. The indicators can burnsteadily or flash, depending on the controlprogram. If a lamp fails, circuitry is provided tointerrupt the microprocessor to indicate aninternal failure. Each LOCOP system has threelamp driver cards.

RELAY CONTROL—Contains 8 relays, allindependently controlled by the control program.Each relay provides normally open and normallyclosed contacts. Circuitry also detects a failure ofthe driver circuits. The circuits will interrupt themicroprocessor to indicate an internal failure.Each LOCOP system has two relay control cards.

SOLENOID DRIVER—Contains 6 solenoiddriver circuits. They are independently controlledby the control program. The circuitry detects afailure of the driver circuits or a shorted solenoid.This circuit will interrupt the microprocessor toindicate an internal failure.

DISPLAY CONTROL/DIGITAL METER—Receives, from the computer control, the digitizedmonitor data. It then directs this data to the asso-ciated digital display card located on the LOCOPfront door. Up to 16 channels may be handled.

ANALOG INPUT/MULTIPLEXER, ANA-LOG-TO-DIGITAL CONVERTER (ADC),AND DIGITAL-TO-ANALOG CONVERTER(DAC)—Comprise the monitor data handlings y s t e m o f t h e L O C O P . T h e a n a l o ginput/multiplexer has 8 input circuits with 10-mAoutput current sources. These inputs are designedto accept a 0- to 10-volt dc signal. The data canbe attenuated or amplified by electronics or thecontrol program. Once conditioned, this cardmultiplexes the data to be digitized by the ADCcard. The digitized data is then sent to the I/Omemory card for storage. The control programthen conditions this data for the digital displaysand analog output card. The analog output cardcan convert up to 8 channels of data to a 0- to10-volt dc signal. This analog signal can be useddepending on the control program. Each LOCOPsystem has two analog input cards, two analogoutput cards, and one ADC card.

VIBRATION MONITOR—Monitors theengine vibration pickup and scales it for controlpurposes. The card also splits the signal and sendsit to the remote monitor outputs and analog inputcard. Also, an electronic switch circuit detects highvibration. This switch signals the microprocessorcontrol via a contact buffer input.

ALARM BOARD—Generates the alarm tonesrequired for the audible alarm system. Seven tonesare possible. The circuitry can also be used toadjust the volume of the audible alarm.

I/E CONVERTER—Converts current inputs(I) to voltage outputs (E). It converts the 4- to20-mA pressure transducer current outputs to a0- to 10-volt dc signal. The circuitry is also usedto calibrate the rpm/TIT analog meter on theLOCOP front panel. An electronic switch closureis adjustable for any predetermined rpm set point.

ALLISON SPEED/TEMP CONTROL BOX—Generates switch closures required by thecomputer control system to control the GTGS.These include engine speed as well as engine TITset points. The unit also supplies the signals forthe analog rpm/TIT meter located on the LOCOPfront door.

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The speed and temperature channels on themodel 139 are almost identical to the channelsused on the model 104 set. A few exceptions areas follows:

The start temperature limit control valveis not used on the model 139. No signalis sent to it at 2,200 rpm or 12,780 rpm.

During start above 2200 rpm, the enginemust accelerate at a rate of 40 rpm/secondover any 3-second period. This is enabledby the 2200-rpm speed channel. If theengine fails to accelerate at that rate, anantistagnation feature will shut down theengine and sound the slow start alarm.

The 1945°F temperature channel has beenreset to 2050°F. This is to allow for higherload transients. The 1880°F temperaturechannel remains the same.

SUMMARY

In this chapter we have discussed the con-struction and operation of the model 104 and

model 139 GTGSs and their differences. We havediscussed the construction of the engine, itssystems, and its control circuits. We have alsodiscussed the reduction gear, generator, andsupport systems. After studying this material andcompleting the associated NRTC, you should beable to start qualifying as an operator of theAllison 501-K17. If your ship does not use thesegenerators for electric power generation, youshould know how GTEs are used in constantspeed applications.

Chapter 8 of this training manual (TRAMAN)will also give you information to help youunderstand shipboard electrical equipment. TheGas Turbine Systems Technician rating is rapidlybecoming one of the major ratings in the field ofshipboard power generation and distribution. Tobecome a competent EPCC operator, you mustknow not only the GTGS, but also the electricplant of the ship.

Remember, before you attempt to operate anyship’s system, but especially one as important asa generator, follow all EOSS procedures. This willhelp prevent any major casualty from occurringbecause of operator error.

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CHAPTER 4

ENGINEERING AUXILIARYAND SUPPORT SYSTEMS

As a GS, you will primarily be assigned tooperate and maintain the GTEs. You will also betasked with the maintenance and repair of someof the auxiliary or support systems. In this chapterwe will describe the lube oil (LO) fill and transfersystem, the main LO system, the fuel oil (FO)systems, the bleed air system, the compressed airsystems, the drainage and ballast systems, thefiremain system, the seawater service system, thesteam and waste heat systems, and the fireextinguishing systems.

The main propulsion plant could not operatewithout FO for the engines and LO for thereduction gears or salt water for cooling. All thesesystems and others are part of the overall mainpropulsion plant and are in your areas ofresponsibility. You will be assigned to performPMS, repair, and maintain the numerous pumps,valves, and piping associated with these systems.You may also be assigned to the oil lab and haveto maintain and test the ship’s FO and LO. Asa member of the oil lab on the CG-, and DD-class ships, your area of responsibility willalso include the waste heat boiler (WHB) waterchemistry.

In volume 1, chapter 7, NAVEDTRA 10563,of this TRAMAN series, you learned about thevarious types of pumps and valves and their uses.In this chapter you will learn about the differentships’ engineering systems, how they relate to thepropulsion plant, and how the pumps and valvesare used in the systems. Since the engineeringsystems vary between ship classes, we will describethe systems in general terms. The examples of thesystems we show in this chapter are from variousship classes. Always consult your ship’s EOSS fordetailed information on these systems. Yourdiligence in the maintenance and upkeep of thesesystems is extremely important since the ship couldnot operate properly if any of these systemsshould fail.

LUBE OILSYSTEM FUNDAMENTALS

To understand the functions and importanceof the LO fill, transfer, and purification system,and the main LO system, you first need to under-stand the fundamentals of lubrication. Thelubrication requirements of shipboard machineryare met in various ways, depending on the natureof the machinery. In the following paragraphs wediscuss the basic principles of friction andlubrication, the effects of friction and fluidlubrication, the classification of lubricants, andthe properties of LO used aboard ship. We alsodiscuss the lubrication systems installed for manyshipboard units and the devices used to maintainLO in the required condition of purity.

FRICTION AND LUBRICATION

The friction that exists between a body at restand the surface upon which it rests is STATICfriction. The friction that exists between movingbodies (or between one moving body and astationary surface) is KINETIC friction. Staticfriction, in addition to inertia, must be overcometo put any body in motion. Static friction isgreater than the kinetic friction, which must beovercome to keep the body in motion.

The three types of kinetic friction are slidingfriction, rolling friction, and fluid friction. Slidingfriction exists when the surface of one solid bodymoves across the surface of another solid body.Rolling friction exists when a curved body, suchas a cylinder or a sphere, rolls upon a flat orcurved surface. Fluid friction is the resistance tomotion exhibited by a fluid.

Fluid friction exists because of the cohesionbetween particles of the fluid and the adhesionof fluid particles to the object or medium that istending to move the fluid. If a paddle is used tostir a fluid, for example, the cohesive forcesbetween the molecules of the fluid hold the

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molecules together and thus prevent motion of thefluid. The adhesive forces of the molecules of thefluid cause the fluid to adhere to the paddle andthus create friction between the paddle and thefluid. Cohesion is the molecular attractionbetween particles that holds a substance or bodytogether; adhesion is the molecular attractionbetween particles that causes unlike surfaces tostick together. In lubrication, adhesion is theproperty of a lubricant that causes it to stick(or adhere) to the parts being lubricated;cohesion is the property that holds the lubricanttogether and enables it to resist breakdown underpressure.

Different materials have cohesion and adhesionin widely varying degrees. In general, solid bodiesare highly cohesive but only slightly adhesive.Most fluids are highly adhesive but only slightlycohesive; however, the adhesive and cohesiveproperties of fluids vary considerably.

Lubrication reduces friction between movingparts by substituting fluid friction for sliding orrolling friction. Without lubrication, moving a100-pound weight across a rough surface isdifficult; however, with lubrication and properattention to the design of bearing surfaces, al-million-pound load can be moved with a motorthat is small enough to be held in the hand. Byreducing friction, lubrication reduces the amountof energy required to perform mechanical actionsand also reduces the amount of energy thatdissipates as heat.

Lubrication is important throughout the ship-board engineering plant. Moving surfaces mustbe steadily supplied with the proper kinds oflubricants. Lubricants must be maintained atspecified standards of purity and at designedpressures and temperatures in the lubricationsystems. Without adequate lubrication, manyunits of shipboard machinery would quite literallygrind to a screeching halt.

A liquid is used for most lubricationrequirements because, in an enclosed space, aliquid is incompressible. Were it not for thisincompressibility, separating moving metalsurfaces from each other (preventing metal-to-metal contact) would be impossible. As long asthe lubricant film remains unbroken, fluidfriction replaces sliding friction and rollingfriction.

In any process involving friction, some poweris consumed and some heat is produced. Over-coming sliding friction consumes the greatestamount of power and produces the greatestamount of heat. Overcoming fluid friction

consumes the least power and produces the leastamount of heat.

Several factors determine the effectiveness ofoil film lubrication, such as pressure, temperature,viscosity, speed, alignment, condition of thebearing surfaces, running clearances between thebearing surfaces, starting torque, and the natureof the lubricant’s purity. Many of these factorsare interrelated and interdependent. For example,the viscosity of any given oil is affected bytemperature, and the temperature is affected byrunning speed; hence, the viscosity is partiallydependent on the running speed.

A lubricant must be able to stick to thebearing surfaces and support the load at operatingspeeds. More adhesiveness is required to make alubricant adhere to bearing surfaces at high speedsthan at low speeds. At low speeds, greatercohesiveness is required to keep the lubricant frombeing squeezed out from between the bearingsurfaces.

Large clearances between surfaces require highviscosity and cohesiveness in the lubricant toensure maintenance of the LO film. The largerthe clearance, the greater must be the lubricant’sresistance to being pounded out with consequentdestruction of the LO film.

High unit load on a bearing requires highviscosity of the lubricant. A lubricant subjectedto high loading must be sufficiently cohesive tohold together and maintain the oil film.

LUBRICATING OILS

Lube oils approved for shipboard use arelimited to those grades and types that provideproper lubrication under all anticipated operatingconditions. In the following paragraphs, we willdiscuss the classification and properties of LO.The Naval Ships’ Technical Manual, Chapter 262,“Lubricating Oils, Greases, Hydraulic Fluids, andLubrication Systems,” is a good source foradditional information (not covered in thefollowing paragraphs) on LO.

Classification of Lube Oils

The Navy identifies LO by symbols. Eachidentification number has four digits and, in somecases, appended letters. The first digit shows theclass of oil according to type and use; the last threedigits show the viscosity of the oil. The viscositydigits show the number of seconds required fora 60-milliliter (ml) sample of oil to flow througha standard orifice at a certain temperature.

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Symbol 3080, for example, shows that the oil isa 3000 series oil and that a 60-ml sample shouldflow through a standard orifice in 80 secondswhen the oil is at a certain temperature (210°F,in this instance). Another example is symbol2135 TH. This symbol shows that the oil is a 2000series oil and that a 60-ml sample should flowthrough a standard orifice in 135 seconds whenthe oil is at a certain temperature (130°F, in thiscase). The letters H, T, TH, or TEP added to abasic number indicate a primary specific usewithin the general category. In this case it indicatesthe oil contains additives for special purposes.

Properties of Lube Oils

Lube oils used by the Navy are tested forseveral properties. These include viscosity, pourpoint, flash point, fire point, autoignition point,neutralization number, demulsibility, andprecipitation number. Standard test methods areused for each test. The properties of LO arebriefly explained in the following paragraphs.

Viscosity—The viscosity of an oil is itstendency to resist flow or change of shape. Aliquid of high viscosity flows very slowly. Invariable climates, for example, automobile ownerschange oil according to the seasons. Oil changesare necessary because heavy oil becomes too thickin cold weather, and light oil becomes too thinin hot weather. The higher the temperature of anoil, the lower its viscosity becomes; lowering thetemperature increases the viscosity. On a coldmorning, the high viscosity or stiffness of the LOmakes an automobile engine difficult to start. Theviscosity must always be high enough to keep agood oil film between the moving parts; other-wise friction will increase, resulting in power lossand rapid wear on the parts.

Oils are graded by their viscosities at certaintemperatures. The grade is determined by thenumber of seconds required for a given quantity(60 ml) of the oil at the given temperature to flowthrough a standard orifice. The right grade of oil,therefore, means oil of the proper viscosity.

Every oil has a viscosity index based on theslope of the temperature-viscosity curve. The slopeof the curve is based on the rate of change inviscosity of a given oil with a change intemperature, but with other conditions remainingunchanged. A low index figure means a steepslope of the curve, or a great variation of viscositywith a change in temperature; a high index figure

means a flatter slope, or lesser variation ofviscosity with the same changes in temperatures.If you are using an oil with a high viscosityindex, its viscosity or body will change less whenthe temperature of the engine increases.

Pour point—The pour point of an oil isthe lowest temperature at which the oil will barelyflow from a container. At a temperature belowthe pour point, oil congeals or solidifies. Lube oilused in cold weather operations must have a lowpour point. (NOTE: The pour point is closelyrelated to the viscosity of the oil. In general, anoil of high viscosity will have a higher pour pointthan an oil of low viscosity.)

Flash point—The flash point of an oil isthe temperature at which enough vapor is givenoff to flash when a flame or spark is present. Theminimum flash points allowed for Navy LO areall above 300°F, and the temperatures of the oilsare always far below that under normal operatingconditions.

Fire point—The fire point of an oil is thetemperature at which the oil will continue to burnwhen ignited.

Autoignition point—The autoignitionpoint of an oil is the temperature at which theflammable vapors given off from the oil will burnwithout the application of a spark or flame. Formost LO, this temperature is in the range of464° to 815°F.

Neutralization number—The neutralizationnumber of an oil indicates its acid content. It isdefined as the number of milligrams of potassiumhydroxide (KOH) required to neutralize 1 gramof the oil. All petroleum products deteriorate(oxidize) in the presence of air and heat; theproducts of this oxidation include organic acids.If organic acids are present in sufficientconcentration, they have harmful effects on alloybearings at high temperatures, on galvanizedsurfaces, and on the demulsibility of the oil withrespect to fresh water and seawater. This lasteffect, in turbine installations, may result in theformation of sludge and emulsions too stable tobe broken by the means available. An increasein acidity is an indication that the LO isdeteriorating.

Demulsibility—The demulsibility, or emulsionproperty, of an oil is its ability to separate cleanly

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from any water present-an important factor inforced-feed systems.

Precipitation number—The precipitationnumber of an oil indicates the amount of solidsclassified as asphalt or carbon residue containedin the oil. The number is reached when a knownamount of oil is diluted with naphtha and theprecipitate is separated by centrifuging. Thevolume of separated solids equals the precipitationnumber. This test detects the presence of foreignmaterials in used oils. An oil with a highprecipitation number may cause trouble in anengine. It could leave deposits or plug up valvesand pumps.

LUBE OIL FILL, TRANSFER,AND PURIFICATION SYSTEM

The LO fill, transfer, and purification systemis shown in figure 4-1. This system provides themeans for storing, transferring, purifying, and

heating MRG and CRP/CPP lube oil. The majorcomponents of this system are the LO storagetanks, LO settling tanks, LO purifier, and inter-connecting piping and valves.

The LO fill, transfer, and purifying system isused to fill the LO storage tanks and to transferLO between the storage, settling, and sump tanks.It purifies the LO with the centrifugal oil purifierand preheats the reduction gear LO before MRGoperation. You can set the system up for eitherbatch purification of one tank or for continuouspurification using the purifier. The LO for thereduction gear is the same type as the hydraulicoil for the CRP system. The purifier is used forboth systems.

STORAGE AND SETTLING TANKS

Replenishment oil for the MRG, CRP systemand, in some cases, other machinery is stored inbulk in the LO storage tanks. These tanks arefilled from a deck connection located near thereplenishment stations. These tanks must be kept

Figure 4-1.—Typical LO system.

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very clean because the oil stored in them can godirectly into either the MRG or the CRP system.

Lube oil levels within these tanks aremonitored by a liquid level indicating system. Thetwo components in this system are the transmitterand the indicating meter.

The transmitter is the level detector unitmounted vertically within the tank by brackets orflanges. A magnet-equipped float moves along thetransmitter subassembly to vary a voltage, whichcauses the meter to show the number of gallonsof oil in the tank.

Storage tanks are nothing more than smallenclosed compartments with fill and suctionpiping connected to them. These storage tanksalso have overflow piping attached to preventoverfilling and overpressurizing the tanks.

Settling tanks are similar to storage tanksexcept that they have heating coils installed inthem to speed up the settling process. Settlingtanks allow the oil to stand while accumulatedwater and other impurities settle to the bottom.The settling action is caused by the difference inspecific gravity of the impurities and oil. The forceof gravity causes several layers of contaminationto form at the bottom of the tank; the numberof layers depends on the different specific gravitiesof the contaminants. The heaters not only speedup the settling but also increase the efficiency ofthe process.

In Navy ships, combined storage and settlingtank capacity is two times the combined capacityof the involved LO sumps. The recommended LOstorage on hand is one for one; that is, for eachgallon of sump capacity, a gallon should be inon-hand storage.

LUBE OIL PURIFIERS

Centrifugal purifiers, frequently called cen-trifuges, are used extensively in naval service toremove LO impurities. A centrifuge is a bowl orhollow cylindrical vessel that rotates at high speedwhile a liquid (in this case contaminated oil) passesthrough it. The centrifugal force created by thehigh rotative speed acts perpendicular to the axisof rotation and causes solid impurities to bedeposited on the bowl’s inner surface. Waterentrained in the oil is segregated in a layerbetween the solid impurities and the remainingpurified oil.

A centrifuge can separate only materials thatare insoluble in one another. For example,gasoline and diesel fuel cannot be separated fromLO; likewise, salt cannot be removed from

seawater. This is because they are in solution.Water, however, can be separated from oilbecause water and oil are immiscible (incapableof being mixed). Also, the specific gravities of thematerials to be separated must differ. Particle size,fluid viscosity, and length of the centrifuge periodinfluence the effectiveness of the centrifugalprocess. In general, the greater the difference inspecific gravity between the liquids to be separatedand the lower the viscosity of the oil, the greaterthe rate of separation. Lube oils are heated beforebeing centrifuged to decrease their viscosity.

Centrifugal purifiers used on naval ships havebowls of two types, tubular and disc. Refer tovolume 1, chapter 7, of this TRAMAN series, foradditional information on these purifiers.

1. Tubular type. The tubular type has a smalldiameter and rotates at a comparatively highspeed. The bowl has a three-wing device that keepsthe liquid rotating at the speed of the bowl andprevents slippage. The tubular bowl is fed througha nozzle at the bottom.

2. Disc type. The disc type is large in diameterand rotates at a comparatively lower speed. Thisbowl is fitted with a series of discs that separatesthe liquid into thin layers. Liquid is ordinarily feddirectly toward a series of holes punched throughthe disc stack; the liquid flows upward throughthese holes, depending on specific gravity.

In both the tubular and disc types, separatedoil moves toward the center for discharge into oneof the covers; the separated water moves towardthe outside and is delivered from the bowl intothe other cover. Solids separated from the liquidsare retained in the bowls.

Some ships are being outfitted with a self-cleaning centrifugal purifier whose operation issimilar to the self-cleaning FO purifier. It iscapable of purifying up to 500 gpm LO to notmore than 0.3 percent water and not more than0.02 percent solids.

Purification of Lube Oil

The purity of LO is essential to the operationof the ship’s machinery. Dirt, sludge, water, orother contaminants will act as abrasives to scoreand scratch metal surfaces. Contaminants in oilsused for hydraulic applications, such as in theCRP system, could clog small ports and filteringmechanisms in the controls.

Two primary methods of purification are inuse at the shipboard level. One method is the

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batch method and the other is the continuousmethod.

BATCH METHOD.—In the batch process,the LO is transferred from the sump to a settlingtank. The oil is heated in the settling tank.There its temperature is maintained at 160±5°Ffor 2190 TEP for several hours by steam-heatingcoils or electric heaters. Water and otherimpurities are stripped from the settling tankthrough a drain valve. The oil is then cen-trifuged and returned to the sump from whichit was taken. Alternatively, oil may be transferredfrom the sump to a settling tank. You canreplenish the sump tank with clean oil immediatelyby transferring oil from the storage tank via thepurifier. After the oil in the settling tank hasbeen heated, allowed to settle, and then stripped,it is centrifuged and transferred back to thestorage tank.

CONTINUOUS METHOD.—In the continuouspurification process, the centrifugal purifier takessuction from a sump tank and, after purifying theoil, discharges it back to the same sump. As theoil passes through a heater, its temperature israised to the correct level. All oil must be returnedto the sump from which it was taken. All shipswith forced lube systems equipped with centrifugalpurifiers will operate the purifiers while underwayuntil no visible water remains in the oil and nowater is discharged from the purifier. Generally,the MRG lube oil system must be purified 12hours daily. On gas turbine ships the CRP oil mustbe purified for 8 hours, with the remaining 4 hoursof the day reserved for cleaning the purifier.

When the main propulsion equipment issecured, the LO should be purified until no wateris discharged from the purifier. Also, all oil in thelube system should be pumped to the settling tanksand renovated each year.

Sampling of Lube Oil

When monitoring LO, you must sample theoil properly because an improper sample producesunreliable test results. You should be sureyour samples are representative of the oil youare testing. Thoroughly clean and inspect thesampling containers. Before using the containers,flush them with the oil to be sampled. Cap allsample containers promptly after sampling toprevent contamination.

Sampling of lube oil should be done the following thedirections of NSTM Chapter 262 and shipboard PMS.procedures. When conducting shipboard tests, you shouldfollow the sampling procedures listed in NavalShips’ Technical Manual, chapter 262, beginningat paragraph 262-8.1.22. After testing is com-pleted, deposit lightly contaminated oil into theLO settling tank for purification and reuse. Placegrossly contaminated samples in the contaminated

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LO holding tank. When applicable, returnsatisfactory samples to the sump to preventinadvertent depletion of the sump. Never disposeof oil samples in the bilges or other pollution-producing areas.

Each ship is required to have a LO manage-ment program. The LO management program hastwo parts.

1. An onboard sampling and testing program2. The Navy Oil Analysis Program (NOAP),

which is an off ship oil test program

In the onboard LO program, all designatedoperating machinery is sampled on a periodicbasis. The samples are then compared to samplesof the original oil installed in the machinery. ALO sample rack is installed in a designated areathat contains the sample bottles. The original oilinstalled in each piece of machinery is sampled.This sample is dated and used as the basis ofcomparison for all other samples. Samples aretaken on the following schedule:

1. Daily—operating machinery at sea or inport

2. Prior to starting all machinery

3. After casualty to machinery4. When ordered by the engineering duty

officer (EDO)/EOOW

The sample rack contains one sample bottlefor each piece of machinery. A log of allsamples taken and the condition of each sample ismaintained and initialed by designated personnel.

The NOAP provides spectrometric analysis ofa ship’s LO at a designated laboratory. Thisprogram can be used to detect accelerated wearin machinery, without the machinery beingdisassembled, long before any other trouble isindicated. Lube oil samples of selected equipmentare submitted to the laboratory on a periodic basisfor examination. The ship is advised of the testresults by the testing activity. The ship maintainsaccurate records of operating hours after majoroverhauls, oil changes, and any repairs effectedas a result of recommendation by the laboratory.

MAIN LUBE OIL SYSTEM

All GTE-powered ship classes have the samebasic LO service system. In this section we willdescribe the basic system and components andpoint out (where applicable) the differences in thedesign of some ships’ LO systems. If no differenceis noted in the description, the reader can assumethe component to be basically the same on allclasses of GTE-powered ships.

SYSTEM LUBE OIL FLOW

The pumps take suction from the MRG sumpthrough check valves. The check valves maintainsystem prime (that is, they ensure the suction lineto the pump and the pump casing remain full) andprevent reverse flow of oil through a securedpump. The pumps supply oil under pressure toa common line where the unloader valve returnsoil in excess of demand to the MRG sump. Oilfrom the common line flows to the LO cooler,where its temperature is reduced to about 120°F.From the cooler, oil flow is divided into twopaths, one to supply the MRG and the other tosupply the two LOSCA coolers. Oil to the MRGflows through the duplex filter into the MRG lubeoil header. From the MRG header, oil isdistributed to lubricate and cool the reductiongear components, the clutch/brake assemblies,and the thrust bearings. The oil then returnsto the sump. Oil to each LOSCA passes througha pneumatically controlled valve. This valvecontrols oil flow to the synthetic LO cooler toregulate temperature at the synthetic oil discharge.Service system LO from the LOSCAs join in acommon line to return to the MRG sump.

SYSTEM COMPONENTS

The reduction gear LO service system is aclosed loop system with the sump tank vented tothe atmosphere. Circulation of the LO (asdescribed in system flow earlier) is accomplishedby pumps. In this section we will describe thecomponents the LO passes through during thiscirculation. They include (1) the LO sump, (2) theLO pumps, (3) the unloading valve, (4) thetemperature regulating valve, (5) the LO cooler,(6) the LO filter, and (7) the main LO header.

Lube Oil Sump

The MRG lube oil sump is located in theinner bottom beneath the MRG. The sump

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contains the supply of oil for the main LOservice system. It collects and retains oil as itreturns from the MRG, main thrust bearing, andpropulsion turbine synthetic LO system coolers.The LO return from the MRG to the main sumphas a convoluted flexible connection boltedbetween the MRG oil pan and the top of thesump. The normal operating capacity is 1500 to1550 gallons, and the low operating level is 1400gallons. When the sump is filled to the operatinglevel, the pump suction bellmouths will besubmerged under all operating conditions. Thepump suctions are located away from theturbulent area so the oil is permitted to deaeratebefore entering the suctions. The sump is designedto allow free drainage of pockets formed bystiffeners inside the sump and to allow access forinspection and cleaning. Lube oil return drainsare located as far as possible from suctionbellmouths. Structural members in the tank actto smooth the turbulence in the oil return area.The sump is equipped with a sludge pit locatedat the lowest point. It is also equipped with aliquid level transmitter, an RTE, pump andpurifier suction connections, and oil returnconnections.

Lube Oil Pumps

Three positive-displacement LO pumps areused to supply oil to the MRG and the LOSCAsfor the propulsion GTEs with an adequateamount of filtered, heated, and purified oilduring normal ship operations.

CG, AND DD LUBE OIL PUMPS.—Three positive-displacement LO pumps areinstalled in each engine room. There are twoelectric-motor driven LO pumps and a third LOpump that is attached to and driven by the MRG.Each of the electric-motor driven units has avertical screw, positive-displacement pump thatis flexibly coupled to a two-speed electric motormounted on a common steel bracket. Resilientmounting is used between the bracket and theship’s structure. The pump is rated at 700 gpmat high speed and 250 gpm at low speed at adischarge pressure of 60 psig. The pumps takesuction from the MRG sump through a commonsuction line and discharge to the LO servicepiping.

The attached LO pump is of a similar designto the motor-driven pumps. The principaldifference is in the larger size and greater ratedcapacity. The attached pump is rated at 1140 gpm

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at 60 psig discharge pressure and 1220 rpm (about168 shaft rpm (srpm)). The attached pump issupported by a bracket immediately above the LOsump top. It is driven by the MRG lower inboardsecond-reduction pinion shaft through a rightangle drive. The angle drive is equipped with amanually operated disconnect device that may beused to disconnect the attached pump when themain shaft is stopped. The attached pump takessuction from the sump through an individualsuction line and discharges into the LO servicepiping system. The pump speed is proportionalto shaft speed; therefore, the attached pump doesnot deliver enough oil by itself to lubricate theMRG and to cool the GTE synthetic oil untilhigher shaft speeds are reached. The attached LOpump is engaged or disengaged by a lever attachedto the pump coupling.

The motor-driven pumps supply oil to thesystem when the propulsion shaft is stopped andaugment the attached pump at low shaft speeds.The motor-driven pumps are controlled by theECSS pump logic as a function of pressure at theinlet to the MRG lube oil header. The output ofthe attached pump is not controlled and isproportional to shaft speed. Primary systempressure regulation is accomplished by theunloader valve. When the ship’s speed increasesand the total pump output exceeds the regulatingcapacity of the unloader, MRG inlet pressureincreases. The ECSS pump control logic thensequences the motor-driven pumps to change toa slower speed or secure to maintain oil pressurein the normal operating range. When the pumpcontrol logic has sequenced both motor-drivenpumps to secure, the attached pump supplies thetotal LO system requirements. A similar controlsequence operates to maintain oil pressure whenshaft speed decreases. As shaft speed decreasesand LO pressure drops, the ECSS pump logic willstart the appropriate pump(s) and control theirspeed to maintain normal LO pressure.

The pumps may be controlled locally at theirrespective controllers. With the LOCAL-REMOTE selector switch in LOCAL, the STOP-SLOW-FAST selector switch is operative. Withthe LOCAL-REMOTE selector switch in theREMOTE position, control is transferred to theECSS.

FFG LUBE OIL PUMPS.—This class of shipalso has three LO pumps. Two of the LO pumpsare two-speed, motor-driven, vertically mounted,screw-type pumps. The third LO pump is an air-motor driven, vertically mounted, screw-type

pump. The system controls allow either electricpump to be designated NORMAL with the otherdesignated as STANDBY. The normal pump runsat low speed only for preheating the LO and runsat high speed during normal operating conditions.With the pump controller mode switch in theAUTO position, operation of the pumps iscontrolled by a set of pressure switches. If the oilpressure to the reduction gear hydraulically mostremote bearing begins to drop below 13 psig, apressure switch closes and causes the standbypump to start operating at low speed. If the oilpressure continues to drop below 11 psig, anotherpressure switch closes and the standby pumpswitches to high speed. A further drop in pressureto 9 psig closes a third pressure switch. It alsocauses the air-motor driven coast down pump tostart operating by opening the solenoid valve tothe coast down pump air motor.

When the oil temperature is below 90°F,preheating of the oil is required. A connection tothe lube oil fill, transfer, and purification systemallows use of one of the LO service pumps tocirculate oil through the LO purifier heater.Priming lines are provided at each pump so thatthe operation of either service pump will maintaina continuous oil prime to the other two pumps.A relief valve set at 80 psig is located at eachservice pump discharge to protect the system fromoverpressurization.

If the propeller shaft is rotating during anelectric power failure on the ship, the electricpumps stop. This loss of pressure causes the LOcoast down pump to start and continue to rununtil the propulsion plant can be secured. Theduration of operation of this pump is limited bythe quantity of air stored in the HP air flasksprovided in the engine room. The discharge of thecoast down pump goes into the reduction gear oilinlet header via the LO service filter. Thedischarge bypasses the rest of the LO servicesystem. If the electric pumps restore normalsystem pressure to 15 psig, a pressure switch opensand the air solenoid valve that controls air flowto the pump motor closes and stops the coastdown pump. The coast down pump also stops ifthe propulsion shaft stops rotation.

Unloading Valve

This air pilot-operated valve senses the oilpressure at the reduction gear hydraulically mostremote bearing and regulates the oil supply flowto maintain 15 psig at that bearing. If the sensedpressure exceeds 15 psig, the valve will open and

return excess system flow to the LO sump tank.The valve is fully open at a sensed pressure of 20psig. Control air from the ship’s LP vital air mainis used for the operation of this valve.

Temperature Regulating Valve

This air pilot-operated valve is located at theinlet to the LO cooler and regulates the amountof oil flow through the cooler. The temperaturesensing element is mounted in the oil supplypiping to the reduction gear. Based on the signalfrom the temperature sensor, the valve regulatesthe amount of flow through the cooler andbypasses the rest. The valve is set to maintain a110 ± 5°F oil temperature to the reduction gear.Control air from the ship’s LP vital air main isused for operation of this valve.

Lube Oil Cooler

The LO coolers are designed to maintain theLO temperature at 110 ± 5°F. The coolers on thedifferent class ships have physical differences, butthey function the same. We will describe thesedifferences in the following paragraphs.

CG, AND DD LUBE OIL COOLER.—A LO cooler is installed in each LO service systemdownstream from the LO pumps. The cooler hasa shell assembly, a tube bundle, and inlet andoutlet water boxes. The cooler is a single-pass shelland tube type of heat exchanger. Seawater is usedas the cooling medium. It enters the inlet waterbox through the inlet connection, makes one passthrough the tubes, and is discharged through theoutlet water box. Seawater flow is regulated bya pneumatically operated valve controlled by atemperature sensor installed in the LO pipingdownstream from the cooler. The LO inlet is atthe opposite end from the water inlet, resultingin counterflow heat transfer.

FFG LUBE OIL COOLER.—This cooler ismade of two shell and tube type of heatexchangers piped in series. Seawater from themain seawater cooling system circulates throughthe tubes in a single pass through each shell ofthe cooler in series. The LO flows through eachshell in series. The oil enters the cooler throughthe upper shell and leaves the cooler through thelower shell. Vent connections are provided onboth the upper shell and water box, and drainconnections are provided on the lower shell andwater box.

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Lube Oil Filter

The LO filter has two separate filter housingsconnected by interlocked inlet and outlet valvesarranged so only one housing is in operation ata time. Each filter housing contains 14 filterelements rated at 65 microns. You can clean andreuse the filter elements. Each filter housing hasvent and drain connections. The filter is installedin the piping downstream from the LO cooler toremove particulate matter from the LO. The filterhas a single cast steel body mounted on afabricated steel base. The filter body contains twofilter chambers and a diverting valve assembly.The diverting valve connects the filter chambersto the inlet and outlet ports. The filter chambersare covered by bolted steel plates.

A manually operated changeover assemblypositions the diverting valve to place the right orleft filter element in service. The selector lever ispositioned over the chamber selected. A hydraulicinterlock prevents the shifting of oil flow to anopen (nonpressurized) filter chamber. An inter-lock cylinder is connected to each of the filterchambers. When a differential pressure existsbetween the chambers, the cylinders engage anotch in the diverting valve cam plate andpositively lock the selector lever. The changeoverassembly has a balancing valve that is used toequalize pressure between the chambers to allowshifting. The assembly also fills the filter chamber

after cleaning. Each filter chamber has a vent anda drain.

The liftout filter elements are pleated wirecloth, supported by inner and outer perforatedmetal tubes. Magnets, supported inside each filterelement, remove ferrous particles from the oil.

Header

Oil is supplied to the MRG and accessories bythe ship’s main LO service system through a singleoil inlet LO header. The header has spray barassemblies equipped with spray nozzles tolubricate all gear and pinion teeth. The spraynozzles are arranged to direct oil across the full.width of the teeth at the gear mesh. This properlylubricates tooth bearing surfaces and dissipatesheat generated during operation.

Safety orifice plates are used for journal andthrust bearings. The openings are sized to allowsufficient lubrication under normal conditions butto restrict excessive flow, such as that caused byextreme bearing wear or bearing failure. Theseorifice plates are installed in the flange jointsconnecting the oil supply line to each bearing.Orifice plugs are installed in the bearing seats forthe high-speed pinions and input shafts.

SYSTEM MONITORING

During operation, another one of your dutiesas watch stander is to monitor the LO system.

Figure 4-2.—Liquid sight indicator.

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Various components/devices installed in thesystem will assist you in this duty. We willdescribe a few of these aids in the followingparagraphs.

A liquid sight indicator (fig. 4-2) is providedat each main bearing. Each indicator has afitting with a bull’s eye through which youcan see a stream of oil flowing from the bearing,a fitting for a dial-type thermometer, and a wellfor installation of remote reading RTEs.

Lube oil pressure at the inlet to the header issensed by both a pressure transducer and apressure switch. The transducer sends signals toECSS for METER/DDI display, pump logicoperation, data logging, and HEADER PRESSHI/LO alarming at the PAMCE and the PLOE.The pressure switch provides the permissives forthe turning gear and GTE starting.

Most remote bearing LO pressure is sensed bya transducer located at the lower outboard first-reduction gear bearing.

A temperature switch, located in the clutch/brake oil inlet, is set to open contacts at 130°Fto prevent clutch/brake operation. A temperaturesensitive bellows actuates a switch to open or closeelectrical contacts at the set point.

A temperature transducer, located at theinlet to the header, will provide you with bothmeter displays and a HEADER TEMP HI/LOalarm at the PAMCE and the PLOE.

FUEL SYSTEMS

The gas turbine ships carry two types of FOaboard-fuel, naval distillate, NATO symbol F-76(formerly designated as diesel fuel, marine(DFM)), and JP-5, NATO symbol F-44. Fuel,naval distillate is identified as MIL-F-16884.

Fuel, naval distillate is the type of FO normallyused for the GTEs, with JP-5 being an alternateFO that can be used when necessary. While JP-5may be used for the ship’s propulsion plant, itsmain purpose is for use in the helicopter assignedto the ship for antisubmarine warfare (ASW)operations. Both of these FOs must be deliveredto the equipment in a clean and water-free state.This is the purpose of the ship’s FO system.

The shipboard FO system is basically amethod of receiving, storing, purifying, andremoving FO from the ship. The bulk FO is storedthroughout the ship in storage tanks. The FO isthen taken from the storage tanks through thetransfer system to the service tanks. The transfersystem removes water and contaminants from theFO and prepares it for use in the GTE. Theservice tanks stow the FO either in use or FOready to be used in the engines. The FO is takenfrom the service tanks, through the ship’s FOservice system where it is further conditionedbefore use.

The fuel, naval distillate, and JP-5 fuel oilsystems are separate systems. Both have the FOfill and transfer system and the FO service system.We will discuss these systems separately in thefollowing sections.

NAVAL DISTILLATE SYSTEM

Fuel, naval distillate is the FO used for themain propulsion plant and generators on the CG-,DD-, and FFG-class ships. Naval distillateis the main type of FO carried aboard ships andused in the FO fill and transfer and the FOservice system.

Fuel Oil Fill and Transfer System

The FO fill and transfer system for F-76 hasa fill and transfer header, storage tanks, and atransfer system. We will discuss these individuallyin the following paragraphs.

THE FUEL OIL FILL AND TRANSFERHEADER. —The fill and transfer header is asystem of piping and valves connecting the maindeck filling stations to the storage tanks. Thissystem allows FO to be taken from the storagetanks to the service tanks. It also provides thecapability to defuel the ship.

Fueling and defueling operations begin at themain deck fueling stations. Gas turbine ships havefueling stations on the port and starboard sidesforward and aft.

Ships are fueled both at sea and in port. Themain difference between fueling at sea and in portis the method used to connect the supplyingstation to the ship. At sea the probe fueling system

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Figure 4-3.—Probe fueling system.

(fig. 4-3) is used. The probe method is the mostcommon method used and is standard amongships of the U.S. Navy. Various adapters areavailable for fueling from ships not equippedwith the probe unit. Part of this system is theprobe receiver and the hose assembly. They areconnected to deck filling connections on theoutboard side of the receiving ship. During inportrefueling, the supplying activity’s hose is boltedto a flanged fitting on board the receiving ship’sfueling station.

With the commanding officer’s approval, thechief engineer along with the oil king sets up andcontrols the fueling operation. The oil king alignsthe system as specified in the EOSS and controlsthe fueling operation. Standard refueling stationsare manned and the entire operation is monitoredfrom a central point on the ship. Various tests ofthe FO are required before, during, and at thesecuring of fueling. The oil king is responsible forthese tests and also the reports that must besubmitted.

The FO flows from the receiving station to themain header pipe and from there to the storagetanks through various valves. The valves are setup in a manifold system on the FFG-class shipsand are located in auxiliary machinery room No.1 (AMR1). On the CG-, and DD-classships, FO flows from the deck riser through amotor-operated valve that can be used as athrottling valve to maintain FO flow. From there

the FO enters the main header and from there tothe FO banks through branch lines. Each FO bankhas its own motor-operated valve. These valvesare operated from the fuel console and are eitherfully opened or fully closed.

The storage tank valves on the CG-, and DD-class ships are electrically operated from thefuel control console located in CCS. Except forthe manual operation of the valves at the fuelingstation, the entire fueling operation can beconducted and monitored at the fuel controlconsole. These valves can be opened and closedmanually if needed. A diagram of the FO fill andtransfer header piping on the DD-class ship isshown in figure 4-4.

STORAGE TANKS.—The FO storage tanksare nothing more than large enclosed compart-ments with piping connected to them.

The CG-, and DD-class ships areprovided with seawater-compensating systems. Inthis system, the storage tanks are always keptcompletely filled with either FO or seawaterballast or a combination of both. The receivingtank is connected to a bank of storage tanks bysluice piping between tanks. As a receiving tankbecomes full, FO overflows into the adjoiningtank in the bank. This continues until all tanksin the bank are full. During the fueling operation,seawater in the tank bank is displaced by the FO

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Figure 4-4.—Piping diagram of a DD-class ship fill andtransfer header.

and is discharged overboard through an overflowline from the overflow expansion tank.

When FO is taken from the storage tanks forship’s use on gas turbine ships, seawater from thefire main provides a positive head on the systemto the suction side of the transfer pump. Seawaterreplaces the FO in the tanks and maintains theproper ship’s trim.

CAUTION

Because of the danger of overpressu-rizing the ship’s receiving system duringrefueling, maintain extremely close liaisonbetween the receiving ship and the supplyship relative to flow rates and line pressure.Means for throttling flow to each tankbank is provided to prevent tank over-pressurization by use of the throttlingvalve. Keep a close watch on liquid levelsand receiving tank pressures of banksbeing filled on ships with compensatingsystems.

The clean ballast system provides completeseparation between the ship’s FO storage tanksand the seawater ballast system. Tanks designatedfor FO storage are used for this purpose only. Fuelfill, transfer, and stripping systems are isolated

Figure 4-5.—Typical gas turbine FO tank level indicatorsystem.

from the drainage, ballast, and bilge systems andare used solely for FO storage and management.Tanks used for ballast are so designated and canbe filled with seawater for ship stability and trim.Some ship classes, such as the FFG, have amodified clean ballast system. Designated FOtanks can be ballasted with seawater through thissystem whenever the total FO load is reducedbelow a set percentage and additional ballast isrequired.

The rated full capacity of a FO tank is95 percent of the total capacity. The rated fullcapacity is computed after allowance has beenmade for all obstructions in the compartment. Theremaining 5 percent of the total tank capacity isreserved to allow for FO expansion. Accordingly,when FO is received, tanks should not be filledbeyond their rated capacity. This filling require-ment does not apply to ships having seawatercompensating systems since these tanks arealways 100 percent full. Expansion tanks arep r o v i d e d o n t h e C G - , a n d D D - c l a s sships to provide for FO expansion caused bytemperature changes.

An electric level indicator with a magneticfloat (fig. 4-5) is used for FO tanks on gasturbine ships. It is replacing the pneumatic-typesystems on ships with water-compensating systemsbecause of its improved reliability and accuracy.The Navy Oil Pollution Abatement Programrequires installation of a magnetic-float levelindicator with a high-level alarm in all FO tanksthat overflow directly overboard.

This type of indicator has a magnetic float,transmitter (or sensor), and primary andsecondary receivers (meters). The transmitter stem

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is composed of a rod or series of rods mountedvertically within the tank. The magnetic float iscylindrically shaped and has a hole in the center.As it moves up and down on the surface of thefluid, the magnetic float operates tap switchesin the rod. The electrical resistance of thetransmitter changes according to which rodswitches are closed. This provides an indicationof tank level. The float movement is transmittedto a receiver that is calibrated in gallons.

Magnetic-float, liquid-level indicators in tanksthat overflow directly overboard have integral,high-level alarms to warn of an impending over-board oil discharge. These alarms are set to soundwhen the tank has reached 95 percent of totalcapacity. This alarm warns that the tank willoverfill and that oil will be discharged overboardunless the operator takes preventive action(s). Onmost gas turbine ships, the FO system ismonitored from a central point on the ship. Asystem control panel has gauges and alarms that

indicate FO levels in the tanks, indications of valvealignment, alarms for high and low tank levels,and, in the seawater-compensated system, analarm for receiving tank overpressurization.

TRANSFER SYSTEM.—The FO transfersystem transfers FO from the storage tanks to theservice tanks. In the transfer process, the FO iscleaned for use in the GTEs. The system hastransfer pumps, heaters, and centrifugal purifiers.

Figure 4-6 is a basic diagram of the FOtransfer system for the DD-class ship. It shouldgive you a good idea of how the system works.The oil king’s first step is to decide from whichstorage bank FO is to be taken and to whichservice tank it is to go. The FO is moved fromthe storage tank by the transfer pump through theFO transfer heater. The heater warms the FO tothe proper temperature for cleaning by thepurifier. The FO purifier removes water andcontaminants as FO is transferred to the service

Figure 4-6.—DD-class ship fuel oil system.

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tanks. The FO in the service tanks can also berecirculated through the purifier and back to theservice tanks by realigning the valves. The FOmust be circulated for a minimum of 3 hoursbefore a service tank is placed in operation. Thisprovides a means of continuously reducing theamount of solid contaminants in the FO.

The CG- , and DD-c l a s s sh ip s a r ebeing furnished with self-cleaning centrifugalpurifiers (SCCPs). The purifier is a vertical, direct-drive, centrifugal, self-cleaning (solids ejecting)machine that has the capacity to purify 110 gpmof contaminated diesel fuel, marine. The FOcontaminated with water and solids is fed into thepurifier. It separates the pure FO from thecontaminants and returns the purified FO to theship’s FO system. The water is continuouslypassed from the purifier through the ship’spiping to a waste oil tank. Separated solids in theform of sludge are retained within the bowlduring the cycle. Cleaning the bowl during purifieroperation is referred to as “shooting” the bowl.The ejected sludge is also passed to the waste oilsystem. The purifier can remove water from acontaminated mixture comprised of as much ashalf water, half FO. Also, under emergencyconditions, the purifier can process 100% water fora period of 5 minutes without any water dischargefrom the fuel discharge port.

Fuel Oil Service System

The FO service tanks are similar to storagetanks except they are not saltwater ballasted. TheFO service tanks have the same type of liquid-levelindicating system as other tanks aboard ship. Themajor concern for the service tanks is cleanliness.The FO service tanks must be maintained in aclean state of readiness. To maintain cleanliness,you must allow only clean FO to enter theservice tanks. The components of this system thatwe will discuss are the FO strainers, the FO heater,and the filter/coalescer.

FUEL OIL STRAINERS.—A wire-meshbasket strainer is normally installed between theservice tank and the booster pump suction to filterout large solid particles. Figure 4-7 is an exampleof a duplex FO strainer. Refer to volume 1,chapter 6, of NAVEDTRA 10563 for moredetailed information on this type of strainer.

The FO enters the top section of the strainerbody and is directed into one of the wire-meshbaskets. Large, solid particles are trapped insidethe strainer basket, and clean FO travels on

Figure 4-7.—Duplex FO strainer.

through the outlet. Duplex strainers contain twoseparate strainer housings and baskets and achangeover mechanism that is a shaft with inletand outlet valves attached to it. As the handle ismoved, one set of valves opens and the other setcloses, isolating one strainer assembly. Thestrainers have differential pressure gauges andalarm indicators to alert the operator when thestrainer is dirty.

FUEL OIL BOOSTER PUMPS.—Each FOservice system has two booster pumps to providethe system pressure. The FO booster pump is avertical, screw-type, positive-displacement pumpthat is driven by a two-speed electric motor. Thistype of pump is found on the CG-, and DD-class ships. A sliding vane pump is used onthe FFG-class ships. Directly following the pumpdischarge is a relief valve. Since the pump ispositive displacement, a relief valve is required toprotect the system and the pump. The relief valvebypasses FO back to the pump inlet.

FUEL OIL HEATER.—Fuel oil heaters areinstalled in the service system after the FO booster

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pumps. The heaters are heat exchangers of theconventional shell and U-tube type. Either steamor hot waste water is used with a temperature-regulating valve to maintain the FO at normaloperating temperatures. An alarm in the systemindicates high FO temperature to the plantoperator.

FILTER/COALESCER.—The filter/coalescer(also called the coalescer) is the last conditioningstation before the FO is used in the GTEs. Thecoalescer filters sand, dust, dirt, and scale fromthe FO. The coalescer also coalesces waterparticles and removes essentially all free waterfrom the FO supplied to the propulsion gasturbines.

The coalescer (fig. 4-8) is a self-contained,static, two-stage unit that combines the processof filtration and water separation in one housing.The basic principle of operation is that con-taminated FO enters the unit through the inletport and flows into and through the coalescingelements. The flow through the coalescer elementsis from the inside to the outside. The coalescerelements remove solid contaminants from the FO.As FO passes through the elements, entrainedwater coalesces into large droplets that fallto the bottom of the coalescer (sump) where theyaccumulate.

After passing through the coalescer elements,the FO passes through the hydrophobic screen andthe separator elements, which remove the finaltraces of coalesced water that have not fallen by

Figure 4-8.—Filter/coalescer assembly.

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their own weight into the sump. The flow throughthe separator elements is from the outside to theinside. The FO, free of contaminants, then flowsout of the coalescer through the discharge valveinto the FO system.

When the water/sediment level in the sumpreaches a preset level, the automatic drain valvedumps into the water/sediment waste oil system.A sampling valve is provided at the dischargepoint for testing discharged FO.

As you can see, both the compensated andnoncompensated FO systems are basically thesame in their operation. However, the quality ofthe FO must meet stringent requirements. Theserequirements help to protect the GTEs fromserious damage, such as corrosion of the hotsection, fouling of engine controls, and pluggingof fuel nozzles. This level of FO quality is achievedthrough the continuous purification, sampling,and testing of FO throughout the system. This isthe responsibility of the oil king on board the ship.

JP-5 SYSTEM

The JP-5 system provides FO to the helicopterfueling station and to the small boat refuelingstation. It also transfers JP-5 to the ship’s FOservice system under emergency conditions tooperate the main engines and generators. Onthe CG-, and DD-class ships, JP-5 can beintroduced into the system through the systempiping just before it enters the FO booster pumps.On the FFG-class ships, JP-5 is normally providedto emergency head tanks, which provide enoughFO for the normal cool down period (5 minutes)of a main engine.

The JP-5 system is basically similar to theship’s FO and transfer system in that it hasrefueling stations, storage tanks, transfer pumps,service tanks, and filter separators that provideclean FO to the equipment. Onboard FO capacityfor JP-5 is much less than for fuel, naval distillate.

JP-5 is taken on board from topside fuelingstations and transferred to the storage tanks. Thestorage tanks are noncompensated tanks and havethe same type of tank level indicators as the fuel,naval distillate tanks. The FO is transferred fromthe storage tanks to the service tanks through theJP-5 transfer pump and filter separator. The filterseparator removes water and contaminants fromthe FO before it reaches the service tanks. Thetransfer piping system also branches off beforeit reaches the service tanks. This provides JP-5for emergency use in the ship’s FO system andalso to the small boat refueling station.

The FO from the service tanks is used forhelicopter (helo) refueling and has its own JP-5

service pump and filter separator. The servicesystem provides the capability to refuel andrecirculate FO for the helo station. Helo defuelingcapability is also provided. This capability isnecessary because FO removed from the helo isreturned to the storage tanks or diverted to aseparate contaminated FO tank. A stripping pumpis provided on both types of ships for removalof water and sludge accumulations on the bottomsof the tanks.

As with the fuel, naval distillate, stringentrequirements for FO purity are necessary. Theresponsibility for testing the FO again belongs tothe oil king.

BLEED AIR SYSTEM

Bleed air, as we discussed in chapter 2 of thisTRAMAN, is compressed air taken from portson different stages of the engines. On all classesof ships, the LM2500 GTE provides customerbleed air for shipboard use from the 16thstage of the compressor. On the CG-, DD-, and

class ships, bleed air is also provided fromthe 14th stage of the GTG compressor. Bleed airis used aboard ship for starting, anti-icing, maskerair, and prairie air.

BLEED AIR START SYSTEM

Bleed air used for starting is extracted fromthe compressor section of the GTE and passesthrough a regulating valve. The bleed air isregulated at 75 psi and has a maximumtemperature of 925°F. It then enters the bleedair header and is used for the various purposesmentioned previously.

The CG-, and DD-class ships usestarter air differently from the FFG-class ships;therefore, the systems differ in their method ofcooling the bleed air and directing it to the starter.

On the CG-, and DD-class ships, bleedair is the primary method of starting the GTEsand SSGTGs. The bleed air of the four GTEsand three GTGs enters a common header andcan be used to start any other engine or generator.Refer to figure 4-9, a piping diagram of the

Figure 4-9.—Piping diagram of a DD bleed air system in the forward engine room.

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bleed air system on a DD-class ship, as we describethe system.

Bleed air is taken from any operating GTE andgenerator through a bleed air regulator valve,which reduces the pressure to 75 psig. It thenenters the header. The various valves thatcontrol the flow can be operated from the PACCin CCS or the PLCC in the engine room. TheAUTO MODE can be used to automatically setthe valves in sequence during GTE start, or theycan be sequenced individually by the operator.The operator can also operate the valve manuallyby overriding the electrical signal at the valve.

Bleed air for starting goes through twoseparate pipes. Hot bleed air flows to the mixingvalve through the high-temperature bleed airvalve. Bleed air also flows through the masker airvalve through the masker air cooler where it iscooled to about 190°F. The cool bleed air thenflows through a filter to remove any solidcontaminants and then to the masker/starttransfer valve. In the start position themasker/start transfer valve allows the cool bleedair to flow to the mixing valve. In the mixingvalve, the hot bleed air and cool bleed air aremixed to maintain a temperature of about 400°to 450°F. Air then flows through a start air filterand then to the motor air-regulator valve. Themotor air-regulator valve regulates start air at 45psig for starts and 22 psig for motoring. Anothervalve in the start system is the mixing bypass valve.This valve allows only the cool bleed air to passto the starter during motoring.

Start air on the FFG-class ships flows fromthe GTE into a common header through areducing valve where it is reduced to 75 psig. Itthen passes through the bleed air cooler, whichmaintains the air at a temperature of about 400°F;from there it passes to the start air system andto the motor air-regulator valve. This valveoperates the same as on the CG-, and DD-class ships.

ANTI-ICING AIR SYSTEM

The anti-icing systems on the CG-, and DD-class ships differ greatly from the FFG-classships. We will describe these systems separately.

CG, and DD Anti-Icing System

The gas turbine anti-icing systems take hotbleed air from the bleed air header and distributeit to each GTM and GTGS intake to prevent theformation of ice under an icing condition. An

icing condition exists when the inlet airtemperature to a GTE is 41°F or less and thehumidity of the inlet air is 70 percent or greater.

Bleed air from the header enters the anti-icingsystem piping for each GTM and GTGS and isdirected to the anti-icing, air-flow regulatorvalves. The forward and after bleed air headerrisers provide the hot bleed air for each GTM andGTGS in the No. 1 and No. 2 engine rooms. Thebleed air header in the No. 3 generator roomprovides the hot bleed air for the No. 3 GTGS.The anti-icing, air-flow regulator valves controlthe flow of hot bleed air into the intake of eachGTE. This maintains the temperature of theinlet air to each GTE at 38°F, or greater, duringengine operation. Each valve is a double-pneumatic, piston-actuated, butterfly-vane,regulating valve. This valve is electronicallycontrolled by an associated anti-icing temperaturecontroller. These controllers are enabled ordisabled by the seven anti-icing ON/OFF push-button switch indicators on the PLCC andPACCs. (NOTE: This system is described as itcurrently exists. SHIPALTS have been issued thatremove the electronic controls of the valves andmake them manually operated.)

The controller used to operate the anti-icingvalve for each GTE intake combines andcompares three signals with the fixed temperaturesignals. The three input signals are CIT, NG G, andbulk air temperature. The fixed temperaturesignals are 38°F or bulk air temperature. Thecomparison of these signals determines thetorque motor control positioning signal. Thissignal drives the anti-icing valve torque motor,which positions a poppet valve in the valve’spneumatic regulating control assembly. Thepoppet valve, in turn, regulates the amount ofpressure the 100 psig ship’s service (SS) air canexert on the valve’s pneumatic actuating pistons;the position of the pistons determines the valvesetting. When SS air pressure on the pistons is notworking, a spring in the valve’s actuator assemblymaintains the valve’s butterfly vane in the closedposition.

When the GTM anti-icing temperaturecontroller is enabled, it maintains the temperatureof the inlet air in the intake at 38°F. The controllermaintains this temperature by comparing bulk airtemperature to the controller’s 38°F fixedtemperature reference. However, when changesin engine speed are made, the speed sensor (NG G)signals the controller to complement immediatelythe increase or decrease in intake air flow witha corresponding increase or decrease in hot bleed

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air flow. The ambient air temperature sensorsignal determines the magnitude of valve positionchange that will accompany any given enginespeed change. Following an engine speed change,the controller will again regulate the temperatureof the inlet air in the intake to 38°F. It does thisby comparing the bulk air temperature to thecontroller’s 38°F fixed temperature reference.

The controller used to operate the anti-icingvalve for each GTGS intake combines andcompares one input signal (duct air temperature)with the fixed temperature signals (38°F) toproduce a torque motor control position signal.The anti-icing valve used on a GTGS is the sameas that used on a GTM.

When the GTGS anti-icing temperaturecontroller is enabled, it maintains the temperatureof the inlet air in the intake at 38°F. Again thecontroller compares duct air temperature to the38°F fixed temperature.

After the bleed air passes the anti-icing, air-flow regulator valves, it becomes anti-icing air andis piped to the GTGS intakes. Anti-icing airentry into a GTGS intake is made through an8-inch pipe. The hot anti-icing air flows into theintake duct and mixes with the intake air. Nomanifolds or nozzles are used.

Injection of hot anti-icing air into the GTEintakes is accomplished through the U-shapedmanifolds mounted at the 02 level above thesilencers inside each duct. The manifolds areconstructed from 8-inch diameter pipe with1 1/4-inch holes drilled along the sides of eachleg. Because of the larger cross-sectional area andcapacity of the propulsion intakes, manifoldsmust be used to mix the air thoroughly.

FFG Anti-Icing System

In the FFG anti-icing air system (fig. 4-10),bleed air is taken from the common header and

Figure 4-10.—FFG anti-icing system.

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flows through the reducing valve where it isreduced to 38 psi. It then branches out into twopiping systems going to the demister pads. Whenanti-icing is activated, bleed air is dischargedon the inlet side of the demister pads throughflexible piping to prevent icing on the demisterpads for both module cooling air and combustionair. Bleed air is also provided to the intakes formodule cooling and combustion air to heat theinlet air after it has passed through the demisterpads.

MASKER AIR SYSTEM

Because of the existing differences between theship classes, we will describe their masker airsystems separately.

CG, and DD Masker Air System

The CG, and DD, masker air systemtakes hot bleed air from the bleed air system, cools

it to 190°F, and distributes it to the maskeremitter rings outside the ship’s hull. This reducesor modifies the machinery noise being transmittedthrough the hull to the water. Refer to figure 4-11,a diagram of the CG, and DD masker airsystem, to help you understand the followingparagraphs.

Bleed air at 500° to 800°F and at 75 psig fromthe bleed air header enters the masker air systemwithin each engine room and is directed to themasker air cooler valve. After the hot bleed airhas passed through the masker cooler valve, it ispiped to the masker air cooler where it is cooledto 190°F. The masker air cooler is a shell and tubetype of cooler. It uses seawater as the coolingmedium. The cooled masker air is piped throughto the masker air filter to remove any solidcontamination and then to the masker/starttransfer valve. The masker/start transfer valvecontrols the flow of the 190°F masker air to eitherthe masker air system or to the gas turbinestart/motor air system. Push buttons at the

Figure 4-11.—CG, and DD masker air system.

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control consoles or, in an emergency, manualoverride can be used to select the position of thevalve.

After the masker air passes through themasker/start transfer valve, it is piped to themasker air pressure-regulator valves. Theregulating valve maintains a 30 psig regulatedpressure in the masker emitter ring flowmanifolds. Masker air then passes into theemitter flow distribution manifold. As the maskerair leaves the manifold and enters each branchline, it passes through a flowmeter orifice to amanual flow control valve. The flowmeter orificecreates the differential pressure required tooperate its associated flowmeter. The manual flowcontrol valve establishes the prescribed masker airflow to its respective emitter ring. From themanual flow control valve, masker air continueson through a check valve and a shutoff valve. Itthen flows into the hollow emitter ring on theship’s outer hull. The emitter ring has a series of1/16-inch diameter holes in its outer wall throughwhich the air escapes.

FFG Masker Air System

In the FFG masker air system, the dischargeheader from the bleed air heat exchanger dividesinto two branch headers, one for the prairie/masker air and one for the starting air. Betweenthe bleed air heat exchanger and the two branchheaders are a temperature switch and an RTD.The temperature switch shuts the bleed airreducing valve when the bleed air dischargetemperature reaches 425°F. The RTD supplies atemperature signal to the auxiliary controlconsole (ACC) for display and alarm (400°F)indication.

The prairie/masker header divides into twobranches, one for prairie air and one for maskerair. The prairie/masker branch header has aprairie isolation valve. The masker air systemcontains a pressure-reducing valve to reduce thepressure from 75 psig to 28 psig. The masker airsystem divides into two branches, one for theforward emitter belts and one for the aft emitterbelts. The forward and aft masker flow controlvalves are operated by push buttons from theACC. Venturi-type flowmeters are provided ineach masker system branch to measure airflow.

The emitter belts are located forward and aftin port and starboard halves, each half belthaving a separate air connection. The masker airsystem discharges bleed air through each of thefour emitter connections at a rate of 425 standard

cubic feet per minute (scfm) at an approximatedischarge pressure of 12 psig. The emitters areperforated with 3/64-inch holes through whichmasker air discharges from the keel to the designwaterline. An orifice plate is fitted into theemitter belt halves on the port side to balance theair flow. A check valve is provided to prevent thebackflow of seawater into the system.

PRAIRIE AIR SYSTEM

The prairie air system modifies the thrashingnoise produced by the ship’s propellers to disguisethe sonar signature of the propellers. The systemdoes this by taking hot bleed air from the bleedair header, cooling it, and distributing it to theleading edges of the propeller blades.

The prairie air system is basically the same onall classes of gas turbine ships. Bleed air is directedfrom the header to a prairie air cooler by theprairie air valve. On the CG-, and DD-class ships, the prairie air valve is operated fromthe control console. On the FFG-class ships, theprairie air valve is a thermostatically operatedvalve, which automatically closes when thedischarge air from the cooler exceeds 150°F. Thebleed air is cooled to 100°F on the CG-, and DD-class ships and to 125°F on the FFG. Theseare the maximum prairie air temperatures. Analarm indication is given when these temperaturesare exceeded.

A manually operated flow valve is used toestablish the prescribed prairie air flow to thepropeller. From the prairie air flow control valve,prairie air is piped to the oil distribution (OD) boxon the front of the MRG. At the OD box, theprairie air enters the propeller shaft through arotoseal and travels through the shaft to thepropeller blade. It then enters the water througha series of holes on the leading edge of each blade.

COMPRESSED AIR SYSTEMS

Compressed air systems consist of the SSASor LP air system and the HP air system. Thesystems vary between ship classes and aredescribed in the following sections.

CG, AND DDLOW-PRESSURE AIR SYSTEM

The SSAS is the general-purpose air system.It provides LP air throughout the ship foroperation of most pneumatically operated

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equipment and pneumatic controls. It suppliespurified LP air to the electronics and to the HPair system dryers. Some uses of LP air in theengineering plant include the following areas:

FO fill and transfer compensating system

WHB control air

Seawater temperature control valves

FO coalescer

Clutches and/or brakes

The system has LP air compressors, air dryers,purifiers, main receivers, and a piping system. Thepiping system has valves, reducing stations, andconnections necessary to distribute compressed airto various services. A reducing station is providedin the HP air system to supplement the SSASwhen compressed air consumption exceeds ship’scompressor output. Automatic shutoff valves,called priority valves, are installed downstreamfrom all mission essential (vital) equipment andupstream from all nonessential (nonvital) services.If air pressure falls below a prescribed setting,these valves close and eliminate use of non-essential services during the reduced pressureperiod.

Ships have so many variations as to the typeand number of compressors, the system pressuresettings, and priority valve settings that we willnot attempt to cover this material. Refer to theship’s equipment technical manuals and EOSS fora more in-depth description of each individualsystem.

CG, AND DD,HIGH-PRESSURE AIR SYSTEM

The HP air system provides HP air to theweapons systems, aviation equipment, gas turbinestarting, and backup air for the SSAS. The systemhas two compressors that supply 3000 psig of airto the storage flask. The air then goes into thesystem through a dehydrator. The dehydratorprovides moisture-free, oil-free, and contaminant-free air to the system.

The HP air system is primarily maintained byA Division. As a GS, you will find it is used inthe engine room as the primary/emergency airstart for the ship’s main engines and generators.The HP air flasks are located in each engine roomand the No. 3 generator room. Air for the main

engine start is reduced to 250 psig by the HPreducing valve and then to 85 psig through a seriesof orifices. The ships do not have HPair start capability for its main engines. The CG-class ships have air pressures of 220 psig throughthe reducing valves and 45 psig through theorifices. All ships have HP air start capability forthe ships’ generators. The 3000 psig of air isreduced to starting pressure by the start air valve.The 3000 psig of air is also used to back up theLP air supply through a reducing station in theNo. 1 engine room. The pressure varies betweenships. For the proper setting, consult your ship’sEOSS.

FFG LOW-PRESSURE AIR SYSTEM

The SS air is provided by two LP, screw-typecompressors that have a capacity of 100 scfm ata discharge of 125 psig. The compressors provideair to a vital air main, a nonvital air main, anda loop branching off the vital air main thatsupplies air to electronics equipment. Dry air isdelivered to the electronics equipment by theprocessing of air from the vital main throughdehydrators. The vital air main piping is crossconnected between the two compressors andprovides control air to the vital services in themachinery spaces. The nonvital services are fedfrom the nonvital air main through priority valves.The priority valves are located between the vitaland nonvital air mains. These priority valves aredesigned to shut off air to the nonvital air mainif the demands on the whole system (vital andnonvital) are greater than the compressors canprovide and if the pressure falls to 85 psig.

A cross connection through a manifold reduc-ing station automatically provides HP air to thevital air main. The HP air at 3000 psi is reducedto the SSAS pressure and thereby backs up thevital air main. The reducing station is set at80 psig so it will deliver air when the vital mainhas dropped to 80 psig.

FFG HIGH-PRESSURE AIR SYSTEM

The FFG HP air system has two HP aircompressors capable of providing 3000 psig to thesystem. Each compressor is provided with an airdehydrator to remove solid contaminants andparticulate and vaporous water and oil fromthe air. An air flask is installed at eachcompressor downstream of the dehydrators. Theair compressors are designed for continuousautomatic operation. A pressure switch located

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in the discharge piping from each compressorautomatically controls the starting and stoppingof the compressor based on pressure in the HPair main. Relief valves are provided throughoutthe system to provide protection from over-pressurization. Some uses of HP air in theengineering plant include the following areas:

Ship’s service diesel generator (SSDG)starting

Emergency LO coast down pump

Propulsion shaft brake

Back up for LP air system

LM2500 GTE start

DRAINAGE ANDBALLAST SYSTEMS

This section describes the three primarysystems that make up a ship’s drainage system,the major equipment that makes up each system,and the function of each system in support of thepropulsion plant. The systems are the maindrainage system, the secondary drainage system,and the ballast system. The purpose of thesesystems is to provide a means for dewatering themain engine room(s) (MER) and the AMRs, aswell as several other spaces both forward and aftof the machinery spaces. Always refer to yourship’s EOSS for detailed information on thesesystems.

MAIN DRAINAGE SYSTEM

The main drainage system has two types ofsubsystems, the main drainage eductor subsystem(a fixed-eductor subsystem) and the main drainagebilge pump subsystem (a positive-displacementpump subsystem). The fixed-eductor subsystemis arranged with the other main drainage sub-system so they can be cross connected. Bothsubsystems are primarily associated with drainagewithin the main machinery spaces and with branchlines that serve various auxiliary space bilgesthroughout the ship. The main drainage systemalso takes suction from and discharges to the cleanballast tanks, the FO overflow and ballast tanks,and the FO or ballast tanks through interlockedmanifolds for ballasting and deballasting.

The main drainage system will normally havethe following major components:

1.

2.

3.

4.

5.

6.

Eductors of 1250 gpm capacity (in eachengine room and auxiliary space).Suction stop-check valves (one for eachdrain well and each waste water tank).Deck-operated gate valves used to isolatesections of the system. These valves areequipped with manual local and remoteoperators.Discharge stop-check valves to preventinadvertent flooding of other spaces duringeductor operation.Interlocked valve manifolds to provideconnection between the main drainage,ballast, and firemain system.Various valves, gauges, and indicating andcontrol devices to support the eductorsystem.

The main drainage bilge pump subsystemserves the same drainage main as the eductor sub-system. However, it uses an electric motor-drivenpump to remove drainage. This system also hascross-connect fittings to provide a backup pumpfor the bilge pump installed in the oily waste watersystem. It allows the pump in that system tobackup the pump in the main drainage system.

SECONDARY DRAINAGE SYSTEM

The secondary drainage system is an in-dependent fixed-eductor system primarilyassociated with dewatering the following types ofspaces:

The chain locker

The eductor rooms

The magazine service rooms

The guided missile launcher system(GMLS) magazines

The steering gear room (usually served bya separate drain pump, but considered partof the secondary drain system)

BALLAST SYSTEM

The ballast system is used to ballast anddeballast clean ballast, FO overflow and ballast,and FO or ballast tanks. Seawater connections

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from the firemain system through interlockingmanifolds provide the source of ballast water.

FIREMAIN SYSTEM

The firemain system (also called fire andflushing system) is a dual-purpose system. Itcombines the services normally provided by theauxiliary seawater cooling system besides thenormal services provided by the fire and flushingsystem. This system provides the following typesof service:

1. Fire fighting The seawater service system is the ship’s2. Ballast and flooding control principal cooling water system. This system3. Sanitary and waste disposal distributes seawater throughout the engineering4. Countermeasures plant at prescribed pressures and flow rates for5. Electronics cooling cooling LO, compressed air, and auxiliary6. Auxiliary machinery cooling machinery. Although the different ship classes7. Weapons cooling provide the same basic services, they are set up8. Sprinkling system differently. Therefore, we will describe them9. Flushing individually.

A simplified schematic of a firemain isshown in figure 4-12. This schematic showsthis system as having five pumps feedingtwo firemains, one on the port and the otheron the starboard side. The port is also referredto as the upper main and the starboard asthe lower main. These mains can be cross-connected or isolated by opening or closing thevalves designated Z.

SEAWATER SERVICE SYSTEM

Figure 4-12.—Firemain diagram.

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CG, AND DDSEAWATER SYSTEMS

During normal operations, seawater is suppliedto the seawater service system through one of thethree seawater service pumps. When thesystem demand increases, a second pumpcan be started or seawater can be supplied throughone of three fire main reducing stations. The seawatermain also provides backup cooling to the SS generators. Ifthe generator cooling system fails, the seawatermain automatically cuts in.

The systems on the CG-, and DD-classships are basically the same. The basic system hasthree seawater service pumps that supply coolingwater to a variety of equipment. These pumps arecentrifugal pumps that can be controlled locallyat their respective motor controllers or remotelyfrom the PACC. These pumps take suctionthrough a sea chest and then through ahydraulically operated valve. This valve iscontrolled from the damage control deck. It isused in case of damage to the system piping toprevent flooding from the sea. This valve can alsobe manually overridden at the valve location.From there flow is through a manual suctionvalve, a manual discharge valve, and a check valvethat is used to prevent backflow to the pump.Relief valves protect the seawater system andassociated equipment from overpressurization.Pressure settings on the relief valves andreducing stations and system pressure itself varybetween ships. Consult your ship’s EOSS for theproper settings and alarm conditions.

Reducing stations are provided on the DD-class ships to reduce pressure for useon the various equipment. However, designmodifications to the system pressure on the CG-class ships have eliminated most of the reducingstations. The ones remaining are for the firemain-to-seawater system and the CRP cooler.

Temperature regulation of the reduction gearLO cooler, control of the waste heat boilercondensers, and the condensate drain coolers isdone by pneumatically operated temperatureregulators. These regulators control the flow ofseawater through the coolers to maintain thetemperature of the liquid being cooled withinprescribed limits. The CG-class ships have a CRPcooler that is temperature regulated.

Nine manual/hydraulic operated butterflyvalves are associated with the seawater servicesystem. Three of these valves control the flow ofseawater to the three seawater pumps, as mentionedpreviously. Six valves are installed at various

locations along the seawater service main tocontrol the flow of seawater through the main.

To prevent marine growth and systemcontamination, the system has simplex, duplex,basket, and Y-type strainers located throughoutthe system.

FFG SEAWATER SYSTEMS

The FFG-class ships have three separatesystems within the seawater cooling system. Thesesystems are

1. the main propulsion reduction gear coolingsystem,

2. the SSDG cooling system, and3. the auxiliary cooling system.

Main Propulsion ReductionGear Cooling System

Two propulsion seawater circulating pumpssuction directly from the sea and discharge to thereduction gear LO cooler. Each pump can supply100 percent of system capacity and serves as astandby for the other pump. Each pump has itsown sea suction line that suctions from thesea through its own independent sea chest andsuction valve. Each pump discharges to acommon header through its own strainer anddischarge valve. The common header is connectedto the reduction gear LO cooler. Cooling waterdischarged from the LO cooler is piped overboardthrough a common pipe and the LO cooler over-board discharge valve. Each seawater circulatingpump can be started and stopped either locallyor remotely.

SSDG Cooling System

Each SSDG has its own dedicated seawatercooling system and an emergency cooling watersupply from the firemain. Each SSDG coolingsystem has a seawater circulating pump, a duplexstrainer, and motor-operated suction and over-board discharge valves. Each pump takes suctionfrom its own sea chest by way of its own suctionline and valve. The pump’s discharge passesthrough a duplex strainer and then branches intomultiple paths to provide cooling water to thevarious coolers of the SSDG. The outlet of thecoolers then joins into a single discharge linebefore going overboard through the motor-operated discharge valve. The seawater circulating

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pump for each SSDG is interlocked to startautomatically whenever the SSDG starts.

Emergency cooling water from the firemainsystem is piped directly to each diesel generatorcooling system at a point downstream of theduplex strainer. The firemain interface has amotor-operated emergency cooling valve and apressure-regulating valve. The motor-operatedvalve is electrically connected to the generatoroutput and opens on start-up and closes uponsecuring the diesel. The pressure-regulating valvecontrols firemain flow and pressure by openingwhenever the normal cooling water systempressure drops below 35 psig. The two SSDGs inAMR2 are provided with one common emergencyfiremain cooling water supply. The SSDGs inAMR1 and AMR3 have their own emergencyfiremain cooling water supplies.

Auxiliary Cooling System

The firemain also provides direct seawatercooling to various nonpropulsion auxiliary equip-ment. Such equipment includes the LP andHP air compressors, air-conditioning plants,refrigeration plants, and some electronic coolingwater systems. The firemain in the engine roomprovides cooling water to the propulsion gasturbine, the bleed air cooler, the prairie air cooler,and the gas turbine starting/motoring air cooler.The firemain in AMR3 provides filtered seawaterfor cooling, lubricating, and flushing the sterntube shaft seal and the stern tube bearing.

STEAM AND WASTEHEAT SYSTEMS

On the CG-, and DD-class ships, steamis generated by three WHBs using the hot exhaustgas from the GTGSs as the heat source. Thissteam is used for numerous support systemfunctions, which will be described in the nextparagraph. On the FFG-class ship, these samefunctions are performed by the waste heatcirculating system. The primary purpose of thewaste heat circulating system is to conserve theship’s expenditure of energy. This is accomplishedby using waste heat from the SSDGs.

CG, AND DD STEAMDISTRIBUTION SYSTEM

Steam from the WHBs is piped to the port andstarboard steam mains and auxiliary machinery

rooms at 100 psig. It is distributed for the follow-ing equipment and usage:

FO system service heaters, service tankheating coils (when used), and transferheaters

LO system purifier heaters and settlingtank heaters

Seawater suction sea chest steam out

Hot water heating system

Mk 26 GMLS anti-icing system

Distilling plant steam air ejectors and feed-water heating through a 100/50 psigreducing station

Galley equipment, steam kettles, dish-washers, the dough proofer, and thegarbage disposal area through a 100/50psig reducing station

Filter cleaning room

Laundry dryer and presses

Antisubmarine rocket (ASROC) heatingand cooling system (where applicable)

Heating, ventilation, and air conditioning(HVAC) system preheaters and reheaters(where applicable)

FFG WASTE HEATDISTRIBUTION SYSTEM

Each SSDG is supported by two jacket waterheat exchangers. One heat exchanger cools thejacket water using seawater as a cooling mediumand the other cools the jacket water with the wasteheat circulating system. The waste heat circulatingsystem is a pressurized closed loop hot-watersystem. It provides heating to the followingservices:

Distilling plants Nos. 1 and 2

Potable water heater

Hot potable water accumulator

LO purifier heater

FO service heaters Nos. 1A and 1B

FO transfer heaters Nos. 1 and 2

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FIRE-EXTINGUISHING SYSTEMS

The fire-extinguishing systems discussed in thissection are limited to fixed equipment. Theportable fire-fighting equipment is mentioned forinformation purposes only. The fire-fightingsystems are numerous and vary among thedifferent ship classes. The fire-fighting systemsdiscussed here include the Halon 1301 system, theaqueous film forming foam (AFFF) system, andthe fixed CO2 system. Other systems or fire-fighting equipment used onboard ship include theaqueous potassium carbonate system, portableCO2 fire extinguishers, and portable potassiumbicarbonate (PKP) extinguishers. You will haveto qualify on the systems pertinent to your shipduring your general damage control qualifications.

HALON 1301FIRE-EXTINGUISHING SYSTEM

Halon fire extinguishing is accomplished byflooding a space with Halon 1301 gas to interruptthe chain reaction during combustion. Halon 1301is a colorless, odorless, electrically nonconductivevapor that puts out fires by using a differentprinciple than most other fire-extinguishingsystems. While CO2, water, or foam attack fireby smothering, cooling, or separating the fuelfrom its oxygen source, Halon combines with thefuel vapors/oxygen molecules in such a way asto stop the combustion process from occurring.The amount of Halon 1301 gas stored on thevarious class ships is solely dependent on thenumber and volume of the spaces being protected.

Although Halon 1301 is a very low toxicityvapor allowing limited exposure without detri-mental effects, it decomposes upon contact withflames and on hot surfaces above 900°F. Whilethis action is necessary for the product tofunction effectively as a fire-extinguishing agent,it also results in the formation of severalnew chemical compounds, which have differentproperties. These post combustion products arelethal in large concentrations, but they are easilydetectable at sublethal levels by eye, skin, andmucous membrane irritation. At higher sublethallevels, a sour taste becomes evident.

AQUEOUS FILM FORMINGFOAM SYSTEM

The AFFF system provides fire protection forareas of the ship where major fuel and/or oil fires

are likely to start. The AFFF system mixesconcentrated AFFF with seawater from thefiremain. A mixture of 6 percent foam and94 percent seawater is used to blanket (smother)a fire. After the water is initially drained off, afilm remains denying oxygen to the fuel source.Being sealed off from reignition allows timefor cooling off. Each AFFF station aboard shipsupports several hose reel/sprinkling heads inits area. Each AFFF station usually has a con-centrate storage tank and a foam proportioner.The mixture discharged from the proportionersis piped either to sprinkling heads or hoseconnections.

FIXED FLOODING CO2 SYSTEM

Independent fixed flooding CO2 systems areinstalled in the GTE modules and certain otherauxiliary spaces on various classes of ships. WhenCO2 release is activated, a time delay permitspersonnel to escape from the space before CO2is actually released. A pressure switch in eachsystem activates audible and visual alarms locallyand remotely (usually at the DCC). Ventilationfans serving the affected area are also shutdown.

SUMMARY

We have described the functions and opera-tions of the following auxiliary and supportsystems for the gas turbine powered ships in thischapter: the LO fill and transfer system, the mainLO system, the FO systems, the bleed air system,the compressed air systems, the drainage andballast systems, the firemain system, the seawaterservice system, the steam and waste heat systems,and the fire extinguishing systems. You will needto become familiar with all of these systems toproperly operate the engineering plant. While themain engines are the heart of the engineeringplant, without the support systems the ship wouldnot operate.

As you can see in reading through this chapter,the systems vary greatly between ship classes andeven between ships of the same class. You shouldstudy your own ship’s engineering plant and readthe ship’s EOSS and technical manuals to be ableto operate, repair, and maintain your individualship’s equipment.

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CHAPTER 5

PACC AND PLCC FORDD- AND CG-CLASS SHIPS

Up to this point we have discussed theoperation and the construction of the gas turbineengineering plant. One of the revolutionaryaspects of the gas turbine plant is its ability to beoperated locally or from a remote central point.Local operation is accomplished at the PLCC,while the central point is the PACC in theCCS. Systems that are not controlled in theCCS may at least be monitored from there. Thisallows for reduced watch standing outside theCCS as opposed to older ships that requiredwatch standers throughout the plant. Also,the EOOW and propulsion, electrical, anddamage control watch standers have a quickerlook at all vital parameters associated with plantoperation.

The CCS is manned 24 hours a day either inport or at sea. At sea it is normally manned byan EOOW (either an officer or senior enlisted),a PACC operator (usually a senior GS pettyofficer), an EPCC operator (usually a pettyofficer GSE or EM), and a DCC operator(normally a Damage Controlman (DC) or a HT).A fuel king will monitor the fuel system controlconsole (FSCC) when necessary. Normally, thein-port watch in the CCS is stood by a single watchstander, who is usually a qualified engineeringpetty officer. At some point you will stand watchin the CCS. Therefore, you should becomefamiliar with all operations that may occur in theCCS.

After reading this chapter and completing theassociated NRTC, you should have a good under-standing of the functions of the PACC and PLCCfor the DD- and CG-class ships. This material ismeant for training purposes only. It is not meantto replace the EOSS or technical manuals.

You should have no problem qualifying as awatch stander if you seek the help of anexperienced watch stander, use the knowledge

gained in this chapter, follow the EOSS, andcomplete the PQS requirements.

The abbreviations and acronyms for an itemmay differ between the ship classes. For example,on the DD-class ships, GB is the abbreviation usedfor generator circuit breaker. On the FFG-classships, generator CB is the abbreviation used forgenerator circuit breaker. In this book we will usethe abbreviation/acronym appropriate for theclass ship discussed.

PROPULSION AND AUXILIARYCONTROL CONSOLE

The PACC is a five-bay console (fig. 5-1) witheight front panels and an integrated throttlecontrol (ITC) panel. The primary purpose of thePACC is to house the controls and status/alarmindicators of the four gas turbine modules (GTMs)and all the auxiliary equipment for operating themain GTMs for both engine rooms. The operator,when seated facing the PACC panels, is facingthe bow of the ship. All the controls andindicators on the two left bays correspond to theequipment in engine room No. 1, which drives theport shaft of the ship. All the controls andindicators on bays No. 3 and No. 4 are relatedto the equipment in engine room No. 2, whichdrives the starboard shaft of the ship. Thecontrols and indicators on bay No. 5 are directlyrelated to the ship’s auxiliary subsystems and theGTM/GTG bleed air systems. We will try, wherepossible, to describe the PACC panels from leftto right, top to bottom. The figures used in thischapter will show the PACC and PLCC for theDD-class ship. If the section or subsection of theconsole on a CG-class ship is different, we willuse inserts only of that particular section of theCG-class PACC and PLCC. In some instances,where the components are directly related, we maydescribe a component out of sequence.

5-1

Figure 5-1.—PACC.

ENGINE ROOM NO. 1 PANEL

Figure 5-2 shows the engine No. 1 paneldivided into five sections for engine room No. 1.These sections are labeled RDCN GEAR LUBO,CRP, FUEL OIL, GTM 2B (including alarm,manual start push-button indicators, and torqueand LO pressure meters for both GTMs), andLUBE OIL.

RDCN GEAR LUBO Section

The first section on the panel, the RDCNGEAR LUBO section, is used to monitor theMRG LO system. It has an alarm indicator anda pressure meter. The parameters for this panelare sensed at the lower outboard first reductiongear bearing. The alarm indicator set point is 5psig. The meter reads 0 to 25 psig. Because thereis a certain amount of head pressure in the LOsupplied to this bearing and its sensor, the metertends to read 1 to 3 psig higher than actual LOheader pressure.

5-2

Figure 5-2.—PACC—engine No. 1 panel.

CRP Section

The next section on the panel, the CRPsection, is used to monitor the CRP system. It hassix alarm indicators (seven on the CG), a meter,

and a push-button control indicator (two on theCG). The first alarm indicator is labeled SUMPTANK TEMP HI/LO. It is a red indicator thatilluminates when the CRP sump tank LOtemperature is below or exceeds its alarm set

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point. To the right is an alarm indicator labeledOIL TEMP HI. It is an amber indicator thatilluminates when the temperature of the LO fromthe pump to the system exceeds its alarm set point.The next alarm indicator is labeled SUMP LEVELLO. It is also an amber indicator that illuminateswhen the CRP sump tank LO level is below 500gallons. To the right is an alarm indicatorlabeled OIL HEAD TK LEVEL LO. It is anamber indicator that illuminates when the CRPhead tank LO level is below 10 gallons. On thethird row is the alarm indicator labeled FILTERS∆P HI. It is a red indicator that illuminates whenthe LO pressure across either of the three filterson the hydraulic oil power module (HOPM) ofthe CRP system exceeds its alarm set point. Thelast alarm indicator on the DD console is labeledELECTRIC PUMP FAULT. It is a red indicatorthat illuminates when the electric pump isrunning and pump discharge pressure drops below100 psig for more than 5 seconds.

On the CG console, the last alarm indicatoris labeled HYDRAULIC PRESS LO. It illuminatesred when the pump discharge pressure dropsbelow 100 psig for 5 seconds.

The only meter associated with the CRP islabeled HYD PRESS TEMP. It is a dual-indicating meter used to monitor the pressure andtemperature of the HP oil at the output of theHOPM to the OD box.

The push-button control indicator on the CGconsole under the label PUMP MODE has a split-legend indicator, labeled AUTO/MANUAL. Ifthe AUTO mode is selected by the PACCoperator, the electric CRP pump will come on theline if any one of the following conditions are true:

1. The attached pump output pressure is< 100 psig for 1 second.

2. Shaft speed is < 90 rpm for 10 seconds.3. If the pitch mismatch > 10 percent for 1

second.

NOTE

On the CG-class ship, if the electricpump control mode is in auto, once thehydraulic oil pressure recovers (as a resultof pump speed increase or other operatoractions) the electric pump must be manuallysecured by the PACC operator.

The push-button control indicator on theDD console under the label ELEC PUMP has asplit-legend indicator labeled RUN/STOP. It isused to control the CRP electric LO pump andilluminates (either green or red) to indicate thestatus and operator command to the pump.

FUEL OIL Section

This section is used to monitor the FO servicesystem. It has 11 alarm indicators, 10 statusindicators, a meter, 4 valve control switches, athree-position rotary switch for pump modecontrol, 6 push-button control indicators, and2 station-in-control status indicators.

The first two alarm indicators are a pair offunctionally identical indicators. They are labeledPUMP B FAULT and PUMP A FAULT. Theseindicators are red and illuminate when either FOservice pump is running and the pump dischargepressure drops below 35 psig for 5 seconds. Thenext alarm indicator is labeled FILTER ∆P HI.

5-4

it is a red indicator that illuminates when thedifferential pressure across the fuel coalescerexceeds 30 psid. The alarm indicator labeledFILTER WATER HI is a red indicator. When itis illuminated, the water level in the fuel coalesceris high. The alarm indicator labeled SUCTIONSTR ∆P HI is a red indicator. When it isilluminated, the differential pressure across theFO suction strainer exceeds 4 psid. The alarmindicator labeled HEADER TEMP HI/LO is ared indicator. When it is illuminated, the headerFO temperature either exceeds 130°F or is below80°F. The alarm indicator labeled DRAIN TANKLEVEL HI is a red indicator that indicates theFO leak detection tank fuel level exceeds 2.5gallons. The alarm indicator labeled HEATERTEMP HI illuminates red to indicate that the FOheater discharge temperature is > 140°F. The lastalarm indicator labeled HEADER PRESS LOilluminates red when the FO header pressure is< 40 psig.

The next group of alarm and status indicatorsare pairs of functionally identical indicators. Thefirst pair of alarm indicators labeled FILTER BBLOCKED and FILTER A BLOCKED areamber indicators. When they illuminate, thedifferential pressure across their respectivecoalescer exceeds 25 psid. Below this pair are twostatus indicators labeled GTM B BYPASS OPENand GTM A BYPASS OPEN. These two statusindicators were part of the original system design,but due to later system modifications, neitherindicator is functional. The next pair of statusindicators TK B SUCT VALVE OPEN and TKA SUCT VALVE OPEN are green indicators.They illuminate when their respective FO servicetank suction valves open. Next are two statusindicators labeled TK B SUCT VALVE CLOSEDand TK A SUCT VALVE CLOSED. Theyilluminate red when their respective FO servicetank suction valves close. Next are two statusindicators labeled TK B RECIRC VALVE OPENand TK A RECIRC VALVE OPEN. Theyilluminate green when their respective FO servicetank recirculating valves open. The last pair ofstatus indicators are labeled TK B RECIRCVALVE CLOSED and TK A RECIRC VALVECLOSED. They illuminate red when theirrespective FO service tank recirculating valvesclose.

Under the label HEADER is a dual-indicatingmeter. This meter monitors the TEMP andPRESS of the FO system. The FO system

temperature is sensed at the FO heater outlet andthe FO system pressure is sensed at the coalesceroutlet. A second meter, located to the right of theHEADER dual-indicating meter was originallydesigned for this console. It has been deleted bydesign changes and the space on the consoleblanked off.

Under the label SERVICE TANK VALVESare two covered toggle control switches. They area pair of functionally identical switches labeledB OPEN/CLOSED and A OPEN/CLOSED.

5-5

Each toggle switch controls its respective tank’ssuction and recirculation valves. The PACCoperator uses these toggle switches to commandthe respective FO tank suction and recirculationvalves either open or closed. Under the labelEMERG FUEL TRIP are a pair of functionallyidentical, covered toggle control switches labeledB and A. The PACC operator uses these toggleswitches to close the emergency FO trip valves.These valves must be manually reopened at thevalve.

Under the label PUMP are the six push-buttoncontrol indicators. There are two columns of threepush buttons for each pump (B or A). The PACCoperator uses these push buttons to control thepump speed of either or both FO pumps. Thepush buttons labeled FAST and SLOW are greenstatus indicators that illuminate the status orcommand to the respective pump, depending onthe operating mode the PACC operator selects.The push buttons labeled STOP are red indicatorsthat illuminate the status or command to therespective pump.

Under the EMERG FUEL TRIP toggleswitches are two status indicators. The firstindicator is green and labeled CCS CONTROL.It illuminates when CCS has control of the FOsystem. The other indicator is amber and labeledPLCC CONTROL. It illuminates when controlof the FO system is at the PLCC.

Under the label PUMP MODE is the three-position rotary switch. The positions are labeledB LEAD, MANUAL, and A LEAD. The PACCoperator uses this rotary switch to select eitherthe manual mode of pump operation or theautomatic mode. The automatic mode is selectedby placing the rotary switch in either theB LEAD or A LEAD position. The positiondesignated by the PACC operator determineswhich pump is the lead pump and which pumpis the standby pump.

GTM 2B Section

The GTM 2B section is used to monitorvarious parameters of the GTM 2B. It has 30alarm indicators (32 on the CG console), 9 statusindicators (7 on the CG console), 2 dual-indicatingmeters, and the GTM 2B MANUAL STARTcontrols with 12 push-button control indicators(9 on the CG console) and 2 status indicators. Theindicators are arranged in three columns. We will

describe them from left to right and top tobottom.

The first alarm indicator labeled MODULEFIRE illuminates red when a fire occurs in theGTM module. It can be activated either by theUV sensors in the module or an RTE in theoverhead of the module. The alarm indicatorlabeled LUBO PRESS LO TRIP illuminates redwhen a GTM shutdown at 6 psig LO pressureoccurs. The alarm indicator labeled PLA ACTFAIL illuminates red when the voltage level to thePLA is out of limits or an overtorque conditionexists on the GTM. The first alarm indicator onthe second row across is labeled FUEL TEMP LO.It illuminates amber when the FO temperature tothe GTM is below 80°F. The alarm indicatorlabeled FUEL FILTER BLOCKED illuminatesamber when the differential pressure of the filteron the GTM exceeds 27 psid. The alarm indicatorlabeled FUEL WAX FORMING illuminates redwhen the FO temperature at the MFC is 60°F orbelow.

The first alarm indicator on the third rowdown is labeled LUBO LEVEL LO. It illuminatesred when the LO level in the LOSCA is 8 gallonsor less. The alarm indicator labeled LUBOSUPPLY PRESS LO illuminates red when the LOpressure to the GTM is 15 psig or less. The alarmindicator labeled LUBO COOLER OUT TEMPHI illuminates amber when the LO temperatureat the outlet of the LOSCA exceeds 250°F. Thealarm indicator labeled LUBO LEVEL HI on thefourth row illuminates amber when the LO levelin the LOSCA is 40 gallons or more. The alarmindicator labeled LUBO SUPPLY FILTER BLKilluminates amber when the differential pressureof the LO supply filter in the GTM moduleexceeds 20 psid. The alarm indicator labeledLUBO SCAV FILTER BLK illuminates amberwhen the differential pressure of the LO scavengefilter on the LOSCA exceeds 20 psid.

Beginning on the fifth row, the next five alarmindicators labeled SCAV TEMP A HI, SCAVTEMP B HI, SCAV TEMP C HI, SCAV TEMPD HI, and GRBX SCAV TEMP HI are allfunctionally identical indicators. They illuminatered when the respective LO scavenge temperatureis > 300°F. The next alarm indicator (on the CGconsole) is labeled BLOW IN DOOR OPEN. Itilluminates red when the blow-in doors in theuptakes are open.

On the seventh row, the first alarm indicatoris labeled COOLING SYSTEM FAIL. Itilluminates red when the cooling system fanpressure is out of limits or the vent damper is not

5-6

open. The alarm indicator labeled GG OVER-SPEED illuminates red if the GG speed is > 9700rpm. The alarm indicator labeled COOLING AIROUT TEMP HI illuminates amber when themodule cooling air is > 350°F.

On the eighth row, the first alarm indicatoris labeled GG VIB HI. It illuminates red when theGG vibration is at 6 mils or higher. The alarmindicator labeled GG VIB STOP illuminates redwhen an auto shutdown of the GTM at a GGvibration of 7 mils occurs. The alarm indicatorlabeled PT INLET GAS TEMP HI illuminatesred if T5.4 is > 1500°F.

On the ninth row, the first alarm indicator islabeled PT VIB HI. It illuminates red when powerturbine vibration is at 7 mils or higher. The alarmindicator labeled PT VIB STOP illuminates redwhen an auto shutdown of the GTM occurs ata power turbine vibration of 10 mils. The alarmindicator labeled PT OVERSPEED illuminatesred if power turbine speed exceeds 3700 rpm.

On the tenth row, the next pair of alarmindicators, labeled PT OVSP NO 1 TRIP and PTOVSP NO 2 TRIP, are functionally identicalindicators. They illuminate red when an autoshutdown of the GTM occurs. This is caused bythe respective PT speed sensor detecting a PTspeed of 3960 ± 40 rpm. The alarm indicatorlabeled PT OVERTEMP TRIP illuminates red ifan auto shutdown of the GTM occurs due to T5.4exceeding 1625°F.

On the CG console, the first alarm indicatoron the eleventh row is labeled MDL ACCESSDOOR OPEN. It illuminates amber when a dooron the GTM module is open. The alarm indicatorlabeled FIRE DETECTOR FAIL illuminatesamber if the fire detection circuitry fails orif a UV sensor in the GTM fire detection systemfails.

The first status indicators on the twelveth andthirteenth rows are labeled NO 1 FUEL VALVEOPEN and NO 2 FUEL VALVE OPEN. Theyare a pair of functionally identical indicators.They illuminate green to indicate the respectivefuel supply valve is open. The second status/alarmindicators on the twelveth and thirteenth rows arelabeled TACH NO. 1 LOSS and TACH NO. 2LOSS. They are a pair of functionally identicalindicators. They illuminate amber if the respectivespeed sensor detects a PT speed of < 100 rpm (or

a speed sensor failure). The last status indicatoron the twelveth row is labeled BLEED AIRVALVE OPEN. It illuminates amber when thebleed air valve is open. The last status indicatoron the thirteenth row is labeled BLEED AIRVALVE CLOSED. It illuminates green when thebleed air valve is closed.

The first two alarm indicators on the four-teenth row are labeled GG VIB SENSOR FAILand PT VIB SENSOR FAIL. They are a pair offunctionally identical indicators. These two alarmindicators are NOT on the CG console. Theyilluminate amber if one of the GG or one of thePT vibration sensors fail. The last status/alarmindicator labeled STARTER CUTOUT illuminatesamber if the starter fails during a start or whenthe GG speed reaches 4500 rpm and the start airvalve closes.

Under the label TORQUE is a dual-indicatingmeter labeled 2B and 2A. This meter indicates thetorque output of the respective PTs and reads inft/lb. The signals to these meters come from therespective GTMs and are conditioned by the FSEEbefore being sent to the console for display. Underthe label GTM LUBE OIL PRESS is a dual-indicating meter labeled 2B and 2A. This meterindicates the GTM LO supply pressure of therespective GTM. The signals for these meterscome from the discharge side of the respective LO

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supply pump and are sent to the console fordisplay.

In the subsection labeled GTM 2B MANUALSTART are 12 push-button control indicators (9on the CG console) and 2 status indicators. Thefirst push-button control indicator (not on theCG console) is labeled FUEL PURGE ON andilluminates amber when activated by the PACCoperator. The PACC operator uses this pushbutton to dump cold fuel from the GTM to thewaste oil drain tank. This push button is normallyused when the module FO temperature is below80°F.

The next push-button control indicator is asplit-legend type labeled AUTO BRAKE CLUTCHMODE/MAN BRAKE CLUTCH MODE(AUTO BRAKE MODE/MAN BRAKE MODEon the CG console). The AUTO BRAKECLUTCH MODE (AUTO BRAKE MODE onthe CG console) must be illuminated when an autosequence start is initiated at the PACC. It workswith the AUTO INITIATE start/stop mode.Automatic clutch and brake commands aretransmitted to the PLCC MRG control circuitry.The MAN BRAKE CLUTCH MODE (MANBRAKE MODE on the CG) portion of thisindicator illuminates white when the PACCoperator wants to perform a manual start of theGTM. The PACC operator will command thedifferent statuses of the clutch and brake usingthe four momentary-contact push buttons tothe right of this indicator. They are labeledCLUTCH ENGAGE (not on the CG console)(illuminates green to show command), CLUTCHDISENGAGE (not on the CG console) (il-luminates white to show command), BRAKE ON

(illuminates red to show command), and BRAKEOFF (illuminates green to show command).

The push-button control indicator on thesecond row labeled IGNITER ON illuminatesgreen when the PACC operator commands theigniters on during a manual start. It alsoilluminates when the igniters are energized duringan auto initiate start. The next split-legend,push-button control indicator is labeled VENTDAMPER OPEN/VENT DAMPER CLOSED.It illuminates to show the command to the ventdamper. On the third row is a split-legend, push-button control indicator labeled MAIN FUELVALVE OPEN/MAIN FUEL VALVE CLOSED.It illuminates to show the command to the fuelsupply valve during a manual start, auto start,manual stop, or auto stop. The split-legend, push-button control indicator labeled COOLING FANON/COOLING FAN OFF illuminates to showthe PACC operator’s command to the cooling fanduring a manual start. It also illuminates when theelectronics generates the command during an autostart. On the fourth row is a split-legend, push-button control indicator labeled BLEED VALVEOPEN/BLEED VALVE CLOSE. It illuminatesto show the PACC operator’s command to thebleed air valve during a manual start. It alsoilluminates when the electronics generates thecommand during an auto start. The push-buttoncontrol indicator labeled STARTER AIR ONilluminates to show the PACC operator’scommand to the start air regulating valve duringa manual start or when the starter air is onduring an auto initiate start.

The two status indicators at the lower rightare labeled CCS CONTROL and PLCC CON-TROL. The CCS CONTROL indicator illuminatesgreen when the PACC has control of the GTM.The PLCC CONTROL indicator illuminatesamber when the PLCC has control of the GTM.

5-8

LUBE OIL Section

This section is used to monitor the MRG LOsystem. It has one dual-indicating meter, acolumn of six alarm indicators (seven onthe CG console), three status indicators, sixpump push-button control indicators, and athree-position rotary switch for pump modecontrol.

The dual-indicating meter is labeled HDRTEMP/HDR PRESS. It is used to monitorthe temperature and pressure of the LO atthe MRG header. The temperature side reads indegrees Fahrenheit and the pressure side readspsig.

The alarm indicator labeled HEADER PRESSHI/LO is the first of the six alarm indicators. Itilluminates red if the MRG LO pressure exceeds27 psig or drops below 15 psig. Next is HEADERTEMP HI/LO, which illuminates red if the MRGLO temperature > 130°F or is < 90°F. The thirdone is SUMP LEVEL LO, which illuminatesamber if the LO level in the MRG sump dropsbelow 1400 gallons. The alarm indicator labeledHEATER TEMP HI illuminates amber if the LOdischarge temperature of the LO service systemheater exceeds 170°F. The fifth alarm indicatoris labeled SETTLING TK TEMP HI. Itilluminates amber if the temperature of the LOin the settling tank exceeds 170°F. The last oneis STRAINER DP HI. It illuminates red if thedifferential pressure across the LO strainerexceeds 10 psid.

Under the label PUMP are the six push-buttoncontrol indicators. There are two columns of threepush buttons for each pump (B or A). The PACCoperator uses these push buttons to control thepump speed of either or both LO pumps. Thepush buttons labeled FAST and SLOW are greenstatus switch/indicators that illuminate to showthe status or command to the respective pump,depending on the operating mode the PACCoperator selects. The push buttons labeled STOPare red status indicators that illuminate toshow the status or command to the respectivepump. On the CG console, the additional alarmindicator labeled LO PURIFIER MALFUNCTIONilluminates red when a malfunction of the MRGLO purifier occurs.

The status indicator labeled PURIFIER ONilluminates green when the MRG LO purifier isrunning. Under the PURIFIER ON indicator aretwo status indicators. The first status indicatoris green and labeled CCS CONTROL. Itilluminates when CCS has control of the LO

system. The other status indicator is amberand labeled PLCC CONTROL. It illuminateswhen control of the LO system is at thePLCC.

Under the label PUMP MODE is the three-position rotary switch. The positions are labeledB LEAD, MANUAL, and A LEAD. The PACCoperator uses this rotary switch to select either themanual mode of pump operation or the automaticmode. In the MANUAL mode the PACCoperator can start (slow or fast) or stop theelectric LO pumps. The automatic mode isselected by placing the rotary switch in either theB LEAD or A LEAD position. The positiondesignated by the PACC operator determineswhich pump is the lead pump and which pumpis the standby pump.

MIMIC PANEL

Figures 5-3 and 5-4 show a detailed view ofthe DD- and CG-class ships’ PACC MIMIC

5-9

Figu

re 5

-3.—

DD

PA

CC

MIM

IC p

anel

.

Figu

re 5

-4.—

CG

PA

CC

MIM

IC p

anel

.

Figure 5-5.—Main center section of the DD MIMIC panel.

panels. The MIMIC panel provides a schematicrepresentation of the four GTMs, clutches,reduction gears, and shafts. For this reason it iscalled the MIMIC panel. The left side of theMIMIC panel contains the status/alarm indicatorsand manual start push-button control indicatorsfor the GTM 2A, an MRG bearing mimic on theCG console, PLA and vibration meters, andvibration select switches for GTM 2A and 2B. Theright side of the MIMIC panel is identical to theleft but labeled for GTM 1A and 1B. The maincenter part of the MIMIC panel displays the statusof each GTM, which station has control of theindividual engine rooms, which engines areconnected to the main shaft, the alarms and statusindicators for the individual engines, and theautomatic mode selectors (ENGINE SELECT,PLANT MODE CONTROL, and PLANT MODESELECT).

GTM 2A Section

The GTM 2A section is a mirror image of theGTM 2B section. The alarm indicators and status

indicators were described under the GTM 2Bsection of the engine No. 2 panel and will not bedescribed again.

Main Center Section

Figure 5-5 shows the main center section ofthe DD and CG MIMIC panel. This section has84 status/alarm indicators (80 on the CG console),2 meters, and 4 push-button control indicators.

We will only describe one engine of the leftengine group mimic section, as the indicators areidentical for both engines and engine groups. Theonly difference in the engine groups is the left oneis labeled GTM 2B/GTM 2A, while the right oneis labeled GTM 1B/GTM 1A.

Starting with the first status indicator underthe GTM 2B label is an indicator labeled OUTOF SERVICE. It illuminates amber when the keyswitch at the PLCC is in the out of serviceposition. When illuminated, it prevents start ofthe GTM. The status indicator labeled SECUREDilluminates white if the auxiliary systems are not

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running or are not ready. These auxiliary systemsare the FO, LO, MRG, and bleed air systems. Thestatus indicator labeled STAND BY illuminateswhite when the auxiliary systems are ready. Thesystems and conditions required for this indicatorto illuminate are as follows:

FO header pressure > 40 psig

LO header pressure > 9 psig

MRG turning gear disengaged

Bleed air header pressure > 40 psig

The status indicatorilluminates white when

labeled RUNNING

the GTM has NG G > 4300 rpm,

T5.4 > 400°F, and

the clutch is disengaged.

The status indicator labeled ON LINEilluminates white when the engine is running andthe clutch is engaged. The status indicatorlabeled BRAKE ON illuminates red when the PTbrake is on, and the status indicator labeledBRAKE OFF illuminates green when the PTbrake is off.

The next four status indicators are for theclutches. The first two on the left are labeledCLUTCH ENGAGED and CLUTCH DISEN-GAGED. They illuminate (either green or white)to indicate the clutch status. The two clutch alarmindicators on the right are labeled CLUTCHFAIL TO ENGAGE and CLUTCH FAIL TODISENGAGE on the DD console. On the CGconsole they are labeled CLUTCH FAIL TOENGAGE and CLUTCH LOCKED OUT. Oneither the DD or the CG console, these indicatorsilluminate amber to indicate the clutch status.

Between the two engine mimics, under thelabel STATION IN CONTROL, are three statusindicators. These status indicators and theconditions required for them to illuminate are asfollows:

PILOT HOUSE—It illuminates greenwhen the pilot house is in control.

CCS PORT—It illuminates green when theCCS is in control of the port MER.

LOS NO 2—It illuminates red when thelocal operating station has control.

The following alarm indicators, located to theleft and right of the edgewise meter labeledTORQUE, are on the DD PACC console. We willdescribe these 12 alarm indicators first, thendescribe the 3 alarm indicators that are differenton the CG PACC.

The first alarm indicator on the left side islabeled JOURNAL BEARING TEMP HI. Itmonitors all of the MRG journal bearings andilluminates red if one (or more) of the bearingstemperature(s) exceeds its high temperature setpoint. The alarm indicator labeled THRUST BRGTEMP HI illuminates red if one (or more) of thethree thrust bearings monitored exceeds its hightemperature set point. The three bearingsmonitored are a thrust bearing in each of the twoGTM clutch/brake assemblies and the MRGthrust bearing. The alarm indicator labeledSHAFT BRG TEMP HI monitors the line shaftbearing temperature. It illuminates red when oneor more of the line shaft bearings exceeds its hightemperature set point. The status indicator labeledSHAFT LOCKED illuminates red when the shaftlock mechanism on the MRG turning gear isengaged. The alarm indicator labeled SHAFTTORQUE HI illuminates red to indicate highshaft torque. This indicator is set to alarmat different set points for either one-engineoperation or two-engine operation. The statusindicator labeled OVERTORQUE CONTROLON illuminates amber when the engine is intorque limiting. It flashes intermittently as the

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engine goes in and out of torque limiting, orremains illuminated as long as the engine is intorque limiting.

On the right side of the TORQUE meter arefive alarm indicators. The first one, labeledTORQUE MISMATCH, illuminates red when adiscrepancy exists between actual shaft torque andcomputed shaft torque. The next one, labeledCMD RPM MISMATCH, illuminates red if adiscrepancy exists between actual shaft rpm andcommanded shaft rpm. The third indicator,labeled CMD PITCH MISMATCH, illuminatesred if a discrepancy exists between actual pitchand commanded pitch. The alarm indicatorlabeled WRONG PITCH DIRECTION illuminatesred if the actual pitch moves in the oppositedirection from the commanded pitch setting. Thelast one, labeled SHAFT SEAL PRESS LO,illuminates red when the cooling/sealing waterpressure to the propeller shaft seal drops below12 psig. The status indicator labeled TURNGEAR ENGAGED illuminates red when theMRG turning gear is engaged.

Three alarm indicators, located to the left ofthe edgewise meter labeled TORQUE on the CGMIMIC panel, are different. We will describe theseindicators that are located at the same positionas those described on the DD MIMIC panel.

The first two alarm indicators on the left sideare blank. The alarm indicator labeled REVERSEROTATION monitors the shaft rotation andilluminates red if the shaft is rotating in the reversedirection from designed rotation. The rest of thealarm indicators on this section are identical tothe DD console alarm indicators.

Between the engine group sections under thelabel MODE CHANGE SEQUENCE are the 10status indicators (9 on the CG console) that

illuminate white at various stages in the start ofa GTM. Their sequence of illumination variesdepending on which plant mode logic start of aGTM is selected. We will not describe the variousmode changes in this TRAMAN. For detailedinformation on the plant mode change sequence,consult the applicable NAVSEA technical manualfor either the DD- or CG-class ships. Theindicators on the DD console are labeled asfollows from top to bottom: SELECT ENGINE,MODE CHANGE STARTED, START ENGINE,RELEASE BRAKES, ENGAGE CLUTCH, PLAAT IDLE, MODE CHANGE COMPLETE, DIS-ENGAGE CLUTCH, RESTART OR SELECTALTN, and MODE CHANGE RESET. Theindicators on the CG console are labeled asfollows from top to bottom: MODE CHANGESTARTED, SELECT ENGINE, START ENGINE,RESTART OR SELECT ACTN, RELEASEBRAKES, PLA AT IDLE, APPLY BRAKES,MODE CHANGE COMPLETE, and MODECHANGE RESET.

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Located at the bottom and to the left and rightof the TORQUE meter are two push-buttoncontrol indicators. The left push-button indicatoris identical on the DD and CG consoles. It islabeled TORQUE SENSOR CUTOUT. Whendepressed by the PACC operator, it illuminatesred to indicate the shaft torque limiting isinhibited. Commanding officer’s permission isrequired for the PACC operator to activate thispush button. The other push button on the DDconsole, under the heading SHAFT BRAKE, islabeled ON and OFF. It illuminates either red orgreen to indicate the command to the shaft brake.On the CG console, this push-button indicator isunder the heading STOP SHAFT. It DOES NOTengage the shaft brake. It is labeled ON and OFFand illuminates either red or green to indicate thePACC operator’s command to the on lineengine(s) PT brake. When the PT brakes are ON(engaged), they will allow the shaft to coast to astop.

PLA and VIBRATION Metersand MRG Mimic Section

The other dual-indicating meter under theheading VIBRATION is labeled GG and PT.Associated, and located to the right of this meter,are two toggle switches. The top toggle switchunder the heading FILTER is a two-positionswitch labeled GG FREQ and PT FREQ. Thisswitch is used to select which vibration sensor thesignal displayed on the meter is monitoring, eitherthe GG vibration transducer or the PT vibrationtransducer. The other toggle switch, under theheading ENGINE, is a two-position switch labeled2A and 2B. It is used to select which engine’svibration is to be displayed on the meter.

Two dual-indicating meters are located belowthe GTM 2A (GTM 2B) section at the left andright side of the DD MIMIC panel. These metersare identical and labeled for the related engine.On the CG console this position is filled with amimic of the MRG and has red LEDs to indicatea bearing high temperature. The DDI address foreach bearing is also on this mimic.

The first dual-indicating meter under theheading PLA is labeled 2B and 2A. It displaysthe applicable engine’s PLA position in percentof power.

GTM 1B Section

The GTM 1B section, located in the upperright corner of the MIMIC panel, is a mirrorimage of the GTM 2B section. It has alarmindicators and status indicators identical to theGTM 2B. These were described under the GTM2B section of the engine No. 2 panel and will notbe described again.

GTM 2A Manual Start Section

The GTM 2A MANUAL START section,located in the lower left corner of the MIMIC

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panel, is a mirror image of the GTM 2BMANUAL START section. It has alarm indicatorsand status indicators identical to the GTM 2Bsection. These were described under the GTM 2BMANUAL START section of the engine No. 2panel and will not be described again.

Lower Center Section

The lower center section of the DD MIMICpanel has 8 dual-indicating meters (4 for eachengine group) (10 on the CG PACC, with 5 foreach engine group), 2 ENGINE SELECT sectionsthat have 2 push-button control indicators, aPLANT MODE CONTROL section with 4 push-button control indicators, and a PLANT MODESELECT section that has 3 push-button controlindicators. The CG MIMIC panel also has 4 two-position toggle switches. We will only describe themeters for the engine 2B and 2A group. Themeters for the engine 1B and 1A group areidentical.

The first two dual-indicating meters on the DDconsole, under the headings GG SPEED and PTSPEED, are both labeled 2B and 2A. The signalsdisplayed on these meters originate at the GG andPT speed pickups of the respective engines. TheGG speed pickup is located on the accessorygearbox. The PT speed pickups (two) are locatedin the turbine rear frames. The speed meters readin rpm. The next two dual-indicating meters,under the heading PT INLET, are labeled PRESS2B/2A and TEMP 2B/2A. These meters displaythe pressure (in psia) and temperature (°F x 102)of the respective engines. The signals displayedon these meters come from sensors in the respectiveengine’s turbine midframe. The pressure sensorsare probes that pressurize a transducer, and thetemperature sensors are thermocouples.

The last four dual-indicating meters’ aremirror images of the four just described.Remember, the only difference in the meters istheir label for the engine 1B and 1A group.

On the CG MIMIC panel, the first two dual-indicating meters are labeled VIBRATIONGG/PT and PLA 2B/2A. Associated with thesetwo meters are two toggle switches labeledFILTER GG FREQ/PT FREQ and ENGINE2A/2B. These meters and toggle switches areidentical to the PLA and vibration metersdescribed previously for the DD console. The nextthree dual-indicating meters are labeled GGSPEED 2B/2A, PT SPEED 2B/2A, and PTINLET TEMP 2B/2A. These meters are identicalto those described on the DD console. Adifference in the CG console is that it does NOThave a PT INLET pressure meter.

The last five dual-indicating meters on the CGMIMIC panel are mirror images of the five justdescribed. Remember, the only difference in themeters is their label for the engine 1B and 1Agroup.

The ENGINE SELECT sections at the lowercenter of the MIMIC panel are located on thelower left and right sides of the panel. Eachsection has two push-button control indicatorslabeled 2B and 2A and 1B and 1A, respectively.These push-button indicators illuminate green toindicate the engine(s) selected by the PACCoperator for a start/stop sequence.

The section labeled PLANT MODE CON-TROL has four push buttons. They are labeledCHANGE ENGINE, ENGINE RESTART,START MODE CHANGE, and RESET. Thechange engine command allows for GTMs in thesame engine room to be rotated on and off lineautomatically when in the split-plant mode. Thechange engine mode begins when the STARTMODE CHANGE and CHANGE ENGINE pushbuttons are depressed simultaneously. Thisinitiates a sequence that will start the selectedengine, bring it up to speed, bring the other engineto idle, and secure it (if requested). The system

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may be manually reset by the PACC operatordepressing the RESET push button. If the engineselected to start does not come on line, the PACCoperator may elect to press the ENGINERESTART push button to initiate anotherattempt at starting the selected engine. If thePACC operator does nothing, the system willautomatically reset after 20 seconds.

The PLANT MODE SELECT section hasthree push-button control indicators. They arelabeled SECURE, SPLIT PLANT, and FULLPOWER. These push buttons are used by thePACC operator to automatically place themain propulsion plant in the desired plantconfiguration. The PACC operator selectswhich mode of plant operation he desires theplant to operate. The selected mode illuminateswhite to indicate the command to the systemelectronics.

GTM 1B Manual Start Section

The GTM 1B MANUAL START section,located in the lower right corner of the MIMICpanel, is a mirror image of the GTM 2BMANUAL START section. It has alarmindicators and status indicators identical to theGTM 2B section. These were described under theGTM 2B MANUAL START section of the engineNo. 2 panel and will not be described again.

ENGINE NO. 2 PANEL

Figure 5-6 shows the engine No. 2 paneldivided into five sections for engine No. 1A. Thesesections are labeled RDCN GEAR LUBO, CRP,FUEL OIL, GTM 1 A (including alarm, manualstart push-button indicators, and torque and LOpressure meters for both GTMs), and LUBE OIL.This panel is a mirror image of the engine room No.1 panel shown in figure 5-2. The components arelabeled for the 1B and 1A engines. The meters,switches, and alarm/indicators are identical andwill not be described again.

PACC AUXILIARY/BLEEDAIR PANEL

The PACC auxiliary/bleed air panels for theDD- and CG-class ships’ consoles are shown infigures 5-7 and 5-8. The DD-class ship’s consoleis divided into 14 sections (16 on the CG console).Again, we will describe the DD console and use

inserts to point out the differences between theDD and CG consoles.

WASTE HT BLR Section

This section has 10 alarm indicators (9 on theCG console) and a spare indicator. These alarmindicators are used to monitor the waste heatboilers. Starting at the top of the column, the firstthree alarm indicators on both the DD and CGconsoles are functionally identical, althoughthey are labeled slightly different. These alarmindicators illuminate red if a summary faultcondition has been detected on either Nos. 1, 2,or 3 WHB. After these three, the next two alarmindicators on both consoles are also functionally

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Figure 5-6.—PACC-engine No. 2 panel.

5-18

Figure 5-7.—DD PACC—auxiliary/bleed air panel.

5-19

Figure 5-8.—CG PACC—auxiliary/bleed air panel.

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identical, although they are labeled slightlydifferent. They monitor the forward and aft boilerheader pressure and illuminate red to indicate lowheader pressure in their respective header. Thesixth alarm indicator on the DD console is labeledOILY CONDENSATE. It illuminates red if thepresence of oil is detected in the condensatesystem. The next two alarm indicators onboth consoles are a pair of functionallyidentical indicators. They monitor the salinitylevel of the condensate coolers and illuminatered if a high salinity condition exists oneither condensate cooler No. 1 or No. 2.The last two alarm indicators are functionallyidentical on both consoles, but they arelabeled slightly different. They monitor theforward and aft feed water tank HI/LOlevels and illuminate amber if the feed watertank level is either high or low in the respective

STEAM HEADER PRESS Section

This section has a dual-indicating meter andthree push-button control indicators. It isidentical on both the DD and CG consoles. It isused to monitor and secure (in an emergency) theship’s steam system. The dual-indicating meter isused to monitor the forward and aft steam headerpressure, which is displayed in psig. The three

push-button control indicators are used toemergency stop either the Nos. 1, 2, or 3 WHBsby closing their respective steam stop valves. Theyilluminate red when depressed.

SEAWATER Section

This section is identical on both the DDand CG consoles. It is used to monitorthe main seawater service system and toprovide start/stop control of the three sea-water pumps. It has four alarm indicatorsand three split-legend, push-button controlindicators. The alarm indicators are a set offunctionally identical indicators, each beinglabeled slightly different. Starting at the top,the first three indicators illuminate red ifeither Nos. 1, 2, or 3 seawater pump dischargepressure is low. The fourth alarm indicatorilluminates red if main seawater system pressureis low. The three push-button indicators illuminateeither green or red to indicate the status and

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the operator’s command (RUN/STOP) to sea-water pump Nos. 1, 2, or 3.

to indicate the status/operator command (RUN/STOP) to the respective pump.

FRESH WATER Section

This section is used to monitor the ship’sfreshwater system and to provide start/stopcontrol of the freshwater pumps. This section isfunctionally identical on both the DD and CGconsoles, but it is labeled slightly different.It has four status indicatiors, five alarmindicators, and two split-legend, push-buttoncontrol indicators.

Starting at the top of the column, thefirst four status indicators monitor the high(full) level of the four freshwater tanks.They illuminate green when a full conditionexists in their respective tank. The next fouralarm indicators monitor the low level of thefour freshwater tanks. They illuminate amberif a low-level condition exists in their respectivetank. The last alarm indicator monitors thevital header pressure and illuminates amberwhen the freshwater system pressure is low.Below the alarm indicators are the two split-legend, push-button control indicators. Theyare used to control the forward and aft pumprespectively. They illuminate either red or green

HP AIR Section

The HP AIR section is used to monitorthe ship’s HP air system. It has seven alarmindicators and two status indicators. Thealarm/status indicators in this section arefunctionally identical on both the DD andCG consoles, but they are labeled slightlydifferent. Starting at the top of the column,the first two alarm indicators monitor theNo. 1 compressor for a summary fault orlow discharge pressure. They illuminate redif a summary fault condition or low dis-charge pressure condition occurs on the No. 1compressor. The next two alarm indicatorsmonitor the No. 2 compressor for a summaryfault or low discharge pressure. They illuminatered if a summary fault condition or lowdischarge pressure condition occurs on theNo. 2 compressor. The next three alarmindicators monitor the two engine room flasksand the emergency generator No. 3 flasksfor a low-pressure condition. They illuminatered if this condition occurs at either flask.The last two indicators are status indicatorsthat monitor the No. 1 and No. 2 compressors.

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They illuminate green when the respectivecompressor is running.

REFRD Section

This section monitors the ship’s refrigerationplant and is identical on both the DD and CGconsoles. It has two alarm indicators thatilluminate amber if a summary fault conditionis detected on either the No. 1 or No. 2refrigeration plant.

SEWAGE and SEWAGE/WASTESections

These sections monitor the sewage and wastesystems and serve the same purpose on bothPACCs. They are functionally identical, but theyare NOT physically identical. On the DD console,this section is labeled SEWAGE and has six alarmindicators. On the CG console, it is labeledSEWAGE/WASTE and has 25 alarm indicators.We will describe the DD console alarm indicatorsand then the CG console alarm indicators.

The SEWAGE section monitors two sewageplants, two waste drain tanks, and twoincinerators. The six alarm indicators are actuallythree pairs of functionally identical indicators.Starting at the top of the column, the first twoalarm indicators illuminate amber if a summary

fault is detected on either sewage plant No. 1 orplant No. 2. The next pair of alarm indicatorsmonitor the waste drain tank levels. Theyilluminate amber if a high-level condition occurson either waste drain tank No. 1 or No. 2.The next two indicators monitor the ship’sincinerators. They illuminate amber if a summaryfault is detected on either incinerator No. 1 orNo. 2.

The CG console SEWAGE/WASTE sectionmonitors three sewage system tanks, the oily waterdrain tank and the GT drain tank in engine roomNo. 1, the waste oil and oily waste drain tanksin AMR1, the oily water drain tanks in AMR2and engine room No. 2, the GT drain tank inengine room No. 2, the GT drain tank and theoily water drain tank for SS/E gtr (generator)No. 3, the three oily water separators, the surgetank levels, and the oily condensate of the oilywater separators.

Starting at the top of the column, the first ninealarm indicators monitor the sewage systems,Nos. 1, 2, and 3. They illuminate amber if eithera high, low, or overflow tank level conditionexists on the sewage holding tanks or sumps forsystems Nos. 1, 2, or 3, respectively.

The tenth and eleventh alarm indicatorsmonitor the engine room No. 1 oily water draintank and gravity drain tank, respectively. Theyilluminate amber if a high level occurs ineither tank. The thirteenth and fourteenth alarmindicators monitor the level of the waste oil draintank and the oily waste holding tank in AMR1.They illuminate amber if a high level occurs inthe respective tank. The fifteenth alarm indicatormonitors the level of the oily water drain tank inAMR2. It illuminates amber if a high leveloccurs in this tank. The sixteenth and seventeenthalarm indicators monitor the engine room No. 2

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oily water drain tank and gravity drain tank. Theyilluminate amber if a high level occurs in theirrespective tank. The eighteenth indicator monitorsthe level of the oily water drain tank in the GTG3enclosure. It illuminates amber if a high leveloccurs in the tank.

The next four indicators are status indicatorsthat monitor oily water separators No. 1 andNo. 2. They illuminate either green to indicatethe respective separator is running or amber toindicate the respective separator is shut down. Thenext two alarm indicators monitor the surge tankhigh or low level, respectively. They illuminateamber if either alarm condition exists in therespective tank. The last indicator is an alarmindicator which monitors the condensate of theoily water separators. It illuminates amber toindicate an oily effluent is being discharged fromthe separators.

DISTILLING Section

This section monitors the distilling plants andhas four alarm indicators. The first two alarmindicators monitor the salinity of distilling plantNo. 1 and plant No. 2. They illuminate amberwhen a high salinity condition exists at therespective distilling plant. The next two alarmindicators monitor the distilling plant No. 1 andNo. 2 dump valves. They illuminate amber whenthe respective dump valve has opened due to highsalinity or during system startup.

AIR COND Section

This section monitors the ship’s air con-ditioning plants and has three alarm indicators(four on the CG console). These three (four) alarmindicators monitor summary alarms on A/Cplants Nos. 1, 2, and 3 (and A/C plant No. 4 ofthe CG-class ships). The alarm indicatorsilluminate amber if a summary alarm is detectedon the respective A/C plant.

SS AIR Section

This section monitors the SSAS and has sixalarm indicators (nine on the CG console) and twostatus indicators (three on the CG console). Thesealarm indicators and status indicators monitor thetwo LP air compressors and receivers (three onthe CG console). The alarm indicators foreach plant monitor for a summary fault (red),compressor discharge pressure low (red), andreceiver pressure low (red). If a monitoredcondition occurs, the appropriate indicator willilluminate. The status indicators illuminate green

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when the respective LP compressor (either 1, 2,3, or 4) is running.

NOTE

The next three sections, CHILLEDWATER, AEGIS PUMPS, and the COM-BAT DRY AIR section, are applicableonly to the CG console.

CHILLED WATER Section

This section has four alarm indicators used tomonitor the ship’s A/C chilled water system. Thealarm indicators actually monitor the level ofchilled water in the four system’s expansion tanks.The alarm indicators illuminate amber to indicatean expansion tank low-level condition exists onthe applicable expansion tank(s).

AEGIS PUMPS Section

This section monitors the aegis weaponssystem cooling water pumps on the CG console.It has two status indicators and two alarmindicators. The status indicators illuminate greenwhen the applicable aegis cooling water pump(No. 1 or No. 2) is running. The alarm indicatorsilluminate amber if the respective aegis coolingwater pump discharge pressure is low.

COMBAT DRY AIR Section

This section monitors the moisture content ofthe combat system’s dry air system on the CGconsole. It has four alarm indicators thatilluminate amber if a high moisture content hasbeen detected at the applicable monitoring station.

AIR CONTROL Section

Under the heading AIR CONTROL at thebottom of the auxiliary/bleed air panel are threesections labeled ENG ROOM 1, ENG ROOM 2,and GTG 3. These sections are used to monitorthe air systems of the GTMs in the applicableengine rooms. The alarm indicators in the sections

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labeled ENG ROOM 1 and ENG ROOM 2 areidentical as to the systems monitored, but theydiffer in the engines monitored. We will describethe alarm indicators only in the ENG ROOM 1and GTG 3 sections. The alarm indicatorsthat are the same on the GTG 3 sectionand ENG ROOM 1 section will not be describedseparately.

ENG ROOM 1 SECTION.—Under thisheading are three alarm indicators that monitorthe engine room air systems. The alarmindicators are labeled PRAIRIE AIR TEMPHI, START AIR OVERTEMP, and HIGHPRESS AIR LO. These indicators illuminatered when the parameter of the applicable systemmonitored exceeds or drops below its designedset point.

The GTM air systems for ENG 2A, ENG 2B,and GTG 1 are each monitored by three identicalalarm indicators. These alarm indicators arelabeled ICING, ANTIICING INSUFFICIENT,and DUCT PRESS LO. Either alarm indicatorilluminates red if the monitored parameter for thatengine exceeds or drops below its designedoperating parameter. The next two alarmindicators, labeled MASKER AIR OVERTEMPand BLEED PRESS LO, are located under theheadings ENG 2A and ENG 2B, respectively. Asthese systems are common to both engines, onlyone of each alarm indicator is required in eachengine room. These alarm indicators illuminatered if the monitored parameter is not in thedesigned operating range.

GTG 3 SECTION.—This section has fivealarm indicators and is used to monitor the

GTG 3 air systems. The alarm indicators areidentical to those on the ENG ROOM 1 and ENGROOM 2 sections. There is a slight difference inthe labeling of the last alarm indicator. It islabeled STARTER AIR OVERTEMP viceSTART AIR OVERTEMP. Both alarm indicatorshave the same function.

PORT SHAFT DEMANDS PANEL

This panel is functionally identical on bothconsoles, but has slight physical differences. Thepanel shown in figure 5-9 is for the DD console.It has the start/stop and emergency controls forGTM 2B, DDIs to monitor shaft speed, an alarmtest section, a power supply monitoring section,and a console malfunction monitoring section. Itis located on the left-hand side of the PACC inbay No. 1. This panel is divided into sixsections labeled PORT SHAFT PROPULSIONDEMANDS, 2B EMERGENCY CONTROLS,MALFUNCTION, TEST, 2B START/2B STOP,and POWER.

PORT SHAFT PROPULSIONDEMANDS Section

This section has two thumbwheels and twoDDI displays. The PACC operator uses thethumbwheels to select a plant parameter addresswhich will be displayed in the adjacent DDI.These selected parameters are displayed in theappropriate units of measurement. The PORTSHAFT PROPULSION DEMANDS section onthe CG console is functionally the same, but it

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Fig

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5-9.

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has slight physical differences from the DDconsole as shown in the following graphic.

2B EMERGENCY CONTROLS Section

This section is identical on the DD and CGconsole. It has an alarm indicator, a guardedtoggle switch, and three push-button controlindicators. The alarm indicator illuminates redwhen the PACC operator performs an emergencystop using the guarded toggle switch directly belowthe EMERGENCY STOP status indicator orwhen an emergency stop command is generatedby the electronics. The first control indicator isa split-legend, push-button indicator labeled FIRESYS DISABLED/PUSH TO RESTORE. The topportion of this indicator illuminates red whenthe GTM fire detection system is temporarilydisabled. When illuminated, a module fire stopis prevented from being generated. If thesymptoms causing the casualty are restored priorto the normal stop timing out, you may restorethe fire system by depressing this switch when thebottom label illuminates red.

The second push-button control indicatorlabeled CO2 RELEASE INHIBIT is used by thePACC operator to disable the CO2 system whilepersonnel are in the module. It illuminates redwhen it is depressed at the PACC, PLCC, or whenthe CO2 inhibit switch at the module is activated.The third push-button control indicator, labeledBATTLE OVRD ON, illuminates red when thePACC operator depresses it to activate thebattle override electronics.

MALFUNCTION Section

This section has 10 alarm indicators used tomonitor summary alarms of the console. The firstalarm indicator, labeled CONSOLE SUMMARY,illuminates red if an alarm condition has beendetected in the PACC. The next five alarmindicators across and down are functionallyidentical. They are labeled ENCLOSURE NO. 1,2, 3, 4, and 5, respectively. These alarm indicatorsilluminate red if a console malfunction is detectedin one of the five bays of the PACC. The nexttwo alarm indicators are a pair of functionallyidentical indicators labeled POWER SUPPLY Aand POWER SUPPLY B. They illuminate red ifan alarm condition exists in their respective PACCpower supply. The last two alarm indicators arelabeled PLOE NO. 1 and PLOE NO. 2. Theyilluminate red if a summary alarm has beendetected in the respective PLOE electronics.

TEST Section

The TEST section is used for testing all thePACC alarm and status indicators and the siren,horn, and bell. It has three momentary-contactpush buttons, a three-position toggle switch, andan eight-position, rotary selector switch. The CGconsole also has a rotary switch to the left of theTEST section which is used to vary the volumeof the bell, horn, and siren.

Under the heading INITIATE are the threemomentary-contact push buttons labeled BELL,HORN, and SIREN. The PACC operator maytest either audible alarm by depressing theappropriate push button. On the CG console, theoperator may select a comfortable volume bydepressing the appropriate push button androtating the ALARM VOLUME switch to theacceptable level.

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The three-position toggle switch is labeledSTATUS, OFF, and ALARM. If it is in the OFFposition, testing of the alarm and status indicatorsis inhibited. In the ALARM position, the alarmindicators on the panel selected by the rotaryselector switch will be tested. In the STATUSposition, the status indicators on the panel selectedby the rotary selector switch will be tested. Theeight-position rotary selector switch is labeledENG 2 AUX, 2B, 2A, MIMIC EOT, 1B, 1A,ENG 1 AUX, and AUX.

labeled PLA AT IDLE is next. It illuminates greenwhen the PLA is at the 0 percent setting. Belowit is a status indicator labeled COOLING AIRSYS READY. It illuminates green when the ventdamper is open and the cooling fan is operatingproperly. A push button, labeled INITIATE, isat the top of the next column on the DD console.It is used to manually initiate a start.

On the CG console, a status indicator is at theposition of the INITIATE push button on the DDconsole. This status indicator is labeled INHIBSTART MRG PRESS LO. It illuminates to alertthe PACC operator to check the MRG LO

GTM 2B START/GTM 2B STOP Section pressure before initiating a start and will not allowa start of the GTM while illuminated. Below this

This section is used by the PACC operator to indicator is a status indicator labeled GG ATstart/stop the GTM. It has 9 status indicators IGNITION SPD. It illuminates green when the(10 on the CG console) and 3 alarm indicators, GG speed is > 1200 rpm. The next status indicatora start initiate push button, a three-position rotary is labeled IGNITION and illuminates green whenstart/stop mode selector switch, a stop cancel push T5.4 is > 400°F. The last status indicator underbutton, and a stop initiate push button. the 2B START heading is labeled START COM-

PLETE. It illuminates green when GG speed isUnder the heading 2B START is the first > 4300 rpm.

alarm indicator, labeled FALSE START. It To the right of these indicators, under theilluminates amber if one of two conditions has heading START/STOP MODE, is the three-occurred: (1) < 1200 NGG 20 seconds after the position rotary switch. The three positions arestart air valve opens; (2) T5.4 < 400°F 40 seconds labeled AUTO INITIATE, MANUAL INITIATE,after the main fuel valves open at 1200 NG G. The and MANUAL CONTROL. This switch is usednext indicator is labeled ALIGN START AIR by the PACC operator to select the starting andSYSTEM and is a dual status/alarm indicator. As stopping modes.a status indicator, it illuminates amber in a steady Under the heading 2B STOP is an alarmstate to show the air start system is being aligned indicator, three status indicators, and the last twofor start. As an alarm indicator, it comes on push buttons. The alarm indicator is labeledflashing to show the air start system will not INTERNAL FIRE and illuminates amber if anproperly align (either valve failed to properly internal (post-shutdown) fire occurs. This alarmposition or anti-icing air is on). Below this indicator illuminates if T5.4 is > 700°F 3 minutesindicator is the status indicator labeled START after the shutdown is complete. The statusALIGN COMPLETE. It illuminates green after indicator labeled STOP INITIATED illuminatesthe logic circuits check alignment of the green when a stop has been initiated. The statusfollowing: GTM in service, start air system indicator labeled PLA AT IDLE illuminates greenaligned, HP start priority check, fuel temperature, when the PLA has come to the idle (0 percent)and bleed air valve closed. A status indicator position. When this indicator illuminates, a

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5-minute cool-down timer is activated in thecontrol electronics. At the completion of the cool-down time, the status indicator labeled FUELVALVES CLOSED illuminates green and the fuelvalves close, which secures the GTM. The firstpush button is labeled CANCEL. It is used by thePACC operator to cancel a normal stop of aGTM. The other push button is labeledINITIATE and is used by the PACC operator tostart a normal stop of a GTM.

ENGINE ORDER TELEGRAPH(EOT) PANEL

This panel is shown in figure 5-10. Its mainfunction is concerned with EOT signals (rpm andpitch signals) for both engine rooms. The EOTpanel is divided into nine sections. The extremeleft and right portions have the GTM 2A andGTM 1B EMERGENCY CONTROLS sectionsand GTM 2A and GTM 1B START/STOPsections. These sections are mirror images of theGTM 2B EMERGENCY CONTROLS and GTM1A START/STOP sections covered on the engineNo. 2 demands panel. We will not describe thesecontrols and indicators again.

The other five sections of this panel are labeledPORT MANUAL THROTTLE, ENGINE ORDERTELEGRAPH, STBD MANUAL THROTTLE,

ALARM ACK, and THROTTLE TRANSFER.The manual throttle sections are identical.

PORT MANUAL THROTTLE Section

This section is a mirror image of the STBDMANUAL THROTTLE section. It has two push-button control indicators and four rotaryswitches. The push-button control indicator underthe heading THROTTLE CONT. is a split-legendswitch/indicator. It is labeled AUTO/MAN andilluminates green to indicate the PACC operator’sselection of either AUTO (which is integratedthrottle control) or manual control of thethrottles and pitch. When this switch is in theMAN position, the PACC operator uses the threerotary selector switches labeled MANUALPITCH and MANUAL PLA (2B/2A) to set thepitch (– or +) and the PLA of the respectiveengine(s) to the required percent of power.

The second push button is a status indicator/switch labeled SEASTATE ADJUST ON whichilluminates amber when depressed. The PACCoperator depresses this switch electing to changethe reaction time of the PLA electronics due tosea state conditions or following EOP. Afterdepressing this switch, the operator uses the ten-position rotary selector switch labeled SEASTATE to manually set the PLA electronicsreaction time.

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Figu

re 5

-10.

—E

OT

pan

el.

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ENGINE ORDER TELEGRAPH Section

This section is a set of digital displays usedprimarily as a backup throttle communicationssystems. This system is used when the PACC isin control of the throttles. The digital displaysare identical for the port and starboard shaft.There are three digital displays and a set ofthumbwheels to indicate PITCH and RPM foreach shaft. The digital displays are labeledACTUAL, ORDERED, and SET. Each shaft hasthree push-button indicators under the headingsPORT ACKNOWLEDGE and STARBOARDACKNOWLEDGE. These push buttons are labeledPITCH, STD ORDER, and RPM. Between thesetwo headings is a set of three push buttons underthe heading PLANT MODE ACKNOWLEDGE.The push buttons are labeled SECURE, SPLITPLANT, and FULL POWER. The PACCoperator uses these push buttons to acknowlegethe respective change of plant mode order fromthe officer of the deck (OOD).

The digital display of the pitch and rpm,labeled ACTUAL, is the actual pitch setting andrpm of the shaft at that moment in time. Thedigital display of the pitch and rpm, labeledORDERED, is the commanded pitch setting andshaft rpm from the OOD. The digital display ofthe pitch and rpm, labeled SET, is the pitch andrpm selected by the thumbwheels by the PACCoperator.

The actual RPM and PITCH are digitallydisplayed at the SCC, PACC, and PLCC. Whenthe OOD orders the SCC operator to change RPMand/or PITCH, the following events occur:

The SCC operator sets the new values ofRPM and PITCH on the thumbwheels andthen depresses the RPM and PITCHALERT push buttons.

These signals are sent to the PACCand PLCC where they appear on thedigital displays labeled RPM and PITCHORDERED. At the same time, an audiblealarm is sounded and the RPM and/orPITCH ACKNOWLEDGE push-buttonlights begin to flash.

When the PACC is in control of the throttle,the operator responds in the following manner:

The operator sets the new RPM and/orPITCH on the thumbwheels and depresses

the flashing RPM and/or PITCHACKNOWLEDGE push button.

l The light stops flashing and the audiblealarm is turned off.

l The operator then manually changes theproper PLA and/or PITCH potentiometeror moves the ITC lever.

ALARM ACK Section

The ALARM ACK section has two pushbuttons (three on the CG console) labeled HORNand SIREN (and BELL). The PACC operatoruses these push buttons to acknowledge andsilence an audible alarm (either horn, siren, orbell).

THROTTLE TRANSFER Section

This section has two push buttons for control/display of the station in control of the throttle.They are labeled PILOT HOUSE and CCS.Throttle/pitch control is possible at one of threelocations (PLCC, PACC, or SCC).

For the SCC to have integrated throttlecontrol, both the PLCC and PACC must havetheir remote stations selected. That is, the PLCCmust have at least one GTM and EOT controltransferred to the PACC. The PACC must havethe throttle control transferred to the SCC. At thePLCC, only manual throttle and pitch control fortheir respective GTMs is available. Manualcontrol of an individual GTM may be transferredto the PACC from the PLCC. At the PACC, eachGTM may be controlled manually by rotarypotentiometer controls which operate the same asthe lever controls found at the PLCC. Either orboth GTMs may then be placed in auto control.For the PACC operator to transfer throttlecontrol from the PACC to the SCC, both GTMsmust be in auto throttle control. The PACCoperator may take throttle control from theSCC at any time. The PLCC operator may takethrottle/pitch control from the SCC or PACC atany time.

STARBOARD SHAFT DEMANDS PANEL

This panel is shown in figure 5-11. It isdivided into four sections. These sections are

Figure 5-11.—Starboard shaft demands panel.

labeled 1A EMERGENCY CONTROLS, 1ASTART/1A STOP, STBD SHAFT PROPULSION

The fourth section, labeled SHIP SPEED,

DEMANDS, and SHIP SPEED. The first threehas a meter that displays the actual ship’s

sections are identical to, and have been describedspeed through the water. The speed is displayedin knots. Associated with and to the left of

previously in, the port shaft demands panelsection.

the speed meter is a matrix chart, labeledSPEED CALIBRATION, which equates standard

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Figure 5-12.—Bleed air control panel.

orders to knots (speed), shaft rpm, and pitchsettings.

BLEED AIR CONTROL PANEL

This panel is shown in figure 5-12. It is dividedinto three sections (two of which are identicalexcept for labeling). This panel has the controlpush-button indicators and valve status indicatorsfor the automatic/manual controls related to thebleed air system for each engine room. It also hasfive push-button control indicators for the maskerair, a push-button control indicator for the prairieair, and valve status indicators for the GTG3. Inaddition, this panel has a thumbwheel controlleddemand digital display of various conditions thatexist within the control system along with a printpush button for printing thumbwheel selectedinformation.

Port and Starboard Engine Room Sections

The first section on the left of this panel is forthe port engine room. It has 16 split-legend, push-button control indicators. Nine of these indicators(three for each engine) control the INTAKEHEATERS, ANTIICING, and STARTER AIR

for ENG 2A, ENG 2B, and GTG 1. Five of thesecontrol indicators control the masker systemvalves and the motor air regulator valve. The lasttwo of the control indicators are for theautomatic/manual operation of the masker airsystem valves and to select their control mode.

Under the heading INTAKE HEATERS arethe manual control indicators (ON/OFF) for theintake heaters of the respective engines. Under theheading ANTIICING are the manual controlindicators (ON/OFF) for the antiicing valves ofthe respective engines. Under the headingSTARTER AIR are the control indicators usedto select the starting air mode (NORMAL,EMERGENCY, or MOTOR) for the selectedengine. The five control indicators for themasker system are for manual control of themasker system valves when the control indicatorunder the heading CONTROL MODE is in theMANUAL position. When this control indicatoris in the AUTO position, the PACC operator canperform an automatic sequence (either ON/OFF)of all the masker valves by depressing thecontrol indicator under the heading MASKER.

The second section is for the starboard engineroom and has the identical control indicatorsmentioned in the first section. The exception

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being this section is labeled for ENG 1A, ENG1B, and GTG 2.

Group and Auxiliary Demands Section

This is the third section of the panel. It hasfive split-legend, push-button control indicators(four on the CG console). Only three are used onthe DD console. These push buttons are used tocontrol the anti-icing air, the bleed air, and theprairie air on the DD console. The CG consolehas these same push buttons with a fourth pushbutton used to control the GTG3 intake airheaters. This section also has a digital display witha thumbwheel for parameter address selection anda PRINT push button.

INTEGRATED THROTTLECONTROL PANEL

This panel is shown in figure 5-13. It isused by the PACC operator to control thepropeller pitch and engine’s PLA. Integratedthrottle control (or automatic throttle control)is available at the PACC and the SCC. Thereare two levers, one for each shaft, for simul-taneous control of the GTMs and controllablereversible propeller. These levers can bemechanically latched together to control bothshafts simultaneously or unlatched for individualshaft control.

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Figure 5-13.—ITC panel.

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NOTE

The major difference between thePACC ITC and the SCC ITC is that thePACC ITC has provisions for pitch trim,while the SCC ITC does not. Therefore,the two ITCs are not interchangeable.

Table 5-1 shows the rpm and pitch relation-ship over the range of the throttle lever. In theahead direction, shaft rpm is held at 55 untilpropeller pitch reaches 100 percent. After thispoint, shaft rpm is increased and pitch remainsat 100 percent. In the astern direction, shaft rpmis held at 55 until propeller pitch reaches –49 per-cent. After this point, shaft rpm is increased andpitch remains at –49 percent.This system is called ITC because the infor-

mation for both pitch and rpm for an engine roomis given by one analog reference voltage. Tworeferences, one for each shaft, are generated byeach of the levers at the console (PACC or SCC)that has control.

PROPULSION LOCALCONTROL CONSOLE

The propulsion local control equipment(PLOE) is the engine room control equipmenton the DD- and CG-class ships. Two identicalPLOEs are on each ship, one in each engineroom. PLOE No. 1 is located in MER 2, whilePLOE No. 2 is in MER 1. Each PLOE has twounits of which the major unit is the PLCC.The second unit is the propulsion local controlelectronics enclosure (PLCEE). This unit housesthe power supplies for the PLCC. Other thanon/off control, no operator functions areavailable at the PLCEE.

The PLCC is divided into six panels and aPLA and pitch control section. These panels arethe GTM B PANEL, the GTM A/B PANEL, theGTM A PANEL, the SELF TEST PANEL, theEOT PANEL, and the ALARM TEST PANEL.Figure 5-14 shows the console’s six panels and thePLA and pitch control levers.

Table 5-1.—RPM-Pitch Relationship

Figure 5-14.—PLCC—major sections.

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GTM B PANEL FUEL OIL, GTM B, and EMERGENCYCONTROLS.

The GTM B panel (fig. 5-15) has the controlsand status indicators for GTM B and the controlsand alarm/status indicators for the FO servicesystem. This panel is divided into three sections,

FUEL OIL Section

This section (with one exception) is a mirrorimage of the FO section on the PACC engine No. 2

Figure 5-15.—GTM B panel.

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panel that was described previously. The oneexception is that on the PLCC FO section, thelower left, push-button control indicator underthe heading CONTROL TRANSFER is labeledREMOTE/LOCAL vice CCS CONTROL/PLCCCONTROL. The PLCC operator uses this pushbutton to transfer control of the FO system to thePACC in CCS.

GTM B Section

The GTM B section has 23 alarm/statusindicators (25 on the CG console), 4 toggleswitches, a two-position key switch, 2 timers,16 push-button control indicators (13 on theCG console), and 2 dual-indicating meters (1on the CG console). These components are allused for the control/monitoring of GTM B in theapplicable engine room.

Under the heading GTM B, the first fivehorizontal rows of alarm/indicators have alreadybeen described in the PACC engine No. 2 paneldescription. Under the heading WATER WASHis an alarm/indicator labeled TANK EMPTY. Itilluminates amber when the water wash tank isempty of water wash or rinse solution. The two-position toggle switch under the heading WASHis labeled ON/OFF. It is used to open/close thewater wash solenoid valves. To the right of thisswitch on the DD console is a two-positiontoggle switch labeled SPARE that is not used.However, on the CG PLCC this switch is usedto control the water wash heaters. It is under theheading HEATERS and is labeled ON/OFF.

To the right of the HEATERS toggle switchare two status indicators, labeled OUT OFSERVICE and NORMAL. These status indicatorsshow the actual position of the key switch locatedbelow them. The status indicator OUT OFSERVICE illuminates amber when the key switchis in the OFF position. This position electronicallylocks out the start air valve so that the GTMcannot be started or motored. The indicatorNORMAL illuminates green when the key switchis in the ON position and the GTM is ready tooperate, provided other external parameters aremet.

To the right of the key switch under theheading START COUNTER is a digital counter.This counter registers a start each time T5.4 is> 400°F and NGG is > 4300 rpm for 0.25 seconds.To the right of this counter, under the headingGTM TIMER, is the other digital counter. Itrecords the actual running time (in hours) for theGTM once the START COUNTER requirementshave been met.

Under the heading MANUAL START are 12push-button control indicators (9 on the CGconsole) used for the manual start of the GTM.All but one of these control indicators weredescribed under the description of the PACCGTM B panel. The one exception is on the DDPLCC. It is a push-button control indicatorlabeled FUEL LOW TEMP OVRD. If the FOtemperature is below 80°F, the PLCC operatorcan depress this push button. It provides a logicoverride step that allows the GTM to be startedin the MANUAL or AUTO initiate mode.

Below and to the left of the MANUALSTART push-button control indicators are threeadditional push-button control indicators (twoon the CG console). The first push-buttoncontrol indicator is a split-legend type labeledCOMPUTER TEST ON/PASS. When depressed,it starts a test of the torque computer andilluminates PASS if the test was satisfactory.Below this control switch is a momentary contactpush-button control indicator labeled PT OVSPTRIP RESET. This switch is depressed to resetthe main fuel valves after an overspeed trip.

NOTE

Do NOT depress this switch until theengine comes to a complete stop. Ifdepressed, the fuel valves may reopen,causing a post shutdown fire.

To the right of this switch (DD console only)is a third push-button control indicator labeledVIB ANALYSER TEST ON. When depressed,it tests the vibration analyser circuits in the PLCC.

The two dual-indicating meters (one on theCG console) are identical to the ones describedpreviously on the PACC MIMIC panel.

The last two toggle switches are of the two-position guarded type. They are used by thePLCC operator to test the individual integrity ofthe MAIN FUEL VALVES (NO 1 or NO 2).Below these toggle switches under the headingCONTROL TRANSFER is a split-legend,control push-button labeled ENABLE/INHIBIT.This push button enables the transfer of controlof the GTM controls to the PACC.

EMERGENCY CONTROLS Section

The emergency controls section is a mirrorimage of the 2B emergency controls section onthe PACC engine room No. 1 demands paneldescribed previously.

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GTM A/B PANEL

The GTM A/B panel (fig. 5-16) has the alarmindicators for the GTMs A and B, and thecontrols and indicators for the various air systems.This panel is divided into-three sections. The firstsection has 22 alarm indicators (23 on the CG

console) for each engine, and 11 alarm indicatorsfor the air and MRG system. It also allows thePLCC operator to monitor the air systems of theengines in ENG RM 1, ENG RM 2, and GTG3.This monitoring ability consists of three alarmindicators per engine and an alarm indicator forthe HP air system of both engine rooms and

Figure 5-16.—GTM A/B panel.

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GTG3. This section of the GTM A/B panel alsohas 4 dual-indicating meters, 20 push-buttoncontrol indicators (21 on the CG console), and2 toggle switches. Ail of these alarm indicators,push-button control indicators, dual-indicatingmeters, and toggle switches have been previouslydescribed on the PACC.

The last two sections of this panel are theDDIs. They are a mirror image of each other. TheDDI system is an operator information system.The system is used to verify parameters, check thesystem’s operation, and troubleshoot systemmalfunctions. Any parameter monitored can bedisplayed at any DDI location. The DDI systemuses a three-digit address to probe the memoryof the computer and find the value of the

parameter. The DDI displays this value in thedisplay windows. To use the DDI system, you

determine the address for the requiredparameter,

dial the address in the SELECT thumb-wheels, and

observe the value of the parameter in thedisplay window.

In the DDI system, the values are continuallyupdated at the rate of four times a second.

GTM A PANEL

The GTM A panel (fig. 5-17) has the controlsand status indicators for the GTM A and the

Figure 5-17.—GTM A panel.

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Figure 5-18.—Self test panel.

controls and alarm/status indicators for the CRPand MRG LO system. This panel is divided intofive sections, GTM A, CRP, LUBE OIL,EMERGENCY CONTROLS, and RDCN GEARLUBO.

GTM A Section

The GTM A section of the GTM A panel isa mirror image of and performs the samefunction as the GTM B section of the PLCC GTMB panel.

CRP Section

This section of the GTM A panel on the PLCCis NOT a mirror image of the CRP section on thePACC engine room No. 2 panel, but it does havethe identical alarm indicators and push-buttoncontrol indicators. These indicators will not bedescribed again. The difference between the twosections is that this section of the GTM A panelhas a single edgewise meter to monitor HYDPRESS vice the dual-indicating meter found onthe PACC which monitors both the pressure andtemperature.

LUBE OIL Section

This section has the identical alarm indicators,dual-indicating meter, push-button controlindicators, and three-position rotary switchdescribed on the LUBE OIL section of the PACCengine No. 2 panel. There are three controlindicators on this panel that are slightly different.The PLCC LUBE OIL section does not have thePURIFIER ON indicator. Also, under theheading CONTROL TRANSFER is a split-legend, push-button control indicator labeledREMOTE/LOCAL. This push button is used totransfer LO system control to and from thePACC. It illuminates the CCS CONTROL/PLCC CONTROL status indicator at the PACC.The PLCC LUBE OIL section also has anadditional edgewise meter under the headingSUMP LEVEL. This meter displays the MRGsump level in gals x 102.

SELF TEST PANEL

The self test panel (fig. 5-18) is used to testthe GTM start, the GTM stop, and the coolingair control electronics. It also has the start/stopcontrols for GTM B. This panel is divided intotwo sections labeled START/STOP SELF TESTand GTM B.

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START/STOP SELF TEST Section

This section is used to conduct a static test ofthe start sequencer, normal and emergency stopcircuits, and the cooling air monitor circuit cardsof either GTM A or GTM B. It has two pushbuttons, two rotary selector switches, and eightstatus indicators. These buttons, switches, andindicators are used in conjunction with proceduralsteps outlined in the EOP and table 2-16 ofNAVSEA S9234-BT-MMO-010, PropulsionLocal Operating Equipment (PLOE), Volume 1.

GTM B Section

This section is used to start and stop the GTM.It is divided into two subsections labeled STOPand START.

STOP SUBSECTION.—This portion of thepanel has one alarm indicator, five push buttons,and three status indicators. The alarm indicatoris labeled INTERNAL FIRE. It is an alarm thatindicates an internal (post-shutdown) fire. If 3minutes after shutdown T5.4 is > 700 °F, thealarm will activate.

The push buttons are active only when theSTART/STOP MODE switch is in the MANUALINITIATE position. The push buttons are asfollows:

INITIATE—When depressed, it starts anormal stop of the GTM.

CANCEL STOP—It is used to cancel anormal stop of the GTM.

FIRE STOP RESET, EMER STOPRESET, NORMAL STOP RESET—These are logic circuitry reset push buttonsfor each of the indicated sequences (activeeven in manual control mode).

The status indicators are as follows:

STOP INITIATED—It illuminates toindicate a stop has been initiated.

PLA AT IDLE—It illuminates to indicatewhen the PLA reaches idle. At idle, a5-minute cool-down timer begins.

FUEL VALVES CLOSED—It Illuminateswhen the cool-down period is over. Aftercool down, the fuel valves close, whichsecures the GTM.

START SUBSECTION.—The start half ofthe panel has two alarm indicators, six statusindicators, two push buttons, and a rotary selectswitch. The two alarm indicators are as follows:

FALSE START—This alarm indicates oneof two alarm conditions: (1) < 1200 NGG,20 seconds after the start air valve opens;(2) T5.4 less 400°F, 40 seconds after themain fuel valves open (1200 NGG).

ALIGN START AIR SYSTEM—This isactually a dual-function (status and analarm) indicator. As a status indicator, itcomes on steady to show the air startsystem is being aligned for a start. As analarm indicator, it comes on flashing toshow the air start system will not properlyalign (either the valves failed to properlyposition or anti-icing air is on).

The status indicators are as follows:

START ALIGN COMPLETE—It illu-minates after the logic circuits checkalignment of the following: (1) GTM inservice, (2) start air system aligned, (3) HPstart priority check, (4) fuel temperature,and (5) bleed air valve closed.

PLA AT IDLE—It illuminates to indicatePLA is at 0 percent.

COOLING AIR SYS READY—It illu-minates to indicate the vent damper is openand the cooling fan is operating properly.

CG AT IGNITION SP—It illuminates toindicate that GG speed is > 1200 rpm.

IGNITION—It illuminates to indicateT5.4 is > 400°F.

START COMPLETE—It illuminates toindicate GG speed is > 4300 rpm. (Oncethe start logic has been reset, electronically,the above status indicators extinguish.)

The two push buttons are active only in theMANUAL INITIATE mode. These two pushbuttons are as follows:

INITIATE—It is used to initiate aMANUAL INITIATE start.

RESET—It is used to reset the logiccircuitry for the MANUAL INITIATEstart sequence.

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Figure 5-19.—EOT panel.

Under the heading START/STOP MODE isthe two-position, rotary select switch labeledMANUAL INITIATE and MANUAL CON-TROL. This switch allows you to select thestarting and stopping mode.

EOT PANEL

The EOT panel (fig. 5-19) is divided into twosections labeled ALARM ACKNOWLEDGE andENGINE ORDER TELEGRAPH.

ALARM ACKNOWLEDGE Section

This section has two push buttons (three onthe CG console). They are the main interfacebetween you and the control console. Each timean alarm is activated, an audible alarm sounds.Amber (potential danger) alarms sound a hornand red (danger) alarms sound a siren. When anyalarm activates, the recommended procedures tofollow are listed as follows:

Identify the alarm condition. The alarmindicator will come on flashing, and theaudible alarm sounds.

Acknowledge the alarm. Depress theproper alarm acknowledge push button.This action silences the audible and causesthe alarm indicator to glow steadily.

Investigate the alarmed condition follow-ing EOCC.

ENGINE ORDER TELEGRAPH Section

When the SCC does not have throttle control,the OOD must inform the station in control ofspeed requirements. This is done through theEOT. The EOT is a communications system. Ittransmits propulsion command informationbetween the station in command (SCC) and thestation in control of the throttles (PLCC or thePACC).

The EOT section has two major subsections,the standard order push-button/status indicatorsand the digitized EOT.

The standard order push-button indicatorsection has 13 push buttons. Under the headingBACK, three of the push buttons are labeledFULL, 2/3, and 1/3. The next push button islabeled STOP. Under the heading AHEAD areseven push buttons labeled 1/3, 2/3, STD, FULL,FLANK 1, FLANK 2, and FLANK 3. The lasttwo push buttons are at the bottom of the panelunder the digitized EOT. These push buttons arelabeled RPM ACK and PITCH ACK. These 13push buttons provide for communication ofstandard orders to the PLCC. Standard orders areinitiated at the SCC by moving the ITC lever to

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the commanded standard order position anddepressing the standard order ALERT push-button indicator. This transmits the order tothe PACC and PLCC for that shaft (port orstarboard). The commanded standard orderacknowledge push-button (RPM ACK/PITCHACK) indicator flashes at both the PLCC andPACC, but the EOT bell annunciator only soundsat the station which has control of that engineroom (PACC or PLCC). During a standard EOTorder change, the new order is displayed by theflashing indicator and the old order is displayedby the steady illuminated indicator at all threeconsoles (SCC, PACC, PLCC). If the PLCC hascontrol, the operator can acknowledge the orderby depressing the flashing standard order pushbutton. This silences the bell, and the flashingindicator illuminates steady.

The digitized EOT section contains threealarm indicators, five status indicators, theALARM ACKNOWLEDGE push buttons, aTORQUE SENSOR CUTOUT push button, anda CONTROL TRANSFER push-button/statusindicator.

The alarm indicators are as follows:

TORQUE MISMATCH—It illuminatesred to indicate a mismatch of torquebetween the PT and the propulsion shaft.These values are electronically measuredby the FSEE and the shaft torque sensor.More than a 25 per cent difference of thetwo torque values for > 60 seconds willactivate this alarm.

OVERTORQUE CONTROL ON—It illu-minates yellow to indicate that overtorquecontrol has been activated either in theFSEE (PT torque limiting) or by theconsole electronics (shaft torque limiting).This indicator illuminates when limiting isoccurring. If after 20 seconds the over-torque condition still exists, the alarm willsound.

WRONG PITCH DIRECTION—It illu-minates red to indicate a differencebetween the commanded pitch, theposition of the pitch control lever, and theactual pitch of the propeller. If the wrongdirection condition exists for longer than20 seconds, an audible alarm is sounded.If a wrong direction condition exists and

shaft rpm is > 60, the console electronicswill bring the PLA to idle.

The status indicators are as follows:

FULL AHEAD PITCH—It illuminatesgreen to indicate + 100 percent propellerpitch.

AHEAD PITCH—It illuminates green toindicate +16 to +100 percent propellerpitch.

ZERO PITCH—It illuminates green toindicate – 16 to +16 percent propellerpitch.

BACK PITCH—It illuminates green toindicate – 16 to – 49 percent propellerpitch.

FULL BACK PITCH—It illuminatesgreen to indicate – 49 percent propellerpitch.

The TORQUE SENSOR CUTOUT is a push-button control indicator that electronicallyoverrides shaft torque limiting. Shaft torqueis sensed by a torsion meter installed onthe propeller shaft. If propeller shaft torquebecomes too great, an electronic signal isgenerated to limit PLA of the GTM. Thisaction limits the power of the GTM untilshaft torque is within normal power limits.When the torque sensor cutout is activated,propeller shaft torque is NOT electronicallylimited.

At the bottom center of the panel, under theheading CONTROL TRANSFER, is a push-button control indicator labeled LOCAL/REMOTE. It is the control transfer push-buttonfor the following functions:

GTM controls, start/stop functions

Clutch/brake controls

CRP pump control

EOT control

The control transfer button is used with the GTMENABLE/INHIBIT push buttons discussed inGTM controls and indicators.

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Figure 5-20.—Alarm test panel.

ALARM TEST PANEL

The alarm test panel (fig. 5-20) is dividedinto four sections labeled GTM A, TEST,POWER, and MALFUNCTION.

GTM A Section

The GTM A section is a mirror image of theGTM B section on the PLCC SELF TEST panel.

TEST Section

This section is used to test the alarm and statusindicators on the various panels of the console.Under the heading INITIATE are three pushbuttons labeled BELL, HORN, SIREN, and athree-position toggle switch labeled STATUS,OFF, and ALARM. Under the heading SELECTis a three-position rotary switch labeled LEFT,CENTER, and RIGHT.

The alarm and status tests are performed byselecting the panel of the console (left, center, orright panel) to be tested with the SELECT switch.By placing the toggle switch to the ALARMposition, all the alarm indicators on the selectedpanel illuminate flashing. After the ALARM test,the toggle switch is placed in the OFF position.At this point, the alarms illuminate steady until

the operator depresses the ALARM ACK pushbutton to turn them off. Moving the toggle switchto the STATUS position illuminates all the statusindicators for the selected panel. After theSTATUS test, the toggle switch is placed back inthe OFF position and all the status indicatorsextinguish. During a panel STATUS test, anydigital display will indicate 888***. This providesa test of all segments of each digit of the digitaldisplay.

The push buttons under the heading INITIATEare used to test the audible alarms. There are threecategories of audible alarms. They are, in orderof increasing priority, the BELL, the HORN, andthe SIREN.

POWER Section

This section is used to monitor the consolepower supplies. It has an alarm indicator labeledEMERGENCY and a status indicator labeledNORMAL. When the EMERGENCY indicatoris illuminated, the console is being supplied by theUPS system (150 volts dc). Under normalconditions the NORMAL status indicator isilluminated, indicating the console is beingsupplied by 120 volts ac from ship’s power.

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MALFUNCTION Section PLA AND PITCH CONTROL LEVERS

This section has four alarm indicatorswhich are normally not illuminated. The alarmindicators are as follows:

POWER SUPPLY—It illuminates red toindicate a summary fault condition at thePLCEE power supply.

CONSOLE—It illuminates red to indicatea summary fault condition at the PLCC.

S/CE—It illuminates red to indicate asummary fault condition at the PAMISEsignal conditioning enclosure.

S/CE EMER POWER ON—It illuminatesred to indicate the signal conditioningenclosure is using UPS emergency power.

Figure 5-21 shows the PLA (throttle) andPITCH control levers which are electronicallyconnected to the PLA of the GTM and to theCRP electronic enclosure, respectively. Thethrottle levers are graduated in percentage of PLAfrom 0 to 100 percent for each PLA. The pitchlever is graduated in percentage of pitch travelfrom 0 to 110 percent (ahead) and from 0 to – 65percent (astern).

SUMMARY

In this chapter, we have presented informa-tion to familiarize you with the controls andindicators located on the consoles of the DD- andCG-class ships. The main consoles of other classesof gas turbine-powered ships will be described inlater chapters of this TRAMAN. Do not attempt

Figure 5-21.—PLA (throttle) and PITCH control levers.

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LM2500 GTE operation until you understand howthe control stations operate.

The material presented so far has given youa basic understanding of the general lay out ofthe CCS and the engine room consoles. As a GS,you will be assigned watches at these console

watch stations. By the knowledge learned in thischapter, by using PQS and EOSS, and yourexperience standing under instruction (U/I)watches, you should be able to qualify in yourship’s various watch stations. Remember, beforeyou attempt any operation at these consoles, youmust be familiar with and use the EOSS.

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CHAPTER 6

PCC AND LOP FOR FFG-CLASS SHIPS

Operation of main propulsion GTEs is donefrom several different locations. The major classesof Navy ships that use the LM2500 GTE havethree control points. The first control station isin the engine room. It is called the local operatingpanel (LOP) on the FFG-class ships. On the CG-and DD-class ships, it is called the propulsionlocal control console (PLCC). It is called the shaftcontrol unit (SCU) on the new 51 classships. The engine-room control consoles are theprimary control consoles. This is not to say thatthe engine-room console is in control all the time.When we say primary control console, we meanit may take control from any other remotestation at any time. For example, on a shipoperating with the throttle control at the pilothouse, if the engine-room operator places thethrottle control to local, automatically the engineroom assumes control of the throttle operation.

The next level of control is in the CCS. TheCCS is normally the control station for starting,stopping, and monitoring the LM2500 GTE. Onthe FFG-class ships the console in this station iscalled the PCC. In this chapter we will discussonly the PCC located in the CCS and the LOPlocated in the MER on an FFG. The othercontrol consoles located in CCS are discussed indepth in later chapters. On the twin-shaft GTE-powered ships, the main engine control is calledthe propulsion and auxiliary control console(PACC).

The third level of control is on the bridge. Thisstation, known as the ship control console (SCC)(or bridge control unit (BCU) on the 51class), may have direct throttle control of theengineering plant. This allows the officer of thedeck (OOD) to have direct throttle and pitchcontrol, eliminating the need to pass an engineorder verbally to CCS. Quicker maneuvering ofthe ship is possible with control at the SCC.

Gas Turbine Systems Technicians on the FFG-class ships, like those on the other class GTE-powered ships, stand most of their watches in theCCS. The watch standers in CCS are responsible

for operating and monitoring the ship’s engineer-ing plant. To stand these watches, you must befamiliar with the operation of the equipment inCCS. This equipment includes the PCC, the DCC,the EPCC, the ACC, and the bell and dataloggers. Some of this equipment, along with shipclass differences, have been discussed in previouschapters. Chapters 8 and 9 of this TRAMANcontain additional information on the EPCCs andthe ACCs.

The equipment design allows for a minimumnumber of watch standers for the entire engineer-ing plant. Alarms and status indicators keep theCCS operators aware of plant conditions. Digitaldisplays and meters show the parameters, whileswitches and push buttons allow control of theequipment.

Just knowing the location of the lights, pushbuttons, and switches is not enough. You mustalso know the operation of the entire plant.Without a working knowledge of the plant,pushing the wrong push button could endangerthe equipment, the ship’s maneuverability, or yourshipmates.

After reading this chapter, you should befamiliar with the operation of the PCC in the CCSand the LOP in the MER and be able to discusshow they relate to the engineering plant. Likeother material in this TRAMAN, this chapter willonly familiarize you with the equipment. Toqualify on any engineering watch station, youshould always use the EOSS and the PersonnelQualification Standard (PQS).

After reading this chapter and completing theassociated NRTC, you should gain enoughknowledge to start qualifying on the propulsionconsoles in CCS and the MER. While you maynever work on an FFG-class ship, this chaptershould provide you enough equipment informa-tion to help you advance in rate. As you becomesenior in the GS rating, this introduction to theFFG control equipment will be helpful in yourwatch-station qualifications.

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Figure 6-1.—PCC panel breakdown.

PROPULSION CONTROL CONSOLE

The PCC is the console normally used tooperate the ship’s main GTEs and propulsionequipment. It is the largest component of thePCS. The PCC provides all the controls andindicators necessary to start, control, and securethe ship’s propulsion system and its related

auxiliaries. During this description of the PCC wewill attempt, where possible, to describe the panelsfrom left to right and top to bottom.

PCC CONTROLS AND INDICATORS

The PCC is subdivided into panels (fig. 6-1).On the top outboard sections of the console are

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Figure 6-2.—PCC fuse panel.

a fuse panel (left side) and a status and fuse panel(right side). In the center of the top section of thePCC is the demands panel. On either side of thedemands panel are the engine start panels (1A onthe right side, 1B on the left side). On the middlesection of the PCC from left to right are theseawater cooling panel, the engine 1B panel, theFO service system panel, the engine 1A panel, andthe reduction gear LO panel. The lower sectionof the PCC is the propulsion control panel. Thispanel has the throttle controls, the propeller pitchhydraulic oil panel, and an MRG bearing mimicdisplay.

Follow the related figures as we discuss thevarious PCC control and indicating panels. Theparenthetical letters referenced in the text are

shown on the figures. Refer to these letters to findthe section of a panel when it is discussed.

Fuse and Status Panels

The fuse panel (fig. 6-2) is located to the leftof engine start panel 1B. This panel has sevensections of fuses, two of which contain spare fusesfor the panel. The other sections are labeledSEAWATER COOLING, FUEL SYSTEM, GEARLUBE OIL, PROPELLER HYDRAULIC PUMP,and TRANSDUCERS—24 VDC. When a gener-ated command is not received, troubleshootersshould begin by checking the associated fuses. Theonly time voltage is applied across the fuse is whena command is transmitted.

6-3

Figure 6-3.—PCC status and fuse panel.

To the right side of engine start panel 1A isthe status and fuse panel (fig. 6-3). It hasindicators for the PCC, the LOP, and the powersupply enclosure and two sections of fuses.

On the upper left side of the status and fusepanel are three status indicators for the PCC. Thefirst indicator is labeled OVERTEMP and is usedto monitor the internal temperature of theconsole cabinet. This is set at 160°F. Thesecond indicator is a split-legend indicator.The upper half is labeled 28VDC UPS AVAIL-ABLE. This indicator illuminates when 28volts dc from the power supply enclosureassembly (PSEA) is available. The lower halfof the indicator is labeled HEATERS ONand illuminates when the console heatersare energized. It will not be illuminatedduring a lamp test. The last indicator for thePCC on this section of the panel is the MAINTMODE indicator. It illuminates when theoperate/test switch of the processor on themaintenance panel is in the test position. Theonly time this should illuminate is when amaintenance person is working on the system.If it is illuminated, the DDIs and programmedcontrol may or may not be operating.

The next indicator on this section is for theLOP. It is labeled OVERTEMP. This indicator

illuminates when the internal temperature of theLOP is greater than 160°F. The last indicator onthis panel is for the power supply enclosure andis labeled ALARM. It illuminates when amonitored voltage in the PSEA has fallen belowits set point or the internal temperature of thePCC or LOP console is high.

Underneath these indicators are two sectionsof fuses. The section to the left is 28VDC fusesfor the power fed to the panels. The fuses in theright section are for the 115VAC fed to othercomponents indicated on the panel.

Engine Start Panels

The two engine start panels are mirror imagesof each other. They have identical push buttonsand indicators. These indicators and controls areused to monitor or control the start of one of theGTEs. Figure 6-4 shows panel 1B.

PRESTART STATUS SECTION.—Theprestart status section (A) has 10 split-legendindicators that display the status of 18 componentsin the plant before start. These 18 indicators arecalled the GTE prestart permissives. We will startour description at the top outside indicator andgo across the top row, and then continue with the

6-4

Figure 6-4.—Engine start panel 1B.

indicators on the second row. The indicators andwhat they represent are as follows:

Top Row:

1. PROP PITCH ZERO—The propellerpitch is at zero (automatically bypassed forstart of the second GTE).

2. SHAFT BRAKE DISENGAGED—Theshaft brake is disengaged (automaticallybypassed for start of the second GTE).

3. TURN GEAR NOT ENGAGED—Theturning gear motor is not engaged to thegearbox and is not locked.

4. ACC COVER CLOSED—The clutchaccess doors on the MRG are closed.

5. STARTER NOT MOTORING—TheGTE starter is not motoring (turning).

6. ENGINE WASH OFF—The GTE is notbeing water washed.

7. SEAWATER COOLING ON—The sea-water cooling pressure is greater than 7psig, and the discharge valve is open.

8. GEAR LUBE OIL ON—The LO supplypressure at the hydraulically most remotebearing of the MRG is greater than 9 psig.

9. BLEED AIR VALVE CLOSED—Thebleed air valve on that GTE is closed.

Second Row:

10. LOP NOT IN CONTROL—The controlof the GTE is not at the LOP.

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11. ENGINE NOT RUNNING—The NGG isless than 1200 rpm, T5.4 is less than400°F, and fuel manifold pressure is lessthan 50 psig.

12. ENCL FANS READY—The enclosurefan is ready to run depending uponautomatic fan circuitry.

13. PT BRAKE NOT ENGAGED—The PTbrake for that GTE is not engaged.

14. FUEL SUPPLY ON—One of the twofuel tanks has more than 20 percent,the fuel supply cutoff valve is open,and the fuel supply pressure is greaterthan 8 psig.

15. SEQ NOT IN OFF-LINE MODE—Thesequencer mode switch is not in the off-line position.

16. COASTDOWN PUMP OFF—The MRGcoastdown pump is not running.

17. THROTTLE AT IDLE—The GTE PLAis in the idle position.

18. HALON SYS READY—The Haloninhibit switch is not on and the Halonsystem is ready.

READY TO START.—The READY TOSTART indicator (B) only illuminates when the18 prestart permissives are met. The GTE is notdesigned to be started in either the automatic ormanual mode until this indicator illuminates.

STARTING SYSTEM SECTION.—TheSTARTING SYSTEM section (C) has twoindicators used to display abnormal conditions inthe starting air system. The STARTER AIRPRESS LOW indicator illuminates when thestarting air pressure drops below 35 psig assensed by one of two pressure transducers. TheREGULATOR SHUTOFF VALVE FAIL TOCLOSE indicator illuminates when the start airvalve on the GT has not closed and the GG speedhas reached 4900 rpm.

SEQUENCER MODE SELECTOR SWITCH.—The SEQUENCER MODE selector switch (D) isa three-position rotary switch used to determinethe operating mode of the start/stop sequencer.The three modes are OFF LINE, AUTO, andMANUAL. The off-line position will prevent theGTE from being started at the PCC. This modeis normally used only during maintenance, waterwashing, and motoring. The auto position allowsthe AUTO SEQUENCE START push button tobe used to start the GTE using the start/stopsequencer. In the manual position, the operator

has to start the GTE using the manual pushbuttons and do the start sequencing.

START SEQUENCING.—The start sequencingsection (E, F, and G) has 10 push buttons andindicators used to control or monitor the GTEstart. An additional indicator (H) in this sectionindicates when the GTE is at idle. The automaticstart section (E) has a push button and threeindicators used to start the GTE in the automaticmode. The AUTO SEQUENCE START pushbutton is depressed to initiate the auto startsequence in the start/stop sequencer. This actionwill only start the sequence if the sequencer modeselect switch (D) is in AUTO, and the READYTO START indicator (B) is illuminated. The firstindicator to illuminate during an auto startsequence is the STARTER RUNNING indicator.This shows the starter regulator/shutoff valve isopen. The next indication is for IGNITION ON.This indicator shows that the igniters are energizedthrough the start/stop sequencer. The thirdindicator is a split-legend type that readsFUEL/FLAME. The FUEL indicator illuminateswhen the fuel manifold pressure is greater than50 psi. The FLAME indicator illuminates whenPt5.4 is greater than 400°F.

The three center indicators (F) are used toshow out-of-tolerance conditions during a GTEstart. These three conditions will also cause anautomatic shutdown. These indicators are labeledNGG FAIL TO REACH 1200 RPM, FAIL TOLIGHT OFF, and NGG FAIL TO REACH 4500RPM. These indicators illuminate when therelated condition occurs.

The three manual start push buttons (G) areused to manually sequence the start/stopsequencer during a manual start. The pushbuttons are labeled STARTER ON, IGNITIONON, and FUEL ON. These push buttons are usedwhen the sequencer mode selector switch (D) isin the MANUAL or OFF LINE mode. When theSTARTER ON push button is depressed, it opensthe starter shutoff/regulator valve. Depressing itagain will close the valve, although it willautomatically close at 4500 rpm (NGG). TheIGNITION ON push button is a momentarypush-button switch. When this push buttonis depressed, it energizes the igniters. It de-energizes them when it is released. The FUEL ONpush button is also a momentary-type switch.Depressing it causes the fuel valves to open.During a start, these valves are latched open bythe sequencer.

The ENGINE AT IDLE lamp (H) illuminateswhen NGG is between 4900 and 5000 rpm.

6-6

Figure 6-5.—Demands panel.

ENGINE 1B WATER WASH SECTION.—The engine water wash section (I) has one split-legend, latching-type, push-button switch and twoindicators. The ON/OFF switch/indicator isenabled when (1) the water wash control is inREMOTE at the engine room controller, (2) thesequencer mode switch on the PCC is in the OFFLINE position, and (3) the engine control modeswitch is in the PROGRAMMED position. Whenthese conditions have been met, depressing theON/OFF switch signals the processor to start theengine wash sequence. The indicator labeledFAILURE illuminates if any of the followingconditions occur: (1) initially if the wash and therinse tanks are not full, (2) if the wash cyclehas started and the wash tank is not emptywithin 4 minutes, and (3) if the rinse tank is notempty within 10 minutes. The indicator labeledCOMPLETE illuminates when the automaticengine wash cycle is finished.

ENGINE 1B TORQUE CMPTR SECTION.—The torque computer TEST push button/indicator(J) is used to perform a confidence check of theGTE torque computer. When this push button is

depressed, it “plugs in” a set of fixed values thatreplace the normal GTE parameters to calculatethe GTE’s torque and horsepower. Thesecalculated values are then compared to fixedreference values in the FSEE. If the resultis correct, the TEST push button/indicatorilluminates by a test passed signal from the FSEE.If it does not illuminate, the torque computer isnot working correctly. This test should only bedone when the GTE is secured or at idle. This isbecause the normal GTE parameters are beingreplaced with a fixed set of parameters and noovertorque protection exists during this time.

LAMP TEST.—The LAMP TEST pushbutton (K) is used to check the condition of thelamps. When it is depressed, all the indicators andlight emitting diodes (LEDs) on the top panel,except the HEATERS ON indicator, shouldilluminate.

Demands Panel

The demands panel (fig. 6-5) has five sectionswith information and controls for auto shutdown

6-7

status, time, logger commands, power supplystatus, and selected parameter values.

AUTO SHUTDOWN STATUS SECTION.—The auto shutdown status indicators (A) are LEDswhich illuminate red when an auto shutdownoccurs, either on GTE 1A or 1B. An auto shut-down may occur because of vibration, low LOpressure, or high T5.4. These indicators areextinguished by depressing and holding theAUTOMATIC SHUTDOWN push button on theGTE 1B/1A panel.

TIME SECTION.—The time section (B) hasan LED digital display of the time in hours,minutes, and seconds generated by the PCC real-time clock.

LOGGERS SECTION.—The loggers section(C) has two sets of thumbwheels and two push-button switches. The thumbwheels are used to setthe month and day into the processor for use onthe automatic logger. These must be updateddaily. The push buttons are momentary-contacttypes labeled DATA LOGGER PRINT andBELL LOGGER PRINT. When either pushbutton is depressed, it will cause the data or belllogger to print.

POWER SECTION.—The power section isdivided into two subsections, the PCC (D) andthe LOP (E). These two subsections providepower supply status for the logic power suppliesin the PCC and LOP. They also provide console115-volt ac status for the PCC. These indicatorsare split-type and both halves are normallyilluminated. If either half of an indicator isdark, perform a lamp test. If the lamp testis satisfactory, check the indicated power suppliesfor malfunctions.

PARAMETERS SECTION.—The parameterssection (F) has three digital display subsectionsthat the operator can use to monitor multiple,selected parameters. Each subsection contains adisplay, a thumbwheel, and a toggle switch. Thethumbwheel is used to select an address, foundon a DDI listing, that calls up the selectedparameter. The parameter is displayed with thedecimal in the proper position and with the unitsused to measure the parameter. The toggle switchis used to display either the high-alarm limit, theactual value, or the low-alarm limit. Anothertoggle switch, located on the lower left side of theparameters section, is used with either of the other

Figure 6-6.—Main seawater cooling panel.

three toggle switches. It allows the operator toverify the high/low reset value of the parameterdisplayed.

MAIN SEAWATER COOLING Panel

The MAIN SEAWATER COOLING panel(fig. 6-6) is located on the left side of the middle

6-8

panel of the PCC. It is used to control andmonitor the operation of the engine-room mainseawater system. This system is used to cool thereduction gear 10. This panel has a meter tomonitor seawater pressure, a low pressure alarmindicator to the bottom right of the meter, fivemomentary-contact push-button indicators andfive split-legend indicators.

The supply pressure meter and the LOWPRESSURE alarm are used to monitor mainseawater cooling pressure. Normal pressure is 30to 35 psig. The alarm will sound at 7 psig aftera 10-second delay.

This panel allows opening and closing controlof the two pump suction valves and one overboarddischarge valve, and start/stop control of the twoseawater pumps. The three valves controlled from

the PCC are the pump 1A suction valve, the pump1B suction valve, and the overboard dischargevalve. (NOTE: The panel is labeled for pump andsuction valves 1 and 2. Pump 1 controls 1A pumpand suction valve 1 controls 1A suction valve.Pump 2 controls 1B pump and suction valve 2controls 1B suction valve.) Each valve has anOPEN/CLOSE push button to operate the valveand an OPEN/CLOSED indicator to show theactual valve status. Also, each pump has anON/OFF push button to start and stop the pumpas well as a RUNNING/OFF indicator to showthe status of the pump.

Engine Panel

The PCC engine panel (fig. 6-7) has many ofthe same controls and indicators found on the

Figure 6-7.—Engine 1B panel.

6-9

LOP. It contains the controls, indicators, andmeters needed to operate the GTE. The GTE 1Aand GTE 1B panels are mirror images of eachother. We will describe the independent pushbuttons, indicators, and sections of the GTE 1Bpanel in our discussion; keep in mind that the 1Apanel has identical features.

BATTLE OVERRIDE.—BATTLE OVER-RIDE (A) is a guarded, illuminated, push button.You can use it at the PCC only if the PCC is thestation in control. This switch will illuminate whenactivated and overrides the following shutdowns:

1. Low GTE LO pressure2. High GTE vibration3. High T5.44. PLA failure for

a. PCS command signal out of limits,b. PT shaft torque out of limits, andc. PT speed out of limits.

BATTLE OVERRIDE will not override a flame-out or a PT overspeed trip.

TORQUE LIMITING IN EFFECT.—TheTORQUE LIMITING IN EFFECT indicator (B)illuminates any time the torque limiting circuit isrestricting the movement of the PLA. This is doneuntil the torque on the GTE is within safe limits.Then the torque limiting circuit will allow the PLAto advance to the command position, providedthe PLA doesn’t send the GTE into an over-torque condition. If it does, then the torquelimiting circuit will take over as before. This willcontinue until the command is obtained, or thecommand is reduced to a lower setting.

STOP SECTION.—The STOP SECTION (C)is located above the LO section on the enginepanel. The controls on the stop section are usedto perform normal and manual stops. Thissection has three indicators, two push buttons,and a switch used for GTE stopping.

The first indicator is labeled NORMAL STOPFAILURE. This indicator illuminates if 90seconds after the completion of the 5-minutecooldown timer, T5.4 is above 400°F or fuelmanifold pressure is above 50 psig. The firstcontrol is a push button labeled NORMALSTOP. It is used to initiate a stop using thestart/stop sequencer in the FSEE. This sequence,upon initiation, allows the GTE to run at idle for5 minutes. After 5 minutes, it de-energizes the fuelshutdown valves, causing the GTE to shut down.

This sequence may only be initiated if the GTEis at idle. By advancing the throttle above idle,you can interrupt the normal shutdown any timebefore the fuel valve closure.

The indicator labeled FUEL OFF is illuminatedany time fuel manifold pressure is below 50 psig.The indicator labeled NORMAL STOP COM-PLETE, when illuminated, indicates T5.4 isbelow 400°F and fuel manifold pressure isless than 50 psig within 90 seconds after thecompletion of the 5-minute cooldown timer.

The other push button in this section is labeledMANUAL STOP. When it is depressed, the fuelshutdown valves are de-energized, causing theGTE to stop. This stop should only be done afterthe GTE has been allowed to cool down for5 minutes to prevent GTE damage.

The three-position switch located below theMANUAL STOP push button is labeled FUELSHUTDOWN VALVE TEST. This switch isspring-loaded to the OFF position. Moving theswitch to either the valve 1 or valve 2 positionwill shut the corresponding fuel shutdown valveand should stop the GTE if the valve is operatingproperly. This switch is used during PMS totest the integrity of each of the fuel shutdownvalves.

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ENCLOSURE SECTION.—In the followingparagraphs we will describe the switch/indicatorsof the ENCLOSURE section (D).

The first switch/indicator is located at the topleft side of the enclosure section. It is a split-legendindicator. The upper half is FLAME DETALARM and illuminates when the UV sensorhas sensed a flame in the enclosure. The lowerhalf, HALON FLOOD, is a momentary-contactswitch. Depressing this switch releases the primarybank of Halon if the manual inhibit switch is inthe ACTIVE position at the enclosure. (NOTE:No automatic release of Halon is available intothe enclosure.)

The next indicator in this column is theACCESS DOOR OPEN/HEATERS ENERGIZEDindicator. The upper half of this indicator is fedfrom switches at the two GTM doors and indicatesthat a module door is open. The lower half of thisindicator indicates the module heater is energized.The enclosure heater keeps the enclosure airtemperature above 60°F. This temperature isrequired to prevent fuel waxing (fuel hardening)in the GTE fuel system. Control of the heater isprovided on the LOP. Indication of the heaterstatus is provided on both the PCC and the LOP.

The OVERTEMP CUTOUT indicator willilluminate when the heater is de-energized becausethe enclosure temperature was 145°F and theheater was on. The ICING detector indicatormeasures the temperature and humidity of theincoming combustion air. When icing conditionsoccur (temperature below 41°F and humidityabove 70 percent), this indicator will illuminateand an alarm will sound at the PCC.

The ANTI-ICING VALVE OPEN/ANTI-ICING VALVE CLOSED indicator shows theactual position of the anti-icing valve. Below thisindicator is the ANTI-ICING ON/ANTI-ICINGOFF momentary-contact switch/indicator. It isused to open and close the anti-icing valve andto indicate the operator’s command to the valve.

The last indicator in this column has a legendabove it labeled BYPASS DAMPER. Switches atthe bypass damper provide signals to the PCC toilluminate the OPEN/CLOSED status indicatorof the bypass damper.

The FIRE HALON SYSTEM DISABLEDindicator, located at the top of the next column,

is next to the FLAME DET ALARM indicator.It illuminates when a loss of continuity in the fireor the Halon system occurs. This is caused by lossof continuity between the flame detector andsignal conditioner or loss of 115-volt ac power tothe detection system. Power is supplied by the115-volt ac CB in the FSEE.

The next indicator down is a split-legendindicator. The upper half, labeled HIGH TEMP,is the indicator fed from the two temperatureswitches (set at 400°F) in the enclosure. The lowerhalf, labeled FAN RUNNING, illuminates whenthe enclosure fan is running.

The next indicator down is a momentary-contact switch/indicator labeled FAN RUN/FANSTANDBY. It selects the mode of operation forthe ventilation fan. In the FAN RUN position,the fan will be running. In the FAN STANDBYposition, the fan automatically starts when theGTE is running below 3000 hp or the GTE is notrunning and the enclosure temperature is above125°F. The fan automatically shuts down underthe following conditions:

Halon is discharged into the enclosure.

The GTE is running above 3000 hp.

The GTE is not running and the enclosuretemperature is below 125°F.

The vent damper closes.

To start a GTE, the fan controller must be inthe remote position and the control switch on thePCC should be in the FAN STANDBY position.

The last three indicators down are for thevent damper. The VENT DMPR OPEN/VENTDMPR CLOSED indicator shows the position ofthe vent damper. The VENT DMPR OPEN/VENT DMPR CLOSE switch/indicator is formanual control. It is only functional whenthe AUTO VENT CONTROL/MAN VENTCONTROL switch/indicator is in the MANVENT CONTROL position. The AUTO VENTCONTROL/MAN VENT CONTROL switch/indicator is used to select the mode of operationfor the ventilation damper, either automatic ormanual. In automatic mode, the ventilationdamper will open under the following conditions:

The ventilation fan is running.

The GTE is running.

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The GTE is not running and the outsideair temperature is above 70°F.

The damper will close automatically under thefollowing conditions:

Halon is discharged into the enclosure.

The GTE is not running and the outsideair temperature is below 70°F.

In the manual mode, damper control circuitsautomatically close the damper if Halon isdischarged into the enclosure.

GAS GENERATOR SECTION.—This section(E) has two meters and four indicators for theGG of the GTE. The AIR INTAKE LOWPRESSURE alarm is used to indicate when thedifferential pressure exceeds 7.5 in.H2O. This ismeasured between the ambient air and thecombustion air intake, downstream from themoisture separator. The PRESSURE RATIOmeter continually monitors the condition of theGG. The input of this meter comes fromcomputations between the Pt2 and Pt5.4.

The GG SPEED meter displays the speed ofthe GG. Associated with this meter is theOVERSPEED alarm, which has a set pointof 9700 ± 100 rpm. Below the OVERSPEED

indicator are the controls and indicators for theBLEED AIR VALVE. The OPEN/CLOSEDindicator illuminates to indicate the actualposition of the valve. The OPEN/CLOSE push-button control is used to open and close the valveand will illuminate to indicate the operator’scommand.

EMERGENCY STOP AND VIBRATIONSECTION. —This section (F) has two switch/indicators and a vibration subsection with a meter,a switch, and an indicator.

The EMER STOP switch/indicator can beinitiated by the operator at any time and in anycontrol mode. Depressing the EMER STOPswitch/indicator on the PCC will cause theindicator to illuminate and the circuitry in theLOP and the FSEE to immediately de-energizethe PT overspeed trip switch. This causes bothautomatic fuel shutdown valves to close, whichcauses the GTE to shut down.

The AUTOMATIC SHUTDOWN switch/indicator illuminates to indicate an automaticshutdown has occurred. This switch resets theautomatic shutdown electronics. The PCS initiatesautomatic shutdown for the following parameters

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after a GTE is running and provides indicationof each shutdown on the PCC.

T5.4 above 1530°F.

GTE oil pressure below 6 psig.

High GT vibration (GG above 7 mils orPT above 10 mils).

Flameout (T5.4 less than 400°F after PTfuel manifold pressure becomes greaterthan 50 psig and after an GTE run signalis obtained).

The meter in the VIBRATION subsection isalways reading the vibration on the GTE at theposition selected by the switch. The switch is afour-position switch. It allows you to look at thetwo different vibration pickups. One is locatedon the GG and the other is on the PT. Eachpickup senses both GG and PT vibration. Atracking filter for each pickup separates GGvibration from PT vibration depending onvibration frequency. Limits apply to frequencyand not pickup location. The HIGH VIBRATIONindicator will illuminate when the vibrationon the GG reaches 6 mils or the PT reaches7 mils. An automatic shutdown occurs when GGvibration reaches 7 mils or PT vibration reaches10 mils.

FLAMEOUT. —The FLAMEOUT indicator(G) will illuminate when T5.4 drops below 400°Fafter the fuel manifold pressure becomes greaterthan 50 psig and after a GTE run signal isobtained. When this happens, an automatic shut-down will occur.

ENGINE LUBE OIL SECTION.—TheENGINE LUBE OIL section (H) monitors theoperation of the engine’s LO supply and scavengesystems. The engine LO section of the panel isonly for monitoring purposes and has no controlfunctions. It has a meter and seven indicators usedto detect abnormal conditions of the engine LOsystem.

The left column of three indicators monitorsthe GTE scavenge oil. Starting at the top of theleft column, the first indicator is labeled HIGHPRESSURE. It will illuminate and an alarm willsound when scavenge pressure is above 130 psig.The second indicator is labeled LOW PRESSUREand will illuminate and an alarm will sound whenscavenge pressure drops below 5 psig. The thirdindicator is labeled HIGH TEMP and willilluminate and an alarm will sound when any ofthe five scavenge temperature RTDs detect atemperature above 300°F. When this alarmsounds, the operator should use one of the DDIslisted at the bottom of the column (ACCESSORYGEAR BOX, SUMP A, SUMP B, SUMP C, orSUMP D) to identify which scavenge temperatureis high.

The right column has four indicators andmonitors the GTE lube oil supply. The firstindicator at the top of the column is labeledTANK LEVEL LOW and is used to monitorthe level of the LOSCA lube oil tank. Theindicator illuminates and an alarm soundswhen the tank level falls to 9.6 gallons. Thesecond indicator is labeled COOLER DIS-CHARGE TEMP HIGH. It monitors the outlettemp of the oil leaving the LOSCA cooler.It illuminates and an alarm sounds if thetemperature of the oil exceeds 250°F. Thethird indicator is labeled FILTER HIGH AP. Thisindicator illuminates and an alarm sounds whenthe differential pressure across the LOsupply filter exceeds 20 psid.

The SUPPLY PRESSURE meter displays thesupply pressure of the LO. Associated with themeter is the LOW PRESSURE alarm indicator.This indicator illuminates and an alarm soundswhen the engine LO pressure drops to 15 psig.

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(Remember, an auto shutdown will occur if LOpressure drops to 6 psig.)

POWER TURBINE SECTION.—The PTsection (I) monitors the operation of the PT. Ithas two meters, two push buttons, and fiveindicators.

The first meter is the INLET TEMP (T5.4)meter. It displays the temperature of the gasentering the PT. Associated with this meter is theINLET TEMP HIGH alarm indicator for highT5.4. It has an alarm set point of 1500°F. Anautomatic shutdown will occur if T5.4 reaches1530°F and battle override is not on.

The second meter, the PT SPEED meter,shows the speed of the PT. The meter is fed fromtwo sensors mounted on the rear frame of theturbines that sense PT speed.

To the right of this meter is an OVERSPEEDTRIP indicator. It illuminates if either of thesensors senses a PT speed greater than 3960 ± 40rpm. This causes the GTE to shut down becausethe fuel shutdown valves are de-energized.

Directly below the OVERSPEED TRIPindicator is the OVERSPEED TRIP RESET pushbutton. It is used to reset the overspeed trip andto latch the fuel valves during manual starts.

Below the OVERSPEED TRIP RESET pushbutton is a split-legend indicator. It is labeledOVERSPEED SIG A LOSS/OVERSPEED SIGB LOSS. These indicators will illuminate when thePT speed drops below 100 rpm or a malfunction

in either speed circuit occurs. When the PT speedbecomes less than the loss-of-signal setting onboth speed signal input channels or greater thanthe overspeed setting on either speed signal inputchannel, the fuel shutdown valves de-energize (theGTE will shut down). If the PT speed loss signaloccurs on only one channel, the GTE willcontinue to run.

The bottom part of this section has a legendabove it labeled TURBINE BRAKE and is usedto control and monitor the operation ofthe turbine brake. The TURBINE BRAKEACTUATOR AIR LOW indicator, located at thebottom between the meters, will display when theair pressure to the brake actuator is too low. Itilluminates when brake air pressure is less than70 psig. The turbine brake indicator is a split-legend indicator that displays the actual status ofthe brake, either ENGAGED or DISENGAGED.The momentary-contact push button/indicatornext to it is used to control the brake. Thispush button will illuminate to show the operatorcommand to the brake. Depressing it will eitherENGAGE or DISENGAGE the brake assembly.The turbine brake will not engage unless the PTspeed is below 250 rpm.

ENGINE FUEL SUPPLY SECTION.—TheENGINE FUEL SUPPLY section (J) has thecontrol and monitor components used to operatethe fuel supply to the GTE.

Starting at the top, which is labeled EMER-GENCY FUEL SUPPLY, is a split-legend indica-tor labeled VALVE OPEN/VALVE CLOSED.It monitors the actual valve status of theemergency JP-5 supply valve. This valve’snormal position is closed. It is held closed

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The PCC has an indicator and control for theFUEL SUPPLY CUTOFF VALVE. The split-legend indicator is labeled VALVE OPEN/VALVE CLOSED. It illuminates to indicate theactual position of the valve, either open or closed.The split-legend, push-button control is labeledVALVE OPEN/VALVE CLOSE. It illuminatesto indicate the operator’s command, either openor closed.

electrically. Upon loss of power the emergencyJP-5 valve will open. This allows the GTEs to runon JP-5 from a 350-gallon head tank.

Under the emergency fuel supply indicatoris a meter labeled SUPPLY PRESSURE. Itdisplays the pressure of the fuel from thefuel service system to the GTE. Under thismeter and associated with it is the LOW FUELPRESSURE alarm indicator. It illuminatesand sounds an alarm at 8 psig. Fuel supplypressure is sensed after the fuel supply cutoffvalve.

CLUTCH SECTION.—The clutches on theFFG-class ship are synchronized self-shifting. Theonly operator action required to engage anddisengage them is the removal of the brake andoperation of the throttle.

The CLUTCH section (K) of the panel hasfour indicators and one push button. The firstindicator is labeled CLUTCH ACCESS COVEROPEN. This indicator illuminates if the accessdoor to the clutch is open. The next two indicatorsdisplay the clutch status and are labeled CLUTCHDISENGAGED and CLUTCH ENGAGED. Thefourth indicator is a split-legend indicatorlabeled CLUTCH LOCKED IN/CLUTCH NOTLOCKED IN. This indicator displays the statusof the lock-in/lock-out mechanism of the clutch.Locking out the clutch provides for operation ofthe GTE without turning the MRG. For normaloperation the clutch must be locked in. The lastindicator is a split-legend, push-button controllabeled LOCK VALVE OPEN/LOCK VALVECLOSE. This indicator was a design featureoriginally installed, but never used. It performsno function.

Fuel Oil Service System Panel

Located between the two engine panels is thefuel oil service system panel (fig. 6-8). The panelis divided into two identical sections labeled FUELSYSTEM 2 and 1. Each section has controls andindicators used to operate the fuel system oneither No. 1 or No. 2 tank, pump, heater,prefilter, or filter/separator. The system can becross-connected to allow one tank and pumpcombination to supply either or both GTEs.

An operator can monitor the FO service tankby using the split-legend alarm indicator (A) atthe top of the panel labeled HIGH/LOW. It alertsthe operator when a tank is either full or needsrefilling. The meter (B) labeled TANK LEVEL(1 or 2) indicates the actual level (in gallons) ofthe tank. The FO tank suction and return valve’ssplit-legend indicator (C) labeled OPEN/CLOSED

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Figure 6-8.—Fuel oil service system panel.

shows the actual status of both valves. Bothvalves must be in the same position forthis indicator to illuminate. These valvesdetermine the tank that is supplying fuel tothe fuel pump and where the excess fuel isreturned. The valves are operated by thesplit-legend, push-button indicator (D) labeledOPEN/CLOSE. It will illuminate to show theoperator’s command to the valves.

The next split-legend indicator (E) labeledPUMP SUCTION OPEN/PUMP SUCTIONCLOSED is for the pump suction valves (one perpump). It illuminates to indicate the actualposition of the valve. These valves are electricallyinterlocked with the pump start/stop pushbuttons to ensure the valves are open before thepump starts.

Three push buttons and a control mode switchcontrol the two service pumps. The three pushbuttons are labeled LOW SPEED (F), HIGHSPEED (G), and STOP (H). They will illuminateto indicate the actual status of the pump. Thepump (1 or 2) CONTROL MODE switch (I) isused to set the pumps in the MAN (manual) modeor the AUTO SPEED ADVANCE mode. Eachpump is a two-speed pump. In the manual modethe operator selects the speed of the pump (lowor high) by depressing the proper push button.In the automatic mode, a drop in fuel pressurewill shift the pump from low to high. If low speedis again desired, the operator must shift the speedback to low. The pump discharge valve indicator(J) is labeled PUMP DISCH OPEN/PUMPDISCH CLOSED. The valve is equipped with alimit switch to send a signal to the PCC whichwill illuminate the indicator to show the actualposition of the valve. This valve is operatedmanually at the valve.

The HEATER DISCHARGE TEMP HIGH/LOW alarm (K) is a split-legend indicator alarmfor high or low temperature. If the temperatureof the fuel leaving the heater exceeds 110°F, thehigh indicator illuminates and an alarm sounds.Likewise, if the temperature drops below 60°F,the low indicator illuminates and an alarm sounds.

A fuel prefilter is used in the system to removelarge particulate matter. If its ∆P exceeds10 psid, the PREFILTER STRAINER HIGH ∆ Pindicator (L) illuminates and an alarm sounds. Asecond filter, called the FILTER/SEPARATOR,is used to separate smaller particles and water. Ifthis becomes clogged and the DP is 12 psid orhigher, the FILTER/SEPARATOR HIGH ∆ Pindicator (M) illuminates and an alarm sounds.

Gear Lube Oil Panel

The gear LO panel (fig. 6-9) is used tocontrol and monitor the flow of LO to the MRG.

The first indicator (A) is labeled SUPPLYHIGH TEMP and illuminates if the MRG LOtemperature exceeds 130°F. If the MRGhydraulically most remote bearing pressure dropsto 9 psig, the indicator (B) labeled REMOTE

Figure 6-9.—Gear lube oil panel.

BEARING LOW PRESS illuminates and analarm sounds. The operator can monitor the LOpressure at the PCC by using the hydraulicallymost remote bearing pressure on the meter (C)labeled REMOTE BEARING PRESS.

Control is available from the PCC for the twomotor-driven, two-speed pumps. The rotary

two-position switch (D) labeled PUMP CON-TROL MODE is used to select either the AUTOor MAN (manual) control mode. The next split-legend indicator (E) labeled PUMP 1 and PUMP2 illuminates to indicate which pump is assignedthe NORMAL position. Normal and standbypump assignment is done by a switch on the LOpump controller in the engine room.

If the LO pressure drops to 9 psig, or if bothelectric pumps lose power, a third air-driven pumpprovides oil to the MRG. This pump is called aCOAST DOWN PUMP. It has an indicator (F)labeled PUMP RUNNING on the PCC to showwhen it is running. The coastdown pump will onlyrun if the shaft is turning. Also, it will stop if theLO pressure exceeds 15 psig. The next indicatordown (G) is labeled AIR PRESSURE LOW. Itilluminates and sounds an alarm to alert theoperator when the air supply to the coastdownpump is low. It activates at 2700 psig.

The speed control push buttons are used formanual speed control of the electric LO pumps.They are labeled LOW SPEED (H), HIGHSPEED (I), and STOP (J). They will illuminateto indicate the status of the pump(s). The operatormay use these push buttons in the manual modeto STOP, run in HIGH SPEED, or run in LOWSPEED the normal or standby LO pumps. First,the NORMAL PUMP is selected (its selection isshown by the NORMAL PUMP ASSIGNMENTPUMP 1/PUMP 2 indicator (E)). Then, theoperator manually starts the selected pump to startthe LO system. After the LO system is started,the operator may put the system in automatic byplacing the PUMP CONTROL MODE switch (D)to AUTO. In the AUTO mode, the pumps cycleup in speed in response to pressure decreases. Ifthe pressure drops to 15 psig, the NORMALPUMP shifts from LOW SPEED to HIGHSPEED. A drop in pressure to 13 psig causes theSTANDBY PUMP to start in LOW SPEED. Afurther decrease in pressure to 11 psig causes thestandby pump to go to HIGH SPEED. Whensystem pressure returns, the pumps must bemanually cycled to lower speeds or off.

The next indicator (K) labeled SUMP LEVELLOW, alerts the operator when the level of theMRG oil sump drops below 870 gallons. Theindicator (L) next to SUMP LEVEL LOW is theSTRAINER HIGH AP. If the differential pressureacross the LO strainer exceeds 12 psid, thisindicator illuminates and an alarm sounds.

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Propulsion Control Panel

The propulsion control panel (fig. 6-10) is thebottom panel of the PCC. This panel has thecontrols and indicators for the propeller hydraulicsystem, shaft speed and propeller pitch, MRGmonitoring, and control transfer.

PROPELLER HYDRAULIC SYSTEM SEC-TION.—This section (A) has a meter, eightindicators, and two control push buttons. Theyare used to operate the hydraulic system of thecontrollable pitch propeller.

Normally, the hydraulic pressure is suppliedto the system by the pump that is driven by thereduction gear (main pump). When this pumpcannot provide the proper pressure, it must beaugmented by the standby motor-driven pump.Two control push buttons are used to operate themotor-driven pump. The split-legend, push-button indicator labeled STANDBY/MANUALis used to select the mode of operation. If thestandby mode is selected and illuminated, whenthe shaft speed drops to about 105 srpm, themotor-driven pump starts. When the pushbutton is placed in the manual mode, the motor-driven pump must be started by the operator. Tostart the pump, the operator uses the split-legend,push-button indicator labeled MANUAL RUN/MANUAL STOP. When the motor-driven pumpis running, the indicator labeled MOTORRUNNING illuminates. Both pumps have suctionstrainers in the pump suction lines and dischargefilters in the pump discharge lines. These filtersare monitored by indicators labeled SUCTION

STRAINER HIGH DP and DISCHARGEFILTER HIGH DP. They will illuminate andactivate an alarm when either the suction straineror discharge filter are in an alarm condition.

The SUPPLY PRESSURE meter monitors theCPP hydraulic supply pressure. Associated withthis meter is the indicator labeled OIL PRESSLOW. If supply oil pressure drops to 40 psig, thisindicator illuminates and sounds an alarm.

The next indicator is labeled OIL TEMPHIGH. It illuminates and sounds an alarm to alertthe operator that the oil temperature in the systemhas exceeded 160°F. Under the label OIL LEVELLOW is the next split-legend indicator labeledHUB TANK/SUMP TANK. This indicatormonitors the oil level of the sump and head tanks.If the level in the head tank falls to 35 gallons,the HUB TANK indicator illuminates and soundsan alarm. If the sump tank level drops below 425gallons, the SUMP TANK indicator illuminatesand sounds an alarm.

ENGINE ORDER TELEGRAPH (EOT)SECTION. —Located below the propellerhydraulic section, is the EOT section (B). This isused to relay engine orders from the bridge to thePCC. When the bridge orders a change of speed,one of the pointers in the EOT will point to therequested speed. The PCC operator, toacknowledge the order, moves the other pointerto match the bridge pointer. This is doneusing the knob below the EOT. If the pitchof the propeller and the EOT indicate opposite

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directions (ahead and astern), the EOT WRONGDIRECTION indicator at the top of the EOTilluminates and sounds an alarm.

SHAFT PERFORMANCE MONITORINGSECTION. —Located to the right of the propellerhydraulic system panel are the indicators used tomonitor the propeller shaft performance. Thissection (C) has three meters used to monitorshaft horsepower, torque, and speed; shaftingindicators; shaft brake controls; and indicatorsand engine mode select controls.

The SHAFT POWER edgewise meter displaysshaft power. It displays in horsepower andreceives its input from the processor. The nextedgewise meter is used to display SHAFTTORQUE. This parameter is also sent from theprocessor and is displayed in ft-lb. The third meteris a horizontal edgewise meter that shows SHAFTSPEED. Associated with the shaft speed meterand to the left of it is the SHAFT STOPPEDindicator. It illuminates when the shaft isrotating less than 1/5 rpm. To the right side ofthe shaft speed meter is the SHAFT REVERSEROTATION indicator. It illuminates when thepropeller shaft is rotating in the reverse (counter-clockwise) direction. Next to this indicator is the

SHAFT IDLE MODE switch. This switch is notfunctional in this system and has only oneposition (NORM). To the right of the switch isthe TOTAL SHAFT REVOLUTIONS counter.This counter shows total shaft revolutions of thepropeller.

The ASTERN PITCH indicator illuminateswhen the pitch of the propeller is in the asterndirection.

The shaft brake subsection is located belowthe SHAFT SPEED meter. One control pushbutton and two indicators are used to displayconditions of the shaft brake. The shaft brakeACTUATOR AIR LOW PRESS alarm indicatoralerts the operator if the air pressure used tooperate the shaft brake drops below 1150 psig.The split-legend indicator labeled ENGAGED/DISENGAGED is for the shaft brake andilluminates to show the actual status of the shaftbrake. The split-legend, push-button indicatorlabeled ENGAGE/DISENGAGE is used to applyand release the shaft brake. It will illuminate toindicate the operator command to the brake. Itmay only be applied if the following conditionsare met:

Shaft speed is less than 75 rpm.

Throttles are at idle.

Pitch is at zero.

Only the station in control of the GTE(s)may apply the shaft brake electrically.

When these permissives are met, the controlpush button activates the shaft brake. If one ofthese permissives is lost, the shaft brake willrelease.

The next indicator is labeled PRAIRIE AIRHIGH TEMP. It will illuminate and sound analarm when prairie air temperature exceeds 135°F.

Below the shaft brake subsection are twoindicators, one per GTE, labeled LOCAL LOCK-OUT IN EFFECT. The indicator on the left isfor the 1B GTE and the indicator on the right isfor the 1A GTE. When either of these indicatorsare illuminated, it means control of that GTE isat the LOP. In this subsection are two GTEcontrol mode rotary switches, one per GTE.These switches are used to place the GTEs ineither REMOTE MANUAL or PROGRAMMEDmode. The remote manual mode is usedwhen a GTE is started or stopped. It is also analternate method of operating the throttle/pitchcombination if programmed control fails.Programmed control is the normal operatingthrottle mode used after the GTE is started.

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MODE SETTING AND REDUCTION GEAR mode and the PROPULSION MODE is set in theMONITORING SECTION.—This section (D) is SPEED mode. When the rough weather dampinglocated to the right of the shaft performance circuit is used, the processor attempts to even outsection and is used to set propulsion modes and PLA actuator command signals during rough seaprogrammed control locations and to monitor the conditions. This is to reduce hunting (fluctuation)reduction gear bearings. of the propeller srpm.

The first control switch is used only inprogrammed mode and is labeled PROPULSIONMODE. This switch has two positions, POWERand SPEED. When placed in the POWERposition, the processor automatically adjuststhe pitch and PLA commands to provide aconsistent load on the GTE. To do this, theprocessor uses the torque computer. At powersabove full pitch, an almost linear relationshipbetween the position of the programmed controllever and steady state srpm exists. In the powermode, the GTE or GTEs are kept at a steadypower level. In some sea states and/or under somemaneuvering conditions, the srpm will vary aboveor below a normal value. This variation in thepower mode is normal and expected.

The next section has 29 LEDs to monitorreduction gear bearing high temperature, onefor each bearing in the MRG and the line shaftbearing. Associated with each LED is a number,1 to 29; placing zeros in front of these numbersmakes three-digit numbers. You will then have theDDI number for that bearing. If you use thesenumbers as reference numbers, 1 to 26 are for thebabbitt bearings; the sensors are in the babbitt andare sensing babbitt temperature. Numbers 27 and28 are for the thrust bearings; number 29 is forthe line shaft bearing.

The other position of the PROPULSIONMODE switch is the SPEED mode. Whenoperating in the speed mode, the processorautomatically adjusts the propeller pitch signalsand the PLA actuator signals to provide aconstant propeller srpm. To do this, the processoruses built-in power schedules and propeller srpmfeedback. The programmed control lever gives theoperator fine control of srpm. The operator canmake careful adjustments to ship’s speed inrelatively calm seas and during alongsideevolutions.

Under the control switches is an indicatorlabeled PROGRAMMED CONTROL FAILURE.This indicator illuminates and sounds an alarmwhen the processor has failed or has not madea complete cycle and has stopped. If this occurs,the processor will have to be restarted. Until theprocessor is restarted, the DDIs and the loggersmay not be operating properly.

The next indicator is labeled PILOTHOUSEIN PROGRAMMED CONTROL. When this in-dicator illuminates, the control of the propulsionsystem is at the pilot house.

Just to the right of the propulsion mode switchis the ROUGH WEATHER DAMPING switch.This is an ON/OFF switch. This switch is onlyoperative when operating in programmed ‘control

Below the PROGRAMMED CONTROLFAILURE indicator is a two-position PRO-GRAMMED CONTROL LOCATION switch. Itdetermines the location of the programmedcontrol. The programmed control location rotaryswitch, when positioned to CCS, shows that thecontrol of the programmed mode is at the PCC.The other switch position is PILOTHOUSE. With

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the switch in this position, control of programmedcontrol is at the pilot house (SCC).

On the right-hand side of the PROGRAMMEDCONTROL LOCATION switch is an indicatorlabeled CCS PROGRAMMED CONTROL.When this indicator is illuminated, the control ofthe propulsion system is at the PCC.

SHAFT CONTROL SECTIONS.—The lowersections of the propulsion control panel (E, F,and G) have the levers and indicators used to

operate and monitor the speed and pitch of thepropeller shaft.

The section to the left (E) is the PITCH CON-TROL LEVER. It controls propeller pitch in theremote manual mode. To the right of this leveris an edgewise meter labeled PITCH. It shows theactual pitch position. Above this meter is anindicator labeled FULL AHEAD AND LOCKED.This indicator illuminates when the pitch of thepropeller is full ahead and mechanically lockedat the OD box.

The next section labeled REMOTE THROT-TLE CONTROL (F) has two levers for controllingthe speed of the GGs, one lever for each GG.These levers can be locked together so that whenthe GTEs operate together, their speed will be thesame. On either side of the REMOTE THROT-TLE CONTROL levers are edgewise meterslabeled THROTTLE LEVER POSITION, onefor each GTE. The meters are always showing theposition of the throttle in percentage of power.This is regardless of how the GTE or GTEs arebeing controlled. Above each edgewise meter isa split-legend indicator. The upper half reads PLAFAIL, the lower half reads PLA IDLE. When thePLA IDLE indicator illuminates, the throttles aresetting at the idle position; the idle position is 13degrees of PLA. When the PLA FAIL indicatorilluminates, the throttle is at some position lessthan 13 degrees of PLA, or a processor failurehas occurred.

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The last section (G) to the right is the PRO-GRAMMED CONTROL lever. This lever is onlyfunctional when the engine control mode switchof either GTE is in the PROGRAMMEDposition. The programmed control mode is theprimary mode of operation. The propulsionsystem can be operated in the programmedcontrol mode using either one or both GTEs.

The last edgewise meter on this panel is labeledPILOTHOUSE THROTTLE POSITION. Itindicates the actual position of the pilot housethrottle lever and is used by the PCC operator toensure the PROGRAMMED CONTROL LEVERat the pilot house is in the same position as thePROGRAMMED CONTROL LEVERPCC prior to transferring control.

at the

Operational Adjustments Panel

The last subsection in the engines section isRPM MODE. It also has two adjustmentpotentiometers; both of the potentiometersare associated with operating the plant inprogrammed control with the propulsion modeswitch in the speed position. The upper poten-tiometer is for adjusting the LOOP TIMECONSTANT. In other words, it provides anadjustment to change the response time of thesubroutine when the GTE is operating in the RPM(speed) MODE. The lower potentiometer is foradjusting the LOOP GAIN CONSTANT. Itprovides an adjustment to change the amountof feedback used in computing the throttleThe last panel on the PCC is the operational

adjustments-panel (fig. 6-11). It is located behind commands in the RPM MODE.

the second door from the left in the front of thePCC. The operational adjustments panel issubdivided into four sections. From left to rightthese sections are ENGINES, SHAFT TURNS,PITCH TRIM, and TIME SET.

ENGINES SECTION.—This section has sixrecessed, screwdriver adjustable potentiometers.They provide calibration parameters for engineand propeller subroutines of the softwareprogram.

At the top is the BIAS subsection with twoadjustment potentiometers. These are used toadjust the output of each GTE to 20,500 hp whenthe GTEs are operating in the power mode inprogrammed control with the programmedcontrol lever set at full power.

The next subsection in the engines section isfor the WASH SPEED. It has two indicators; theupper potentiometer is for setting the UPPERLIMIT speed at which the starter will beturned OFF during a water wash. The lowerpotentiometer is for setting the LOWER LIMITspeed at which the starter will be turned ONduring a water wash.

Figure 6-11.—Operational adjustments panel.

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SHAFT TURNS SECTION.—This sectionhas two subsections. The LOGIC UPDATEsubsection has six thumbwheels. They are usedto update the logic used by the processor to printthe total number of shaft turns on the belllogger. Below these thumbwheels is a push-buttonswitch labeled ENTER. When this switch isdepressed, it loads the value dialed on the logicupdate thumbwheels into the applicable registers.Located next to the LOGIC UPDATE subsectionis the COUNTER subsection. It has two toggleswitches. Both switches are spring-loaded. Theupper switch is used to control logic that drivesthe mechanical TOTAL SHAFT REVOLUTIONScounter (fig. 6-10, section C). The upper switchis used with the lower switch to update the counterprior to the ship getting underway. When theswitch is at the rest (NORMAL OPERATE)position, the counter (on the PCC panel) willcount as a function of the shaft revolutionsensor. When the switch is held in the UPDATEposition, the counter will count as a function ofthe FAST/OFF/SLOW (lower) toggle switch. TheFAST/OFF/SLOW spring-loaded, toggle switchis enabled when the NORMAL OPERATE/UPDATE toggle switch is in the update position.The switch position at OFF (middle or rest) willnot allow the counter to count. When the switchis held in the FAST (upper) position, the counterwill count at the rate of 10 revolutions per second.When the switch is held in the SLOW (lower)position, the counter will count at the rate of onerevolution per second.

PITCH TRIM SECTION.—The next sectionof the operational adjustments panel is thePITCH TRIM section. This section has threerecessed, screwdriver adjustable potentiometers.They allow compensation between the propellerpitch subroutine of the software program and theequipment that performs the propeller pitchadjustment. The top potentiometer is for AHEADTRIM. It is adjusted to give 23.5 feet pitch,when operating in programmed control, with acommand equal to or greater than ahead 2/3. Themiddle potentiometer is for ASTERN TRIM. It isadjusted to give – 14.7 feet pitch, when operatingin programmed control, with a command equalto or greater than back 1/3. The bottom poten-tiometer is for EFFECTIVE ZERO. It is used toadjust pitch to zero thrust, when operating inprogrammed control, with a command of stop.

TIME SET SECTION.—The last section ofthis panel is the TIME SET section. It is used by

the operator to set the clock on the DEMANDSpanel. It has three spring-loaded toggle switches.From left to right, the toggle switches arelabeled HOURS, MINUTES, and SECONDS.These switches are three-position, toggle switches.The center position is labeled OFF. In the OFFposition, the clock will display and countautomatically. Moving the HOURS switch up orto the FAST position and holding it there causesthe hour portion of the clock to increment at therate of 10 hours per second. Moving the switchto the lower or SLOW position and holding itthere causes the clock to update at the rate of1 hour per second. The middle switch is forMINUTES. Its positions are also labeled FAST/OFF/SLOW. With the switch in the OFF (middleor rest) position, the clock will count auto-matically. Moving and holding the switch in theup or FAST position causes the minute portionof the clock to update at the rate of 1 minute persecond. Moving and holding the switch in thedown or slow position causes the minutes portionof the clock to update at the rate of 1 minute every3 seconds. The last switch is for SECONDS. Thisswitch in the OFF (middle or rest) position allowsthe clock to operate automatically. Moving theswitch to the up or FAST position causes the clockto update at the rate of 10 seconds per second.Moving the switch to the down or STOP positionstops (or freezes) the clock.

PCC CONTROL MODES

The PCC controls the operation of thepropulsion system in the programmed controlmode or the remote manual control mode.

Programmed Control Mode

The programmed control mode is the primarymode for controlling the propulsion system. Inthis mode the operator controls a single(PROGRAMMED CONTROL) lever. This leverprovides an input to the processor. The processoruses this input to set the pitch of the propellerblades and the speed of the GTE(s).

Two methods of control are used in theprogrammed mode. They are power control andspeed control. In the power control mode, thepitch of the propeller is set to maximum. TheGTEs are operated at their lowest possible speeds.The power mode is an open-loop, temperature-compensated mode using the torque computer inthe FSEE to maintain constant GTE loading.Power control is also used for low-noise

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operations. When better maneuvering response isneeded, the throttle is operated in the speedcontrol mode. In this mode the ship’s speed ischanged by changing the propeller pitch up tomaximum with srpm remaining constant. In thespeed mode, srpm remains constant while built-inpower schedules of the program vary GTE speed.The speed mode is also called closed-loop,constant shaft speed mode.

CAUTION

The programmed control mode must notbe used when the propeller blade pitch isbeing controlled from the OD box or whenit has been locked in the full-ahead posi-tion. Since no input has been made to theprocessor that the propeller blade pitch isbeing operated manually or has been lockedin the full-ahead position, the processorwould continue computing and transmittingpropeller pitch commands. This will resultin damage to the equipment.

Remote Manual Mode

The remote manual mode at the PCC is usedwhen a GTE is started from the PCC. It is alsoan alternate method of operating the propulsionequipment if a programmed control failureoccurs. This method requires the operation ofthree levers, one for propeller pitch and one forthe speed of each GTE. Normally, a combinationof programmed control and remote manualcontrol is used only when GTEs are started orstopped, when maintenance is performed, orwhen damage has occurred. When one GTE is inprogrammed control and the other is in remotemanual, the remote manual pitch lever isinoperative. The pitch is controlled by theprogrammed control lever.

GTE STARTING AND STOPPING

You can start a GTE from the PCC in theautomatic or manual mode. In the automaticmode, the operator initiates the start at the PCC.The start/stop sequencer in the FSEE will startthe GTE. The sequencer also provides the statusindications for the operator to follow the startsequence. Automatic starting is inhibited if the18 prestart permissives have not been met and theREADY TO START indicator at the PCC isextinguished.

Manual starts from the PCC require theoperator to activate circuits and sequence the startmanually. The start/stop sequencer provides

status indications of the start sequence to theoperator. The start/stop sequencer will prohibita start until the prestart permissives have been metand the READY TO START indicator on thePCC start panel is illuminated.

You can shut down (secure) the GTE byselecting one of the three operator-initiatedmodes. The fourth mode is a processor-generatedshutdown. The modes of stopping are as follows:

Normal stop—operator initiated

Manual stop—operator initiated

Emergency stop—operator initiated

Automatic shutdown—logic initiated

Normal stops are performed in the remotemanual mode. The operator, following the EOSS,must bring the GTE to idle. When the normal stoppush button is depressed, it initiates a normal stopsequence, performed by the start/stop sequencer.This allows the GTE to run for 5 minutes at idlebefore fuel valve closure, which allows the GTEtemperatures to equalize (cool). This cooldownperiod lengthens GTE life. A normal stopsequence may be cancelled by the operatormoving the throttle control lever off idlemomentarily.

The PCC operator may perform manual stopsfrom the PCC in the remote manual mode. Theoperator is required to sequence this stop. TheGTE should be run at idle for 5 minutes beforethe GTE is manually stopped.

The PCC operator may activate the emergencystop at any time and in any operating mode,regardless of the console in control. You caninitiate the emergency stop by depressing theemergency stop push button. This causes theGTE’s fuel valves to close.

Automatic shutdowns may occur during startsor when the GTE is running. The automaticshutdowns de-energize the fuel valves, causingthe GTE to shut down. The conditions duringstart that cause an automatic shutdown are asfollows:

NGG fails to reach 1200 rpm within 20seconds after start is initiated.

Failure to reach 400°F T5.4 within 40seconds after the fuel valves are energized.

NGG fails to reach 4500 rpm within 90seconds after start is initiated.

Engine LO pressure is below 6 psig 45seconds after start is initiated or GTEspeed is above 4500 ± 200 rpm.

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During GTE operation, the following condi-tions cause an automatic shutdown:

GG flameout—T 5.4 is below 400°F withfuel manifold pressure above 50 psig.

T5.4 is above 1530°F.

Npt is above 3960 ± 40 rpm.

GTE lube oil pressure is less than 6 psig.

GG vibration is above 7 mils.

PT vibration is above 10 mils.

LOCAL OPERATING PANEL

As we discussed previously, the engine-roomconsoles are the primary operating stations for theLM2500 GTE. The primary purpose of theengine-room consoles is to allow you to operatean engine room independent of all other controlpoints. If the SCC or CCS is damaged, you couldstill control the GTEs from the engine room.These consoles are also used as maintenancestations for operations, such as water washing andas a central monitor for many engine-roomparameters.

NOTE: I f BATTLE OVERRIDE is The LOP (fig. 6-12) is the engine-roomapplied, it inhibits all automatic shutdowns console on the FFG-class ship. It is located on theexcept flameout and PT overspeed. starboard side, upper level of the engine room,

Figure 6-12.—LOP controls and displays.

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near the propulsion equipment. The LOP has thenecessary controls and indicators to permitdirect local (manual) control of the propulsionequipment. The direct local mode of control,although still electronic, permits operation ofthe equipment independent of the programmedsequence from the computer. It is normally anunmanned console. However, you can use it if anemergency occurs or for control duringmaintenance. You may find it easier to under-stand the operational procedures for the LM2500GTE by following the operation of the pro-grammed sequence. For this reason, we discussedthe FFG LM2500 operational procedures whenwe discussed the PCC.

The LOP is divided into the following sixsections:

1. Local operating station instrument panel(LOSIP)

2. LOP top panel engine 1A3. LOP top panel engine 1B4. Status panel5. LOP bottom panel6. Fuse panel

LOCAL OPERATING STATIONINSTRUMENT PANEL

The LOSIP (fig. 6-13) is located at the top ofthe LOP. The LOSIP is divided into two sections,one for each GTE. Their layouts are identical. TheLOSIP is only a monitoring panel and has nocontrol functions. It is used to monitor conditionsof the systems of the LM2500 GTE and selectedparameters.

From left to right the monitoring sections areLUBE OIL, FUEL, THROTTLE, ENCLOSURE,GG, and PT. The parenthetical letters referencedin the text are shown on figure 6-13 and indicatethe six sections of the LOSIP.

LUBE OIL Section

The LO section (A) is used to monitor theparameters associated with the LM2500 GTE LOsystem. It has a five-position rotary selector switchand four edgewise meters. The TEMP selectorswitch on the left is labeled A, B, C, D, andACCESSORY GEAR BOX. It is used to selectthe scavenge temperature to be monitored.By rotating the selector switch to the desiredposition, you may monitor the selected parameteron the first edgewise meter, labeled TEMP. Thesecond edgewise meter, labeled FILTER ∆P, isused to monitor the scavenge filter (located on theLOSCA) differential pressure. The third edgewisemeter, labeled TANK, indicates the LOSCA tank

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level. The fourth edgewise meter, labeled ∆P, isused to indicate differential pressure across theLO supply filter (located in the GTM).

FUEL SYSTEM Section

The FUEL section (B) monitors the fuel systemof the GTE and has two meters. The first meteris labeled FILTER DP and monitors fuel filter (theGTE-mounted filter) differential pressure. Thesecond edgewise meter is labeled SUPPLY TEMPand monitors the fuel supply temperature.

THROTTLE Section

The THROTTLE section (C) has one edgewisemeter, labeled POSITION. It indicates the throttleposition in percentage of GTE power inincrements of 0 to 100 percent.

ENCLOSURE Section

The ENCLOSURE section (D) has twoindicators and an edgewise meter. The first split-legend indicator is labeled OPEN/CLOSED andis used to monitor the actual status of the ventdamper. The second indicator is labeled FLAMEand, when illuminated, indicates that a flame (fire)has been sensed in the module. It receives its signalfrom the UV sensors in the enclosures. Theedgewise meter is labeled TEMP and indicates thetemperature of the enclosure. A momentary-contact push button, labeled LAMP TEST (notconsidered part of the enclosure section), islocated below the two indicators. It is used to testthe proper operation of the bulbs in the twoindicators of the enclosure section.

GAS GENERATOR Section

This section (E) is used to monitor the GG. Ithas three edgewise meters. The first meter, labeledINLET AIR PRESS, monitors GG inlet airpressure (Pt 2), the pressure of the air entering thecompressor. The center edgewise meter, labeledINLET AIR TEMP, monitors the compressor airinlet temperature (T2). The right edgewise meter,labeled DISCHARGE PRESS, monitors the CDP.

POWER TURBINE Section

This section (F) has two edgewise metersused to monitor PT parameters. The left edgewisemeter, labeled INLET PRESS, is used to measurePT inlet pressure (Pt5.4). The second edgewisemeter, labeled GAS GENERATOR PRESSURERATIO is used to monitor GG pressure ratio.

LOP TOP PANEL

The LOP top panel (fig. 6-14) is used tocontrol either, or both, of the GTEs. Although

Figure 6-14.—LOP top panel.

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Figure 6-14.—LOP top panel—Continued.

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the GTEs are controlled from this panel, theoperations are in the manual mode. The LOP hasno computer functions. The LOP top panel isdivided into two sections, the engine 1A andengine 1B sections. These engine sections arealmost mirror images of each other. Thedifferences in the two panels will be pointed outas we cover the related area. As we did with thePCC, we will cover the LOP from left to right,top to bottom.

The first indicator at the top left is labeledBATTLE OVERRIDE. It is a guarded, illumi-nated push button. It can be manually activatedat any time, regardless of the station in control.Normally, you must have the commandingofficer’s permission to activate BATTLE OVER-RIDE. Refer to your ship’s standing orders forevents which will allow you to activate this switchautomatically without the commanding officer’spermission. This requirement is mandated becausethis switch overrides the following safetyshutdowns:

1. GTE LO pressure is low.

2. GTE vibration is high.

3. T5.4 is high.

4. PLA failure for the following conditions:

a. PCS command signal is out of limits.

b. PT shaft torque is out of limits.

c. PT speed is out of limits.

BATTLE OVERRIDE does not override aflameout or a PT overspeed trip.

The next indicator is a split-legend type labeledECM PWR AC ON/ECM PWR DC ON. Theupper half of the indicator indicates ac power ison to the FSEE. This ac power is used for theigniters, the anti-icing valves, and the firedetection sensors. The lower half of the indicatorindicates dc power is on. This dc power is usedfor the FSEE electronics and the GTE fuel valvecontrol circuit.

The third push-button indicator is labeledENGINE 1B(1A) LOCAL LOCKOUT. It is usedto place the LOP in control of the associated

GTE. It is a guarded type of push button usedto take control from the PCC. By re-depressingit, you can transfer the control to the PCC. Whenthe GTE control is at the PCC, the fourthindicator labeled ENGINE 1B CONTROL INREMOTE LOCATION will illuminate.

The fifth indicator is a guarded type of pushbutton labeled EMER STOP. This push buttonis used to stop the GTE in an emergency. You canactivate the emergency stop push button at theLOP regardless of what station has control. Thispush button closes both GTE fuel valves andcauses the GTE to shut down.

ENCLOSURE Section

The ENCLOSURE section (A) monitors themodule cooling and air intake system. It has threeindicators and four control switches. The firstindicator is labeled FAN RUNNING. When it isilluminated, it indicates the enclosure fan isoperating. The second indicator is labeled ICING.When it is illuminated, it indicates the intake airis below 41°F and the humidity is above70 percent. The third indicator is a split-legendpush button labeled HEATERS ON/HEATERSOFF. It is used to turn the enclosure heater onor off. When it is illuminated, it indicates theactual status of the heaters. The last indicatoracross in this column is a split-legend indicatorlabeled ANTI-ICING VALVE OPEN/ANTI-ICING VALVE CLOSED. When it is illumi-nated, it shows the actual status of the anti-icingvalve.

The first indicator across the second columnis a split-legend, push-button indicator labeledFAN RUN/FAN STBY. It is used to turn theenclosure cooling fan on or return it to a standbycondition (off). When it is illuminated, it indicatesthe status of the enclosure fan. The next indicatoris a push button labeled ANTI-ICER ON. Itilluminates to indicate a command has been sentto open the anti-icing valve. When this button isdepressed again, it will close the anti-icing valve.The last indicator in the enclosure section is a split-legend push button labeled VENT DAMPEROPEN/VENT DAMPER CLOSE. The illumi-nated portion of this indicator shows the operatorcommand to the vent damper.

The horizontal edgewise meter (B) labeledINTAKE AIR TEMP is used to monitor the

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temperature of the outside air in °F. This meteris located above the GG section (E) of the LOPtop panel.

To the right of the meter is a push-buttonindicator labeled AUTOMATIC SHUTDOWN(PRESS TO RESET). It illuminates to indicatean emergency shutdown has occurred on therelated GTE. The automatic shutdowns are asfollows:

PT inlet temp (T5.4) high—above 1530°F

Engine LO pressure low—below 6 psig

GG vibration high—above 7 mils

PT vibration high—above 10 mils

Flameout: T5.4 less than 400°F with fuelmanifold pressure above 50 psig

When one of these conditions is met, theautomatic shutdown circuitry closes the two mainfuel valves. You depress the AUTOMATICSHUTDOWN button to reset the automaticshutdown circuitry, once the GTE has come toa complete stop.

START/STOP Section

The START/STOP section (C) contains thecontrols to start and stop the GTE. It has oneindicator, three push-button indicators, anda rotary switch. The split-legend indicatorlabeled VALVE OPEN/VALVE CLOSED is theSTARTER REGULATOR STATUS indicator. Itilluminates to display the open or closed statusof the starter regulator valve. The first push-button indicator, labeled STARTER ON, is amomentary switch. When it is depressed, it opensthe starter regulator valve and closes it whenreleased. The second push-button indicator islabeled IGNITION ON. It is also a momentary-type switch. When it is depressed, it turns the GTEignitors on; when it is released, the ignitors areturned off. The last indicator is a split-legend pushbutton labeled FUEL ON/FUEL OFF. Itilluminates to show the operator command toenergize or de-energize the fuel shutdown valves.By depressing it once, you can open the fuelvalves. Re-depressing it closes the valves. Youmust always keep the push button in the FUELOFF position when control is at the PCC.

The rotary switch is labeled FUEL SHUT-DOWN VALVE TEST. It is used to test each fuelvalve. The switch is spring-loaded to the OFFposition. To test an individual valve, you mustturn the switch to the desired valve and hold it.You must keep the switch held to that positionuntil the NGG is at zero. Then depress the FUELON/FUEL OFF push button to close the othervalve and keep both valves closed.

FUEL Section

The FUEL section (D) contains a meter, anindicator, and a push button associated with theGTE fuel supply. The edgewise meter, labeledSERVICE SUPPLY PRESSURE, displays thefuel supply pressure from the ship’s fuel system.The split-legend push button, labeled VALVEOPEN/VALVE CLOSE, controls and illuminatesto display the status of the module fuel cutoffvalve located under the enclosure. The split-legendindicator, labeled VALVE OPEN/VALVECLOSED, illuminates to show the actual fuelsupply valve status.

GAS GENERATOR Section

This section (E) monitors parameters associatedwith the GG. It contains three edgewise meters,two indicators, and an illuminated push button.

The first edgewise meter is labeled INLETTEMP. This meter displays the T5.4 of the PT.You have to multiply the number displayed by1000 to determine the actual temperature.

The indicator is labeled OVERSPEED. It willilluminate and activate an alarm when the speedof the GG exceeds 9700 ± 100 rpm. The split-legend indicator, labeled OPEN/CLOSED,displays the status of the GTE’s 16th-stageBLEED AIR VALVE. The bleed air push-buttonindicator, labeled OPEN/CLOSE, controls theoperation of the GTE bleed air valve. It willilluminate either open or close, depending on thecommand that is selected.

The second edgewise meter is labeled SPEED.This meter monitors NG G. The readings from thismeter are multiplied by 1000 to determine GGspeed. The third edgewise meter is labeled STARTAIR PRESSURE. It displays the pressure of theair available to start the GTE.

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VIBRATION Section

This section has an alarm indicator, anedgewise meter, and a rotary selector switch. Thealarm indicator, labeled HIGH VIBRATION,illuminates and sounds an alarm when a GTEvibration exceeds the maximum set point. Thesemaximum set points are GG at 4 mils and PT at7 mils. An automatic shutdown occurs when GGvibration reaches 7 mils or PT vibrationreaches 10 mils. The edgewise meter, labeledVIBRATION, will display the vibration on theGTE at the position selected by the rotary switch.The rotary selector switch, labeled GASGEN/POWER TURBINE, is a four-positionswitch. It allows you to look at the two differentvibration pickups. One of the pickups is locatedon the GG and the other is on the PT. Eachpickup senses both GG and PT vibration. Atracking filter for each pickup separates GGvibration from PT vibration, depending onvibration frequency.

SEAWATER COOLING SUPPLYPRESSURE and REDUCTION GEARLUBE OIL REMOTE BEARINGPRESSURE Meters

These edgewise meters are mirror images ofeach other as to location, but not to function.The edgewise meter (G) labeled SEAWATERCOOLING SUPPLY PRESSURE is located onthe engine 1B panel and is used to display theseawater supply pressure to the reduction gearcooler. Below this edgewise meter is a push-button indicator labeled LAMP TEST. It isused to test the lamps in the engine 1B sectionof the LOP. The edgewise meter (H) labeledREDUCTION GEAR LUBE OIL REMOTEBEARING PRESSURE is located on the engine1A panel. It displays the MRG most remotebearing pressure. Below this meter on the engine1A panel is an alarm indicator labeled REMOTEBEARING LOW PRESS. This indicator illumi-nates and sounds an alarm which alerts theoperator if the most remote bearing pressure fallsbelow 9 psig. The LAMP TEST push buttonbelow the indicator tests the lamp status for theengine 1A panel.

ENGINE LUBE OIL Section

The ENGINE LUBE OIL section (I) has twoedgewise meters and an indicator to monitor the

engine LO supply. The first edgewise meter,labeled COOLER DISCHARGE TEMP, monitorsthe temperature of the LOSCA cooler outlet.The second edgewise meter, labeled SUPPLYPRESSURE, monitors the engine LO supplypressure. The indicator, labeled LOW ENGINEOIL PRESS, illuminates and sounds an alarmwhen the engine LO pressure is below 15psig.

POWER TURBINE andOUTPUT Section

This section (J) has six indicators, an edgewisemeter, and three push-button indicators. The firstindicator, labeled FLAME OUT, illuminates andsounds an alarm to alert you if conditions for aflameout exist. This condition occurs if T5.4drops below 400°F when the fuel manifoldpressure is above 50 psig. It also initiates anautomatic shutdown. The second indicator,labeled INLET TEMP HIGH, illuminates andsounds an alarm to alert the operator of a highT5.4. This will occur at 1500°F PT inlettemperature.

The edgewise meter, labeled SPEED, is usedto monitor the speed of the PT. Associated withthis meter is an indicator and push button. Theindicator, labeled OVERSPEED TRIP, illumi-nates when an overspeed trip occurs. Theindicator is set at 3960 ± 40 rpm. The push-buttonindicator, labeled OVERSPEED TRIP RESET,is used to reset the overspeed trip circuitry afteran overspeed trip occurs.

CAUTION

Do not depress the OVERSPEED TRIPRESET until the GG has come to acomplete stop. The fuel valves can re-open,causing a post-shutdown fire.

The next indicator is a split-legend type labeledENGAGED/DISENGAGED. It illuminates todisplay the actual position of the turbine brake.The second push-button indicator is a split-legendtype, also. It is labeled ENGAGE/DISENGAGEand controls the operation of the PT brake. Theindicator illuminates to indicate the signal that isbeing sent to the turbine brake.

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The bottom two indicators illuminate todisplay the status of the GTE clutch. Theseindicators are labeled CLUTCH ENGAGED andCLUTCH DISENGAGED.

The third push-button indicator, labeledFUEL PURGE VALVE OPEN, operates theGTE’s fuel purge valve. When this push buttonis depressed, it opens the fuel purge valve to allowabout 3 gallons of cold fuel to drain from the GTEsystem. In this way, cold fuel is drained from theGTE before starting. The fuel purge valve isoperated only when motoring the GTE.

With the exceptions noted in the previoussections (two edgewise meters, one alarmindicator, and the LAMP TEST push button), allof the indicators, push buttons, edgewise meters,and rotary switches described on the LOP toppanel are identical on both the engine 1A andengine 1B panels. The following indicators, pushbuttons, and rotary switch are located on theengine 1A panel and are NOT on the engine 1Bpanel.

A push-button indicator (K), labeledALARM ACK, is located on the engine 1Apanel at the position shown. It is amomentary-contact push button used bythe operator to acknowledge an alarm.When it is depressed, it will cause theflashing alarm indicator to illuminate ina steady state and silence the alarm.

A split-type indicator (L), labeled EN-GAGED/DISENGAGED, illuminates toindicate the status of the MRG turninggear. The turning gear must be engagedand disengaged manually at the MRG.

A section (M), labeled AUDIBLEALARMS, has two push-button indicatorsand a rotary switch. The first push-buttonindicator, labeled SIREN TEST, isdepressed by the operator to test the alarmsiren. The rotary switch, labeledVOLUME, is actually a rheostat used toadjust the volume of the audible alarms.The second push-button indicator, labeledHORN TEST, is depressed by the operatorto test the alarm horn.

LOP STATUS PANEL

The LOP status panel (fig. 6-15) is located tothe right of the 1A GTE top panel. It containsthree illuminated indicators for the LOP powersupplies and five fuse holders for the 115 voltsac for the console heaters and blowers.

The first indicator is a split-legend indicator,labeled 115 VAC SS AVAILABLE/+28 VDCUPS AVAILABLE. It displays the status of115-volt ac ship’s service power and 28-volt dcpower. These indicators will illuminate wheneach source of power is available. The secondindicator is also a split-legend type, labeled115 VAC UPS AVAILABLE/HEATERS ON.It illuminates to indicate 115-volt ac UPS isavailable and when the console heaters are on.The third indicator, labeled OVERTEMP,illuminates and sounds an alarm to indicateconsole overtemperature.

The 115 VAC fuse section contains the fusesfor the power and return for the heater relay,power and return for the heaters and blowers, anda spare fuse holder.

Figure 6-15.—LOP status panel.

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Figure 6-16.—LOP bottom panel.

LOP BOTTOM PANEL

The LOP bottom panel (fig. 6-16) has apitch control lever, two edgewise meters,three indicators, a push-button indicator, andtwo throttle control levers. Only manual throt-tle and pitch control is available at theLOP.

The first lever, labeled PITCH CONTROL,controls the pitch of the propeller. It is onlyoperative when the LOP is in control of bothGTEs. An indicator, labeled ASTERN PITCH,illuminates when the propeller pitch is actually inthe astern direction. The first edgewise meter,labeled PITCH, displays the actual propellerpitch. The second edgewise meter is horizontaland labeled SHAFT SPEED. It displays the speedof the shaft in rpm. The second indicator,labeled ENGAGED/DISENGAGED, and thepush-button indicator, labeled ENGAGE/DIS-ENGAGE, control and monitor the SHAFTBRAKE. When you depress the shaft brakecontrol push button, it will illuminate thecommand selected. The shaft brake will onlyactivate when the following permissives are met:

Pitch at zero

Shaft speed below 75 rpm

Throttles at idle

Station in control

The shaft brake indicator will illuminate to displaythe actual status of the shaft brake, eitherENGAGED or DISENGAGED.

The third indicator, labeled PROP HYDRAU-LIC PRESS LOW, will alert you when the CPPhydraulic system pressure is below 40 psig.

The two REMOTE THROTTLE CONTROLlevers, labeled ENGINE 1B and ENGINE 1Arespectively, control the power level of each GTE.The throttles are controlled in increments ofpercent power.

LOP FUSE PANEL

The LOP fuse panel (fig. 6-17) is located onthe lower left section of the LOP. It contains the28-volt dc fuses for the LOP, the enclosures, andthe transducers that input to the LOP.

SUMMARY

This chapter has introduced you to the opera-tion of the FFG-class ship engineering plant fromthe PCC in the CCS and the LOP in the MER.Most GSs assigned to an FFG-class ship will standwatches at one time or another in the CCS. Forthis reason, you should be very familiar with thecapabilities of these consoles. Like all othermaterial in this TRAMAN, this chapter waswritten to form a basis to start your qualificationsat watch stations on your ship. Even if youare not assigned to an FFG-class ship, yourknowledge of this material will help you advancein rate and make you more valuable to the Navy.

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In no way is this material meant to be a these sources, you should have no problemone-stop source for qualifying you as an becoming a qualified watch stander. Remember,FFG watch stander. You should use the before you attempt any operation at theseEOSS, the PQS, ship information books, and consoles, you must be familiar with and use thetechnical manuals for this process. By combining EOSS.

Figure 6-17.—LOP fuse panel.

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CHAPTER 7

MACHINERY CONTROL SYSTEMFOR DDG-51 CLASS SHIPS

Up to this point we have discussed operation,construction, and control of the gas turbineengineering plant on the Perry-, Spruance-, andKidd-class ships. One of the revolutionary aspectsof the gas turbine plant is its ability to be operatedfrom a central, remote location. This central pointis known on all classes of gas turbine ships as thecentral control station (CCS). The CCS is theprimary control watch station for operating nearlyall major engineering equipment. Systems that arenot controlled in the CCS may at least bemonitored from there. This allows for reducedwatch standing outside the CCS as opposed toolder ships that required watch standers through-out the plant. Also, the EOOW and propulsion,electrical, and damage control watch standershave a quicker look at all vital parametersassociated with plant operation.

Currently, three major designs exist for gasturbine CCSs; one for the Perry-class frigates, onefor the Spruance and Kidd classes, and one forthe Arleigh Burke class. In this chapter we discussthe Arleigh Burke-class ship’s machinery controlsystem (MCS) in CCS.

After reading this chapter and completingthe associated NRTC, you should have a goodunderstanding of the function of the CCS. Thismaterial is meant for training purposes only.It is not meant to replace the EOSS or technicalmanuals.

With the help of an experienced GSE and byusing the knowledge gained in this chapter,following the EOSS, and completing PQS require-ments, you should have no problem qualifying inall aspects of CCS operations.

MACHINERY CONTROLSYSTEM (DDG-51)

The DDG-51 Arleigh Burke-class ship’s MCSprovides centralized and remote monitoring and

control of the propulsion, electrical, auxiliary, anddamage control systems. The major units of theMCS are shown in figure 7-1. The four consoleslocated in CCS are the PACC, the EPCC, theDCC, and the engineering officer of the watch/logging unit (EOOW/LU). The shaft controlunit 1 (SCU 1) and the SCU 2 are located in mainengine room (MER) 1 and MER 2, respectively.The repair station console (RSC) is located inrepair station 2.

The MCS is the newest system the Navy hasfor controlling the GTE-powered engineeringplant. In this chapter we will describe onlythe controls and monitoring provided by theEOOW/LU, the PACC, and the SCUs. TheEPCC will be described in chapter 8, and the DCCand RSC will be discussed in chapter 9 of thisTRAMAN.

ENGINEERING OFFICER OFTHE WATCH/LOGGING UNIT

The EOOW/LU (fig. 7-2) has two panelassemblies (A1 and A2) and a keyboard controlsection. It is located in the CCS and is the watchstation for the EOOW. This console is a see-overconsole that has two plasma display assemblies(described later in this chapter). Although, onlya bulkhead can be seen over the console, theEOOW/LU was chosen to be see-over, in caseduring the design of CCS, the console would becentrally located and the EOOW would need theview. These displays are used by the EOOW toobtain the current status of the machinery plant.The console also has a bell logger, a bubblememory unit, and an AN/USH-26(V) cartridgetape unit installed in the front. The bell loggeris a high-speed printer that can print bellcommands as well as changes in propulsion systemstatus.

Embedded in each of the MCS consoles is anAN/UYK-44 computer that performs centralized

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Figure 7-2.—Overall view of the EOOW/LU (door removed).

monitoring and controlling functions for theconsole. Through multiplexers, the computermonitors plant status and generates controlcommands. Through panel distributors, thecomputer lights lamps, sounds sirens, anddetects button actions. The bubble memoryin the consoles serve the same function asthe disk drives on a personal computer:it holds data. The principle function of thebubble memory units for all consoles is tostore the computer program that “runs” theconsole. The bubble memory unit is alsoused to load programs into the bubble memorycassettes that store the programs for thecomputers in the consoles. A detailed descriptionof the bubble memory is discussed later inthis chapter.

The AN/USH-26(V) tape unit is used as a datalogger to record machinery status changes andalarm conditions for the MCS. This tape unitis also used in the bubble memory loadingoperations.

PANEL ASSEMBLY Al

The Al panel is divided into three sections.These sections have the controls and indicatorsfor the fuse assembly, the bubble memory, andthe AN/USH-26(V) tape unit.

Fuse Assembly Section

The fuse assembly section has nine 28-voltdc power loss indicator/fuse holders. Eachindicator illuminates white to indicate a lossof power to its respective unit. Starting atthe left on the top row, the first fuse isfor the console cooling fans. The next twofuses are for the left and right plasma screens,respectively. On the second row, the firstfuse is for the transformers. The secondfuse is for the bridge control unit (BCU)plasma display, and the third fuse is forthe combat information center (CIC) plasmadisplay. On the third row, the first fuse

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is for the console indicators and relays. The nexttwo fuses are spares.

Bubble Memory Section

The bubble memory system stores digital data,like a floppy or hard disk of a personal computer.In the DDG-51 MCS, the data is the computerprogram that operates the console. When theconsole is powered up, the computer automaticallyloads the program from the bubble memorycartridges. (This “bootstrap” function of thecomputer is equivalent to a personal computer’sAUTOEXEC program.) A lot of computer datais stored magnetically—such as on floppy andhard disks. In the bubble memory, the data bitsare stored as magnetic bubbles. Bubbles improvereliability because they are moved, stored, read,or written electrically; there are no mechanical,moving parts. The bubbles do not have to movepast a read/write head, as opposed to the floppyor hard disk. The main advantage of the bubblememory is its resistance to electromagneticinterference.

The bubble memory cassettes store a uniqueprogram for each of the AN/UYK-44 computers.The cassettes are loaded from the AN/USH-26magnetic tape unit in the EOOW/LU using theAN/UYK-44 input/output controller, the bubblememory drive, and the work station plasmadisplay and keyboard in the EOOW/LU.

The bubble memory is contained in anenclosure of welded aluminum alloy. The majoritems of the unit are two 256K-byte (256thousand) memory cassettes, interface andcontrol circuit card assemblies, and a dc powersupply. These units (not shown) are enclosedbehind the access doors in the front of the panel.The front panel has a power on/off switch andseven LED indicators. The power on/off switchis a two-position toggle switch (normally on) thatcontrols power to the bubble memory drive. Thefirst LED, labeled POWER, illuminates green toshow power is turned on to the bubble memorydrive. The top row of three LEDs, labeled DRO(at the right), are for memory drive No. 0. Thefirst LED in the top row, under the label WP,

illuminates red to show the write protect functionis operating. The second LED, under the labelRDY, illuminates yellow to show main power hasbeen applied to the cassette drive and it is readyto read/write. The third LED, under the labelBSY, illuminates yellow to show data is beingtransferred. The second row of three LEDs arefor memory drive No. 1 (DR1) and are identicalto the first row.

AN/USH-26 Section

Figure 7-3 shows the AN/USH-26 with thedoor removed for clarity. It is a data cartridgemagnetic tape storage and data transfer device.It is used with the AN/UYK-44 computer in theEOOW/LU for loading bubble memory cassettesand for logging data associated with the DDG-51machinery. It operates under the control ofthe AN/UYK-44 and, during normal on-lineoperation, requires minimal operator interface.The tape unit contains two tape drive assemblies,a card cage assembly, power supplies, amaintenance panel, and front panel controls andindicators.

The two tape drive assemblies, labeled DRIVE0 and 1, respectively, are identical and have iden-tical controls and indicators. Each tape drive hasan alarm indicator, a two-position toggle switch,a rotary switch, and four LEDs. We will describeonly the controls and indicators for drive 0.

Starting at the top left of the tape driveassembly is the alarm indicator, labeled HOT. Itis an incandescent bulb with a red cover lens.When the bulb is illuminated, it shows the tapedrive assembly temperature > 165°F. It will alsoilluminate when the ALARM/ENABLE/TESTswitch (described later), located at the lower rightof the control panel, is set to the TEST position.

Below the alarm indicator is the two-positiontoggle switch, labeled ON LINE/OFF LINE. It

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Figure 7-3.—AN/USH-26 front panel controls and indicators (door removed).

is used to place the tape drive in the operational(on line) or non-operational (off line) condition.Below this toggle switch is a rotary switch labeledEJECT/UNLOAD. The rotary switch is used bythe operator to unload or mechanically eject thetape cartridge from the tape drive assembly.

At the bottom of each tape drive assembly isa horizontal row of four LEDs. The first LEDat the left, labeled SEL, has a clear lens andilluminates to show the respective tape drive hasbeen selected. The second LED, labeled SAFE,illuminates to show the respective tape drive is fileprotected (cannot be written over). The thirdLED, labeled BUSY, illuminates to show therespective tape drive is performing a motioncommand. The last LED, labeled OPR INT,illuminates to show that some form of operatorintervention is required for the respective tapedrive.

Located towards the bottom right corner ofthe unit, and mounted vertically, is a three-position toggle switch and two LEDs. The toggleswitch positions are labeled CMPTR1 /MPX/CMPTR2. When the toggle switch is in theCMPTR1 position, the top LED illuminates toshow the AN/USH-26(V) is operating withcomputer 1. In the MPX position, the AN/USH-26(V) is operating with computer 1 or computer 2,or with both computers 1 and 2 (multiplex).In the CMPTR2 position, the bottom LED

illuminates to show the AN/USH-26(V) isoperating with computer 2.

To the extreme right of the four LEDs fordrive No. 1 is an LED, labeled BATTLE SHORT,and a two-position toggle switch, labeledON/OFF. When the toggle switch is in the ONposition, the overtemperature shutdown is dis-abled and the LED illuminates red. When thetoggle switch is in the OFF position, the over-temperature shutdown is enabled. To the right ofthe BATTLE SHORT toggle switch is a two-position return-to-neutral toggle switch, labeledMASTER CLEAR. When activated to eitherposition, it resets the AN/USH-26(V) electronics.

Below the LED labeled BATTLE SHORT isan LED labeled POWER and a two-position toggleswitch labeled ON/OFF. When set to the ONposition, it enables primary power to theAN/USH-26(V) and the LED labeled POWERilluminates. In the OFF position, primary powerto the AN/USH-26(V) is disabled.

To the right of the POWER toggle switch andLED is the last LED and a three-position toggleswitch. The LED is labeled OVERTEMP andilluminates red when the ambient temperaturewithin the AN/USH-26(V) > 140°F. The three-position toggle switch is labeled ALARMENABLE/OFF/TEST. When set to the ENABLEposition, the audible alarms are enabled. In theOFF position, the audible alarms are disabled.

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When set to the TEST position, the audible alarmssound and all the LEDs labeled HOT andOVERTEMP illuminate.

PANEL ASSEMBLY A2

The A2 panel is used by the EOOW to monitorselected parameters of the engineering plant.There are basically three sections on this panel;the console section, which has two LEDs, a three-position rotary select switch, and a momentary-contact push button; the plasma display section,which has two plasma displays; and the printersection, which has a thermal printer and itscontrols and indicators.

Console Section

The two LEDs are mounted at the top and tothe left of the left plasma display. The firstLED is labeled CONSOLE TEMP HIGH. Itilluminates red to show an overtemperaturecondition exists in either of the console powersupplies. The second LED is labeled UPS IN USE.It illuminates to show the console is operating onbattery power.

Below the two LEDs is the three-positionrotary switch labeled CONTROLLED DISPLAY.The three positions of this switch are labeledLEFT, NONE, and RIGHT. This switch is usedto connect the plasma display keyboard to the left,right, or neither plasma display. Beneath theCONTROLLED DISPLAY rotary switch is themomentary-contact push button labeled LAMPTEST. When depressed, it performs an opera-tional test of the two LEDs labeled CONSOLETEMP HIGH and UPS IN USE.

Plasma Display Section

The plasma display provides the operatorwith machinery status and alarm informationrequired to control and monitor the propulsionmachinery. This section contains two plasmadisplays, which use the keyboard, locatedon the keyboard control section, to requestvarious displays. At any one time, only oneof the plasma displays functions as a con-trollable display. The plasma display providesoperator information in two display modescalled status/alarm and summary. In addition,up to nine lines of analog status informationmay be displayed on the lower portion ofthe display. The display is driven by theAN/UYK-44 computer over a 16-bit paralleldata channel. The operator controls the datapresented on the controllable display by typingcommands into a keyboard that is switchablebetween the plasma displays.

Printer Section

The bell logging function for the MCS isimplemented by a medium-speed, microcomputer-controlled thermal printer that mounts to the frontof the EOOW/LU. The printer accepts ASCII-coded character data from the AN/UYK-44computer and prints the characters in a 40-columnformat at a rate of 160 lines per minute. Thecharacters print out on 4 1/4-inch wide heatsensitive paper. The printer forms each characterby printing predetermined dots within a 7 by9 dot matrix.

The logger prints bell commands as well aschanges in the propulsion system status. Thebell log printout is initiated when any of thefollowing events occur:

A change in control station for either shaft

A change in bridge order mode

When the BCU is in the rpm/pitchordering mode and there is a change in anordered shaft speed or ordered propellerpitch

When the BCU is in the maneuvering bellsmode and the BCU programmed controllever is moved to a new order band

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Figure 7-4.—Plasma display keyboard.

Automatically every hour on the hour

When the BELL LOGGER PRINT pushbutton on the PACC or BCU or the specialfunction key on the EOOW/LU keyboardis depressed

Mounted vertically down the left side of theprinter are two toggle switches, two LEDs, andtwo fuse holders. The first toggle switch, labeledSLEW/TEST, is a three-position return-to-centertype. When placed in the SLEW position, it causesthe paper to advance through the printer. In theTEST position, the printer will print a repetitivetest pattern. Each pattern is a full character setof the printer. The LED indicator below thistoggle switch is labeled LOW PPR. It illuminatesgreen to show that less than 15 feet of paperremain on the supply roll.

Below the LOW PPR indicator is anotherLED labeled PWR ON. This LED works with thetwo-position ON/OFF toggle switch locateddirectly below it. When the switch is in the ONposition, the LED illuminates green to indicatepower is available at the printer. In the OFFposition, power is secured to the printer and theLED is not illuminated. The two fuse holders arelabeled 2A FUSE and SPARE. The first fuseholder contains the 2-amp fuse that providesovercurrent protection for the printer power

supply circuits. The other fuse holder has a spare2-amp fuse for repairs.

KEYBOARD CONTROL SECTION

The operator at the EOOW/LU uses thissection to input commands to the plasma displayassemblies. The keyboard assembly (fig. 7-4)

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consists of a standard keyboard with 16 functionkeys and arrow and home keys imbedded in anumerical keypad. We will describe the functionkeys, standard keyboard, and the arrow/homekeys from left to right and top to bottom.

Function Keys

These keys are arranged in two rows of eightkeys each across the top of the keyboard. The firstsix keys across the top row are not used.The seventh key is labeled CONTROLLABLEPLASMA WORKSTATION SELECT. Whendepressed, it switches the plasma displayconnected to the keyboard from controllableplasma display to work station plasma displayor vice versa. The eighth key is labeled DISPLBRT↑. The operator uses this key to increase thebrightness of the plasma display in fixed steps witheach activation of the key.

The first six keys in the second row areused by the operator to enter damage controlsymbols in the manual entry and edit message.The seventh key is labeled BELL LOG PRINT.When depressed, it causes a bell log to be printedon the thermal printer. The eighth key in thesecond row is labeled DISPL BRT↓. The operatoruses this key to decrease the brightness of theplasma display in fixed steps with each activationof the key.

Standard Keys

Because most of the standard keys are self-explanatory, we will describe only the keys thathave special functions. The first key on the toprow, labeled ESC, is used to terminate a commandfunction and return to the menu list. The thirdkey, labeled 2, is used during alarm tablemodification to decrease alarm delays. For delaysbetween 1 and 30 seconds, each activation of thiskey decreases the delay by 1 second. For delaysbetween 30 seconds and 10 minutes, eachactivation of this key decreases the delay by5 seconds. The ninth key, labeled 8, is usedduring alarm table modification to increase alarmdelays. For delays between 1 and 30 seconds, eachactivation of this key increases the delay by1 second. For delays between 30 seconds and10 minutes, each activation of this key increasesthe delay by 5 seconds. The last key on the firstrow, labeled BACK SPACE, serves as an erasefunction by moving the cursor back one spacewith each activation when in the manual entry andedit mode.

The last key on the third row, labeledRETURN, is used by the operator interchangeablywith the last key on the fourth row, labeled LINEFEED, to enter a manual entry message. The firstkey and the next-to-last key on the fourth row areboth labeled SHIFT. While depressed, either keyenables entry of the upper character on dual-character keys. It has no effect when used withthe single-character keys.

Arrow/Home Keys

Only four of these keys are used by theoperator. They are used in conjunction with eitherof the SHIFT keys to perform the followingfunctions:

SHIFT →6.—Scrolls the plasma displayone line at a time from the current displaytoward the most recent log entry.

SHIFT ←4.—Scrolls the plasma displayone line at a time from the current displaytoward the oldest log entry.

SHIFT ↓2.—Advances from the presentCURRENT STATUS LOG displayed tothe next newest CURRENT STATUSLOG (advances in time).

SHIFT ↑8.—Advances from present theCURRENT STATUS LOG displayed tothe next oldest CURRENT STATUS LOG(backwards in time).

The operator may also use the ↓2 and the ↑8(without the SHIFT key) to perform the same timedelay modifications of the 2 and 8 keys on thestandard keyboard.

PROPULSION AND AUXILIARYCONTROL CONSOLE

The PACC operates in conjunction with theSCU 1 (in MER 1) and the SCU 2 (in MER 2).The SCUs provide the local control for four GTEsthat drive the port and starboard shafts, and theyprovide the interfaces with the auxiliary machineryplant. The PACC communicates with the SCUsand with other consoles in the MCS over the ship’sdata multiplexing system (DMS).

The majority of panels and controls areidentical on the PACC and the SCUs. The majordifference in the two consoles is in the quantity

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Figure 7-5.—PACC.

of equipment monitored. The PACC is designedto monitor four GTEs, two MRGs, and theirassociated auxiliary systems. The SCU is designedto monitor two GTEs, one MRG, and theirassociated auxiliary systems. Where the sectionbeing described on the PACC is identical to asection on the SCU, we will place an (*SCU).Later in this chapter we describe the SCUscovering only the areas of the consoles that aredifferent from those on the PACC.

The PACC provides for centralized controland monitoring of all propulsion engines, thereduction gears, the shafts, and the propellers.The PACC also provides control and monitoringfor auxiliary machinery, such as air conditioning,chilled water cooling, potable water supply, andthe firemains. The control of the propulsionengines and propulsion auxiliaries is normally atthe PACC when the ship is underway. The PACC(fig. 7-5) on the DDG-51-class ship is dividedinto three panels (*SCU), PROPULSIONMONITOR PANEL (Al), THRUST/AUXILIARY

PANEL (A2), and PLASMA DISPLAY KEY-BOARD PANEL (A3).

PROPULSION MONITOR PANEL (Al)

The operator uses this panel to monitor andcontrol the propulsion GTEs, the MRGs, andtheir support systems. The panel is basicallydivided into three sections. For ease of descriptionwe will call them the CONSOLE, PLASMADISPLAY, and PROPULSION sections.

Console Section

The operator uses the console section (*SCU)to test the console audible alarms and tomonitor the console power supplies. It has fourmomentary-contact push buttons, a rotary controlswitch, and two LEDs.

The four momentary-contact push buttons arelocated horizontally under the heading AUDIBLEALARMS TEST and are labeled SIREN, HORN,BELL, and BUZZER, respectively. The operator

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uses these push buttons to test the respective console is operating on the emergency poweraudible alarm. The rotary control switch is located source.directly below these audible alarm test pushbuttons. It is used by the operator to adjust thevolume of the audible alarms.

The two LEDs are located to the right of thealarm test push buttons and are labeled TEMPHIGH and UPS IN USE, respectively. The TEMPHIGH indicator will illuminate amber to showpower supply temperature is excessive. The UPSIN USE indicator will illuminate red to show the

Figure 7-6.—A1 panel propulsion section.

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Plasma Display Section

The plasma display section contains twoalphanumeric plasma displays. They displayup-to-date system status in the form ofstatus/alarm, summary groups, and demanddisplays. The plasma displays are identicalto the units (discussed previously) on theEOOW/LU.

Propulsion Section

The operator uses the propulsion section(fig. 7-6) for the actual monitor and con-trol of the propulsion GTEs, the MRGs, and theirsupport systems. Again, for ease of description,we will break the section down to four sub-sections called GAS TURBINE, STARTINGAIR, FUEL OIL, and REDUCTION GEARsubsections.

Figure 7-6.—A1 panel propulsion section—Continued.

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GAS TURBINE SUBSECTION.—In thissubsection we will describe only the controls andindicators for GTE 2B. The controls andindicators for GTE 2A, 1A, and 1B are a mirrorimage. There are 6 LEDs, 3 LED meters, and 11push buttons for each GTE in this subsection.

Starting at the top left below the heading GASTURBINE 2B is a horizontal row of four LEDs.The first LED, labeled TEMP HIGH, illuminatesred to show T5.4 has exceeded the alarm setpoint. The second LED, labeled ICING,illuminates amber to show icing conditions existat the gas turbine inlet. The third LED, labeledAUTO SHUT DOWN, illuminates red to showan automatic shutdown of the GTE has beeninitiated. The last LED, labeled PRESS LOW,illuminates red to show the GTE LO supplypressure has fallen below the alarm set point.

Located below the four LEDs are three LEDmeters. The meter to the left is labeled PWRTURB INLET TEMP. It illuminates to displaythe actual T5.4 in °F. This meter has a range of0 to 2000. The center LED meter is labeled GASGENERATOR SPEED. It has a range of 0 to12,000 and illuminates to show the actual Ng g.The last LED meter is labeled LUBO SPLYPRESS. It has a range of 0 to 100 and illuminatesto show the actual GTE LO supply pressure.

Mounted vertically below the T5.4 LED meterare two push buttons for the bleed air. They arelabeled VALVE OPEN and VALVE CLOSE,respectively. These push buttons are used by theoperator to open/close the GTE bleed air valveand will illuminate individually to show the valvestatus.

To the right of the two bleed air pushbuttons is a vertical row of four push buttons.The top push button is labeled MOTOR.When depressed by the operator, it illuminatesamber and places the GTE in a motor state.The second push button, labeled ON LINE,illuminates green when depressed to bring theGTE to the on line state. The third pushbutton, labeled ON, illuminates green to bringthe GTE to the on state. The last pushbutton in the row is labeled NORM STOP/CLDN. When depressed, it illuminates greento bring the GTE automatically to the cooldown and then to the off state. To the leftof this push button is an LED labeled OFF.

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The LED illuminates green (after a 5-minute cool-down period) when the off state is reached.

To the right of the four vertical push buttonsis a vertical row of three push buttons. The toppush button, labeled EMER STOP, is a guarded-type push button used by the operator toemergency stop the GTE in the event of anunsafe condition. When depressed, it illuminatesred and causes the GTE to go directly to off andbypass the cool-down period. Below the EMERSTOP push button is two push buttons labeledBATTLE OVRD ON (illuminates amber) andBATTLE OVRD OFF (illuminates green). Theoperator uses these push buttons to activate ordeactivate the battle override feature of thecontrol electronics. When activated, battleoverride prevents all auto shutdowns (exceptoverspeed) and speed limiting during criticaloperating conditions.

To the right of these three push buttons andbelow the LUBO SPLY PRESS LED meter is anLED and two push buttons. The LED illuminatesred to show a fire has been detected in the GTEmodule. The push button, labeled PRI HALONRLSE, is a red backlighted guarded type. Whendepressed, it initiates the primary halon releasesequence to the GTE module. It illuminates toindicate the sequence has started. During therelease sequence, a PRI HALON ACTUATEDmessage is displayed on the plasma display.Several seconds later, the PRI HALON RLSEindicator illuminates to indicate the Halon systemhas been pressurized. The push button, labeledRSV HALON RLSE, is a red backlighted guardedtype. When depressed, it initiates the secondaryhalon release sequence to the GTE module. Itilluminates to indicate the sequence has started.

STARTING AIR SUBSECTION.—This sub-section is used by the operator to select whichsystem will be used to start the GTE. It has twopush buttons. The top push button is labeledHIGH PRESS. When depressed, it illuminatesamber to indicate the operator has selected HPair for the GTE start. The second push buttonis labeled BLEED AIR. When depressed, itilluminates green to indicate the operator hasselected bleed air for the GTE start.

FUEL OIL SUBSECTION.—The operatoruses this section to control the GTE FO valves.

It has one LED and four identical pairs of pushbuttons used to monitor/control the two fuelsystems (1B and 1A). Each system has a verticalcolumn of four push buttons. The LED iscommon to both systems. We will only describethe four push buttons for the 1B system.

At the top of this subsection is an LED,labeled PRESS LOW, which monitors bothsystems. It illuminates red to show a low fuelpressure condition exists on a running GTE.The first two push buttons are labeled MODULEVALVE OPEN (illuminates green) andMODULE VALVE CLOSE (illuminates amber),respectively. The operator uses these push buttonsto open/close the module fuel valve, whichpermits or shuts off fuel flow to the module.When depressed, they will illuminate appropriately.The next two push buttons are labeled PURGEVALVE ON (illuminates amber) and PURGEVALVE OFF (illuminates green), respectively.The operator uses these push buttons to open/close the GTE fuel purge valve when purging thefuel system. When depressed, they will illuminateappropriately.

REDUCTION GEAR SUBSECTION.—Thissubsection has two mirror image MRG mimics.It is used to monitor the port and starboardMRGs. Each mimic has an LED meter, 4 LEDindicators, 11 push buttons, and 2 digitalindicators. We will describe only the port MRGmimic.

The LED meter, labeled HYDR MOSTREMOTE BRG PRESS, is located on the left sideof each mimic. It has a range of 0 to 100 psig andis used to indicate actual LO pressure at the MRGmost remote bearing. Associated with this LEDmeter, and located to the right of it, is an LEDlabeled PRESS LOW. When illuminated, itindicates pressure at the most remote bearing isat or below the alarm set point. To the right ofthis LED indicator, under the heading MOTORDRIVEN SERVICE PUMPS, are nine push-button indicators. They are used to control theLO pumps. The push button labeled MANUALis common to both 1B and 1A LO systems. It isan amber backlighted push button that, whendepressed, allows the operator to have manualcontrol of the LO pumps speed.

Eight of the push buttons (four for eachsystem) are pairs that are identical as to function.

We will describe only the four push buttons forthe 1B LO system pumps. The first push button,labeled AUTO LEAD, is a green backlighted pushbutton used to select pump 1B(1A) as the leadpump in automatic control mode. The secondpush button, labeled HIGH SPEED, is a greenbacklighted push-button indicator the operatoruses to place pump 1B(1A) in high speed (manualmode) and illuminates to indicate pump speed inthe automatic mode. The third push button,labeled LOW SPEED, is a green backlightedpush-button indicator the operator uses to placepump 1B(1A) in low speed (manual mode) andilluminates to indicate pump speed in theautomatic mode. The last push button for the LOpumps, labeled OFF, is a green backlighted push-button indicator the operator uses to stop pump1B(1A).

The last two of the 11 push buttons on themimic are under the heading BRAKE MODE.They are labeled ON (illuminates amber) and OFF(illuminates green), respectively. These pushbuttons are used by the operator to control thePT brakes. When the push button labeled ON isdepressed, it causes the GTEs to go to idle, PTbrakes to engage (if NPT is below 2300 rpm), andpropeller pitch to go to zero. Depressing theBRAKE MODE OFF push button when the brakemode is on causes the PT brakes to release,removes the idle speed and zero pitch commandand allows these commands to return to thedemand set on the programmed control lever.

To the right of these two push buttons are thelast two LED indicators on the mimic. Thefirst LED, labeled BEARING TEMP HIGH,illuminates red to indicate a reduction gearbearing temperature is at or above its alarm setpoint. The operator identifies the specificbearing causing the alarm on the plasma display.The LED, labeled TURNING GEAR ENGAGED,illuminates amber to show the turning gear isengaged.

The first of the two digital indicators is locatedbelow and to the left of the nine push buttons usedto control the motor-driven LO pumps. It isunder the heading SHAFT SPEED and labeledACTUAL RPM. It has a range of 0 to 200 rpmand displays the actual shaft rpm. To the rightof this indicator, under the heading PROPPITCH, is the second digital indicator. It islabeled ACTUAL PERCENT and indicates actualpropeller pitch in percentage of maximum designfor ahead (+) and astern (–) pitch.

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THRUST/AUXILIARY PANEL (A2)

Figure 7-7.—A2 panel.

The operator uses this panel (fig. 7-7) tocontrol and monitor auxiliary and propulsionauxiliary systems. For ease of explanation,we will divide the panel into sections anddescribe each section individually. These sectionsare the INDEPENDENT AUX, PROPULSIONAUX, CONSOLE, THRUST SETTING, CON-TROL LOCATION, and PROGRAMMEDCONTROL LEVER.

Independent Aux Section

This section is used to control and monitorthe seawater cooling system. It has five LEDsand ten push buttons. The LEDs are usedto alert the operator when the seawater coolingsystem pressure in a monitored space is ator below its alarm set point. The spacesmonitored by these LEDs are engine rooms#1 and #2, auxiliary machinery rooms #1and #2, and the air conditioning machinery andpump room.

The ten push buttons are five sets ofidentical pairs. Each push button of thepair is labeled ON or OFF, respectively.These push buttons are used to start or

stop the respective seawater cooling pumpfrom the PACC. The pumps are labeled leftto right #5, #4, #3, #2, and #1.

Propulsion Auxiliaries Section

The operator uses this section of the panel tomonitor and control the BLEED AIR (port andstarboard), PROP HYDRAULICS (port andstarboard), and FUEL SERVICE (port andstarboard) systems.

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Figure 7-7.—A2 panel—Continued.

BLEED AIR.—Under the heading BLEEDAIR, there is an LED indicator and four pushbuttons for each (port and starboard) bleedair system. The LEDs, labeled PRESS LOW,illuminate amber if the respective bleed air headerpressure falls below its alarm set point. The firsttwo push buttons are for the PRAIRIE AIR valve.They are labeled ON and OFF, respectively, andilluminate green to indicate the status of oroperator’s command to the valve. The last twopush buttons are for the HULL MASKER valves.They are labeled ON and OFF, respectively, andilluminate green to indicate the status of oroperator’s command to the valve.

PROP HYDRAULICS.—Under the headingPROP HYDRAULICS, there are two LEDindicators and four push buttons for each (portand starboard) propeller hydraulic system.

The two LEDs are located under the headingPORT(STBD). The first LED, labeled FLOWHIGH, illuminates amber when the respectivepropeller hydraulic oil flow rate is at or above the

preset alarm limit. The second LED is labeledFLOW LOW. It illuminates amber when therespective propeller hydraulic oil flow rate is ator below the preset alarm limit.

Mounted vertically and below the two LEDsare the four push buttons under the headingELEC PUMP. The first push button is labeledMANUAL. When depressed, it illuminates amberto indicate the operator has manual control of theelectric LO pump. The second push button islabeled AUTO. When depressed, it illuminatesgreen to indicate the pump is in the automaticmode. The third push button is located underthe AUTO push button and is labeled ON. Itilluminates green to indicate the pump status oroperator command to the pump. This pushbutton is active in the MANUAL or AUTOcontrol mode. The last push button is labeledOFF. It illuminates green to indicate the pumpstatus or operator command to the pump. Thispush button is also active in the MANUAL orAUTO control mode.

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FUEL SERVICE.—Under the heading FUELSERVICE are the controls and indicators used bythe operator to monitor the port and starboardfuel service system. It has an LED, three pushbuttons for pump control, and two push buttonsfor valve control for each of the four systems. Thesystems and pumps are labeled PORT (2-B and2-A) and STBD (1-B and 1-A). As the controlsand indicators for each system are identical, wewill describe only the port 2-B system.

The LED is located under the heading TANK2-B LEVEL LOW. It illuminates amber when theFO level in the service tank is below the alarm setpoint. The first three push buttons are locatedvertically under the heading PUMP 2-B. They arelabeled HIGH SPEED, LOW SPEED, and OFF,respectively. Each push button illuminates greenwhen the pump is in the state indicated either asa result of the automatic control feature oroperator actuation.

The last two push buttons are located underthe heading SUCTION AND RTN VALVES.They are labeled OPEN and CLOSE, respectively.These push buttons are used by the operator toopen and close the FO service tank suction andreturn valves. When depressed, the push buttonsilluminate green when both valves are in theposition commanded (full open or full closed).

Console Section

This section is located between the PROPUL-SION AUX section and the port THRUSTSETTING section. It has three push buttonsmounted vertically. The first push button, labeledALARM ACK, is used by the operator to silenceaudible alarms, cause flashing alarm indicatorsfor active alarms to go to a steady state, andplasnia display alarm messages to change fromunacknowledged to acknowledged state. Thesecond push button, labeled BELL LOG PRINTis used by the PACC operator to obtain a bell logprintout at the EOOW/LU. The last pushbutton, labeled LAMP TEST, is used by the

PACC operator to test control panel indicators.When depressed, all indicators light, all LEDmeter segments light to indicate full scale, anddigital displays will indicate all 8’s.

Thrust Setting Section

There is a thrust setting section for each shaft(port and starboard). The sections are mirrorimage so we will describe only the port thrustsetting section. These sections are located to theupper left and upper right side of the programmedcontrol levers. Each section has an LED andfour digital displays. The LED, under the headingEOT ALERT, illuminates amber to indicate adifference exists between the BCU port programcontrol lever (order) setting and the PACCprogram lever (actual) setting. Two of the digitalindicators are located under the heading SHAFTSPEED. The first indicator is labeled ORDERRPM. It is a three-digit display that indicates theport shaft speed (order) as determined by thesetting of the BCU programmed control lever. Thesecond indicator is labeled ACK RPM. It is athree-digit display that indicates the port shaftspeed (actual) demand output as determined bythe position of the PACC programmed controllever.

The other two digital indicators are locatedunder the heading PROP PITCH. The firstindicator is labeled ORDER PERCENT. It is asign plus three-digit display that indicates theordered port propeller pitch as determined by thesetting of the BCU programmed control lever. Thesecond indicator is labeled ACK PERCENT. Itis a sign plus three-digit display that indicates theport propeller pitch (actual) demand output as

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determined by the position of the PACCprogrammed control lever.

Control Location Section

There is a control location section for eachshaft (port and starboard). The sections aremirror image so we will describe only the portcontrol location section. These sections are locatedto the lower left and lower right side, respectively,of the programmed control levers.

Each control location section has threeLEDs and three push buttons. The first LED islabeled THRUST CONTROL LOCAL LOCK-OUT. It illuminates red when either SCU MODESELECTOR (on the SCU) is in the LOCKOUTmanual position. It indicates control is at theSCU. The other two LEDs are located under theheading PRPLN/AUX. The first LED, labeledCTL CONT STA, illuminates green to indicatecontrol of the port propulsion unit and propul-sion auxiliaries is at the PACC. The second LED,labeled LOCAL, illuminates green to indicatecontrol of the port propulsion unit and propul-sion auxiliaries is at SCU-2.

Programmed Control Lever Section

The programmed control levers on the PACCprovide power commands to the gas turbine

propulsion engines and propeller pitch commandsthrough the DMS and the SCU. These commandsfrom the control levers are synchro analog signals.The analog signals are then converted to digitaldata for transmission over the DMS network. Theprocessor in the SCU outputs the digitalcommands to digital-to-analog converters in theinput/output multiplexer. (The multiplexer is inthe SCU.) The analog signals are then used tocontrol the gas turbine propulsion engine speed,then the shaft rpm, and finally the propellerpitch.

This section has two control levers usedto control speed of the GTEs and propellerpitch for each shaft. The left lever controlsthe port shaft, GTE 2B, and GTE 2A.The right lever controls the starboard shaft,GTE 1B, and GTE 1A. The movement ofeither lever results in engine speed and propellerpitch demand outputs to control ship speed.Linear scales alongside each lever are markedwith a 10, corresponding with maximumspeed ahead, a –3.3 with maximum speedastern, and 0 to zero thrust. The levers may bemechanically locked together for simultaneouscontrol of both levers.

PLASMA DISPLAYKEYBOARD PANEL (A3)

This panel is identical to the keyboardcontrol panel on the EOOW/LU describedpreviously. The keyboard is common to all thepropulsion consoles in the MCS.

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Figure 7-8.—SCU.

SHAFT CONTROL UNIT

The SCUs (fig. 7-8) are operationally identicaland only minor panel nomenclature makes themphysically different. The SCU is divided into threepanels: the propulsion monitor panel (Al), thethrust/auxiliary panel (A2), and the horizontalkeyboard panel.

The descriptions provided in this section areapplicable to both SCU 1 and SCU 2. Where thenomenclature is different, SCU 2 nomenclaturewill be indicated in parentheses. As in previouschapters, the description of the controls andindicators on the console panels will be coveredfrom left to right, top to bottom.

There are two SCUs, one located in MER 1and one located in MER 2. Each of theseconsoles interfaces with two LM2500 GTEs andtheir associated integrated electronic control (IEC)cabinets. The IEC cabinet performs basically thesame functions as the FSEE on the other classes

of GTE-powered ships. The starboard shaft isdriven by the GTEs in MER 1 and is controlledand monitored by the SCU 1. The port shaft isdriven by the GTEs in MER 2 and is controlledand monitored by the SCU 2. Both SCUs monitorand control the propulsion plants for theirrespective shaft, including auxiliary systems suchas bleed air, fuel service, propeller hydraulics, andLO. Control levers mounted on the SCU providethe thrust setting ability when GTE control is atthe SCU.

PROPULSION MONITOR PANEL (Al)

The controls and indicators on this panel(fig. 7-9) are identical to the controls andindicators on the PACC propulsion monitorpanel, with the exception being quantity. Aspreviously stated, the PACC has the controls andindicators to monitor all four GTEs and bothMRGs, while the SCU has the controls and

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indicators to monitor only two GTEs and oneMRG.

Other than the quantity of controls andindicators, the only major differences in the SCUand the PACC propulsion monitor panel is it hasonly one plasma display and the addition of aSUMMARY ALARMS section on the SCU. Thissection has nine LEDs, each of which monitorsmultiple systems. The first LED, labeled BLEEDAIR, illuminates amber to indicate any one of thealarms related to the bleed air system has beenactivated. The second LED, labeled PROPHYDR, illuminates amber to indicate any oneof the seven alarms related to the propellerhydraulics has been activated. The third LED,labeled REDUCTION GEAR AND SHAFTING,illuminates amber to indicate any one of 36 alarmsrelated to the MRG and shafting has beenactivated. The fourth and fifth LEDs are mountedvertically and are for ENGINE ROOM 1(2). Thetop LED, labeled LUBO, illuminates amber toindicate an alarm related to the LO system in theengine room has been activated. The bottomLED, labeled FUEL OIL, illuminates amber toindicate any one of nine alarms related to the fuelsystem has been activated.

The last four LEDs are for the GAS TURBINE(two for each GTE in the engine room). They aregrouped vertically in pairs for GTE 1B(2B) andGTE 1A(2A). We will describe only the two LEDsfor GTE 1B(2B). The top LED, labeled VITAL,illuminates amber to indicate any one of 23 vitalalarms related to GTE 1B(2B) has been activated.The bottom LED, labeled NON VITAL,illuminates amber to indicate any one of 19 non-vitalalarms related to GTE 1B(2B) has been activated.

THRUST AUXILIARY PANEL (A2)

This panel (fig. 7-10) has the identical controlsand indicators found on the PACC thrust/aux-iliary panel.

The major differences between the SCU paneland the PACC panel are as follows:

Only one PROGRAMMED CONTROLlever for control of the GTEs and shaft forthe applicable engine room

The addition of two manual throttlecontrol levers (located between the PRO-PULSION AUX and the THRUST

SETTING section) for individual controlof the GTEs

One pitch control lever (located to theright of the PROGRAMMED CONTROLlever) for manual control of propeller pitch

A MODE select switch added to theCONTROL LOCATION section

The throttle control levers have been describedon the PACC and will not be covered again. Thepitch control lever is used when the SCU is in themanual mode to vary pitch from 0 to full ahead(+25 feet) or 0 to full astern (– 17 feet). It alsohas a vernier thumbwheel, labeled TRIM, whichis used to make fine adjustments to the pitchsetting.

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Figure 7-9.—SCU propulsion monitor panel.

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Figure 7-9.—SCU propulsion monitor panel—Continued.

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Figure 7-10.—SCU thrust/auxiliary panel.

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The MODE select switch is located to the rightof the LEDs and push buttons of the CONTROLLOCATION SECTION. It is a two-positionrotary switch used to select either the LOCK-OUT MANUAL or NORMAL PROGRAMMEDmode. The SCU operator uses this switch to placethe GTEs and propeller pitch control in theprogrammed control mode after starting theGTEs.

HORIZONTAL KEYBOARD PANEL

This panel is identical to the keyboardcontrol panel on the EOOW/LU described

previously. The keyboard is common to all thepropulsion consoles in the MCS.

SUMMARY

This chapter was written to familiarizeyou with the consoles of the MCS of theArleigh Burke-class ships, it is not enoughinformation for operational or troubleshootingpurposes. This material is provided to giveyou, a junior GS, enough knowledge tobegin qualifying in your assigned watches,using the PQS applicable to the watch stationyou are learning.

The knowledge gained by reading thischapter should also give you enough infor-mation to assist a qualified technician inthe repair of this important equipment. Onlytechnical manuals can give you the in-depthprocedures as to how to troubleshoot andrepair the MCS equipment. Never try towork on this equipment without the propermanuals and supervision by a qualified tech-nician.

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CHAPTER 8

ELECTRICAL PLANT OPERATION

Each class of gas turbine powered ships hasits own distinct EPCC. They are located in theCCS. The EPCC provides the capability of remoteoperation and monitoring of the electrical plant.In this chapter we will describe the EPCC for eachclass of gas turbine-powered ships.

The information in this chapter will helpyou know the location of the controls andindicators on the consoles. This will help youoperate the consoles faster since you willknow where to reach for the control switches.Also, when an indicator illuminates, you willknow what it means. Studying this chapterwill also help you qualify as an operatorof the EPCC. However, the information inthis chapter is for training purposes only.You should NEVER operate any console withoutfollowing the EOSS procedures.

ELECTRIC PLANT CONTROLCONSOLE (DD-CLASS SHIPS)

The EPCC on the DD-class ships contains thecontrols and indicators used to operate andmonitor the ship’s service power generators anddistribution systems remotely. The control systemon the DD-class ships is the EPCE (fig. 8-1).It consists of an EPCC and an electric plantcontrol electronics enclosure (EPCEE). In thissection we will discuss the EPCC. The EPCC issubdivided into four panels, and each panel isdedicated to a particular type of control andmonitoring. The panels are the alarm/statuspanel, the generator status panel, the mimic panel,and the system control panel. We will discuss eachpanel of the console and point out the purposeor the function of each indicator, switch/indicator, or switch. We will also discuss theTOPS, load centers, and the different systemconfigurations.

ALARM/STATUS PANEL

The ALARM/STATUS panel is the upper leftpanel (fig. 8-2). It contains the alarm/statusindicators, 60/400-Hz converter, emergencypower, switchboard, main switchboard grounddetection, load shedding, synchronizing indi-cation, GTGs demand display, and alarmacknowledge sections.

ALARM/STATUS Section

The ALARM/STATUS indicators section isdivided into three subsections, one for each

Figure 8-1.—EPCE (DD-class ships).

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Figure 8-2.—ALARM/STATUS panel.

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SSGTGS. All are the same except No. 3. It hastwo extra alarm indicators. We will discuss thealarms/indicators from the top to the bottom ofthe columns, the GEN column first and then theGTRB column.

GENERATOR COLUMN.—This column hasthe following alarm/indicators:

AIR TEMP. HIGH indicates thetemperature of the air exiting the generatoris too high.

FRONT BRG. TEMP. HIGH indicatesthe temperature sensed in the babbitt ofthe front bearing is above the set limit.

REAR BRG. TEMP. HIGH indicates thetemperature sensed in the babbitt of therear bearing is above the set limit.

STATOR TEMP. HIGH indicates thetemperature in the generator statorwindings have exceeded the preset limit.

VIBRATION HIGH indicates the vibra-tion on the GTE has exceeded the presetlimit.

SPARE indicator.

HEATER ON indicates the heater in thegenerator enclosure is energized.

GAS TURBINE AND REDUCTION GEARSCOLUMN.—This column has the followingindicators:

FIRE indicates that a fire is being sensedin the acoustical enclosure.

ENCL. TEMP. HIGH indicates thetemperature in the enclosure exceeds thepreset limit.

INLET TEMP. HIGH indicates thetemperature of the gases going into the tur-bine section is above the set point.

LUBO PRESS LOW indicates the lube oilpressure to the GTE or the reduction gearhas dropped below the set limit.

LUBO TEMP. HIGH indicates thetemperature of the GTE lube oil is abovethe set point.

LUBO STR. DP HIGH indicates the dif-ferential pressure on the GTE lube oilstrainer is above the set point.

FUEL OIL STR. DP HIGH indicates thedifferential pressure on the fuel oil straineris above the set point.

The No. 3 generator has two more indicatorsdirectly below the indicators just described.

FUEL LEVEL LOW indicates the fuellevel in the tank has exceeded the low levellimit.

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FUEL LEVEL HIGH indicates the fuellevel in the tank has exceeded the high levellimit.

60/400HZ CONV Section

The ship has three 60/400-Hz converters. Thissection has a set of identical indicators foreach converter. The top indicator is POWERAVAILABLE, which illuminates when theconverter is online. The middle indicator is SMY.TEMP. HIGH, which illuminates when thetemperature in the converter exceeds the presetlimit. The bottom indicator is SHUT DOWN,which illuminates when the converter is or hasbeen secured.

EMERGENCY POWER Section

This section has four indicators, one meter,and two ground detect indicators with a switch.The top left indicator is labeled MAIN ENGINEROOM NO. 1. It will illuminate when the shipcontrol system in engine room No. 1 is operatingon the UPS system. The bottom left indicator,MAIN ENGINE ROOM NO. 2, functions thesame but is for the No. 2 engine room. The topright indicator is labeled BATTERY CHARGING.It will illuminate when the UPS battery bank ison charge. The bottom right indicator, BATTERYLOW VOLT, illuminates when the voltage

output by the UPS battery bank is below thepreset limit. Below the indicators is the D-CVOLTS meter. It indicates the output voltage ofthe UPS battery bank. Located at the bottom isthe GROUND DETECT section. It has twoindicators that should be of equal brilliance. Theleft indicator is for the negative lead of the UPScircuitry. The right indicator is for the positivelead of the UPS circuitry. The GROUND TESTpush-button switch is located below the indicators.When you depress the switch, a dimming orextinguishing of an indicator indicates a groundon that side of the circuitry.

SWITCHBOARD Section

This section has three indicators, one for eachSWBD. Each indicator, EMERGENCY PWR.ON, will illuminate when its related SWBD’spower supply fails. When this condition occurs,power is supplied to the SWBD by a set of its own24-volt dc emergency batteries.

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MAIN SWITCHBOARD GROUNDDETECT Section

This section has three indicator lights acrossthe top, PHASE A, PHASE B, and PHASE C.These indicators are normally of equal brilliancy.Below the indicator lights is the SWITCHBOARDSELECT rotary switch. It selects the SWBDthat is being checked. At the bottom of thesection is the GROUND TEST push-buttonswitch. When it is depressed, it connectsthe selected SWBD to the indicator lights.A grounded condition is indicated by oneof the lights going out and the other twolights glowing brighter. The light that goes outis the phase that is grounded.

Load Shedding Switch/Indicator

The LOAD SHED ACTIVATED switch/indicator, when depressed, will output a commandto trip the load shedding breakers. The illumina-tion of the indicator will result when the loadshedding breakers are opened. This may be by the

operator or the ship’s electric plant circuitry. ASPARE indicator is located to the left of the loadshed activated switch/indicator.

SYNCHRONIZING LIGHTS Section

This section contains two indicator lights anda synchroscope meter. The SYNCHRONIZINGLIGHTS will be dark when the generators are inphase. The brilliancy of the lights will varyaccording to differences in the phases. On theSYNCHROSCOPE, the direction of rotation ofthe synchroscope pointer indicates that thefrequency of the on-coming generator is FASTor SLOW with respect to the on-line generator.The speed of rotation is an indication of theamount of difference in the frequency. When thepointer is at the 12 o’clock position, the generatorsare in phase with each other.

GAS TURBINE GENERATORSDEMAND DISPLAY Section

This section contains three sets of displaysand thumbwheel switches. The upper portionis the display and it will display the parameter

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that is addressed by the thumbwheel switch justbelow it.

Alarm Acknowledge

The ALARM ACK push-button switch, whendepressed after an alarm has been received, willsilence the audible alarm and change the flashingalarm indicator to a steady light. The followingindicator lights will continue to flash even afterthe ALARM ACK switch has been depressed:EMERGENCY POWER for the SWBDs, BAT-TERY CHARGING, EMERGENCY POWERfor ENG RM NO. 1 and ENG RM NO. 2 (locatedon this panel), and the EMERGENCY indicatorin the POWER section located on the systemcontrol panel (discussed later in this DD-class shipsection).

GENERATOR STATUS PANEL

The GENERATOR STATUS panel is theupper right panel (fig. 8-3). It has three sections,one with meters and indicators for continuousmonitoring of each generator, a shore powersection, and a bus tie and SWBD section.

Generators Section

This section has three subsections, one foreach generator. The subsections are labeled GEN1SG, GEN 2SG, and GEN 3SG. Since all thesesubsections are identical, we will describe onlyone.

ALARM INDICATORS.—The alarms/indi-cators for the generator are as follows:

HIGH CURRENT indicates the currentexceeds the preset limit.

HIGH FREQUENCY indicates the fre-quency exceeds the preset limit.

HIGH VOLTAGE indicates the voltageexceeds the preset limit.

LOW FREQUENCY indicates the fre-quency has dropped below the preset limit.

LOW VOLTAGE indicates the voltage hasdropped below the preset limit.

METERS.—The four meters in this sectionare the KILOWATTS, AMPERES, HERTZ, andVOLTS meters.

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Figure 8-3.—Generator status panel.

SHORE POWER Section

This section contains one indicator, oneswitch, and three meters. Starting at the top,the first item is an alarm indicator for HIGHCURRENT. It will illuminate when the currenton the shore power exceeds the preset limit.Below this indicator is the PHASE SEQ.toggle switch. When it is in the OFF or down

position, it disconnects the power from thePHASE SEQ meter. With the switch in the ONor up position, it connects the power to thePHASE SEQ. meter. Below this switch is thePHASE SEQ. meter. It is operative when thePHASE SEQ. switch is ON. The PHASE SEQ.meter indicates that the phase sequence of theshore power is incorrect or correct and that allthree phases are present. The next meter is the

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AMPERES meter. The last meter in this section SWBD VOLTAGE SELECT switch located onis the HERTZ meter. the system control panel.

BUS TIE & SWBD Section

This section has a VOLTS meter. The input The next circuit breaker switches belowto this meter is controlled by the BUS TIE & the circuit breakers/indicators for the load

MIMIC PANEL

The MIMIC panel is the lower left panel (fig.8-4). It contains a mimic bus depicting the physicalarrangement of the SWBD and bus ties. The panelhas the controls for the following circuit breakers:generators, bus ties, load centers, and shorepower. It also has the manual start and stopcontrols for the SSGTGSs and the plant controlindicators.

Circuit Breaker Switches/Indicators

All circuit breaker switches/indicators onthis panel are alternate action push-buttonswitches and indicators. Across the top of thepanel are the switches/indicators for the loadcenters. When the FDR. LC11 CLOSE indicatoris illuminated, it indicates the breaker isclosed and feeding power to the load center.When the FDR. LC11 TRIP switch is depressed,it will cause the breaker to trip and the FDR. LC11TRIP indicator will illuminate, indicating thebreaker is tripped and no power is being fed tothe load center. When the FDR. LC11 TRIPindicator is illuminated and the FDR. LC11CLOSE switch is depressed, it will cause thebreaker to close and feed power to the load center.The other indicators are for different load centersand some spares are provided.

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Figure 8-4.—MIMIC panel.

center are the bus tie breakers (BTBs), Theseare labeled BTB 1S-2S CLOSE/BTB 1S-2STRIP. The label identifies the location ofthe BTBs. The first number is the SWBDthe breaker is located on and the secondnumber is the SWBD it will connect with.They work the same as the load centerbreaker switches, except these switches controlthe bus ties that connect the SWBD busestogether.

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The next circuit breaker switches are for thegenerator circuit breaker (GB). These are labeledGB 1SG CLOSE/GB 1SG TRIP. This labelidentifies these as the GB on the No. 1 SWBD.These switches are used to control the breaker thatconnects the generator to the SWBD bus and feedspower to the ship. These switches also work thesame as the load center breaker switches.

through the GTRB START MODE SEL switchto the appropriate generator. The left switch isthe STOP switch. It is a momentary push-buttonswitch. When it is depressed, it will initiate a stopcommand to the appropriate generator.

The last circuit breaker switches are for theshore power. They are labeled SHORE PWR. CBCLOSE/SHORE PWR. CB TRIP. They controlthe shore power circuit breaker that connectsshore power to the ship. They work the same asthe load center circuit breaker switches.

Generators Section

This section has the controls for eachgenerator, labeled GEN 1SG, GEN 2SG, andGEN 3SG. For each generator there are fourindicators and two push-button switches. Theindicators from top to bottom are as follows:

RUN indicates that the generator isrunning.

AUTO STBY. indicates that the generatoris not online but is available for standby/emergency operation.

CCS IN CONTROL indicates that CCS isin control of the generator.

FAIL TO START is not used.

The switch on the right side is the STARTswitch. It is a momentary push-button switch.When it is depressed, it initiates a start command

Gas Turbine Start Mode Selector

Located on the left-hand side of the panel isthe GTRB. START MODE SEL. switch. It is atwo-position toggle switch labeled HP AIR andLP AIR. The switch is spring loaded to the LPAIR position and must be held in the HP AIRposition. You use this switch to select the type ofair pressure used to start the GTE.

Miscellaneous Indicators

Located to the right of center on the panel arefour indicators in a column. These indicators fromtop to bottom are as follows:

AUTO MODE ON indicates that the OPMODE SEL switch, located on the systemcontrol panel, is set to the AUTO position.This means that all VOLTAGE REG andGOV MODE selector switches are set tothe NORMAL position.

SYS. CONFIG CHNG. START indicatesthe ship’s electric plants have started anautomatic configuration change.

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SYS. CONFIG. CHNG. COMPL. indi-cates the automatic configuration changehas been completed.

AUTO RCVY. NOT AVAIL. indicates theEPCE does not have automatic recoverycapability.

Another indicator on this panel is the SHOREPWR. AVAILABLE indicator. It will illuminatewhen shore power is connected to the ship. Thelast indicator is the BT 1S-2S ENERGIZEDindicator. It will illuminate when the 1S or 2SSWBD is energized or shore power is applied toBT 1S-2S.

SYSTEM CONTROL PANEL

The system control panel is the lower rightpanel (fig. 8-5). It contains the following sections:generators, bus tie and SWBD voltage select,synchronizing select and console mode control,system frequency and voltage control, power,malfunction, logic self-test, test, and autoparalleling.

Generators Section

This section has the indicators and controlsfor the governor and voltage regulator mode and

for the frequency and voltage of each generator.These indicators and controls are labeled GEN1SG, GEN 2SG, and GEN 3SG from left to right.

GOVERNOR MODE SWITCH/INDICA-TOR.—This switch/indicator is an alternateaction push-button switch and indicator, labeledGOV. MODE. The normal indication is with theNORMAL portion illuminated. It indicates thegenerator governor control mode is in thenormal operating mode. Depressing this switchwill output a command to the governor to changethe control mode to droop and the DROOPportion of the indicator will illuminate, meaningthe governor control mode is in the droop mode.When the DROOP indicator is illuminated,depressing the switch will output a commandto the governor to change the control modeto normal, and the NORMAL indicator willilluminate.

FREQUENCY CONTROL SWITCH.—Thisswitch is located next to the governor modeswitch/indicator and is labeled FREQ. It is athree-position switch, spring loaded to centerposition. The center position is labeled OFF,which is the normal position of the switch. Whenthe switch is turned to the right or the RAISEposition, it will cause the frequency of thegenerator to increase. When the switch is turnedto the left or the LOWER position, it will causethe frequency of the generator to decrease.

VOLTAGE REGULATOR MODE SWITCH/INDICATORS.—Both of these switch/indicatorsare alternate-action push-button switches andindicators. They are labeled VR. MODE. The topswitch/indicator is AUTO/MANUAL. WhenAUTO is illuminated, it indicates the generatorvoltage regulator control mode is in the automaticoperating mode. Depressing this switch willoutput a command to change the voltage regulatorcontrol mode to manual. It will cause theMANUAL indicator to illuminate, meaningthe voltage regulator control mode is in themanual mode. When the MANUAL indicator isilluminated, depressing the switch will output acommand to the voltage regulator to change tothe automatic operating mode.

The bottom switch/indicator is NORMAL/DROOP. When the NORMAL indicator isilluminated, it indicates the generator voltageregulator control mode is in the normal mode ofoperation. Depressing this switch will output acommand to change the voltage regulator control

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Figure 8-5.—System control panel.

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mode to droop. It will cause the DROOPindicator to illuminate, meaning the voltageregulator control mode is in the droop mode.When the DROOP indicator is illuminated,depressing the switch will output a command tothe voltage regulator to change to the normalmode of operation.

VOLTAGE REGULATOR CONTROLSWITCH.—This switch is located next to thevoltage regulator control mode switch/indicatorsand is labeled VOLT. It is a three-position switch,spring loaded to the center position. The centerposition is labeled OFF, which is the normalposition of the switch. When the switch is turnedto the right or the RAISE position, it will causethe voltage of the generator to increase. When theswitch is turned to the left or the LOWERposition, it will cause the voltage of the generatorto decrease.

BUS TIE & SWBDVOLTAGE SELECT Section

This section is located in the upper right-handcorner of the panel. It is labeled BUS TIE &SWBD VOLTAGE SELECT. It has one rotaryswitch. This switch is used to select from whatlocation the BUS TIE & SWBD voltmeter locatedon the generator status panel will receive itsinput. The top position is labeled OFF. When theswitch is in this position, the meter is OFF.Clockwise around the switch, SWBD 1S is the No.1 SWBD; SHORE PWR. is for the shore powercables; BT 1S-2S is for the bus tie cable betweenthe 1S and 2S SWBDs; BT 1S-3S is for the bustie cable between the 1S and 3S SWBDs; SWBD2S is for the No. 2 SWBD; BT 2S-3S is for the

bus tie cable between the 2S and 3S SWBDs; andSWBD 3S is for the No. 3 SWBD.

Synchro Control Section

This section is located in the lower left-handcorner of the panel. It has two select switches. Thetop switch controls the input to the synchroscopeand synchronizing lights and the bottom switchcontrols the mode of operation of the console andthe paralleling device. These switches are labeledSYNC SELECT and OPR MODE SELECT,respectively.

SYNC SELECT SWITCH.—This is a rotaryswitch used to select between the GBs, the BTBs,or the shore power circuit breaker. It connects theinputs from both sides of the selected breaker tothe synchroscope and synchronizing lights, locatedon the alarm/status panel. This switch also allowsthe breaker selected to receive a manual closecommand when it is operated in the MANUALPERMISSIVE mode.

The switch has an OFF position and aposition for each GB, each BTB, and the shorepower circuit breaker. When the switch is in theOFF position, it will prevent all breakers fromresponding to a manual close command while inthe MANUAL PERMISSIVE mode.

OPR MODE SELECT SWITCH.—This is arotary switch used to select the mode ofoperation of the console and the automaticparalleling device. When the switch is turned tothe left, it is in AUTO. In this position it enablesthe automatic recovery capability and generatorparalleling control device. The middle positionis MANUAL PERMISSIVE. In this positionit routes the close command through thesynchronizing monitor to the breaker selected by

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the SYNC SELECT switch. The right position isMANUAL. When this position is selected, itroutes the close command directly to the breakerselected by the SYNC SELECT switch.

When the switch is turned to the left or theLOWER position, it will cause the voltage ofthe generators to decrease.

SYSTEM Section

This section has two switches, one for frequencyand one for voltage. These switches will adjustthe frequency or the voltage of all generatorsoperating in parallel, providing the governor andvoltage regulator of the generators are in theNORMAL mode of operation.

FREQUENCY SWITCH.—This switch controlsthe frequency of the system and is labeled FREQ.It is a three-position switch, spring loaded to thecenter position. The center position is labeledOFF, which is its normal position. When theswitch is turned to the right or the RAISEposition, it will cause the frequency of thegenerators to increase. When the switch isturned to the left or the LOWER position,it will cause the frequency of the generators todecrease.

VOLTAGE SWITCH.—This switch is usedto control the voltage of the system and is labeledVOLT. It is a three-position switch, spring loadedto the center position. The center position islabeled OFF, which is the normal position ofthe switch. When the switch is turned to theright or the RAISE position, it will causethe voltage of the generators to increase.

POWER Section

This section has two indicators. The topindicator is labeled NORMAL. When it isilluminated, the EPCE is using ship’s power orshore power as the normal power. The bottomindicator is labeled EMERGENCY. When it isilluminated, it flashes. This indicates that theEPCE is using UPS power.

MALF Section

This section is labeled MALF and hastwo indicators. The top indicator is labeledCONSOLE. When it is illuminated, it indi-cates a malfunction in the EPCC continuityinterlock circuit or that a card self-test circuithas activated the card fault output. The bottomindicator is labeled PWR. SPLY. When it

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is illuminated, it indicates a malfunction inthe EPCEE power supply.

LOGIC SELF TEST Section

This section contains one push-button switchand two indicators. The push-button switch islabeled INITIATE and is enabled only when theOPR MODE SWITCH is in the MANUAL PER-MISSIVE or the MANUAL mode of operation.When this switch is depressed, it will initiate a self-test program to test selected EPCC internal logic.The top indicator is labeled PASS and willilluminate after the successful completion of theEPCC self-test. The bottom indicator is labeledFAIL and will illuminate when a malfunction isdetected during a self-test.

TEST Section

This section has two subsections, labeledINITIATE and SELECT. The switches in thesesubsections are used to test collectively theoperation of the status and alarm indicators onthe console and the operation of the horn andsiren.

INITIATE.—The INITIATE subsection hasthree switches. The left switch is a toggle switchwith three positions. The top position is labeledSTATUS. In this position, all the status indicatorson the panel selected by the SELECT switch willilluminate. The middle position is labeled OFF.In this position, no test is being done. Thebottom position is labeled ALARM. In thisposition, all the alarm indicators on the panelselected by the SELECT switch are illuminated.The middle switch is a momentary push-buttonswitch labeled HORN. When this switch isdepressed, a horn will sound. The right switch isalso a momentary push-button switch labeledSIREN. When this switch is depressed, a siren willsound.

SELECT.—The SELECT subsection has arotary switch labeled SELECT used with thethree-position toggle switch. The switch positionsare labeled MIMIC, ALARM STATUS, GENSTATUS, and SYS. CONT. Each position is forone of the panels on the EPCC. When one ofthese positions is selected, that panel’s indicatorsor alarm indicators will be tested.

AUTO PARALLEL Section

This section has three push-button switch/indicators. The switches are labeled GEN 1 & 2PARALLEL, GEN 2 & 3 PARALLEL, and GEN1 & 3 PARALLEL. The switches are enabled only

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when the OPR MODE SELECT switch is in theAUTO position. The indicator portion isilluminated when that condition exists. When oneof the switches is depressed, it will cause theindicated generators to be paralleled.

TURBINE OVERLOADPROTECTION SYSTEM

The TOPS is an automatic protection systemto prevent an overload/overtemperature conditionfrom developing on the remaining SSGTG shouldone of the paralleled generators fail. Primarypower is 120 volts ac and is converted into therequired dc voltages needed for operation. Thesystem has an internal battery to provide a backupsource on power failure.

The TOPS control unit receives analog inputsfrom the PAMISE, such as SSGTGS inlettemperature, rpm, and kilowatt. The control unitalso receives digital inputs from the EPCC, suchas GB, BTB, and shore power circuit breakerstatus. The control unit will process the signalsand provide a listing, or menu, to the display unit.The display unit is essentially a video displayterminal with a pressure-sensitive surface. Theoperator touches the surface to select the menuto be displayed.

Another series of output signals from thecontrol unit go directly to the SSGTGS, SWBD,and the load shed relay. Based upon the resultsof the analysis of the data, the control unit willissue the commands to close the bleed air valves,open GBs, and/or initiate load shed. This is doneindividually or in combination. The control unitwill initiate whatever action is needed tomaintain the vital electrical load.

SYSTEM CONFIGURATION

The electrical system is designed so that twogenerators can supply all electrical loads. Thethird SSGTGS can be put on standby. Then it canautomatically be started and synchronized to thebus if one or both of the on-line generators shouldfail. Automatic failure detection and recovery isavailable only when the EPCC is in control andin automatic mode. Also, the electric plant mustbe in a standard parallel plant or standard split-plant configuration. The different types ofconfigurations are the standard parallel-plantconfigurations, the standard split-plant con-figurations, the nonstandard plant configurations,and the emergency configurations.

Standard Parallel-Plant Configurations

A standard parallel-plant configurationconsists of two generators online and paralleled,with all BTBs closed, connecting the three mainSWBDs in a loop system. Configuration statuslogic at the EPCC identifies the on-line generatorsfor auto recovery control.

Standard Split-Plant Configurations

A standard split-plant configuration consistsof two generators online, but not paralleled. Theoff-line generator SWBD is energized through thebus tie connection to one of the on-line generatorSWBDs. The remaining bus ties are not energized.The configuration status logic at the EPCC canidentify any of these configurations by monitoringthe open and closed status of the GBs and BTBs.

LOAD CENTERS

The load centers are very similar to thedistribution section of a main SWBD. They aresometimes referred to as load center SWBDs.They are located at remote locations from themain SWBDs. The load center uses the same typeof breakers as the main SWBDs to feed the loads.

Nonstandard Plant Configurations

A nonstandard plant configuration is an openloop configuration which energizes all three

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SWBDs from two generators operating in parallel.These configurations are operator selected, or theyare the result of a failure. All electrical distributionfunctions are provided with these configurations.However, automatic recovery capability is notavailable.

Emergency Configurations

An emergency configuration can occur whentwo generators are inoperative, and one generatormust energize the three SWBDs. Other emergencyconfigurations may have all three generatorsonline, with all, two, or none in parallel.

ELECTRIC PLANT CONTROLCONSOLE (CGCLASS SHIPS)

The EPCCs on the CG- and the DDG-classships (fig. 8-6) are very similar to those on the DD-class ships. We will only discuss the differencesin the consoles in this section. This console hastwo more panels than the DD consoles. They arefor the 60/400 Hz converters.

ALARM/STATUS PANEL

The alarm/status panel (fig. 8-7) is the upperleft panel. It contains the following sections:alarm/status indicators, emergency power,generator and gas turbine lube oil meters,synchronizing indication, SWBD emergencypower and main SWBD ground detection, alarmacknowledge, and demand displays.

Figure 8-6.—EPCC (CG- and DDG-class ships.)

Alarm/Status Indicator Section

The alarm/status indicator section is dividedinto three subsections, one for each SSGTGS.These subsections are identical. The only alarms/indicators we will discuss are the ones that areadded or different from the DD-class ships.

GENERATOR COLUMN.—The indicatorsin this column, labeled GEN, are the same as thoseon the DD consoles except the location of a fewof the indicators on the panel and the additionof the LUBO PRESS LOW indicator, which indi-cates the lube oil pressure in the generator dropsbelow the preset limit. All other indicators wereexplained in the description of the DD consoles.

GAS TURBINE AND REDUCTION GEARSCOLUMN.—The indicators in this column, labeledGTRB, are the same as those on the DD consolesexcept the location of a few of the indicators onthe panel and the addition of more indicators.

BLOW-IN DOOR OPEN indicates theblow-in doors are open.

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Figure 8-7.—Alarm/status panel.

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MDL ACCESS DOOR OPEN indicatesthe door to the module is open.

EMERG SW COOLING ON indicates theemergency cooling water is being suppliedto the SSGTGS cooling water system.

All other indicators were explained in the DD-classship section.

Emergency Power Section

The indicators in this section are identical tothose on the DD console. However, there are fouradditional indicators that are all labeled SPARE.

Generator and Gas TurbineLube Oil Meters Section

The three sets of identical meters in thissection provide a means for continuous monitoringof lube oil pressure. The meters are labeled GENLUBO PRESS and GTRB LUBO PRESS, one foreach SSGTG.

Synchronizing Indication Section

The indicators in this section are the same asthe synchronizing indication section on the DDconsole.

Switchboard Emergency Power and MainSwitchboard Ground Detection Section

This section is a combination of the SWBDemergency power section and the main SWBDground detection sections of the DD console. Thissection operates the same as the DD console.

Alarm Acknowledge

This section is the same as the alarmacknowledge section of the DD console.

Demand Display Section

This section is basically the same as thedemand display section of the DD console,except it also shows the unit of measure for theparameter being displayed.

GENERATOR STATUS PANEL

The generator status panel is the uppermiddle panel of the console. It is identical to thegenerator status panel on the DD console.

400-HZ ALARM/STATUS PANEL

This panel and the panel below it, discussedlater, are for the 400-Hz converters. The additionof these two panels to the EPCC is the greatestdifference in the EPCCs on the different class

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Figure 8-8.—400-Hz alarm/status panel.

ships. This panel (fig. 8-8) is divided intothree sections, the alarm/status indicator, grounddetection, and meter sections.

right 1STCA, 1STCB, 3STCA, 3STCB, 2STCA,and 2STCB. The indicators from top to bottomare as follows:

400-Hz Alarm/Status Indicator Section

This section has six columns of indicators, one

CCS IN CONTROL indicates the controlof the converter is at the EPCC.

for each 400-Hz converter. All the columns are LOCAL CONTROL indicates the controlidentical. The columns are labeled from left to of the converter is at the converter.

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SPARE.

TEMP HIGH indicates the temperature inthe converter exceeds the preset limit.

COOLANT FLOW LOW indicates theflow of the coolant in the cooling systemis not within limits.

SHUTDOWN indicates the converter is orhas been secured.

400 HZ GROUND DETECT Section

This section contains three indicator lights,labeled PHASE A, PHASE B, and PHASE C.Under the indicators is the SWITCHBOARDSELECT three-position rotary switch. It isused to select the specific 400-Hz SWBDthat is going to be tested for a ground.The bottom switch is a push-button switchthat is labeled GROUND TEST. When thisswitch is depressed, it will connect the selectedSWBD to the indicator lights to test thatSWBD for a grounded condition.

Meter Section

The meter section contains six ampere meters,one for each 400-Hz converter.

MIMIC PANEL

The MIMIC panel (fig. 8-9) is basically thesame as the MIMIC panel on the DD console.It contains the LOAD SHED ACTIVATEDindicator/switch and the generator controlsection has more indicators and a little differentlayout. The only section we are going to discussis the generator control section because everythingelse functions the same as the DD console.

The generator control sections have eightindicators and two push-button switches. Theswitches are located on the left side of thesection. The top switch is the START switch. Itis a momentary push-button switch. Depressingthis switch initiates a start command throughthe GTRB START MODE SEL switch to theappropriate generator. The bottom switch is theSTOP switch. It is a momentary push-buttonswitch. When the STOP switch is depressed, it willinitiate a stop command to the appropriategenerator. The two columns of indicators havethe same indicators as the MIMIC panel on theDD console. The indicators are as follows:

RUN.

AUTO STBY.

CCS IN CONTROL.

SPARE.

FAIL TO START.

FAN “A” ON indicates the “A” fan isrunning.

FAN “B” ON indicates the “B” fan isrunning.

STBY FAN TRANSFER indicates thecontrol of the standby fan is at the EPCC.

SYSTEM CONTROL PANEL

The system control panel (fig. 8-10) is almostthe same as the system control panel on the DD

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Figure 8-9.—MIMIC panel.

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Figure 8-10.—System control panel.

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Figure 8-11.—400-Hz MIMIC panel.

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console. It has the TEST section with a controlknob for the ALARM VOLUME. It is locatedunder the HORN and BELL test switches. Thealarm siren has been changed to a bell. TheSELECT switch has two added positions for thetwo 400-Hz panels.

400-HZ MIMIC PANEL

The 400-Hz MIMIC panel (fig. 8-11) is thelower right-hand panel. It has a mimic drawingof the ship’s 400-Hz system at the top of the panel.The bottom of the panel contains controls andindicators to operate the converters.

Mimic Section

The mimic section contains a mimic busdepicting the physical arrangement of the SWBDand bus ties. This section of the panel hascontrols/indicators for the BTBs. The BTBswitch/indicators are alternate action push-buttonswitches and indicators. The first number in thelegend on the indicator is the SWBD the breakeris located on. The second number is the SWBDthe breaker connects.

When the BTB 1SF-3SF CLOSE indicator isilluminated, it indicates the breaker is closedbetween the 1SF and 3SF SWBDs. Depressing theBTB 1SF-3SF TRIP indicator will cause thebreaker to trip (open) and the BTB 1SF-3SF TRIPindicator will illuminate. When the BTB 1SF-3SFTRIP indicator is illuminated, you can close thebreaker by depressing the BTB 1SF-3SF CLOSEswitch.

Converter Control Section

This section contains six identical subsections.The subsections are labeled from left toright 1STCA, 1STCB, 3STCA, 3STCB, 2STCA,

and 2STCB. At the top of the section is aswitch/indicator that is an alternate action push-button switch/indicator. The switch/indicator islabeled 400 HZ at the left of the switch/indicator.The switch/indicator is labeled CLOSE/TRIP.When the CLOSE portion is illuminated, itindicates the breaker is closed and feeding powerto the SWBD. When the TRIP switch is depressed, itcauses the breaker to trip and the TRIP indicatorwill illuminate. When the TRIP indicator isilluminated and the CLOSE switch is depressed,the breaker will close.

Next is the 400 HZ PWR AVAIL indi-cator. When it is illuminated, the converteris operating. BUS TIE ENABLE is the nextindicator. When it is illuminated, it meansclose/trip power is available to the breaker.A SPARE indicator is located below the BUSTIE ENABLE indicator. Below the SPAREindicator is the 60 HZ PWR AVAIL indicator.When it is illuminated, 60 Hz power is availableto the converter.

At the bottom of this section is a switch/indicator that is an alternate action push-button switch/indicator. The switch/indicatoris labeled 60 HZ at the left of the switch/indicator. The switch/indicator is labeledCLOSE/TRIP. When the CLOSE portion isilluminated, it indicates the breaker is closedand feeding power to the converter. Depressingthe TRIP switch will cause the breaker totrip and the TRIP indicator will illuminate.When the TRIP indicator is illuminated andthe CLOSE switch is depressed, the breakerwill close.

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Figure 8-12.—EPCC (FFG-class ships).

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ELECTRIC PLANT CONTROLCONSOLE (FFG-CLASS SHIPS)

The EPCC on the FFG-class ships contains thecontrols and indicators used to remotely operateand monitor the SSDGs and power distributionsystem.

The EPCC (fig. 8-12) is subdivided into ninepanels and each panel is dedicated to a particulartype of control and monitoring. The panels are theengine fuel systems panel (A-l), supervisory con-trol status(SCS)/parameters/synchronization/par-alleling panel (A-2), console power status/console

vital power feeder circuit breaker status panel(A-3), SSDG panels (A-4 and A-7), SSDG outputand distribution panels (A-5 and A-8), systemoutput monitor/ground status test/generator 4voltage control panel (A-6), and shore power/generators panel (A-9). The lower portion of theEPCC contains three fuse panels.

ENGINE FUEL SYSTEMS PANEL (A-1)

The ENGINE FUEL SYSTEMS panel (A-1)(fig. 8-13) is the upper left panel. It contains ameter for each fuel tank with associated high- and

Figure 8-13.—Engine fuel systems panel (A-l).

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Figure 8-14.—SCS/synchronization/paralleling/parameters panel (A-2).

low-level alarms. The panel also has push-buttonswitches to control the suction valve on each tankand an indicator to show the position of eachvalve.

Tanks 5-201-1-F and 5-201-3-F are for No. 1SSDG, tanks 3-240-1-F and 3-240-2-F are forNo. 2 and No. 3 SSDGs, and tanks 3-292-4-F and3-292-6-F are for No. 4 SSDG. All tanks have thesame layout, a meter with indicators at the top,the bottom, and to the right of the meter. Theindicators are the HIGH LEVEL and the LOWLEVEL alarm indicators, respectfully. The alarmindicators also have a 3-digit number on theindicator. This number is the DDI address for thatparameter. (When these 3-digit number sequencesare next to an indicator/alarm, they will alwaysindicate a DDI address on this class ship). Thetwo indicators in the middle and to the right ofthe meter are for the suction valve of therespective tank. The top indicator is the positionindicator, and the bottom indicator is a push-button switch that is used to control the valve.Both indicators are labeled SUCTION V OPEN/CLOSED. The top indicator shows the actualposition of the valve. The bottom indicator

shows the command being sent to the valve fromthe console.

The LAMP TEST push-button switch islocated on the lower right corner. It is used to testthe indicator lights on the A-l panel only.

SUPERVISORY CONTROL STATUS/SYNCHRONIZATION/PARALLELING/PARAMETERS PANEL (A-2)

This panel (A-2) (fig. 8-14) is the upper middlepanel. It has the parameter addresses, SCS,synchronization, paralleling, and parameterssections.

SUPERVISORY CONTROLSTATUS Section

The SCS section is divided into six subsections.Four are identical, one for each SSDG; the othertwo are for the overall plant and SCS controlswitch.

The SSDG subsections each contain sixindicators. The indicator circuitry is in operationonly when the SUPERVISORY CONTROL

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MODE switch is in the OVERRIDE or AUTOposition. The six SSDG indicators are as follows:

FAULTY GOVERNOR indicates a problemwith the speed regulation.

BUS VOLTAGE LOW indicates thevoltage on the SWBD is low.

NO JACKET WATER FLOW indicatesthe flow of the diesel’s jacket water hasstopped.

GENERATOR VOLTAGE TOO HIGHindicates the output voltage of thegenerator exceeds the preset limit.

GENERATOR EXCITATION TOO HIGHindicates the ampere level being applied tothe generator field exceeds the preset limit.

GENERATOR CB TRIPPED AUTO-MATICALLY indicates the generator circuitbreaker (CB) has opened. The operatoropening the generator CB can cause thisalarm indication.

The overall plant section alarms are forconditions that could effect the overall electricalplant operations. These alarms are as follows:

REAL LOAD UNBALANCE indicatesthe real or kW load between paralleledgenerators exceeds the preset limit.

REACTIVE LOAD UNBALANCE in-dicates the reactive or ampere load betweenparalleled generators exceeds the presetlimit.

STANDBY GENERATOR NOT AVAILindicates the SCS cannot locate a generatorsetup for automatic operations.

REAL LOAD OSCILLATION indicatesthe real or kW load between paralleledgenerators is oscillating.

LOAD SHEDDING OCCURRED indicatesthe electric plant has opened the loadshedding circuit breakers.

PLANT CORRECTED ALARM indicator/push-button switch indicates the SCS hastaken action to correct the plant followinga malfunction. The indicator will remainilluminated until the PLANT CORRECTEDALARM switch is pressed.

The SUPERVISORY CONTROL FAILUREindicator and the SUPERVISORY CONTROLMODE switch are the last items in this section.The SUPERVISORY CONTROL FAILUREindicator will illuminate when a problem with SCShas been sensed. This could be a hardware or asoftware problem. The SUPERVISORY CON-TROL MODE switch is a three-position switchused to select the operating mode of the SCS. Theleft position is OFF. In this position the SCSprocessor has no monitoring or controllingcapability. The middle position is OVERRIDE.In this position the SCS will monitor the electricalplant for malfunction but will not take anycorrective actions. The right position is AUTO.In this position the SCS will monitor and takecorrective action to maintain the electric plant ina standard configuration.

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SYNCHRONIZATION Section

This section contains two indicator lights, aSYNCHROSCOPE meter, a SYNC TRANSFERswitch, and an ON/OFF switch.

The indicator lights will be dark when thegenerators are in phase. The brilliancy of the lightswill vary according to differences in the phases.

The SYNCHROSCOPE meter shows thedirection and speed of rotation. The direction ofrotation of the synchroscope pointer indicates thatthe frequency of the on-coming generator is FASTor SLOW with respect to the on-line generator.The speed of rotation is an indication of theamount of difference in the frequency. When thepointer is at the 12 o’clock position, the generatorsare in phase with each other.

The SYNC TRANSFER switch is a rotaryswitch used to select between the generator CBsor the bus tie (BT) circuit breakers. It connectsthe inputs from both sides of the selected breakerto the synchroscope and lights. The SYNCHRO-SCOPE ON/OFF switch is used to turn thesynchroscope and lights on and off.

The LAMP TEST push-button switch islocated on the lower right corner. It is used to testthe indicator lights on the A-2 panel only.

PARALLELING Section

This section is labeled PARALLELING butis sometimes referred to as the APD section. Ithas four identical subsections, one for eachgenerator.

The top indicator is labeled APD POWERON. When it is illuminated, the APD has powerapplied to it.

The switch below the APD POWER ON indi-cator is labeled GENERATOR 4 (1, 2, or 3). Itis a three-position rotary switch used to select thebreaker on the No. 4 SWBD that the APD willcontrol. The left position is labeled BT 4-1. Whenthe switch is in this position, the APD is connectedto the BT that connects the No. 4 and No. 1SWBDs. The middle position is labeled BUS. Thisposition is for the generator CB. The rightposition is labeled BT 4-2. It is for the BT thatconnects the No. 4 and No. 2 SWBDs.

The next indicator down is labeled APD TESTPASSED. This indicator will illuminate at thetime the permissives have been met to close thecircuit breaker.

The bottom switch is labeled MODE. It is afour-position rotary switch. The MODE switchis used to select the mode of operation of theAPD. The left position is labeled BYPASS. Thisposition is used only when the APD is inoperative,when APD permissives cannot be met, or whenmanual paralleling by the operator is required.This position bypasses the APD’s CB closingpermissives. The MODE selector switch is springreturned from BYPASS to AUTO. The operatormust hold it in the BYPASS position while theCB control switch (not shown) is turned to theCLOSE position. This is done when the twopoints in the electric plant to be paralleled aresynchronized. Also, the operator has to use theAPD BYPASS position to close a CB to a deadbus and to the last breaker in a ring bus. Thestraight up position is labeled AUTO. In thisposition the APD automatically adjusts the speedof an oncoming generator to synchronize it withan energized portion of the electric system. It thenprovides a signal to close the designated CB. Thenext position is labeled PERM. In this positionthe APD acts as a safety interlock. It prevents theclosing of the designated CB unless the requiredpermissives are met. When operated in this mode,the APD functions as a monitoring device, not

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as a controller. The TEST position is the lastposition. It permits all the features of theAPD automatic mode except the signal to closethe breaker. Instead, it provides a signal toilluminate the respective APD TEST PASSEDindicator light.

The bottom indicator/switch is labeledINITIATE. When this push button is depressed,the APD test sequence is initiated.

PARAMETERS Section

This section has three digital display sub-sections. Each contains a display, a thumbwheel,and a toggle switch. The thumbwheel is used toselect an address, found on a DDI listing, thatcalls up the selected parameter. The parameter isdisplayed with the decimal in the proper positionand with the units used to measure the parameter(psi, rpm, and so forth). The toggle switch on theright of each subsection is used to display eitherthe high-alarm limit, the actual value, or the low-alarm limit. Another toggle switch, located at theleft side of the first subsection, is used with theother toggle switches. It allows the operator toverify the high/low reset value of the alarm.

CONSOLE POWER STATUS/CONSOLE/VITAL POWER FEEDERCIRCUIT BREAKER STATUSPANEL (A-3)

The CONSOLE POWER STATUS/CON-SOLE/VITAL POWER FEEDER CIRCUITBREAKER STATUS panel (A-3) is the upper

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Figure 8-15.—CONSOLE POWER STATUS/CONSOLE/VITAL POWER FEEDER CIRCUIT BREAKER STATUS panel(A-3).

right panel (fig. 8-15). It has the console powerstatus, console, and vital power feeder circuitbreaker status sections.

CONSOLE POWER STATUS Section

This section contains two subsections, one forthe power supplies and the other for the statusof the uninterruptable power.

POWER SUPPLIES.—This subsection hasthe indicators that are illuminated when thepower supply is operating. The left indicatoris 115 VAC MASTER POWER ON. Thenext four indicators are split-legend indicators,with the upper half of each for the primarypower supply and the lower half for thebackup power supply. From left to rightthe power supplies are +24+28 VDC, +15 VDC,–15 VDC, and +5 VDC.

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UNINTERRUPTABLE POWER.—This sub-section has the indicators for the UPS. The leftindicator is labeled NORMAL. When it isilluminated, the UPS is operating in a normalmanner. The middle indicator is labeled ALTER-NATE. When it is illuminated, the power isbypassing the UPS. The right indicator is labeledBATTERY. When it is illuminated, the UPS isoperating on the battery power.

CONSOLE Section

This section contains two indicators. The firstindicator is for console HIGH TEMP. When itis illuminated, the console temperature hasexceeded a preset value. The HEATERS ONindicator is the right indicator. When it isilluminated, the heaters in the console are on.

VITAL POWER FEEDER CIRCUITBREAKER STATUS Section

The illumination of an indicator in thissection of the panel shows that a particularCB is open. The layout of the indicators isby SWBD. The indicators are limited to only thevital CBs.

The LAMP TEST push-button switch islocated on the lower right corner. It is used to testthe indicator lights on the A-3 panel only.

SSDG PANEL (A-4)

The SSDG panel (A-4) is the middle left panel(fig. 8-16). It is subdivided into four columns.The columns are labeled PRIME MOVER (4, 2,3, and 1). Each column is identical, one foreach SSDG. The indicators from top to bottomare as follows:

MANIFOLD PRESS meter monitors thepressure of the fuel in the manifold.

FUEL RETURN HIGH TEMP indicatoris at the top and to the right of the meter.It indicates the temperature of the fuelcoming out of the fuel cooler is above thepreset limit.

ACOUSTIC CELL FIRE WARNINGindicator is to the right of the high

temperature indicator. It indicates the UVsensor in the SSDG enclosure has detecteda fire.

FUEL PRESS FAILURE indicator is atthe bottom of the meter. It indicates thepressure in the manifold is below the presetlimit.

ENGINE SPEED meter monitors thespeed of the SSDG. It is sensed by thePMA mounted on the aft end of thegenerator rotor.

ENGINE TRIP indicator indicates theSSDG has been automatically shut downeither by the overspeed trip, low lube oilpressure, Halon release, or correctiveaction of the SCS.

RETURN TEMP meter monitors thetemperature of the lube oil returning to thesump.

SUPPLY HIGH TEMP indicator is at thetop and to the right of the meter. Itindicates the temperature of the lube oilgoing to the SSDG exceeds the preset limit.

SUMP LOW LEVEL indicator is themiddle indicator. It indicates the level ofthe lube oil sump is low.

SUPPLY PRESS meter monitors thepressure of the lube oil going to the SSDG.

SUPPLY LOW PRESS indicator is at thebottom of the meter. It indicates thepressure of the lube oil going to the SSDGis below the preset limit.

SSDG OUTPUT ANDDISTRIBUTION PANEL (A-5)

The SSDG OUTPUT AND DISTRIBUTIONpanel (A-5) is located in the center of the EPCC(fig. 8-17). This panel contains four identicalcolumns, one for each SSDG (4, 2, 3, and 1).The controls and indicators on this panel areused to monitor and control the output of thegenerator. The sections on this panel are themeter, governor control, voltage regulatorcontrol, and alarm acknowledge and processorgenerated alarm sections.

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Figure 8-16.—SSDG panel (A-4).

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Meter Section

The meters on this panel are used to monitorthe FREQUENCY, CURRENT, VOLTAGE,and POWER. These meters are directly wired tothe SWBD they monitor.

Governor Control Section

This section has two switch/indicators for thegovernor mode and the governor speed. TheGOVERNOR MODE switch/indicator controlsthe governor’s mode of operation. The GOVER-NOR SPEED switch controls the speed of theSSDG.

GOVERNOR MODE SWITCH.—The GOV-ERNOR MODE control switch and indicators arelocated to the left of the FREQUENCY meter.The lights are labeled ISOCHRONOUS andDROOP. The indicator light that is illuminatedindicates the mode of operation the governor isusing. In the ISOCHRONOUS mode, thegenerators maintain constant speed through loadchanges. In the DROOP mode, the speed of thegenerator set varies indirectly with the load. Belowthe indicator lights is the governor mode selectorswitch with two positions, ISOCHRONOUS andDROOP. It is used to select the governor’s modeof operation.

GOVERNOR SPEED SWITCH.—The GOV-ERNOR SPEED switch is located to the right ofthe FREQUENCY meter. It is a three-positionswitch, spring loaded to the center position. Whenthe switch is turned to the right or the INCREASEposition, it will cause the frequency of thegenerator to increase. When it is turned to the leftor the DECREASE position, it will cause thefrequency of the generator to decrease.

Voltage Regulator Control Section

The voltage regulator control section hasthree separate controls for the VOLTAGEREGULATOR MODE, the VOLTAGE REGU-LATOR AUTO ADJUST, and the VOLTAGEREGULATOR. The voltage regulator modecontrols the voltage regulator’s mode of operation.

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The voltage regulator auto adjust section controlsthe output of the generator voltage. The voltageregulator displays the type of voltage regulationused.

VOLTAGE REGULATOR MODE.—TheVOLTAGE REGULATOR MODE control indi-cators and switch are located to the left ofthe VOLTAGE meter. The lights are labeledDIFFERENTIAL and DROOP. The indicatorlight that is illuminated indicates the mode ofoperation the voltage regulator is using. When theDIFFERENTIAL mode light is illuminated, thegenerators maintain constant voltage through loadchanges. When the DROOP mode light isilluminated, the voltage of the generator setvaries indirectly with the load. Below the indicatorlights is the VOLTAGE REGULATOR MODEselector switch with two positions, DIFFEREN-TIAL and DROOP. This switch is used to selectthe voltage regulator’s mode of operation.

VOLTAGE REGULATOR AUTO ADJUST.—The VOLTAGE REGULATOR AUTO ADJUSTswitch is located to the right of the VOLTAGEmeter. It is a three-position switch, springloaded to the center position. When the switchis turned to the right or the RAISE position, itwill cause the voltage of the generators to increase.When the switch is turned to the left or theLOWER position, it will cause the voltage of thegenerators to decrease.

VOLTAGE REGULATOR.—The VOLTAGEREGULATOR indicators are located below theVOLTAGE REGULATOR AUTO ADJUSTswitch. The two indicator lights are labeled AUTOand MANUAL. The No. 4 SSDG also has a three-position selector switch. This switch functionsthe same as those in the same sections on the DDconsoles. The switch positions are labeled AUTO,DEENERGIZE, and MANUAL. This switch isused to control the type of voltage regulation.

Alarm Acknowledge and ProcessorGenerated Alarm Section

This section has two push-button switches,ALARM ACKNOWLEDGE and PROCESSORGENERATED ALARM.

When the ALARM ACKNOWLEDGE push-button switch is depressed after an alarm has beenreceived, the audible alarm will be silenced andthe flashing alarm indicator will change to a steadylight.

The PROCESSOR GENERATED ALARMwill occur when an out-of-tolerance conditionoccurs on equipment being monitored; an alarmis generated in the EPCC by the fault alarmcircuit. The status of the parameter is also checkedby the processor, a special-purpose computer,located in the EPCC. The processor compares thesignal with the alarm set value to determine if anout-of-tolerance condition exists. If the conditiondoes exist, the processor checks the equipmentfault alarm circuitry to determine if the faultalarm has been actuated. If the fault alarm hasnot been actuated but an alarm condition isdetected by the processor, the PROCESSORGENERATED ALARM indicator flashes and anaudible alarm sounds.

SYSTEM OUTPUT MONITOR/GROUND STATUS TEST/GENERATOR 4 PANEL (A-6)

The SYSTEM OUTPUT MONITOR/GROUND STATUS TEST/GENERATOR 4panel (A-6) is the middle right panel (fig. 8-18).It contains the system output monitor section,ground status test section, generator 4, andaudible alarm test switches and rheostat.

SYSTEM OUTPUT MONITOR Section

The SYSTEM OUTPUT MONITOR sectioncontains three meters (FREQUENCY, CURRENT,and VOLTAGE) and two selector switches. Thetop meter and bottom meter inputs are controlledby the bottom selector switch. The selector switchallows the operator to select which input isapplied to the FREQUENCY and VOLTAGE

meters, one of the bus ties, or shore power. Themiddle meter is a CURRENT meter. The inputto this meter is controlled by the upper switch.This selector switch allows the operator to selectwhich bus tie is connected to the CURRENTmeter.

GROUND STATUS TEST Section

The GROUND STATUS TEST section hasthree indicator lights labeled PHASE, and fromleft to right, A, B, and C. These indicators arenormally of equal brilliancy. To the right ofthe indicator lights is a rotary switch labeledSWITCHBOARD. This switch has four positions,one for each SWBD. At the bottom of thissection is a push-button switch labeled BUSGROUND TEST. When this switch is depressed,it connects the selected SWBD to the relatedindicator lights for testing that SWBD for agrounded condition. A ground will be indicatedby one of the lights going out and the other twolights glowing brighter. The light that goes outis the phase that is grounded.

GENERATOR 4 Section

The GENERATOR 4 section has a rheostatand is labeled VOLTAGE REGULATORMANUAL ADJUST. The rheostat is used toadjust the voltage on the No. 4 SSDG when it isin manual voltage regulation.

Audible Test Switchesand Rheostat Section

The audible test switches and rheostat sectionis located at the bottom of the panel. It containstwo push-button switches and a rheostat. Thepush-button switches are for testing the horn andbell. They are labeled HORN TEST and BELLTEST. The rheostat is for controlling the volumeof the audible tones.

The LAMP TEST push-button switch islocated at the bottom to the left of the testswtiches. It is used to test the indicator lights onthe A-4, A-5, and A-6 panels only.

SSDG PANEL (A-7)

The SSDG panel (A-7) is the bottom left panel(fig. 8-19). It is subdivided into four columns. Thecolumns are labeled PRIME MOVER (4, 2, 3, and1). Each column is identical, one for each SSDG.We will describe a column from the top to thebottom.

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Figure 8-18.—SYSTEM OUTPUT MONITOR/GROUND STATUS TEST/GENERATOR 4 panel (A-6).

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Figure 8-19.—SSDG panel (A-7).

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Jacket Cooling Water System Section

The jacket cooling water system circulatesfresh water in the diesel engine jacket. The wateris circulated by an engine-driven pump. The topmeter, the JACKET WTR OUTLET TEMP,provides a continuous display of the jacket watertemperature. The indicator at the top of the meteris the JACKET WATER OUTLET TMP HIGH.It will illuminate when the jacket water outlettemperature exceeds the preset limit. The otherindicator for the jacket water system is theJACKET WTR EXPANSION TANK LOWLEVEL indicator. It will illuminate when thewater level in the expansion tank falls below thepredetermined level.

Seawater System Section

Each SSDG is provided with a motor-drivenseawater circulating pump. The seawater systemis used to cool the jacket water system. Thefollowing alarm indicators and switch/indicatorsare for the seawater system:

SALT WATER LOW SUPPLY PRES-SURE alarm indicates the pressure in theseawater system is below the preset limit.

SALT WATER PUMP RUNNING indi-cator indicates the seawater pump isrunning.

OVERBD V OPEN/CLOSED indicator/switch is used to control the seawateroverboard discharge valve. The upperindicator shows the actual valve position.The lower indicator/switch is used tocontrol the valve from the EPCC.

SUCTION V OPEN/CLOSED indicator/switch is used to control the seawater pumpsuction valve. The upper indicator showsthe actual valve position. The lowerindicator/switch is used to control thevalve from the EPCC.

Exhaust Temperature Section

Diesel engine exhaust temperature is measuredby thermocouples mounted in each cylinderexhaust manifold and at the outlet of the exhaustmanifold. The output from the thermocouples aredisplayed on the meter labeled EXHAUSTTEMP. The switch to the right of the meter islabeled CYLINDER. It is used to select which ofthe 16 cylinders will be displayed on the meter.When any cylinder temperature reaches apredetermined level, the EXHAUST HIGHTEMP alarm/indicator will illuminate.

The LAMP TEST push-button switch is locatedon the lower right corner of the panel. It is usedto test the indicator lights on the A-7 panel only.

SSDG OUTPUT ANDDISTRIBUTION PANEL (A-8)

The SSDG OUTPUT AND DISTRIBUTIONpanel (A-8) is the bottom center panel (fig. 8-20).

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Figure 8-20.—SSDG OUTPUT AND DISTRIBUTION panel (A-8).

It displays a mimic bus depicting the physicalarrangement of the electric plant and BTs. Thepanel is divided into four sections, one for eachSSDG (4, 2, 3, and 1). Each section is the same.The panel contains the controls and indicatorsused to start and stop the SSDG and to controlthe opening and closing of the generator, BTs,and load shedding CB; it also has an indicatorindicating the SWBD control location.

Engine Starting and Stopping Section

describe the switch/indicators from the left toright, and then down.

MANUAL START/AUTO START is asplit-legend, alternate-action push-buttonswitch. When the MANUAL START posi-tion of the indicator is illuminated, theoperator must start the SSDG. If theAUTO START position of the indicatoris illuminated, the control of starting theSSDG is given to the SCS.

The engine starting and stopping section is PRIME MOVER 1 START is a pushlocated across the top of each section. We will button used to start the SSDG. It is

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enabled when the MANUAL START/AUTO START switch is in the MANUALSTART position.

GENERATOR RUNNING AND UP TOVOLTAGE indicates the generator is upto speed and up to voltage.

PRIMER MOVER FAILS TO STARTindicates the SSDG failed to start in therequired time period.

PRIME MOVER 1 STOP is a pushbutton used to stop the SSDG.

GEN SET UP FOR AUTO OPERindicates all the systems and the SWBD areset up for operation of the SSDG in eitherthe manual or auto mode.

STARTING AIR LOW PRESS indicatesthe starting air pressure to the SSDG isbelow the preset limit.

EMER STOP is a guarded push-buttonswitch. Depressing this switch causes fueland combustion air to be shut off, thusstopping the SSDG.

Circuit Breaker Control andSwitchboard Control Sections

Control switches are provided for eachgenerator, BT, and load shedding CB. Thecontrol switches for the generator CBs and BTBsare four-position rotary switches. They arespring returned from the outermost positionon each side to the adjacent innermost position.The two outermost positions are labeled TRIPand CLOSE. When the switch is placed in these

positions, the indicated signal will be sent to thebreaker. The two inner positions of the switch setup a circuit through auxiliary contacts on thebreaker. The CB POSN DIFF FROM SWBDindicator will illuminate if the switch is in anyposition different than the actual breakerposition. To operate a generator CB or BTB, turnthe switch to the desired extreme outermostposition, TRIP or CLOSE. Then release theswitch handle, which returns to the adjacentinnermost position. If the CB POSN DIFF FROMSWBD indicator is illuminated, the switch mustbe turned to the other innermost position. Thiswill make the switch agree with the CB.

The Nos. 1, 2, and 3 SWBDs have an indicatorfor local and remote control. When the LOCALCONTROL indicator is illuminated, control ofthe SWBD is at the SWBD. When the REMOTECONTROL indicator is illuminated, control ofthe SWBD is at the EPCC.

The LOAD SHEDDING CB control switchis a three-position switch, spring loaded to thecenter position. The left position is labeled TRIPand the right position is labeled CLOSE. A blueLOAD SHEDDING CB CLOSED indicator light

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is located above each CB control switch. When SHORE POWER/GENERATORSit is illuminated, the LOAD SHEDDING CB is PANEL (A-9)closed.

The SHORE POWER/GENERATORS panel(A-9) is the bottom right panel (fig. 8-21).It has two sections, shore power and gener-ators.

SHORE POWER Section

This section is located across the top of thepanel. It has indicator lights for the shore powercircuit breakers, a control switch for the breakers,and a meter for current. The indicator lights willonly illuminate when the respective circuit breaker

Figure 8-21.—SHORE POWER/GENERATORS panel (A-9).

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is closed. The control switch can only trip theshore power circuit breakers. The CURRENTmeter provides a continuous display of theamperes the ship is drawing from shorepower.

GENERATORS Section

This section is located across the bottom ofthe panel. It is subdivided into four identicalcolumns, one for each SSDG (4, 2, 3, and 1). Wewill cover a column from the top to the bottom.The columns contain the following indicators,meter, and switch.

COOLING AIR (EXHAUST) HIGHTEMP indicates the air exiting thegenerator cooler is above the presetlimit.

FORWARD BEARING HIGH TEMPindicates the temperature of the bearing isabove the preset limit.

AFT BEARING HIGH TEMP indicatesthe temperature of the bearing is above thepreset limit.

STATOR TEMPERATURE meter providescontinuous temperature monitoring of thegenerator windings.

PHASE rotary switch is used to selectthe input to the stator temperaturemeter. It has four positions, TEST, A, B,and C.

SPACE HEATER ON indicator/switchcontrols the space heater in the generator.The upper indicator shows the actual status

of the heater. The lower indicator/switchcontrols the heater from the EPCC.

The LAMP TEST push-button switch islocated on the upper right corner of the panel.It is used to test the indicator lights on the A-8and A-9 panels only.

ELECTRIC PLANT CONTROLCONSOLE (DDG-51 CLASS SHIP)

The EPCC (fig. 8-22) on the DDG-51class ship is part of the machinery controlsystem (MCS). It contains the controls andindicators needed to remotely operate andmonitor the SSGTGs and power distributionsystem. It exchanges information with the restof the MCS.

The EPCC is subdivided into two panels, theoutput monitor panel (A-1) and the distributionpanel (A-2).

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Figure 8-22.—EPCC (DDG-51 class ships).

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OUTPUT MONITOR PANEL (A-1)

The output monitor panel (A-1) (fig. 8-23) isthe upper panel. It contains the console, summaryalarms, plasma display, power generation anddistribution, system output, and synchronizationsections.

CONSOLE Section

This section is located at the top left side ofthe panel. It has the following controls andindicators:

HORN test push-button switch is used totest the audible alarm.

BUZZER test push-button switch is usedto test the audible alarm.

VOLUME control knob is used to controlthe audible alarm volume.

TEMP HIGH indicator indicates thetemperature inside the console is above thepreset limit.

UPS IN USE indicator indicates theconsole is operating on emergency batterypower.

SUMMARY ALARMS Section

This section is located at the top of the paneland to the right of the console section. Itsindicators are summary alarms for the 60 HZPOWER and for each SSGTG.

The 60 HZ POWER indicator is used toindicate that one of the following events hasoccurred:

A generator voltage regulator has shiftedfrom the primary regulator to the backupregulator.

A generator has high current.

A SWBD has high ground voltage.

The SSGTG portion contains three indicatorlights, one for each SSGTG. The indicator isused to indicate that the following event(s) hasoccurred:

Engine control on battery power

Start air temperature highGenerator set backup relief valve opened.PRI/RSV halon power failureEngine speed highEngine vibration highEngine lube oil supply temperature high

Generator set firemain backup on

Engine inlet air icing

Blow-in door open

Engine inlet-to-atmosphere differentialpressure high

Engine module temperature high

Engine module Halon actuated

Generator cooling air temperature high

Generator stator phase A temperature high

Generator stator phase B temperature high

Generator stator phase C temperature high

Generator front end bearing temperaturehigh

Generator aft end bearing temperaturehigh

Additionally, the following conditions willcause the SSGTG indicator to illuminate.

Engine fuel oil gravity feed tank level high

Engine fuel oil gravity feed tank level low

GTG 3 head tank level high

GTG 3 head tank level low

Generator No. 3 fuel service heatertemperature high

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PLASMA DISPLAY Section

This section is an alphanumeric displaydevice. The plasma display provides the EPCCoperator with machinery status and alarminformation required to control and monitorthe electrical equipment. The plasma displaycan be operated in two different modes,status/alarm or summary group status. Thebottom portion of the display is used forDDI display in both modes. The modes arecontrolled by the plasma keyboard. The plasmadisplay works the same as the other plasmadisplays described in chapter 7.

POWER GENERATION ANDDISTRIBUTION Section

This section is divided into three identicalsections, one for each SSGTG. The sections arelabeled from left to right SSGTG 3, SSGTG2, andSSGTG1. We will discuss the No. 3 SSGTGsection. The top indicator is labeled TURBGEN 3 INLET TEMP HIGH. It indicates thetemperature of the air at the inlet exceeds thepreset limit. The next two indicators are labeledLUBO SPLY PRESS LOW. The left indicator isGEN. This indicator will illuminate when the LOpressure on the generator and reduction gearssystem is below the preset limit. The right

indicator, TURBINE, is for the LO pressure onthe GTE. It indicates the pressure on the GTE isbelow the preset limit.

METERS.—The meters from top to bottomare POWER, CURRENT, VOLTAGE, and FRE-QUENCY. The power, current, and frequencymeters are 270-degree LED meters. The voltagemeter is also a 270-degree LED meter, but itcontains a three-digit LED display on the meter.The meters are black in color and the parameterarea illuminates red in color. Red area increasesaround the 270-degree arch as the parameterincreases.

REGULATOR MODE.—The REGULATORMODE selector switch/indicators are located tothe right of the VOLTAGE meter. The voltageregulator mode switch/indicators are DIFF,DROOP, and MANUAL. The mode that isselected will have its respective indicator illumi-nated. The rotary switch, below the switch/indicators, is used to RAISE or LOWER thevoltage of the generator. It is spring loaded to thecenter position.

GOVERNOR MODE.—The GOVERNORMODE selector switch/indicators are locatedto the right of the FREQUENCY meter. Thegovernor mode switch/indicators are ISO andDROOP. The mode that is selected will have itsrespective indicator illuminated. The rotary switchis used to LOWER or RAISE the frequency of

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the generator. It is spring loaded to the centerposition.

SYSTEM OUTPUT Section

This section has a VOLTAGE meter and aSOURCE switch. The VOLTAGE meter is thesame as the voltage meters on the powergeneration and distribution section. The SOURCEswitch is used to select the input, a bus tie or abus, to the meter.

SYNCHRONIZATION Section

This section has a SYNCHROSCOPE meteron this panel, and the selector switch is locatedon the A-2 panel. The synchroscope functions thesame as the synchroscopes on the FFG console.

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Figu

re 8

-24.

—D

istr

ibut

ion

pane

l (A

-2).

DISTRIBUTION PANEL (A-2) CIRCUIT BREAKER CONTROLS.—The

The distribution panel (A-2) (fig. 8-24) is thelower panel. It contains the air conditioning(A/C), alarm acknowledge, lamp test, SWBD,shore power, load shedding, start air, gas turbinecontrol, and synchronization sections.

AIR COND PLANTS Section

This section has two subsections. ThePOWER section has a RESTR push-buttonswitch. It is used to restore power to A/C plants1, 2, 3, and 4. The other subsection is RESTART.It has four push-button switches, one for eachA/C plant. When a switch is illuminated, it canbe used to restart the indicated A/C plant.

top switch/indicators are for the GBs. Whenthe GEN 3 CB CLOSE indicator is illumi-nated, the breaker is closed. When the GEN3 CB OPEN switch/indicator is depressed, itwill open the CB and cause the indicatorto illuminate. When the GEN 3 CB CLOSEswitch/indicator is depressed, it will send aclose command to the GB and the indicatorwill illuminate. The BT CB switch/indicatorsfunction the same as the GB switch/indicators.A typical label for a BT is 3S-1S BT CBCLOSE and 3S-1S BT CB OPEN. Each breakerhas two switch/indicators.

SWITCHBOARD CONTROLS.—The SWBDsection has three indicator lights. The leftindicator is LOCAL CONTROL. It indicates thatthe control of that SWBD’s breakers is at theSWBD. The other two indicators are under thelabel OUT OF LIMIT. The left indicator is forVOLTAGE. The right is for FREQ. Theappropriate indicator will illuminate when thevoltage or frequency of the related SWBD is notwithin the required limits.

Alarm Acknowledge Section

This section has the ALARM ACK push-button switch. When it is depressed, thefollowing events will occur:

The audible alarms will be silenced.

The alarm indicator will go to a steadystate.

The plasma display will indicate acknowl-edge.

Lamp Test Section

This section has the LAMP TEST push-buttonswitch. When it is depressed, all indicator lightswill illuminate and all LED meter segment lightswill indicate full scale.

Switchboard Section

This section is the upper portion of the lowerpanel. It displays a mimic bus depicting thephysical arrangement of the electric plant and BTs.It has the controls for the GBs and the SWBDs.

SHORE POWER Section

This section has three indicators and oneswitch/indicator. The left indicator is CURRENTHIGH. It indicates the current on shorepower is above the preset limit. The middleindicator is ANY CB CLOSED. It indicatesthat a shore power circuit breaker is closed.The right indicator is AVAIL. It indicatesthe shore power cables are connected andenergized up to the SWBD. The switch/indicatoris ALL CB OPEN. It indicates all shore power

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circuit breakers are open. Depressing this switchcauses all shore power CBs to open.

LOAD SHEDDING Section

This section contains two indicators and twoswitch/indicators. The left side of the section isfor STAGE 2. The right side is for STAGE 1.Each side has an indicator and a switch/indicator.The indicator labeled OCCURRED will illuminatewhen load shedding has occurred in its respectivestage. When depressed, the switch/indicatorlabeled INIT will illuminate and will initiate itsstage of load shedding.

START AIR Section

This section is located on the lower portionof the A-2 panel. It has two switch/indicators.The upper switch/indicator is for HIGH PRESSair starting of the SSGTG. The lower switch/indicator is for BLEED air starting of the SSGTG.

GAS TURBINE Section

This section is located across the lowerportion of the A-2 panel. It has three identicalsections, one for each SSGTG. The left indicatoris for LOCAL CONTROL. It indicates thecontrol of the SSGTG is not available from theEPCC. The middle indicator is ENGINE STARTUNAVAILABLE. It indicates the SSGTG is notavailable to start. The switch/indicator under thisindicator is ON. It indicates the GTE is runningor in start sequence. The push button is used toinitiate a GTE start sequence. The bottomswitch/indicator is OFF. It indicates the GTE issecured or in a stop sequence. The two switch/indicators under the BLEED AIR heading arelabeled VALVE OPEN and VALVE CLOSED.These switch/indicators function like the GBcontrol switch/indicators. The last indicator inthis section is MODULE FIRE. It indicates a firehas been detected in the SSGTG gas turbineenclosure. The last two switch/indicators areguarded push-button switch/indicators. The topone is for PRI HALON RLSE. It is used toactivate the primary Halon release. It willilluminate when Halon has been released from anylocation. The bottom switch/indicator is for RSVHALON RLSE. It functions the same as theprimary switch/indicator.

Synchronization Section

This section is located on the right side of thepanel. It contains a switch/indicator and a rotaryswitch. The switch/indicator, SYNC MON BY-PASS, is used to bypass the synchronizingmonitor in the SWBD. The rotary switch is a ten-position switch. It is used to select the circuit

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breaker the synchronizing monitor circuit ismonitoring.

SUMMARY

In this chapter we described the controlsand indicators of the various class ship’sEPCCs. The description of the controls providedin this chapter will help you understandwhat happens when you depress or turna control switch. The description of theindicators in this chapter show you the con-dition or event occurring if that indicatorilluminates. As a reminder, always consultthe EOSS for the proper operation of theseconsoles. For additional information on theseconsoles, refer to Electric Plant Control Equip-ment, Volume 1, NAVSEA S9300-AU-MMA-010, for the CG-class ships; Electric PlantControl Equipment, Volume 1, NAVSEAS9234-BS-MMO-010, for the DD-class ships;DDG-51 Machinery Control System, ElectricPlant Control Console, Volume 1, NAVSEA9202-AT-MMF-010/16331, for the DDG-51class ships; and Electric Plant Control Console,Volume 1 of 6, NAVSEA 0967-LP-608-4010,for the FFG-class ships.

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CHAPTER 9

AUXILIARY EQUIPMENT AND CONSOLES

Up to this point we have discussed theconstruction, indicators, and controls of the mainpropulsion and electric plant consoles. Alsolocated in the central control station (CCS) of gasturbine-powered ships are important auxiliaryequipment and consoles. This equipment allowsthe CCS watches to monitor and/or controlvarious auxiliary and damage control systemsfrom a central, remote location and provides forthe automatic logging of vital parameters andinformation.

The watches in CCS are responsible foroperating and monitoring the ship’s engineeringplant. For this reason, they must also be familiarwith the operation of the auxiliary equipment andconsoles. This equipment includes the followingunits:

Propulsion and auxiliary machinery infor-mation system equipment (PAMISE)

Fuel system control console (FSCC)

Auxiliary control console (ACC)

Damage control console (DCC)

Bell and data loggers

Repair station console (RSC)

Data multiplex system (DMS)

This equipment allows the number of watchstanders for the entire engineering plant to be keptto a minimum. Alarms and status indicators keepthe CCS operators aware of plant conditions,digital displays and meters show them the vitalparameters, and switches and push buttons allowthem to control the equipment from a centrallocation.

In this chapter, we will first discuss the opera-tion and control of the auxiliary equipment foundon DD-963/993 and CG-47 class ships. We will

then describe the auxiliary equipment found onFFG-7 and DDG-51 class ships. We will describethe indicators and controls associated with eachconsole and related watch-stander responsibilities.

After reading this chapter and completing theassociated nonresident training course (NRTC),you should understand the basic functions of theauxiliary equipment and consoles of gas turbineships. You should also recognize the respon-sibilities of each watch stander as they relate tothe operation and control of this equipment.

The material in this chapter is for trainingpurposes only. It is not meant to replace theEngineering Operational Sequencing System(EOSS) or technical manuals. With the help ofan experienced Gas Turbine Systems Technician(Electrical) (GSE) or Gas Turbine SystemsTechnician (Mechanical) (GSM) and by using theknowledge gained in this chapter, following theEOSS, and completing Personnel QualificationStandards (PQS) requirements, you should haveno problem qualifying in all aspects of theauxiliary consoles in CCS.

PROPULSION AND AUXILIARYMACHINERY INFORMATION

SYSTEM EQUIPMENT

The propulsion and auxiliary machinery infor-mation system equipment (PAMISE) receives,evaluates, and logs the performance parametersof the propulsion plant, electric plant, and selectedship’s auxiliaries. The PAMISE consists of thecentral information system equipment (CISE), adigital computer, signal conditioning equipment(S/CE), and two line printers. The CISE is locatedin CCS. A set of S/CE is located in each of themain engine rooms (MERs). Another set is locatedin CCS. Each signal conditioner functions as acentral gathering point for sensory inputs. Itprocesses these inputs so that they will becompatible for computer use and performs alarmsignal generation as needed.

9-1

Figure 9-1.—DD monitor and control panel.

CENTRAL INFORMATIONSYSTEM EQUIPMENT

Located in CCS, the CISE is composed of theexecutive control unit (ECU), S/CE No. 1, a tapereader, two line printers, and associated powersupplies.

Executive Control Unit

The ECU is the main component of thesystem. It is a special purpose computer thatcollects, analyzes, and distributes the data that willbe used by operators of the engineering plant. TheECU gathers data from the ship’s equipment bycollecting inputs from the S/CEs, propulsion andauxiliary machinery control equipment (PAMCE),and electric plant control console (EPCC).The data are delivered to operators in the formof alarms, status indicators, printed logs, anddigital displays. No propulsion plant control isaccomplished by the ECU.

The ECU has a monitor and control panel thatallows for operator logging requests, demanddisplay information, and date/time information.This control panel is mounted on the front of theECU. Another control panel, the ECU test panel,is located on the rear of the ECU. This panel isused for computer maintenance.

Monitor and Control Panel

On DD-class ships, the monitor and controlpanel of the CISE is divided into seven sections.(See fig. 9-1.) (On CG-class ships, this panel isdivided into six sections.) The sections of themonitor and control panel are as follows:

CALENDAR CLOCK GMT

DEMAND DISPLAY

MALFUNCTION

TREND LOGGING (not applicable on theCG)

PRINT INTERVAL

ALARM STATUS REVIEW

POWER

CALENDAR CLOCK GMT SECTION.—The CALENDAR CLOCK GMT section (A) con-tains a Julian calendar display, a Greenwichmean time (GMT) digital clock, a three-positionrotary switch, a set of four thumbwheels, and a

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spring-loaded, two-position toggle switch. Thecalendar information is displayed in the lightemitting diode (LED) windows under the headingsDAY, HOUR, and SEC. The Julian date iscontinuously displayed in the LED windows underthe heading DAY.

NOTE

Julian dates are numerically sequentialdays of the year. For example, January 1is day 001; January 2 is day 002; December31 is day 365, except in a leap year whenit is day 366.

Under the headings HOUR and SEC, theGMT clock displays the time of day in hours andseconds in the LED windows in the 24-hour clockformat. This clock allows logging to be consistentfrom time zone to time zone without the operatorshaving to note time changes. The rotary switchunder the heading SET FUNCTION has threepositions: DAY, HOUR, and SEC. The operatoruses this switch to select a change in the Juliandate, the hour, or the seconds shown in the LEDwindows. The thumbwheels labeled SET VALUEwork in conjunction with the spring-loadedtoggle switch labeled SET. The operator uses thethumbwheels to dial up the desired data to beshown in the LED windows and raises the toggleswitch to the SET position to load the data intothe computer.

DEMAND DISPLAY SECTION.—The DE-MAND DISPLAY section (B) contains a demanddisplay indicator (DDI), a set of three thumb-wheels, and a push-button switch. The DDIdisplay allows operators to display a selectedparameter by setting up the address on thethumbwheels. The display on the CG-class shipswill also show the unit of measurement of theselected address. You can select and displayany plant parameter as long as it has a DDIaddress.

A PRINT push button (DEMAND DISPLAYPRINT on the CG) is also associated withthe DDI. When depressed, this push buttoncauses the parameter selected by the addressto be printed on the data log. The DDI indexalso has special addresses that allow groupprintouts to be printed on the data log. Print-outs of groups include areas such as powertrain, fuel oil, lube oil, GTM, GTG, and 60-Hz

distribution. Consult your ship’s DDI index forthe addresses of these printouts.

MALFUNCTION SECTION.—The MAL-FUNCTION section (C) has ten alarm indicators,an alarm/status test switch, and an alarmacknowledge push button. The MALFUNCTIONsection on the CG also has a alarm volumecontrol knob. The alarm indicators illuminateeither red or amber to alert the operator whenmalfunctions occur within the PAMISE system.The first alarm indicator, labeled ICC-S/CE 1,illuminates red to indicate a fault in theinformation center console (ICC) No. 1 or inthe S/CE No. 1. The second alarm indicator,labeled ICC NO. 2, illuminates red to indicatea fault in the ICC No. 2. The third alarmindicator, labeled S/CE NO. 2, illuminatesred when a fault in the S/CE No. 2 occurs.The fourth alarm indicator, labeled S/CENO. 3, illuminates red when a fault in the S/CENo. 3 occurs. The fifth alarm indicator islabeled POWER SUPPLY. It illuminates red toindicate a fault in one of the engineering controland surveillance system (ECSS) power supplies.The sixth alarm indicator is labeled CLOCK NOTSET. It illuminates amber when the calenderclock has not reset after a loss of ECU power.The seventh alarm indicator, labeled BELLLOGGER, illuminates amber when the belllogger is not on line or when a fault occurs.The eighth alarm indicator, labeled DATALOGGER, illuminates amber when the datalogger is not on line or when a fault occurs. Theninth alarm indicator, labeled BELL LOGGERPAPER LOW, illuminates amber to indicate thatthere are about ten blank sheets of paperremaining in the bell logger. The last alarmindicator, labeled DATA LOGGER PAPERLOW, illuminates amber to indicate that there are

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about ten blank sheets of paper remaining in thedata logger.

When any of these malfunctions occur, theappropriate alarm flashes and a buzzer sounds.Depressing the ALARM ACKNOWLEDGE pushbutton (labeled ACK on the CG) will silence thebuzzer and cause the indicator to illuminatesteadily. The alarm indicator extinguishes whenthe malfunction clears. On the CG, the volumeof the buzzer can be adjusted by rotating theALARM VOLUME control knob (this featuredoes not exist on the DD). The three-positiontoggle switch allows the operator to test the alarmand status indicators. The three positions of theswitch are labeled STATUS, OFF, and ALARM.

TREND LOGGING SECTION.—The TRENDLOGGING section (D) of the CISE (notapplicable on the CG) allows certain parametersto be printed onto the data log when a selectedlimit is exceeded. The TREND LOGGING sectionhas three groups of thumbwheels, three pushbuttons, and a two-position toggle switch. Thethree thumbwheel groups are labeled FUNC-TION, THRESHOLD, and ADDRESS. TheFUNCTION thumbwheels allow the operator toselect 1 of 16 trend logging memory locations. TheTHRESHOLD thumbwheel allows the operator

to preset the amount of variance of the parameterbefore printout occurs. This range is set between1 to 10 percent of full scale. The ADDRESSthumbwheels allow the operator to select theparameter to be trend logged.

The three push buttons labeled LOAD,INHIBIT, and PRINT are used when the operatoris setting, securing, and reviewing the trendlogging. The two-position switch, labeled ON andOFF, is used to turn on or turn off trend loggingfunctions. The three push buttons are used toprogram the digital computer for trend logging.After placing the toggle switch to the ONposition and setting all the thumbwheels, theoperator depresses the LOAD push button toprogram the selected parameter into trend logging.The PRINT push button signals the data loggerto print out all active trend logging parameters.The INHIBIT push button is used to stop thetrend logging of a selected parameter. Trendlogging is useful for monitoring recently repairedequipment to establish trend data. It is also usefulfor logging of data during full power andeconomy trials.

PRINT INTERVAL SECTION.—The PRINTINTERVAL section (E) contains a two-positionswitch labeled 1 HOUR and 4 HOUR. This switchsets the interval when the data logger willautomatically print a complete plant printout.

ALARM STATUS REVIEW SECTION.—The ALARM STATUS REVIEW section (F) con-tains a push-button switch labeled PRINT. Whendepressed, the switch commands the data loggerto print out all active alarms in the ECSS. Thisfunction is useful to the engineering officer of thewatch (EOOW) when reviewing the active alarmsand out-of-limits parameters before relieving thewatch.

POWER SECTION.—The POWER section(G) consists of three status indicators, under theheading NORMAL, and three alarm indicators,under the heading EMERGENCY. These sixindicators allow the operator to monitor the statusof the power supplies in the PAMISE system. Thefirst indicator, labeled CISE, illuminates green toindicate the CISE is on normal ship’s service (SS)power. The second indicator, labeled CISE,illuminates red to indicate the CISE is on theuninterruptible power supply (UPS). The thirdindicator, labeled S/CE 2, illuminates green to

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Figure 9-2.—ECU test panel.

indicate the S/CE 2 is on normal SS power. Thefourth indicator, labeled S/CE NO. 2, illuminatesred to indicate the S/CE No. 2 is on UPS. Thefifth indicator, labeled S/CE 3, illuminates greento indicate the S/CE 3 is on normal SS power.The sixth indicator, labeled S/CE NO: 3,illuminates red to indicate the S/CE No. 3 is onUPS.

ECU Test Panel

The ECU test panel (fig. 9-2) is located insidethe CISE enclosure at the back of the CISEcabinet. The test panel is the primary interfaceto the ECU. The computer program (operatedonly by experienced GSEs) is loaded, run, andmaintained through this panel. The tape readerpanel (not shown) consists of a punched tapereader, two reels, and a two-position toggleswitch. The tape reader reads the ECSS programfrom a prepunched tape and loads the informa-tion into the memory core of the ECU.

CAUTION

The potential for causing malfunctions tothe entire ECSS network is very high if theequipment is operated by inexperiencedmaintenance personnel. A technician musthave a thorough understanding of theserial data networks, binary logic, anddigital equipment before operating theECU test panel. The operation of the ECUtest panel is beyond the scope of thistraining manual (TRAMAN) and will notbe covered.

SIGNAL CONDITIONING EQUIPMENT

Signal conditioning is done by the PAMISEat the S/CEs No. 1, No. 2, and No. 3. Thepurpose of these S/CEs is to convert all thesensory inputs into a common electrical range of0 to 10 volts dc. This conversion makes theinputs compatible with the rest of the ECSS. TheS/CE No. 1 monitors the electric plant. The

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S/CEs No. 2 and No. 3 monitor the mainpropulsion parameters. The five basic types ofsignal conditioning include

1. voltage signal conditioning,2. current signal conditioning,3. RTE signal conditioning,4. tachometer/frequency signal conditioning,

and5. wattmeter signal conditioning.

Each of these conditioners receives a sensoror external signal conditioner voltage, current,resistive, or frequency input, respectively. Theseinputs are converted to a 0- to 10-volt dc analogsignal and are processed by other electroniccircuitry of the ECSS for alarm generation, analogmeter display, and digital demand displays. ThePAMISE is designed so that discrete contactsensor signals are allowed to pass through thesignal conditioners unaffected.

The S/CE No. 1 is located in CCS and is apart of the CISE. The S/CE No. 2 is located inMER No. 2, and the S/CE No. 3 is located inMER No. 1. The S/CEs consist of a self-test panelthrough which the operator interfaces with theECSS electronics. All three units are basically thesame. We will, however, point out any significantdifferences throughout our discussion.

The self-test panel, shown in figure 9-3 forS/CE No. 1 and in figure 9-4 for S/CEs No. 2and No. 3, provides a method for the ECU togenerate self-test signals to various ECSS

equipment. This panel detects and displaysmalfunctions that occur within the ECSS andprovides for calibration of numerous circuitcards. The serial clock and the system canalso be reset at this panel. The self-test panelconsists of two sections labeled CALIBRATIONand MALFUNCTION. There is one self-testpanel on each of the S/CEs.

CALIBRATION Section

Refer to section A in figure 9-3. TheCALIBRATION section (A) consists of 18 LEDstatus indicators, two toggle switches, and a four-position rotary switch. The operator uses thissection to calibrate and adjust the set points onvarious circuit cards and to display the results ofthese adjustments. The LEDs on this section willvisually display the following information:

Type of calibration

Card out of slot or wrong slot status

Adjustment type

Card type

Results of adjustments

The first toggle switch is a two-position switchlabeled ADJ TYPE. The operator uses this switchto select the type of desired adjustment. Theadjustment type can be either ZERO or GAIN.The other toggle switch is a three-positionswitch. The operator uses this switch to turn the

Figure 9-3.—CISE self-test panel.

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Figure 9-4.—S/CE No. 2 and S/CE No. 3 self-test panel.

calibration panel on or off or to set it forautomatic. In the OFF position the calibrationpanel is disabled. The ON position allows theoperator to conduct adjustments and calibrationsof the various circuit cards. In the AUTOposition, the self-test panel allows for thegeneration of the self-test signal that is distributedto respective ECSS equipment. The four-positionrotary switch, labeled CKT UNDER CAL, allowsthe operator to select the circuit on the circuit cardto be tested.

MALFUNCTION Section

Refer to section B in figure 9-3. TheMALFUNCTION section (B) consists of 13 LEDstatus/alarm indicators, two push-button switchesand ten test jacks. This section provides theoperator with a visual indication of a malfunc-tion within the respective S/CE and the status ofthat system. The first six LED alarm indicatorsilluminate red to provide an indication of amalfunction in the S/CE (and the ECU for S/CENo. 1). The first LED, labeled SERIAL TRANS,indicates a malfunction in serial transmission. Thesecond LED, labeled CONT, indicates a break incontinuity in the S/CE. The third LED, labeledRACK NO. 0 (RACK NO. 2 on S/CEs No. 2 andNo. 3), indicates a malfunction in the respectivelogic rack. The fourth LED, labeled RACK NO. 1(labeled RACK NO. 3 on S/CEs No. 2 and No. 3),indicates a malfunction in the respective logicrack. The fifth LED, labeled OVER TEMP,indicates an overtemperature condition within theS/CE. The last LED in the first row, labeled ECU(labeled ALARM TEST on S/CEs No. 2 andNo. 3), indicates a malfunction in the ECU(indicates an alarm test on S/CEs No. 2 andNo. 3). The next three LED alarm indicators areunder the heading PWR SPLY NO. 1. These

indicators are labeled OVER TEMP, MALF, andON UPS. The first LED, labeled OVER TEMP,illuminates red to indicate an overtemperaturecondition in power supply No. 1. The secondLED, labeled MALF, illuminates to indicate amalfunction within power supply No. 1. The lastLED, labeled ON UPS, illuminates red to indicatethe power supply is on UPS. The next three LEDalarm indicators, under the heading PWR SPLYNO. 2, are identical to the LEDs discussed forpower supply No. 1. The first push-button switchlocated on the left side of the MALFUNCTIONsection is labeled NO GO RESET. The operatoruses this switch to clear the alarms on the CISEor respective S/CE. The other push-button switch,located on the right side of the MALFUNCTIONsection, is labeled SER CLK RESET (labeledALARM TEST on S/CEs No. 2 and No. 3). OnS/CE No. 1, the operator uses this push buttonto reset the serial clock. On S/CEs No. 2 and No.3, the operator uses this push button to conducttests of the S/CE alarms. The last LED indicator,labeled CSL PWR ON, illuminates red to indicatethat CISE console power is on. The 10 test jacksalong the bottom of the MALFUNCTIONsection allow the operator to read various datatest points within the S/CE.

BELL AND DATA LOGGERS

With all the equipment that must be monitoredand all the information that must be logged forfuture reference, it would be nearly impossible fora single operator to operate the console and writein a log. For this reason, two line printers aredesigned to receive information from an ECU andlog this information automatically. These lineprinters, the bell logger and the data logger, areidentical in design and operation. The onlydifference is in the information the printer is

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Figure 9-5.—Line printer.

commanded to print. Figure 9-5 shows a detailedview of one of the line printers.

Bell Logger

DATA LOGGING.—The data logging func-tion provides a record of the values and/or statusof all parameters of interest, either automatically,at selected time intervals, or upon operatordemand.

The bell logger prints only bell signals andreplies to those signals. Bell signals includerpm commands, pitch commands, and station incontrol status. All other logging functions aredone by the data logger.

ALARM LOGGING.—The alarm loggingfunction provides a permanent record of allchanges in alarm conditions as they occur, in-cluding both the alarm itself and its acknowledge-ment or reset.

Data Logger

The data logger is responsible for all loggingfunctions not performed by the bell logger. Thesefunctions include data logging, alarm logging,status change logging, trend logging, and demandprint logging.

STATUS CHANGE LOGGING.—The statuschange logging function records nonalarmingchanges in the discrete status of certain param-eters, such as pump on/off or pump fast/slow.

TREND LOGGING.—The trend loggingfunction provides continuous and automatic

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monitoring of up to 16 operator-selected param-eters and automatic printout if a parameter’svalue changes by more than a preset threshold(percentage).

DEMAND PRINT LOGGING.—The demandprint logging function provides the operator witha printout of an individual item or a group ofitems. To accomplish this, the operator dials upthe address for the information desired to beprinted and depresses the print push button.

If either of the line printers should fail tooperate properly, the remaining operable printerautomatically assumes all logging duties. In thisevent, the priorities for logging time, in order ofhighest to lowest, are as follows:

1. Bell logging2. Alarm logging3. Status change logging4. Trend logging5. Demand and data logging

The line printer control panel consists of twoindicator lights and three toggle switches. The firstindicator light, labeled POWER, illuminates greento indicate electrical power is applied to theprinter. The first switch is a two-position, spring-loaded toggle switch labeled FORM FEED. Itadvances the paper in the printer to the next page.The second indicator light, labeled ON-LINE,illuminates green to indicate the printer is ready

to receive data. The second switch, a two-positiontoggle switch labeled ON/OFF, turns the lineprinter on and off. The last switch is a two-position, spring-loaded toggle switch labeledTEST. This switch tests the printer operation byprinting out a test pattern when the operator raisesthe switch to the TEST position.

FUEL SYSTEMCONTROL EQUIPMENT

The fuel system control equipment is notconnected to any components of the ECSS. It is,however, an important electronic control consoleon the DD-963, DD-993, and CG-47 class ships;therefore, it is discussed in this chapter as is thedamage control console.

The major components of this system includethe fuel system control console (FSCC), two fueloil (FO) transfer local panels, and the JP-5 localcontrol panel. These consoles and panels are anintegrated information and control system. Theyprovide operator control and monitoring fromlocal and remote locations. In most cases, infor-mation generated by one unit of its system isshared by one or more of the other units.

FUEL SYSTEM CONTROL CONSOLE

An FSCC is shown in figure 9-6. This consoleprovides centralized monitoring and control of

Figure 9-6.—Fuel system control console.

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both the FO fill and transfer system and theJP-5 system. The front of the FSCC isdivided into two operator panels; the upperpanel is the FO fill and transfer control panel, andthe lower panel is the JP-5 control panel. (See alsofig. 9-7.) These panels have mimics of theassociated system, vertical reading meters todisplay system parameters and tank levels,indicator lights to display system status, andpush buttons to remotely control motor-operatedequipment.

The FSCC has three main cabinet assemblies(A1, A2, A3), the FO fill and transfer controlpanel (A4), and the JP-5 control panel (AS).Figure 9-7 shows the console outline andcomponent location. The three main cabinetassemblies contain the power supplies, electronichardware, and internal wiring of the FSCC.The FO fill and transfer control panel (A4)has the operator controls and indicators for

the FO fill and transfer system. The JP-5 controlpanel (A5) contains the operator controls andindicators for the JP-5 fill, transfer, and servicesystems.

The indicators and controls on the front panelsof the FSCC will be discussed first, from left toright and top to bottom; followed by the backpanels in the same left-to-right, top-to-bottomfashion. Refer to figure 9-7.

Fuel Oil Fill andTransfer Control Panel

The FO fill and transfer control panel will bediscussed in two sections. (See fig. 9-8.) The uppersection of the panel will be referred to as the fueloil fill section; the lower section as the fueloil transfer section. This system is shown in fullin figure 9-8 and in greater detail in figures 9-9

Figure 9-7.—Fuel system control console—component location.

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Figure 9-8.—Fuel oil fill and transfer panel.

Figure 9-9.—Fuel oil fill section.

9-11

Figure 9-10.—Fuel oil transfer section.

and 9-10. Refer to figures 9-8, 9-9, and 9-10 asyou read the description of each section.

Fuel Oil Fill Section

The FO fill section is shown in detail in figure9-9. The storage tanks are divided into six groupsof tanks known as banks. Each tank group isidentical except for the number of tanks in eachbank. The AFT PORT and AFT STBD storagebanks consist of three tanks. The MID PORT andMID STBD storage banks consist of four tanks.The FWD PORT and FWD STBD storage banksconsist of five tanks. Individual meters providetank level monitoring for each tank in the banks.Since all controls in each tank group are identical,only the AFT PORT storage tank group (A) willbe discussed.

appropriate storage tank. The first split-legendindicator is labeled OPEN and CLOSE. Thisindicator illuminates either open (green) or close(white) to reflect the position of the storage tankrecirculation valve. The last item in this section,labeled EXP TANK, is a drawing representing anexpansion/overflow tank. There are no meters orgauges for this tank on the FSCC.

The first alarm indicator in this section (A),labeled HIGH PRES, illuminates amber toindicate that the pressure in the receiving tank isgreater than 11 psig. The second alarm indicator,labeled HIGH SEA WATER, illuminates amberto indicate that the seawater level is 90 percentor greater in the receiving tank. This meansonly 10 percent of the receiving tank containsfuel, while the other tanks in the bank containseawater. The third alarm indicator, labeledFUEL OVERFLOW, illuminates amber toindicate that the last tank in the bank is90 percent full of fuel. The first meter in thissection is labeled RCVG TANK PRESS. Itdisplays the pressure of the receiving tank, whichis the first tank in the bank. The first indicatorcontrol push button, labeled CLOSE, drives themotor-operated fill valve in the close direction.It illuminates white when the valve is fullyclosed. The second indicator control push button,labeled OPEN, drives the motor-operated fillvalve in the open direction. It illuminates greenwhen the valve is fully open. There are threevertical meters that perform the same function butfor a different tank in the bank. These metersdisplay the fuel level (in gallons) for the

Located between the MID PORT storagetanks section and the FWD PORT storage tankssection are the controls and indicators for themain fill valve of the fuel transfer system. (Refernow to section B of fig. 9-9.) The first split-legendpush-button control under the heading AUTOMODE is labeled NORM and MAN FILL. In theNORM position, the storage bank fill valve forthe bank being filled will automatically close uponreceiving a FUEL OVERFLOW alarm. The mainfill valve will start to close if a HIGH PRES alarmis received. In the MAN FILL position, thestorage bank fill valve and the main fill valve mustbe controlled manually. The meter in this sectionis scaled from 0 to 100 percent to show the amountof opening of the main fill valve. The secondpush-button control, labeled OPEN, is used tomanually open the main fill valve. It illuminatesgreen when the valve is fully open. The third push-button control, labeled CLOSE, is used to closethe main fill valve. It illuminates white to indicatethe main fill valve is fully closed.

Located between the MID STBD storage tankssection and the FWD STBD storage tanks sectionare the controls and indicators for the biocidesystem. (Refer to section C of fig. 9-9.) We willnot describe this system because it has beendiscontinued and removed from most ships. Thissystem will not be indicated at all on the FSCCof newer classes of ships.

Fuel Oil Transfer Section

The FO transfer section shown in figure 9-10consists of two identical systems. The No. 1

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system serves the FWD FO service system and theNo. 2 system serves the AFT FO service system.The transfer system consists of a system of pipesfrom the storage tanks to the service tanks andthe associated equipment necessary to move fuelbetween them. Each transfer system contains twoservice tanks, a FO purifier, a purifier drain tank,a FO heater, and a transfer pump. Since eachsystem is identical, only the No. 2 fuel system willbe discussed. Refer to section A of figure 9-10.

This section has five split-legend indicatorslabeled OPEN and CLOSE. They illuminateeither OPEN or CLOSE to indicate the positionof the manually operated cross-connect valves.There are four indicator control push buttons inthis section. Two are labeled OPEN and two arelabeled CLOSE. These push buttons operate theservice tank fill valves. The OPEN push buttonilluminates green when the valve is fully open. TheCLOSE push button illuminates white when thevalve is fully closed. The three push-button alarmindicators, labeled HIGH PRES, illuminateamber to indicate that the purifier dischargepressure, the transfer pump discharge pressure,or the transfer pump inlet pressure has exceededthe preset limit. The first meter in this section islabeled AFT PORT SVCE TANK. This metermonitors the fuel level in the AFT PORT servicetank. The second meter, labeled AFT STBDSVCE TANK, monitors the FO level in the AFTSTBD service tank. The service tank meters arescaled to indicate fuel levels in gallons. The thirdmeter, labeled PURIF NO. 2 DISCH PRESS,monitors the discharge pressure of the No. 2 FOpurifier and is scaled in psig. The fourth meter,labeled PURIF NO. 2 INLET PRESS, monitorsthe inlet pressure of the No. 2 FO purifier andis scaled in psig. The fifth meter, labeled

HEATER NO. 2 TEMPERATURE, monitors theFO heater discharge temperature. It is scaled indegrees Fahrenheit. The sixth meter, labeled XFRPUMP NO. 2 DISCH PRESS, monitors thedischarge pressure of the No. 2 FO transfer pumpand is scaled in psig. The last meter, labeled XFRPUMP NO. 2 INLET PRESS, monitors theinlet pressure of the No. 2 FO transfer pumpand is scaled in psig. There is one split-legendpush button labeled ON and OFF. This ON/OFFpush-button indicator controls the fuel purifiermotor. This push button turns the purifier motoroff if it is on, but it cannot be used by the operatorto start the purifier motor from the FSCC. TheON portion of the push button is a status indicatorthat shows the purifier motor is running. Thissection has two indicator control push buttons theoperator can use to operate the FO transfer pumpmotor. One push button is labeled OFF and theother is labeled ON. The OFF push buttonilluminates white when the motor is secured. TheON push button illuminates green when the motoris running. There are two split-legend alarmindicators labeled HIGH and LOW. The HIGHindicator illuminates amber when the servicetank level reaches 90 percent. The LOW indicatorilluminates amber when the service tank leveldrops to 10 percent. The last split-legend alarmindicator, labeled 80% FL and 95% FL, monitorsthe FO level in the purifier drain tank. The 80%indicator illuminates steadily when the drain tankis 80 percent full. The 95% alarm indicatorilluminates amber when the level reaches95 percent. The No. 1 FO transfer section(section B of fig. 9-10) is the same as thesection we have just discussed, except thissection contains the meters, indicators, andpush-button controls for the No. 1 fuel transfer/service system.

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Figure 9-11.—JP-5 control panel (FSCC).

JP-5 Control Panel

The JP-5 system is used to supply fuel tohelicopters and small boats. However, JP-5 canbe used as an emergency fuel for main enginesand generators. Filling of the JP-5 storage tanksis controlled from the FSCC. The JP-5 transferand service operations are controlled from theJP-5 local control panel. Refer to figure 9-11 asyou read the following descriptions of this system.Our discussions of the sections of this system willfollow a general left-to-right, top-to-bottomdirection.

There are four push-button control indicatorson the JP-5 control panel the operator uses tocontrol the storage tank motor-operated valves.Two are labeled OPEN and two are labeledCLOSED. The OPEN push button illuminatesgreen to indicate the valve is open. The CLOSEDpush button illuminates white to indicate thevalve is closed. Located between the motor-operated valve control push buttons is a split-legend push button labeled AUTO FILL andMAN. In the AUTO FILL position, the JP-5auto fill system functions to close the JP-5storage tank valve during a fill operation if thatparticular storage tank generates a high levelalarm. In the MAN position, the JP-5 storagetank valves are operated manually when theoperator presses the appropriate OPEN orCLOSED push-button indicator. The JP-5 control

panel has 10 split-legend status indicators labeledOPEN and CLOSED. They illuminate eitherOPEN or CLOSED to indicate the position of themanually operated transfer valves. Associatedwith the two storage tanks are two split-legendindicators labeled HIGH and LOW. The HIGHindicator illuminates amber when the tank levelreaches 90 percent capacity. The LOW indicatorilluminates amber when the tank level drops to10 percent capacity. There are two vertical metersin this section that continuously monitor thestorage tank levels. Since the JP-5 storage tanksare not seawater compensated, the fuel level ismeasured directly from the bottom of the tank.The meters are scaled to indicate fuel level ingallons.

There are two push-button indicators, underthe heading JP-5 TRANSFER located toward thebottom center of the JP-5 control panel. The split-legend push-button indicator labeled PUMPdisplays the JP-5 transfer pump ON or OFFstatus. Depressing this push button turns thepump off if it is running, but the pump cannotbe started from the FSCC. The other indicator,under the heading JP-5 TRANSFER, is an alarmindicator labeled HIGH PRESS. It illuminatesamber to indicate a high differential pressureacross the JP-5 transfer pump filter. The alarmindicator, under the heading JP-5 DRAIN TANK,is labeled HIGH. It illuminates amber to indicatethe drain tank level has exceeded the preset limit.

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There are four alarm/status indicatorsgrouped under the heading JP-5 SERVICE. Thefirst indicator is a split-legend push-buttonindicator labeled HIGH and LOW. It illuminatesHIGH when the PORT JP-5 service tank levelreaches 90 percent. It illuminates LOW if the tanklevel drops to 10 percent. The second split-legendpush-button indicator, labeled HIGH and LOW,performs the same monitoring function for theSTBD service tank. The third split-legend controlpush button displays the service pump ON or OFFstatus. Depressing this push button turns thepump OFF if it is running, but the operatorcannot start the pump from the FSCC. The fourthindicator, labeled HIGH PRESS, is an alarmindicator for the JP-5 service filter separatordifferential pressure. It illuminates amber if thedifferential pressure across the filter separator is15 psid or greater.

Located on the right edge of the JP-5 controlpanel is an annunciator labeled AUDIBLEALARM. It is a buzzer that provides the operatorwith an audible indication that an alarm has beengenerated. Located to the right of the AUDIBLEALARM is a status indicator labeled CONSOLEHIGH TEMP. It illuminates amber to indicatethe internal temperature of the FSCC hasexceeded a preset temperature.

Located on the right of the JP-5 control panelof the FSCC are hazard, fault, and lamp test pushbuttons. Depressing the individual push buttonssends a test signal to the console electronics andactuates the alarms. The first push button is underthe heading FUEL OIL. Depressing this pushbutton, labeled HAZARD ALARM TEST, causesall the alarm indicators on the FO fill and transfercontrol panel to flash at a 4-Hz rate and producesan audible alarm. The operator must then depressthe individual alarm indicators to clear the alarms.In fact, the operator must depress all theindicators before the audible alarm will clear. TheHAZARD ALARM TEST indicates that thealarms are operating correctly within theirprescribed setting. The second push button, underthe heading FUEL OIL AND JP-5, is labeledLAMP TEST. Depressing this push buttonilluminates all lights on the console, allowing theoperator to determine which light bulbs needreplacement. Releasing the push button completesthe test and extinguishes the lights. The last twopush buttons are under the heading JP-5. The firstpush button, labeled FAULT ALARM TEST, isused by the operator to test the system’s alarmcircuitry. If a fault occurs, such as an open inthe wiring, audible and visual alarm indicators are

activated at the l-Hz rate. Depressing the FAULTALARM TEST activates the audible and visualalarm indicators at l-Hz. The operator clears thealarm in the same manner as for the hazard alarm.The second push button under the heading JP-5is labeled HAZARD ALARM TEST. Depressingthis push button allows the operator to performa hazard alarm test of all alarm indicators on theJP-5 control panel.

Depressing the FO hazard alarm test pushbutton during actual fueling operations in theNORM mode will cause the receiving tankcutout valves and the main fill valve to close.Acknowledging the alarm by depressing the alarmindicator will stop the main fill valve fromclosing at whatever point it has reached. Thereceiving tank valves will not stop closing but canbe opened by depressing the OPEN push buttonafter acknowledging the fuel overflow alarm.

Normally there is little maintenance necessaryfor the FSCC. On most ships, the FSCC must betested and calibrated before refueling. To performthese test and calibration procedures, the operatormust be familiar with the rear panel of the FSCC.The rear panels will be discussed in a left-to-right,top-to-bottom fashion. Refer to figure 9-12during this discussion.

Card Cage

Section 1A2A1 houses the card cage. Itcontains the 32 printed circuit boards (PCBs)

Figure 9-12.—Fuel system control console—rear view.

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used in monitoring, alarm, and control functions.The card cage assembly will swing up formaintenance.

Relay Panel Assembly

Section 1A3A2 of the FSCC contains the relaypanel assembly. The nine 24-volt dc relayscontrol FO and JP-5 valve closing. They areenergized by the auto fill circuits. Associated witheach relay is a suppression diode (CR1 throughCR9) to prevent damage to the auto fill logicoutput circuits. The front side of this panel holdsthe spare fuses for the console.

Fuse and Circuit Breaker Panel

Section 1A2A2 of the FSCC has the fuse andcircuit breaker (CB) panel. CB1 is the main powerCB for the FSCC. Fuses 1 through 10 protect theconsole from faults in the 120-volt ac remotecontrol wiring. Three switches, S1, S2, and S3,turn power on and off to the three power supplydrawers.

Calibration Panel

Section 1A1A2 of the FSCC houses thecalibration panel. This panel contains theswitches and potentiometers used in calibratingmeter circuits and setting alarm points for thosefunctions processed by the FSCC.

Storage tank level meter calibration is doneby use of a three-position momentary contactswitch, a full-scale adjust potentiometer, and theassociated zero adjust potentiometer for eachtank. If the switch is pushed to the FULLposition, you can set the full adjust potentiometerto obtain a full-scale reading on the associatedpanel meter. When the switch is in the ZEROposition, you can set the zero adjust potentiometerto obtain a zero panel meter reading.

You can also calibrate the FO receiving tankpressure meter circuits at this panel. A PUSHTO ADJUST FULL SCALE push button isassociated with each receiving tank pressurecircuit. When the push button is depressed, youcan set the panel meter for full scale by adjustingthe full-scale adjust screw on the panel meterassembly.

From the calibration panel, you can adjust thehigh seawater, fuel overflow, JP-5 storage tanklevel HI/LO, and FO receiving tank pressure highhazard alarm set points. When the push buttonfor one of these alarms is depressed, the associatedpanel meter reads the alarm set point. Byturning the corresponding adjust potentiometer,you can adjust the alarm set point to its desiredvalue.

Also located on this panel are two modeswitches. These affect the JP-5 storage tankcircuits. When in the LOCAL ONLY position,only the FSCC panel meter indicates tank level.When in the LOCAL AND REMOTE position,

Figure 9-13.—Fuel oil transfer local panel.

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both the FSCC and the JP-5 local control panel panels to operate indicators energized by the localmeters function. panels.

FUEL OIL TRANSFER LOCAL PANELSPower Supplies

The FSCC has eight dc power supplies locatedin the power supply drawers 1A3A3, 1A2A3, and1A1A3 (+5 V, -5 V, +12 V, and +24 V). Twosupplies are used for each voltage level. Theynormally operate in parallel, sharing the currentload. The LEDs at the power supplies showvoltage output. If one supply of a pair should fail,the LED for that supply extinguishes and the otherpower supply of the pair will automatically supplythe load. Isolation diodes between the powersupplies prevent the failed supply from absorbingcurrent. Each power supply has an output voltageadjust potentiometer (R1) that serves to calibratethe supply within its specified tolerance.

The FSCC sends +24 volt dc power to all threelocal panels for illumination of indicatorscontrolled by the FSCC. The FSCC also receives

Associated with the FSCC are two FO transferlocal panels. (See fig. 9-13.) Panel No. 1, locatedin auxiliary machinery room (AMR) No. 1,monitors and controls the No. 1 FO transferpump, heater, purifier, and associated valves.Panel No. 2, located in AMR No. 2, monitors andcontrols the No. 2 FO transfer equipment.Controls and indicators are similar to those onthe FSCC but pertain only to the equipmentassociated with the particular local panel.Information is exchanged between each of thelocal panels and the FSCC.

The FO transfer local panels are bulkheadmounted. They have an upper and lower frontpanel and a metal enclosure that houses the powersupplies and electronic circuits. The upper andlower front panels swing open for maintenanceand card cage access. Figure 9-14 is an outline of

+24 volt dc power from the three local control the FO transfer local control panel.

Figure 9-14.—Fuel oil and JP-5 local control panels—component location.

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The meters, indicators and controls on thelocal FO transfer panel are identical to those onthe FSCC. Since the FO transfer local panels andthe FSCC contain identical components, we willnot discuss the FO transfer local panels. Figure9-15, however, shows a detailed view of one ofthe local panels.

Normally there is little maintenance necessaryfor the FO transfer local panels besides changinglight bulbs. However, there are circumstances thatarise when the panels are required to be tested andcalibrated. To perform these test and calibrationprocedures, the operator must be familiar withthe internal components of the FO transfer localpanels. We will discuss these components in thefollowing paragraphs. Refer to figure 9-14 whileyou read this discussion.

Power Supplies

Each FO local control panel has four powersupplies, one for each dc voltage level used(+5 V, – 5 V, +12 V, and +24 V). The local +5volt, – 5 volt, and + 12 volt supplies are the sametype as those in the FSCC. The 24-volt supply usedin the local panels is functionally similar to theFSCC 24-volt supply; however, the maximum

Figure 9-15.—Fuel oil transfer local panel No. 1.

power output is less. Each power supply voltageis adjustable. Each local panel sends 24-volts dcpower to the FSCC. This is used to illuminateremote indicators controlled by the local panel.

Card Cage

The card cage, mounted on a hinged panelwith the calibrate panel, houses the 13 PCBs foreach FO local control panel. These cards monitorand control the functions of the local panel.

Power Distribution Panel

Each FO local control panel assembly housesa power distribution panel (not shown). This panelhas the terminal boards for panel connections andthe protective fuses for that particular panel.

Power to a local panel is controlled by one acCB, CB1. This CB is located on the right side ofthe enclosure. (See fig. 9-14.)

Calibrate Panel

Each FO local control panel has a calibratepanel. It serves the monitor and alarm circuits ofthe local panel in the same manner in which the

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Figure 9-16.—JP-5 local control panel.

FSCC calibration panel serves the FSCC circuits.At this panel, you can calibrate the associatedservice tank level, transfer pump pressure, FOheater temperature, and purifier pressure metercircuits. You can also set the alarm points forservice tank level (HI/LO), transfer pumppressure, and purifier discharge pressure at thispanel. All seven meter circuits have modeswitches for selection of LOCAL AND REMOTEor LOCAL ONLY displays.

JP-5 LOCAL CONTROL PANEL

Primary control of the JP-5 fill system isaccomplished from the FSCC in CCS. Transferand service system control is accomplished fromthe JP-5 local control panel located in pump roomNo. 2. The JP-5 local control panel is similar inconstruction to the FO local control panel shownin figure 9-16. The monitoring and controlfunctions of this panel are for the JP-5fill, transfer, and service systems. This panelexchanges information with the FSCC only.

Operator’s Panel

The upper front panel of the JP-5 localcontrol panel has the meters, gauges, indicators,and push buttons necessary to operate the JP-5fill, transfer, and service systems. This panel isthe primary control center for JP-5 transfer and

service operations because the FSCC hasprovisions only for limited monitoring andterminating of these operations.

All pressure monitoring at the JP-5 localcontrol panel is done with pressure gauges. At thetop of the enclosure are gauge cutout valves foreach of the gauges. Because the alarms, indicators,and push buttons are identical to those on theFSCC JP-5 control panel, we will not discuss thesecomponents.

Power Supplies

The JP-5 local control panel has four powersupplies, one for each dc voltage level used (+5 V,– 5 V, +12 V, and +24 V). The arrangement ofthese power supplies in the enclosure is similar tothat in the FO local control panel. Twenty-fourvolts is sent to the FSCC for illumination ofindicators controlled by the local panel. All fourpower supplies are energized by the CB1.

Card Cage

The card cage, mounted on a hinged panelcommon with the calibrate panel, houses the 12PCBs that control and monitor the functions ofthe local panel.

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Power Distribution Panel

The JP-5 local control panel has a powerdistribution panel. It is similar to those in the FOlocal control panels.

Calibrate Panel

The calibrate panel of the JP-5 local controlpanel is similar in function to those in the FSCCand FO local control panels. The only circuitsserviced by this panel are the JP-5 service tanklevel high and low alarm functions. No modeswitches are on this panel. This is because the onlyJP-5 service tank level meters are at the JP-5 localcontrol panel.

OPERATION

This section is limited to general proceduresfor the FSCC and local panel power application,self-test, FO fill control, and turnoff. You canfind detailed instructions for starting, operating,and securing this equipment in the Fuel ControlSystem Consoles technical manual.

Power Application

The FSCC is energized from the fuse and CBpanel. The three power supply panel switches(S1, S2, and S3) should be in the ON position.Placing the main power CB (CB1) in the ONposition then energizes the FSCC. All powersupply indicator lights should be on. Sinceapplication of power to the console may alarmsome circuits, all flashing push-button indicatorsshould be depressed to reset the alarm circuitry.

To energize the JP-5 local control panel andthe FO local control panels, place the ac powerCBs in the ON position. To reset any alarms,depress any flashing push-button indicators.

Self-Tests

The FSCC and the three local panels areequipped with alarm and lamp tests. Depressingthe HAZARD ALARM TEST push button causeseach hazard alarm circuit in the associated panelto activate (4-Hz flashing indicator and 4-Hztone). You must acknowledge each hazard alarm.This test also starts associated remote hazard

Figure 9-17.—Damage control console (DD-963 class).

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alarms. Depressing the FAULT ALARM TESTpush button causes each fault alarm circuit in theassociated panel to start a fault alarm (l-Hzflashing indicator and l-Hz tone). Releasing thepush button will end this test. Depressing theLAMP TEST push button illuminates all indicatorlights that are not checked by one of the alarmtests.

Normal Securing

The FSCC is secured by placing the mainpower CB to the OFF position. The local panelsare secured by placing the AC POWER switch tothe OFF position.

DAMAGE CONTROL CONSOLEFOR DD-963/993 AND CG-47

CLASS SHIPS

This section describes the major componentsand circuit functions of the damage controlconsole (DCC) located in the CCS, adjacent tothe FSCC. The DCC operates as an independentsystem from the FSCC and the ECSS. The onlyinterface between the DCC and the ECSS isinformation received for GTM and GTG fireconditions. The FSCC and the DCC are bothmanufactured by the same vendor. They havemany similar hardware items and circuit designs.

DESIGN AND COMPONENTS

The DCC is composed of three cabinetassemblies bolted together to form the console.(Refer to fig. 9-17.) These three sections, accessiblefrom the rear of the console, contain the cardcages, power supplies, fuse and CB panel, andinterconnection panels. The front side of theconsole houses the operator’s panels, containingall the meters, indicators, and switches necessaryfor normal operation. In the following paragraphs,we will describe the design and components of theDCC in reference to the front and back sectionsof the console.

Operator’s Panels (Front of Console)

The front of the console is composed of twooperator panels: the hazard detection panel (1A4)and the firemain control panel (1A5). The upperpanel is the hazard detection panel; the lowerpanel is the firemain control panel. We will discussboth panels in a left-to-right, top-to-bottomfashion. The DCC operator panels on the CG-class ship are basically similar. We will point outany significant differences during the descriptionof the panels.

HAZARD DETECTION PANEL.—Thehazard detection panel has all the indicators forthe fire, smoke, temperature, and bilge hazardalarm circuits. (Refer to fig. 9-18.) Also provided

Figure 9-18.—DCC hazard detection panel (DD-963 class).

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are push-button indicators the operator uses toconduct panel tests and to acknowledge alarms.The only control functions of this panel arevent fan shutdown and summary fire alarmmanual initiation.

The hazard detection panel contains approxi-mately 380 indicators for fire, smoke, temperature,and bilge alarms. Because the sensors for theseindicators are located throughout the ship, wewill limit our discussion to the most importantindicators.

In the upper right-hand corner is a push-button control indicator labeled SUMMARYFIRE ALARM. This indicator illuminates amberto indicate a fire sensor is activated somewherein the ship. The operator can depress this pushbutton to start a summary fire alarm for a firecondition that is not detected by the hazarddetection circuits. The second push-buttoncontrol indicator is located under the headingVENT FAN SHUTDOWN CONTROL. Theoperator uses this push button to shut down theCIRCLE WILLIAM vent fans and to provide astatus of the vent fans. There is no ON vent fancontrol provided by this push button. When ONis illuminated, this indicates the CIRCLEWILLIAM vent fans have been reset. There arefour CIRCLE WILLIAM push buttons on thehazard detection panel (five on the CG). The thirdpush-button control indicator, located under theheading VENT FAN SHUTDOWN CONTROL,is used to shut down the ZEBRA vent fans andto provide a status of the vent fans. Again, thereis no ON vent fan control provided by this pushbutton. There are three ZEBRA push buttons onthis panel (five on the CG). When ON isilluminated, the ZEBRA vent fans have beenreset. The fourth push-button control is labeledDOOR CLOSE (not applicable on the DD). Thispush button controls the fire boundary doorclosure for the designated fire zone. There are fourDOOR CLOSE push buttons on the CG-classhazard detection panel.

The fifth push-button control, labeled FAULTALARM TEST (FAULT TEST on the CG), islocated towards the bottom, left of center of thepanel. Depressing this push-button indicatorallows the operator to test the fault circuitry ofthe alarm cards for the left portion of the hazard

detection panel. The sixth push-button indicator,labeled HAZARD ALARM TEST (HAZARDTEST on the CG), is located next to the FAULTTEST push button. Depressing this push-buttonindicator allows the operator to test the hazardalarm cards for the left portion of the hazarddetection panel. The seventh push button islabeled ALARM ACK. (The ALARM ACK pushbutton is located next to the HAZARD TESTpush button on the CG.) When depressed, thispush button acknowledges the flashing alarm. Ifthe alarm condition still exists, the alarm indicatorwill illuminate steadily. The alarm indicator willextinguish when the alarm condition no longerexists. The remaining push-button indicators onthe right half of the hazard detection panel aremirror images of the push buttons just described.

FIREMAIN CONTROL PANEL.—The fire-main control panel contains the indicators andcontrols that allow the operator to monitor theperformance and status of the fire pumps,firemain risers, and firemain loops. (Refer tofig. 9-19.) This panel contains a mimic of thefiremain system. Both automatic and manualstarting of fire pumps is done from this panel.The 1000 gallons per minute (gpm) aqueous filmforming foam (AFFF) hangar sprinkler system iscontrolled from this panel. Included are push-button indicators for the start of panel fault,hazard, and lamp tests. This panel has a consolestatus section to display certain abnormalconditions in the console.

The first indicator, under the heading AFTVERTREP, is labeled AFFF FP-180 ON. Itilluminates amber to indicate that the foamproportioner serving the aft vertical replenishmentstation is energized. There is no control functionfor the FP-180s on the DCC, only indications.There are three other indicators on the firemaincontrol panel labeled AFFF FP-180 ON. Theyindicate the status of the other three AFFFstations.

The first split-legend indicator is labeled LOWPRESSURE and METER (not applicable on theCG). There are nine of these indicators on thefiremain control panel to monitor firemain

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pressure at various points in the firemain loop.The LOW PRESSURE portion of the indicatorilluminates red to indicate low pressure at thatpoint in the firemain loop. When depressed, theMETER portion of the indicator illuminates whiteand the LOOP AND RISER PRESSURE meterdisplays the firemain pressure at that point in theloop.

The two push-button indicators, labeled IRSET and IR ON, are located on the top right ofthe firemain control panel (not applicable on theCG). These push buttons are used in conjunctionwith the infrared suppression system. Use of thissystem has been discontinued; therefore, thesepush buttons are inoperative. These push-buttonindicators are not on the DCC of the newer ships.

The split-legend indicator, under the headingZ VALVE, is labeled OPEN and CLOSE. Thereare four of these valves on the firemain controlpanel (three on the CG). They illuminate greento indicate the ZEBRA segregation valves areopen. They illuminate white to indicate the valvesare closed. There is no control of the ZEBRAsegregation valves from the DCC, onlyindications.

Located at the left edge of the panel is anannunciator labeled AUDIBLE ALARM. This isa buzzer that provides the operator an audibleindication that an alarm or fault has occurred.The operator uses the alarm acknowledge pushbutton on the hazard detection panel or

the firemain control panel to silence thebuzzer.

The next indicator is labeled CBR ON GRP4. There are four of these indicators on the fire-main control panel, each with a different groupnumber. These indicators illuminate amber toindicate the respective chemical, biological,radiation (CBR) washdown group has beenactivated. There is no control for the CBRwashdown system on the DCC, only indications.

The four push-button control indicators, overthe heading HGR AFFF CONT, provide controland status of the 1000 gpm foam proportioner andthe hangar sprinklers. The first control indicatorin this section is labeled 1000 GPM AFFF PROPON. When this push button is depressed, acontrol signal is sent to the proportioner forstarting. The push button on the DCC illuminatesamber to indicate the proportioner is on. Thesecond push-button control indicator is labeledSPRG ON. When this push button is depressed,a open command signal is sent to the hangarAFFF sprinkler valve. The push-button indicatoron the DCC then illuminates amber to indicatethe hangar sprinkler system is on. The third push-button control indicator, labeled 1000 GPMAFFF PROP OFF, secures the AFFF foamproportioner and illuminates white to indicate theproportioner is off. The fourth push button in thissection, labeled SPRG OFF, secures the hangarsprinkler system and illuminates white to indicatethe sprinkler system is secured.

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Located in the center of the firemain controlpanel are two horizontal meters. One is labeledLOOP AND RISER PRESSURE and the otheris labeled PUMP DISCHARGE PRESSURE (notapplicable on the CG). The LOOP AND RISERPRESSURE meter displays pressures fromselected points in the firemain loop. This meter,scaled from 0 to 200 psig, is used in conjunctionwith the nine LOW PRESSURE/METER push-button indicators. The PUMP DISCHARGEPRESSURE meter, also scaled from 0 to 200 psig,displays the discharge pressure of any one of thesix fire pumps and is used in conjunction with thesix DISCH PRESSURE indicator push buttons.

The next component is a 0 to 200 psig gaugeand alarm indicator push button labeled PORTPRESS LOW (not applicable on the DD). Thismeter continuously monitors the port loop of thefiremain system. The alarm indicator illuminatesamber to indicate a low pressure on the port loop.There is an identical pressure gauge and alarmindicator labeled STBD PRESS LOW monitorsthe starboard loop.

Located on each firemain riser is a gauge andalarm indicator labeled RISER PRESS LOW (notapplicable on the DD). There are six identicalgauges and alarm indicators, one for each firepump riser. The riser pressure gauge, scaled from0 to 200 psig, monitors the fire pump riser

pressure. The alarm indicator illuminates amberto indicate a low pump riser pressure.

Located on the suction and discharge side ofeach fire pump is a split-legend push-buttonindicator labeled OPEN and CLOSE. Thereare 12 identical OPEN/CLOSE push-buttonindicators on the firemain control panel. Theindicators illuminate green to indicate therespective fire pump discharge or suction valveis open. They illuminate white to indicate therespective fire pump discharge or suction valveis closed. There is no control for the fire pumpdischarge and suction valves on the DCC, onlyindications.

Located at the discharge of each fire pump isan indicator push button labeled DISCHPRESSURE (not applicable on the CG). Thereare six identical indicator push buttons, one foreach fire pump discharge. When depressed,the PUMP DISCHARGE PRESSURE gaugeindicates the fire pump discharge pressure for theselected pump. The DISCH PRESSURE indicatorpush button illuminates white.

Located at the discharge of each fire pump,on the CG console, is a gauge and alarm indicatorlabeled DSCHG PRESS LOW (not applicable onthe DD). There are six identical gauges and alarmindicators, one for each fire pump discharge. Thedischarge pressure gauge is scaled from 0 to 200

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psig and monitors the fire pump dischargepressure. The alarm indicator illuminates amberto indicate a low pump discharge pressure.

Located to the right of each fire pump arethree push buttons that control the starting andstopping of the fire pump. The first push-buttonindicator is a split-legend push button labeledAUTO and INHB. In the AUTO position, thedesignated fire pump is set for automatic startingupon loss of firemain pressure. In the INHBposition, the designated fire pump is inhibitedfrom automatically starting. The fire pump canbe started manually. The second push-buttoncontrol indicator is labeled ON. Each ON pushbutton provides for manual starting of theassociated fire pump from the DCC. It illuminatesgreen to indicate the fire pump is running. Thethird push-button control indicator is labeledOFF. The OFF push button provides for manualstopping of the associated fire pump from theDCC and illuminates white to indicate the firepump is secured.

The firemain control panel has a HAZARDALARM TEST, a FAULT ALARM TEST, anda LAMP TEST push-button indicator on the leftside. These indicators function in a manner similarto that of the hazard detection panel hazard, fault,and lamp tests. These push buttons test thecircuits of the firemain control panel.

Located below the firemain control panel testpush buttons is a push-button control indicatorlabeled ALARM ACK. When depressed, this

push button acknowledges flashing alarms on thefiremain control panel. If the alarm condition stillexists, the alarm indicator will illuminate steadily.The alarm indicator extinguishes when the alarmcondition no longer exists.

The final section on the firemain controlpanel, right side, is labeled CONSOLE STATUS.This section contains five status indicators. Thefirst indicator is labeled POWER SUPPLY FAIL.It illuminates red to indicate one of the dc powersupply voltages has dropped below its limit. Thesecond indicator, labeled HAZARD OSC FAIL,illuminates amber to indicate a failure of thehazard oscillator. The third indicator, labeledFAULT OSC FAIL, illuminates amber to indicatea failure of the fault oscillator. The fourthindicator is labeled CONSOLE HI TEMP. Itilluminates red to indicate one of the threetemperature switches has exceeded 168°F. Thefifth indicator, labeled CARD REMOVED,illuminates amber to indicate a circuit card in theDCC is removed or improperly seated.

Rear Panel (Back of Console)

The rear of the DCC consists of five sections.These sections are labeled card cages, relaypanel assembly, fuse and circuit breaker panel,calibration panel, and power supply drawers. Thefollowing paragraphs describe the components ofthis panel. Refer to figure 9-20 during thisdiscussion.

CARD CAGES.—Sections 1A3A1, 1A2A1,and 1A1A1 house the three card cage assemblies

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Figure 9-20.—Damage control console component location.

with the 155 PCBs used in monitoring, alarm, andcontrol functions. One tab of each card is usedto form a series circuit through all card receptaclesin all three cages and the meter circuit card.Should this circuit be disturbed (card removed),the meter circuit board illuminates the CARDREMOVED indicator on the firemain panel.

RELAY PANEL.—Section 1A3A2 containsthe relay panel. On the front of this panel areseven lighted push buttons. Push buttons S-2through S-7 are used to test the automatic firepump control circuits for pumps 1 through 6.A satisfactory test of a circuit is shown byillumination of the push button after it isdepressed. Push button S-l, LAMP TEST, isused to test the lights on this group of pushbuttons.

On the rear of the panel are nine relays usedfor automatic starting of fire pumps, summaryfire alarms, and to inhibit start-up of fire pumpsduring circuit tests. Associated with each relay isa suppression diode for circuit protection.

FUSE AND CIRCUIT BREAKER PANEL.—Section 1A2A2 of the DCC has the fuse and CBpanel. This panel contains the fuses to protect theconsole’s 120-volt ac fire pump and vent fancontrol circuits. This panel also has the 24-volt

dc fuses supplying the hazard detection and fire-main panels. The main power CB supplying 120volts ac to the console and the three power supplydrawer switches are also on this panel.

CALIBRATION PANEL.—Section 1A1A2has the DCC calibration panel. This panelcontains the push buttons and potentiometersnecessary to set alarm points for low loop and lowriser pressure circuits and to set full scale on bothfiremain panel pressure meters. It also has fusesfor loop and riser pressure transducer circuits.

The LP alarm points for loop and risercircuits are set by depressing the PUSH TOSET ALARM POINT push button and LOWPRESSURE/METER push button at the sametime for a particular point. The LOOP ANDRISER PRESSURE meter reads the alarm setpoint. By adjusting the associated ADJUSTpotentiometer on the calibration panel, youcan set the alarm point to the desired value.Releasing the two push buttons returns thecircuit to the normal condition.

Depressing the PUSH TO SET FULL SCALEpush button for either the loop and riser or pumpdischarge meters sends a full-scale signal to themeter. You can then make the adjustment to themeter by using the mechanical full-scale adjust onthe meter body.

POWER SUPPLIES.—There are nine dcpower supplies in the DCC located in the powersupply drawers. There are two power supplieseach for +5 volts, –5 volts, and +12 volts. Threepower supplies are used for the +24 volts. Eachpower supply has an adjustment potentiometerfor maintenance calibration. Because of theredundant power supplies, console operation isunaffected if one supply for a particular voltagelevel should fail. If one supply of that groupshould fail, the remaining supply or suppliesautomatically assume the load. Isolating diodesprevent the failed supply from absorbing current.The LED for the failed supply extinguishes,indicating that the supply has stopped supplyingvoltage. At the same time, the POWER SUPPLYFAIL light on the firemain panel illuminates. Thisshows that one of the nine power supplies is outof tolerance. The back panel of each power supplydrawer contains the LEDs and ac fuses for eachpower supply and the drawer blower fuses.

OPERATION

This section is limited to general proceduresfor DCC power application, turnoff, and self-tests.

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Detailed instructions for starting, operating, andreceiving this equipment are contained in theDamage Control System Console technicalmanual.

Power Application

The DCC is energized from the fuse and CBpanel. The three power supply panel switches (S1,S2, and S3) should be in the ON position. Placingthe MAIN POWER CB (CB1) in the ON positionenergizes the DCC. All power supply indicatorlights should be on. Since application of powerto the console may cause some circuits to alarm,all flashing push-button indicators should bedepressed to reset the alarm circuitry.

Self-Tests

The hazard detection panel and the firemainpanel are equipped with alarm and lamp tests.There are HAZARD ALARM and FAULTALARM TEST push buttons for each half of thehazard detection panel and for the firemain panel.Exercise each group independently. Momentarilydepressing a HAZARD ALARM TEST switchcauses all hazard indicators for that group toflash. The audible alarm sounds at a 4-Hz rate.Holding the HAZARD ALARM TEST pushbutton depressed and depressing the ALARMACK for the panel will cause all flashing lightsto illuminate steadily and silence the audiblealarm. Then the operator may release theHAZARD ALARM TEST. Depressing ALARMACK again will extinguish all indicators notactually in alarm and restore the circuits tonormal operation.

Momentarily depressing a FAULT ALARMTEST switch will cause all hazard indicators forthat group to flash at a l-Hz rate. The audiblealarm sounds at a l-Hz rate. While holdingFAULT ALARM TEST depressed, the operatorcan depress the ALARM ACK for the panel tocause the audible alarm to silence (indicatorsremain flashing). The operator may then releasethe FAULT ALARM TEST switch. DepressingALARM ACK again will extinguish all indicatorsnot actually in alarm and restore the circuits tonormal operation.

After all fault and hazard tests have beenperformed, use the LAMP TEST to check allindicator lights that were not tested during thealarm tests. Perform these tests upon energizingthe console and at regular intervals duringoperation.

Figure 9-21.—Auxiliary control console.

Normal Securing

The DCC is secured by placing the MAINPOWER CB in the OFF position.

AUXILIARY CONTROL CONSOLE

This section describes the indicators andcontrols of the auxiliary control console (ACC).The ACC is located in the CCS, between thepropulsion control console (PCC) and the EPCC.The ACC is used to operate and monitor thestatus of a majority of the auxiliary systems inthe engineering plant of the FFG-class ship. (Seefig. 9-21.) The following systems may be operatedor controlled from the ACC.

Machinery space ventilation

Fuel filling, transfer, and purificationsystem

Chilled water circulating system

Waste heat water circulating system

Compressed air plants

Main engines starting air system

Air-conditioning and ship’s stores refriger-ation plants

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Figure 9-22.—ACC top panel.

Potable water system, including fill valves

Distilling plants

Masker, prairie/fin stabilizer, and bleed airsystems

Sewage disposal system

Saltwater service system

Drainage system

ACC TOP PANEL

The ACC top panel is shown in figure 9-22.This panel has three digital displays used tomonitor any parameter having a DDI address.This panel also contains indicators that monitorthe console power status and provide panelmonitoring and alarm testing. Refer to figure 9-22as we describe the following sections.

DAMAGE CONTROL Section

The first section on the top panel, under theheading DAMAGE CONTROL, is labeled PANEL

MONITORING (A). This section monitors thedamage control system. The first indicator pushbutton, labeled EMERGENCY CONDITION,illuminates white to indicate an alarm conditionexists on the DCC. The second indicator pushbutton, labeled ALARM DISABLE, provides theACC operator with the option either to enable ordisable the EMERGENCY CONDITION faultalarm.

PARAMETERS Section

The second section is labeled PARAMETERS(B). It contains three identical digital displaysconsisting of a DDI, a set of three thumbwheels,and a toggle switch. The number one digitaldisplay contains an additional toggle switch forchecking the high or low reset value of the selectedparameter. The first item in this section is thedigital display windows labeled VALUE. Thenumerical value of the parameter selected by thethumbwheels is displayed in these windows. Asecond set of windows, labeled UNITS, displaythe unit of measurement of the selectedparameter. The second item is a three-positiontoggle switch (digital display No. 1 only). The top

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position is labeled HIGH RESET. In thisposition, the DDI displays the high reset value ofthe selected parameter. The middle position,labeled ALARM SET VALUE, displays the alarmset point of the selected parameter. The bottomposition, labeled LOW RESET, displays the lowreset value of the selected parameter. This toggleswitch is not on digital displays No. 2 and No. 3.The third item is a set of three thumbwheelslabeled ADDRESS. The thumbwheels are used toselect the address of the parameter to bemeasured. The last toggle switch on the digitaldisplay is a three-position toggle switch. Thetop position is labeled HIGH LIMIT. In thisposition, the DDI displays the high limit of theselected parameter. The middle position, labeledACTUAL, displays the actual value of the selectedparameter. The bottom position, labeled LOWLIMIT, displays the low limit of the selectedparameter.

CONSOLE POWER STATUS Section

The third section of the top panel is labeledCONSOLE POWER STATUS (C). This sectionmonitors the power supplies of the ACC. Itcontains seven push-button indicators. The firststatus indicator is labeled 115 VAC MASTERPOWER ON. It illuminates white to indicate 115volts ac is available to the ACC. The secondindicator is a split-legend status indicator labeledPRIMARY +28 VDC ON and BACK UP +28VDC ON. The upper portion of the indicatorilluminates white to indicate the primary +28 voltdc power converter is in operation. The lowerportion of the indicator illuminates white toindicate the backup +28 volt dc power converteris in operation. The third indicator is a split-legendstatus indicator labeled PRIMARY +15 VDC ONand BACK UP +15 VDC ON. The upper portionof the indicator illuminates white to indicate theprimary +15 volt dc power converter is inoperation. The lower portion of the indicatorilluminates white to indicate the backup +15 voltdc power converter is in operation. The fourthindicator is a split-legend status indicator labeledPRIMARY –15 VDC ON and BACK UP –15VDC ON. The upper portion of the indicatorilluminates white to indicate the primary –15 voltdc power converter is in operation. The lowerportion of the indicator illuminates white toindicate the backup –15 volt dc power converteris in operation. The fifth indicator is a split-legendstatus indicator labeled PRIMARY +5 VDC ONand BACK UP +5 VDC ON. The upper portion

of the indicator illuminates white to indicatethe primary +5 volt dc power converter isin operation. The lower portion of the indicatorilluminates white to indicate the backup +5 voltdc power converter is in operation. The sixthindicator is labeled VERTICAL PANEL 115VAC CONTROL POWER ON. This indicatorilluminates white to indicate 115-volt ac controlpower is available to the ACC vertical panel. Theseventh indicator, labeled LOWER PANEL 115VAC CONTROL POWER ON, illuminates whiteto indicate 115-volt ac control power is availableto the ACC lower panel.

The fourth section of the top panel containsfour push-button indicators and a potentiometer(D). The first push-button indicator, labeledCONSOLE HIGH TEMPERATURE, illuminatesto indicate the console temperature has exceededthe preset limit. The second push-buttonindicator, labeled CONSOLE HEATER ON,illuminates to indicate the console heater isenergized. Heater power is applied when theconsole power circuit is de-energized. The thirdpush-button indicator, labeled HORN TEST,allows the operator to test the level 2 audiblealarm. A level 2 alarm is indicated by a horn. Thefourth push-button indicator, labeled BELLTEST, allows the operator to test the level 3audible alarm. A level 3 alarm is indicated by abell. The potentiometer, labeled VOLUME,allows the operator to adjust the volume of theaudible alarm annunciator.

ACC VERTICAL PANEL

The ACC vertical panel is shown on figure9-23. This panel contains the controls andindicators for seven of the systems on the ACC.Study figure 9-23 as you read the followingdescriptions.

Machinery Space VentilationFans (Emergency Use)

Eight pairs of push-button switches areprovided for emergency control of the machineryspace supply and exhaust fans. Each pair has aFANS RUN and a FANS STOP push button.Status of the fans is indicated by the lights in therespective push buttons. Each machinery spacefan control functions identically. For this reason,we will discuss only one pair of push-buttoncontrols.

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Figure 9-23.—ACC vertical panel.

The first push-button indicator switch islabeled FANS RUN. It is used to start one supplyand one exhaust fan in the machinery space. Thesecond push-button indicator switch, also labeledFANS RUN, is used to start the other supply andexhaust fan in that machinery space. The thirdpush-button indicator switch, labeled FANSSTOP, is used to stop the first set of supply andexhaust fans. The fourth ventilation push-buttonindicator switch, also labeled FANS STOP, isused to stop the second set of supply and exhaustfans.

The machinery space ventilation fans arelocated in the engine room and AMRs No. 1,No. 2, and No. 3. There are supply and exhaustfans in each room. Under normal conditions, thefans are started from the local controllers and left

in the LOCAL/REMOTE mode. This allows foradditional controller operations from both thelocal controller and the remote panel. If anemergency exists, the switches at the ACC areused. The local controller switch must be in theLOCAL/REMOTE position for the push buttonson the ACC to be operational.

Fuel Filling, Transfer, andPurification System Section

This section has controls and indicators forthe purifier, transfer pump, and stripping pumpin the fuel filling, transfer, and purificationsystem. The controls have EMERGENCY STOPpush buttons for each of the components.Indicators are provided to monitor the status ofpurifier speed, discharge, and vibration and thestatus of the transfer pump and the strippingpump. All the equipment monitored is located inAMR No. 2.

The ACC vertical panel contains five push-button controls and indicators for each fuelpurifier. Since both purifier controls andindicators are identical, only one set will bediscussed. The first indicator is labeled NORMALSPEED RUNNING. This indicator illuminatesgreen to indicate the fuel transfer purifier is

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running at normal speed. The second indicator,labeled EXCESS DISCHARGE, illuminates redto indicate the flow through the breakoverswitch is excessive. This usually indicates a lossof purifier seal. The third indicator, labeled HIGHVIBRATION, illuminates red to indicate excessivevibration of the fuel purifier. The fourth indicatoris labeled LOW DISCHARGE PRESSURE. Itilluminates red to indicate the purifier dischargepressure has dropped to 20 psig. The push-buttonswitch, labeled EMERGENCY STOP, is providedto allow the ACC operator to stop the fuel purifierin the event of an emergency.

The TRANSFER PUMPS section of the ACCvertical panel contains controls and indicatorsfor two fuel transfer pumps and one auxiliarytransfer pump. The first three indicators, labeledRUNNING, illuminate green to indicate theNo. 1, No. 2, or auxiliary fuel transfer pump isrunning. The next three push-button switches,labeled EMERGENCY STOP, allow the operatorto stop the respective transfer pump in the eventof an emergency.

The STRIPPING PUMP section contains thecontrol and indicator for the fuel stripping pump.The RUNNING indicator illuminates green toindicate the stripping pump is running. The push-button switch, labeled EMERGENCY STOP,

allows the operator to stop the stripping pumpin the event of an emergency.

The fuel filling, transfer, and purificationsystem is used to distribute fuel from the deckfilling connections to the fuel storage andoverflow tanks. It also discharges fuel fromthe storage and overflow tanks via the deckconnections. It is used to transfer fuel betweenstorage tank groups to adjust trim and list. Oneof its primary jobs is to transfer fuel to theservice tanks via the fuel transfer heaters andcentrifugal purifiers. The system is designed forlocal start-up and unattended operation.

Chilled Water Circulating System Section

This section contains the alarms and indicatorlights that monitor the chilled water circulatingsystem and indicate the status of the chilled watercirculating pump. The alarms alert the operatorto three occurrences: (1) a high or low chilledwater temperature condition, (2) a circulatingpump discharge pressure failure, or (3) a low levelin the chilled water expansion tank.

The ACC vertical panel contains five push-button controls and indicators for the each chilledwater system. Since controls and indicators forthe three chilled water systems are identical,only one set will be discussed.

The first indicator is labeled HIGH TEMPER-ATURE. It illuminates red to indicate the chilleroutlet temperature has exceeded 45°F. Thesecond indicator, labeled PRESSURE FAILURE,illuminates red to indicate the chilled watercirculating pump discharge pressure has droppedbelow 30 psig. The third indicator, labeled LOWTEMPERATURE, illuminates red to indicate thechiller outlet temperature has dropped below35°F. The fourth indicator, labeled EXPANSIONTANK LOW LEVEL, illuminates red to indicatethe expansion tank water level has dropped below20 percent of the tank capacity. The last indicatorin this section is labeled CIRCULATE PUMP

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RUNNING. It illuminates green to indicate thecirculation pump is running.

The chilled water circulating system distributesfresh cooling water throughout the ship forenvironmental control (air-conditioning), elec-tronic equipment cooling, and bubbler drinkingwater cooling. The system can be divided intothree independent loops. Each loop operates inconjunction with an air-conditioning plant. Thecirculating equipment for two loops is located inAMR No. 2. The equipment for the third loopis located in the air-conditioning machinery room.The system is designed for local alignment, localstart-up, and unattended operation. This systemis normally configured in a closed loop with oneair-conditioning plant on line.

Lamp Tests

Two backlighted momentary-action LAMPTEST push buttons are provided on the right-hand side of the panel. These are used to test thelamps on the vertical panel.

Waste Heat Water CirculatingSystems Section

This section contains the controls and alarmsthat indicate the status of the major componentsin the waste heat water circulating system. Push-button switches provide start and stop control

of the system circulating pumps. Alarms areprovided to show three occurrences: (1) ahigh waste heat exchanger outlet temperaturecondition, (2) a high supplementary electric heateroutlet temperature condition, or (3) a low waterlevel in the system compression tank. You canobtain indication of the waste heat system pressureand the supplementary heaters outlet temperatureon the demand display.

The first three push buttons are indicators andcontrols for the diesel engine waste heat system.There are four identical sets of push buttons, oneset for each diesel engine. Since each set isidentical, only one set will be discussed.

The first indicator is labeled HEAT EX-CHANGER OUTLET TEMP HIGH. It illumi-nates red to indicate the heat exchanger outlettemperature has exceeded the preset limit. Thesecond push-button indicator control, labeledCIRCULATE PUMP RUN, illuminates green toindicate the waste heat circulating pump isrunning. The third push-button indicator control,labeled CIRCULATE PUMP STOP, illuminatesred to indicate the waste heat circulating pumpis stopped.

The next indicator is located under the headingSUPPLEMENTAL HOT WATER. The indicatoris labeled ELEC HEATER EXCHANGER OUT-LET TEMP HIGH. It illuminates red to indicatethe supplementary electric heater outlettemperature has exceeded the preset limit.

The last push-button indicator in this sectionis located under the heading HOT WATERCOMPRESSION TANK. This indicator, labeledLOW LEVEL, illuminates red to indicate the hot

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water compression tank has dropped below thepreset limit.

The waste heat exchanger transfers heatgenerated by the SSDG to the waste heatwater circulating system. The waste heat watercirculating system supplies heat to the fuel transferheaters, the fuel service heaters, the LO purifierheater, the distilling plants, and the hot potablewater accumulator tank heating coil. The systemhas four waste heat exchangers and fourcirculating pumps. The pumps start and stopautomatically with the starting and stopping oftheir associated SSDG. The circulating equipmentis located in the three AMRs and the engine room.The system is designed for automatic start-up andunattended operation.

Compressed Air Plants Section

The status of the HP air system and the LPair system is provided by alarms and visualindicators. Push buttons are provided to stop anyof the four compressors in an emergency. Thealarms alert the operator that the air receiverpressure is low, when the HP system after-coolertemperature is high, when the LP system dryerdischarge temperature is high, and when anautomatic compressor safety shutdown hasoccurred. A split-type indicator shows whenpower is being supplied to the compressor andwhen the compressor is running.

There are two air plants. Each one has an HPair system and an LP air system. One of the airplants is located in AMR No. 2 and the secondis located in AMR No. 3. Each of the fourcompressed air systems is provided with indicatorsand a switch at the ACC. The systems aredesigned for local start-up and unattendedoperation. Since the two air plants are identical,only one plant will be discussed.

The HP air section of the ACC consists of fivecontrol indicator push buttons. The first indicatoris labeled AIR RECEIVER LOW PRESSURE.It illuminates red to indicate the HP air receiverpressure is below the preset limit. The secondsplit-legend indicator is labeled COMPRESSORENABLED and RUNNING. The top portion of

the indicator illuminates white to indicate poweris being supplied to the compressor. The bottomportion of the indicator illuminates green toindicate the compressor is running. The thirdindicator, labeled COMPRESSOR AFTERCOOLER HIGH TEMP, illuminates red toindicate the HP aftercooler temperature is abovethe preset limit. The fourth indicator, labeledCOMPRESSOR SAFETY SHUTDOWN, illumi-nates red to indicate an automatic compressorshutdown has occurred. The push-button switch,labeled COMPRESSOR EMERGENCY STOP,allows the operator to stop the HP air compressorin the event of an emergency.

The LP air section of the ACC consists of fivecontrol indicator push buttons. The indicators andcontrols in this section are functionally identicalto those discussed in the HP air section, exceptthey are for the LP air compressor.

Main Engines StartingAir System Section

The starting air compressors in the mainengine starting air system are designed for eitherlocal or remote start-up. This section providescontrols to allow the operator at the ACC toengage or disengage the compressor clutch. Forthe controls to be operational, the local clutchcontroller selector switch must be in the REMOTEposition. This section also provides indication ofthe clutch status and alarms for low compressorLO pressure and failure of the clutch to engage.A meter provides a continuous reading of the airdischarge pressure.

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The starting air compressor (SAC) section ofthe ACC contains the four control indicator pushbuttons for the three SACs. Since each SAC isidentical, only one set of push buttons will bediscussed.

The first indicator in this section is labeledLUBE OIL LOW PRESSURE. It illuminates redto indicate the LO pressure at the SAC isbelow the preset limit. The second split-legendindicator is labeled CLUTCH ENGAGED andDISENGAGED. The top portion of this indicatorilluminates to indicate the SAC clutch is engaged.The bottom portion of the indicator illuminatesto indicate the clutch is disengaged. The thirdindicator, labeled CLUTCH FAILED TOENGAGE, illuminates red to indicate failure ofthe SAC clutch to engage. The last split-legendindicator control push button in this section islabeled CLUTCH ENGAGED and DISENGAGED.This push button allows the ACC operator toengage or disengage the SAC clutch.

The next item on the ACC vertical panel is avertical reading pressure gauge labeled DIS-CHARGE MANIFOLD PRESS. This gaugeprovides a continuous reading of the dischargemanifold air pressure.

The main engine starting air system providescompressed air to the gas turbine (GT) pneumaticstarter. The starter rotates the GG for starting,motoring, or water washing. The starting airsystem uses compressed air supplied from one ofthree SACs. In an emergency, it can usecompressed air from the bleed air system of anoperating engine. Only one compressor is used forstarting, motoring, or water washing. Two of thecompressors are located in AMR No. 2; the thirdis located in AMR No. 3.

NOTE

The location of each SAC may be differenton each flight of the FFG-class ship.

Each SAC is driven by an associated dieselgenerator set. The compressor is driven by thediesel engine via a step-up gearbox and hydraulicclutch. The clutch can be engaged whenever theelectrical load on the respective SSDG is below666 kW. During compressor operation, should thekW load on the SSDG exceed 666 kW, the clutchwill disengage.

Alarm Acknowledge

The ALARM ACK push button is located inthe lower, center portion of the ACC verticalpanel. When an out-of-tolerance condition occursin a system being monitored at the ACC, theassociated fault alarm actuates. The audible alarmis accompanied by a flashing visual light. Theoperator acknowledges the alarm by depressingthe ALARM ACK push button. The audibleportion of the alarm is silenced and the visual lightstops flashing but remains illuminated. The lightremains illuminated until the cause of the alarmhas been cleared. This push button is used toacknowledge any alarm on the ACC.

Processor Generated Alarm

The processor is a special-purpose computerlocated in the EPCC. When an out-of-tolerancecondition occurs on equipment being monitoredat the ACC, the equipment sensor transmits asignal to the equipment fault alarm circuitry in

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the console. The signal is also transmitted to theprocessor through the ACC. The processorcompares the signal with the alarm set value todetermine if an out-of-tolerance condition exists.If the condition does exist, the processor checksthe equipment fault alarm circuitry to determineif the fault alarm has been actuated. If theprocessor detects an alarm condition not providedby the normal fault alarm circuitry, thePROCESSOR GENERATED ALARM indicatorflashes and the parameter audible alarm sounds.

Air-Conditioning Plants Section

The status of the three air-conditioning plantsis provided at the ACC by visual indicators andalarms. Push buttons provide the capability forstopping the air-conditioning compressors in anemergency.

The ACC vertical panel provides controls andindicators for the three air-conditioning plants.Since these controls and indicators are identicalfor each plant, only one air-conditioning plant willbe discussed.

The first split-legend push-button indicator islabeled ENABLED and RUNNING. The upperportion of the indicator illuminates white toindicate power is being supplied to the air-conditioning compressor. The lower portion ofthe indicator illuminates green to indicate thecompressor is running. The second indicator,labeled AUTO SAFETY SHUTDOWN, illuminatesred to indicate an automatic air-conditioningcompressor shutdown has occurred. The push-button switch, labeled EMERGENCY STOP,allows the operator to stop the air-conditioningcompressor in the event of an emergency.

The air-conditioning plants provide chilledwater for the chilled water circulating system.There are three air-conditioning plants. Eachplant can service a separate loop in the chilledwater system. Each plant has a rated capacityof 80 tons of refrigeration. The plants aredesigned for local start-up and unattendedoperation. One plant is located in the air-conditioning machinery room and two are locatedin AMR No. 2.

Ship’s Stores RefrigerationPlants Section

The status of the two ship’s stores re-frigeration plants is provided at the ACCby visual indications and alarms. Push buttonsprovide the operator with the capability ofstopping the compressors in an emergency.An indicator provides the operating status ofthe compressor. Alarms are actuated whenan automatic safety shutdown occurs, whenthe freeze room temperature is too high, orwhen an abnormal chill room temperature isdetected (high or low).

The first two indicator push buttons monitorthe two chill rooms of the refrigeration plant. Theindicators, labeled ABNORMAL TEMPER-ATURE, illuminate red to indicate an abnormaltemperature in the chill room exists. (Thistemperature can be abnormally high or low.) Thethird indicator is labeled HIGH TEMPER-ATURE. It illuminates red to indicate a hightemperature in the freeze room.

The next three indicator push buttons areunder the heading SHIP’S STORES REFRCPRSR. The first indicator, labeled RUNNING,illuminates green to indicate the refrigerationcompressor is running. The next indicator,labeled AUTO SAFETY SHUTDOWN, illumi-nates red to indicate an automatic refrigerationplant compressor shutdown has occurred. Thepush-button switch, labeled EMERGENCY

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STOP, allows the operator to stop the refrigera-tion compressor in the event of an emergency.

potable water system; the masker, prairie,fin stabilizer, and bleed air systems; thesewage disposal system; the distilling plants;the saltwater service system; and the drainagesystem. This panel is shown on figure 9-24.Refer to figure 9-24 as you read the followingdescriptions.

Potable Water SystemSection

The ship’s stores refrigeration plants allow forthe preserving of perishable food stores. Theplants serve one freeze room and two chill rooms.Each plant has a rated capacity of 1.1 tons ofrefrigeration. Both plants are located in AMRNo. 1. They are designed for local start-up andunattended operation.

The indicators for the potable water systeminclude tank level meters and indicators forthe status of the four potable water tanks,the two potable water pumps, and the hotpotable water pump. High- and low-levelalarms are provided for each of the fourtanks. The operator can use the demanddisplays to monitor the tank levels and thepotable water system pressure. Push-buttonOPEN/CLOSE switches for the potable watertank fill valves allow the operator to coordinatethe tank filling operation.

ACC LOWER PANEL

The ACC lower panel contains the switchesand indicators that control and monitor the

The first indicator in the potable watersystem section is labeled PUMP 2 RUNNING.It illuminates green to indicate that potablewater pump No. 2 is running. The indicator

Figure 9-24.—ACC lower panel.

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for potable water pump No. 1 is functionallyidentical.

The second indicator, labeled HOT WATERPUMP RUNNING, illuminates green to indicatethe hot water pump is running.

The next component in this section is avertical reading meter that continuously monitorsthe potable water tank level. There are fouridentical meters, one for each potable water tank.These meters are scaled in gallons. The thirdindicator push button, labeled HIGH LEVEL,illuminates red to indicate the level in the potablewater tank is 90 percent of capacity. There is ahigh-level indicator for each potable water tank.The fourth indicator push button, labeled LOWLEVEL, illuminates red to indicate the level inthe potable water tank is 10 percent of capacity.There is a low-level indicator for each potablewater tank.

The potable water system stores anddistributes brominated water required by theship’s crew and equipment. There are four potablewater tanks. The system is served by twocentrifugal pumps. Either pump can take suctionfrom any of the four tanks. The pump dischargesto either the filling and transfer main or to theservice main. The system is designed for localstart-up and unattended operation. All the systemcomponents being monitored or controlled arelocated in AMR No. 3.

Masker, Prairie/Fin Stabilizer,and Bleed Air Systems Section

Push-button switches allow control of the twosupply cutout valves in the masker air system andthe supply cutout valve in the prairie/fin stabilizerair system. Split-type indicators provide thevalve status. A meter allows the operator tocontinuously monitor the air discharge temper-ature from the bleed air cooler. An alarm isprovided to alert the operator to an air high-temperature condition.

The first split-legend indicator push button islabeled 2 OPEN and CLOSED. The top portionof the indicator illuminates green to indicate theNo. 2 masker supply cutout valve is open. Thelower portion of the indicator illuminates red toindicate the masker supply cutout valve is closed.The second split-legend indicator push button,labeled 1 OPEN and CLOSED, functionsidentically to the No. 2 supply cutout valvecontrol. The third split-legend indicator pushbutton is labeled OPEN and CLOSED. Thisindicator illuminates to indicate the position ofthe prairie air supply cutout valve. The next threesplit-legend push-button switches allow control ofthe two masker air supply cutout valves and theprairie air supply cutout valve.

Located under the masker and prairie airsupply valve controls is a vertical reading meterlabeled AIR DISCHARGE TEMP. This meter

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allows the operator to continuously monitor thebleed air cooler discharge temperature. The push-button indicator located next to the meter islabeled AIR DISCH HIGH TEMP. It illuminatesred to indicate the bleed air cooler dischargetemperature has reached 400°F.

Sewage Disposal System Section

The ACC has alarms and indicators to showthe status of the collecting, holding, and transfer(CHT) tank level, the sump ejection tank level,the sewage holding tank air compressor, themacerator sewage pump, the comminutors, andthe sewage ejection pumps. The level in the CHTtank can be obtained on the demand display.

The first indicator is labeled HOLDINGTANK HIGH LEVEL. It illuminates red toindicate a high level in the sewage collectingholding tank. The second indicator, labeledSUMP EJECTION TK HIGH LEVEL, illumi-nates red to indicate a high level in the sumpejection tank. The third indicator is labeledHOLDING TANK AIR COMPRESSOR RUN-NING. It illuminates green to indicate that theholding tank air compressor is running. Thefourth indicator, labeled MACERATOR RUN-NING, illuminates green to indicate that themacerator sewage pump is running. The fifthindicator, labeled COMMINUTOR 2 RUNNING,illuminates green to indicate that the No. 2

comminutor is running. The sixth indicator,labeled COMMINUTOR 1 RUNNING, isfunctionally identical to the No. 2 comminutorindicator. The seventh indicator is labeledDISPOSAL PUMP 2 RUNNING. It illuminatesgreen to indicate the No. 2 disposal pump isrunning. The eighth indicator, labeled DISPOSALPUMP 1 RUNNING, is functionally identical tothe No. 2 disposal pump indicator.

The sewage disposal system allows for thedisposal of waste from the ship to satisfy theprevailing ecology requirements. The system hasa CHT tank, two comminutors, and two ejectionpumps located in the collecting, holding, andboiler room. It also has the sump ejection tankand macerator sewage pump located in thesteering gear room. Soil and waste drains emptyinto the CHT tank, or directly overboard,depending on the location of the drain within theship. The contents of the sump ejection tank areautomatically pumped through the maceratorsewage pump to the CHT tank when the ejectiontank is filled to 70 percent of capacity. The CHTtank can be emptied by pumping it directly over-board when the ship is in unrestricted waters, toa barge when it is in restricted waters, or toshore facilities when the ship is secured to adock. The system is designed for local start-upand unattended operation.

Lamp Test

The backlighted momentary-action LAMPTEST push button is provided on the right-hand

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side of the panel. This push button is used to testthe lamps on the lower panel.

Fill Valves Section

This section consists of four sets of indicatorand control push buttons for the fill valves of thepotable water tanks. Since each set is identical,only one set of push buttons will be discussed.

The first split-legend indicator is labeledOPEN and CLOSED. The top portion of theindicator illuminates green to indicate the potablewater tank fill valve is open. The lower portionilluminates red to indicate the potable water tankfill valve is closed. The second split-legend push-button switch allows control of the potable watertank motor-operated fill valve.

Distilling Plants Section

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Alarms, lighted indicators, and a push buttonare provided for monitoring and controlling theoperation of the distilling plants. The alarms alertthe operator to a high or low temperature of thedistillate leaving the sterilizer and to a highdistillate salinity condition. A lighted indicatorprovides the status of the three pumps associatedwith each distilling plant. A push button allowsremote operation of the plant’s 3-way solenoidtrip valve. Each distilling plant section on theACC contains four indicators and one controlpush button. The indicators and control for onlyone plant will be discussed.

The first control push button is labeledDUMP. It allows the operator to operate remotelythe distilling plant’s dump valve. The firstindicator is labeled PRINCIPAL PUMPS RUN-NING. This indicator illuminates green to indicatethe three pumps associated with the distillingplant are running. The second indicator islabeled STERILIZER OUTLET HIGH TEMP.It illuminates red to indicate the sterilizer outlettemperature has reached 198°F. The third

indicator, labeled HIGH SALINITY, illuminatesred to indicate the salinity of the distillate hasreached 0.065 equivalent parts per million (epm).The fourth indicator, labeled STERILIZEROUTLET LOW TEMP, illuminates red to indicatethe sterilizer outlet temperature has dropped to160°F.

The function of each distilling plant is tosupply fresh water for the ship’s potable watersystem. It also supplies untreated distilled waterto the GT water wash system, the electroniccooling water system, and the static frequencychangers. There are two independent distillingplants, each producing 4000 gallons of distilledwater per day. Both plants are located in AMRNo. 3.

Saltwater Service System Section

The status of the saltwater service system isprovided by meters and an alarm for firemainpressure. Also, there are alarms for the seawatercooling system pressure in the three AMRs, theengine room, and the air-conditioning machineryroom. Push-button switches and lighted indicatorsprovide control and status of cooling water over-board discharge valves in the engine room, AMRNo. 2, and the air-conditioning machinery room.

The first alarm indicator in this section islabeled PRESSURE FAILURE. It illuminates redto indicate the cooling water pressure from thefiremain system has dropped to 110 psig. Thesaltwater section of the ACC contains fivePRESSURE FAILURE alarm indicators, all ofwhich function identically.

The first split-legend indicator in this sectionis labeled OPEN and CLOSED. The top portionof the indicator illuminates green to indicate theoverboard discharge valve is open. The bottom

portion of the indicator illuminates red to indicatethe overboard discharge valve is closed. Thesecond split-legend control push button is labeledOPEN and CLOSE. This push button allowscontrol of the motor-operated overboard dis-charge valve. There are three pairs of split-legendindicators and control push buttons in thissection of the ACC.

The first vertical reading meter in this sectionis labeled FIRE MAIN UPPER LOOP PRESS.This meter, scaled in psig, provides continuousmonitoring of the upper firemain loop pressure.A second vertical reading meter, labeled FIREMAIN LOWER LOOP PRESS, provides con-tinuous monitoring of the lower firemain looppressure. Located between the two vertical readingmeters is an alarm indicator labeled LOWPRESSURE. This indicator illuminates red toindicate that the firemain pressure in either loophas dropped to 110 psig.

Drainage System Section

The drainage system indicators include alarmsthat indicate a high liquid level in the bilge of eachof the eight rooms being monitored, a high levelin the waste water drain tanks in the three AMRs,and a high level in the oily waste water holdingtank. Indicators also show the status of thesteering gear room drain pump and the bilgepump in AMR No. 2. The demand display maybe used to monitor the level in the oily waste waterholding tank.

The first alarm indicator is labeled HIGHBILGE LEVEL. It illuminates red to indicate theliquid level in the bilge has exceeded the presetlimit. There are eight HIGH BILGE LEVELalarm indicators in this section of the ACC.

The second indicator is labeled BILGE PUMPRUNNING. It illuminates green to indicate thatthe steering gear room bilge pump is running.

The alarm indicator is labeled WASTEWATER DRAIN TANK HIGH LEVEL. It illumi-nates red to indicate that the level in the wastewater drain tank has exceeded the preset limit.There are three WASTE WATER DRAIN TANKHIGH LEVEL alarm indicators in this section ofthe ACC.

The fourth indicator is labeled OILY WASTEDRAIN BILGE PUMP RUNNING. It illuminates

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green to indicate that the oily waste drain tankbilge pump is running.

The last alarm indicator in this section islabeled OILY WASTE HOLDING TANK HIGHLEVEL. It illuminates red to indicate the level ofthe oily waste holding tank has exceeded the presetlimit.

DAMAGE CONTROL CONSOLEFOR THE FFG-7 CLASS SHIPS

The DCC on the FFG-7 class ships has manyof the same features as the DCC on the DD-963and CG-47 class ships. (See fig. 9-25.) From thisconsole, an operator can monitor and controlmany of the damage control systems installed onthe FFG-7 class frigates. The DCC is located onthe damage control side of CCS. These systemsinclude the following components:

AFFF sprinkling system valves

Halon flooding system

High water alarm

Sprinkling systems

High temperature alarms

Supply fans

Fire zone doors

Exhaust fans

Recirculating fans

Ducting closures

Firemain pumps and valves

Figure 9-25.—Damage control console (FFG-7).

DCC UPPER PANEL

The upper panel of the DCC, shown in figure9-26, is used to monitor most of the systems ofthe DCC. This panel is divided into three majorsections, with each section further divided intosubsections. The upper panel also contains apower monitoring section. The three majorsections are labeled as follows:

1. Misc. Fire Fighting2. Alarm and Detection3. Ventilation

The DCC upper panel displays the four firezones on the FFG-class ship. During thediscussion of the alarms, indicators, and controlsof this panel, only FIRE ZONE 1 will bediscussed. The other five fire zones are identical,with the exception of the indicator labels.

Power Monitoring Section

This section contains eight indicators todisplay the status of various console powerrequirements. The first two indicators are located

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Figure 9-26.—DCC upper panel.

under the heading FIREFIGHTING EQUIPPOWER. The first indicator is labeled FIREPUMP CONTROL POWER ON. It illuminateswhite to indicate fire pump control poweris energized. The second indicator is labeledFM VALVES FZ DOOR RLSE CONT POWERON. It illuminates white to indicate the controlpower for the firemain motor-operated valvesand the fire zone door release control isenergized.

Located under the heading CONSOLEPOWER STATUS are six status indicators. Thefirst indicator, labeled MASTER POWER ON,illuminates white to indicate the main power tothe DCC is energized. The second indicator is asplit-legend status indicator labeled PRIMARY+24 & 28 VDC ON and BACKUP +24 & +28VDC ON. The upper portion of the indicatorilluminates white to indicate the primary24/28-volt dc power converter is in operation. Thelower portion of the indicator illuminates whiteto indicate the backup 24/28-volt dc powerconverter is in operation. The third indicator isa split-legend status indicator labeled PRIMARY+15 VDC ON and BACKUP +15 VDC ON. Theupper portion of the indicator illuminates whiteto indicate the primary +15 volt dc powerconverter is in operation. The lower portion ofthe indicator illuminates white to indicate thebackup +15 volt dc power converter is in

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operation. The fourth indicator is a split-legendstatus indicator labeled PRIMARY – 15 VDCON and BACKUP – 15 VDC ON. The upperportion of the indicator illuminates white toindicate the primary – 15 volt dc power converteris in operation. The lower portion of the indicatorilluminates white to indicate the backup – 15 voltdc power converter is in operation. The fifthindicator is a split-legend status indicator labeledPRIMARY 5 VDC ON and BACKUP 5 VDCON. The upper portion of the indicatorilluminates white to indicate the primary +5 voltdc power converter is in operation. The lowerportion of the indicator illuminates white toindicate the backup +5 volt dc power converteris in operation. The sixth push-button indicator,labeled CONSOLE HEATERS ON, illuminateswhite to indicate the console heaters are energized.Heater power is applied when the console powercircuit is de-energized.

Miscellaneous Fire Fighting Section

This section is the uppermost section of the toppanel. It is divided into two subsections, one con-taining the AFFF sprinkling system valves and theother containing the Halon flooding system. TheAFFF sprinkling system valves subsection showsthe status of the four AFFF sprinkling valves.These valves control the sprinkling of AFFF atthe two vertical replenishment (VERTREP) sta-tions, forward (FWD) and aft (AFT), and thesprinkling systems in the two helicopter hangars.These valves are activated locally and their openor closed status is shown on the DCC.

Open and closed valve indication for sprinklercontrol valves at the forward and aft VERTREPand helicopter hangars is provided on the DCCby two indicating lights. The OPEN indicator lightilluminates green to indicate the sprinkler controlvalve is open. The CLOSED indicator lightilluminates white to indicate the valve is closed.

The second subsection contains the Halonflooding system. Halon is the extinguishing agentused to combat fires in high risk areas. The Halonsystem protects both GTM modules; all fourSSDG enclosures; the engine room; all threeAMRs; the recovery, assist, securing, andtraversing (RAST) equipment room; the paintmixing room; and the flammable gas andliquid storerooms. The DCC has indicators,corresponding to the spaces, that display wheneverHalon has been released to one of these spaces.

Halon release and actuation is displayed onthe DCC with two types of indicator arrangements.The first type is for spaces that have only primaryHalon protection. It contains two indicatorslabeled ACTE and RLSE. The associated ACTEindicator illuminates in response to a pressureswitch contact closure that activates when the CO2actuation system is operated. The RLSE indicatorilluminates to indicate Halon release in theassociated space. The second indicator arrange-ment is for spaces that have primary and reserveHalon protection. This arrangement containsthree indicators to display Halon actuation,primary Halon release, and reserve Halon release.The associated actuation indicator illuminates inresponse to a pressure switch contact closure thatactivates when the CO2 actuation system isoperated. The PRI RLSE indicator illuminates toindicate primary Halon release in the associatedspace. The RSV RLSE indicator illuminates toindicate reserve Halon release in the associatedspace.

Associated with the miscellaneous fire fightingsection is a horizontal grouping of alarmindicators, labeled SUMMARY and INDEP. Thefirst indicator is labeled CONSOLE HIGH TEMPALARM. This alarm indicator illuminates red toindicate the console temperature has exceeded thepreset limit. The second alarm indicator, labeledAFFF SPRKLNG ACTUATION ALARM,illuminates red when any one of the AFFFsprinkling system alarms occur. The thirdindicator, labeled MISSILE CO2 FLOOD INNERRING ALARM, illuminates red to indicate CO2flooding for the inner ring of the missile launcher.

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The fourth alarm indicator, labeled HALONFLOODING ACTUATION ALARM, illuminatesred when any one of the Halon flooding systemsalarms occurs. The fifth alarm indicator is labeledMISSILE CO2 FLOOD OUTER RING ALARM.It illuminates red to indicate CO2 flooding for theouter ring of the missile launcher.

Alarm and Detection Section

The alarm and detection section of the upperpanel is located below the MISC FIRE FIGHTINGsection and contains three subsections. Thesesubsections are high water levels, sprinklingsystems, and high temperature.

The high water level indicators monitor waterlevels in spaces that have high potential forflooding. There are 11 of these alarms for spaces,such as the engine room, AMRs, and several otherequipment rooms. The indicator light illuminatesred to indicate the water level has exceeded thepreset limit in its associated space.

Four alarm indicators are in the sprinklingsystems subsection. These indicators display thestatus of sprinkling systems other than the AFFF

systems. These systems are located in threemagazine spaces and in the trash disposal room.The sprinklers use salt water from the firemainsystem. The alarm indicator illuminates red toindicate the fire fighting sprinkler system isactivated.

The last major subsection in this section is thehigh temperature section. There are 81 indicatorsactivated by temperature sensors locatedthroughout the ship. They alert the operator ifa fire is detected in one of the ship’s spaces. Theindicator illuminates red to indicate the temper-ature of a compartment has exceeded the presetlimit. The indicator also illuminates to indicatethat there is an excess of smoke in a compartment.

Associated with the alarm and detectionsection is a horizontal grouping of summary andindependent alarm indicators. The first alarmindicator in this section is labeled VITAL COMPTHIGH WATER ALARM. It illuminates red toindicate a high water level at one of the locationsmonitored. The second alarm indicator, labeledMISSILE MAG. SPRINKLING ALARM,illuminates red to indicate activation of themissile magazine sprinkling system. The thirdalarm indicator, labeled SPRINKLING SYSTEMACTUATION ALARM, illuminates red toindicate one of the sprinkling systems is activated.The fourth alarm indicator is labeled MISSILEMAG. CPRSN TNK LOW PRESS ALARM. Itilluminates red to indicate low pressure in themissile magazine compression tank. The fifthindicator, labeled MISSILE MAG. DRAINAGEEDUCTOR ALARM, illuminates red to indicatethe missile magazine eductor is in operation. Thesixth alarm indicator is labeled VITAL COMPTSMOKE & HIGH TEMP ALARM. It illuminates

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red to indicate high temperature or excess smokein one of the locations monitored.

Ventilation Section

The largest section of the top panel is theventilation section. This section contains foursubsections, three of which monitor fan status andone that monitors duct closures. No control isavailable here, only monitoring capability.

The top subsection is used to monitor thesupply fans. Twenty-four split-legend indicatorsdisplay either running or stopped status of thesupply fans. The top portion of the indicatorilluminates green to indicate the fan is RUNNING.The bottom portion of the indicator illuminateswhite to indicate the fan is STOPPED.

The exhaust fans section, located below thesupply fan section, has 23 split-legend indicators.They monitor the on/off status of 23 exhaustventilation systems. The top portion of theindicator illuminates green to indicate the fan isRUNNING. The bottom portion of the indicatorilluminates white to indicate the fan is STOPPED.

NOTE

The recirculation fans section, located belowthe exhaust fan section, has 28 split-legendindicators. The 28 recirculation systems have theirstatus displayed in this portion of the panel. Thetop portion of the indicator illuminates green toindicate the fan is RUNNING. The bottomportion of the indicator illuminates white toindicate the fan is STOPPED.

Below the recirculation system monitoringsection are 46 indicators that monitor ductingclosures. They display the open/closed status ofa variety of watertight, blowout, and fire zoneclosures. The top portion of the indicatorilluminates green to indicate the duct closure isOPEN. The bottom portion of the indicatorilluminates white to indicate the duct closure isCLOSED.

Located on the lower left side of the upperpanel is a switch labeled LAMP TEST SWITCH.This switch allows the operator to test theindicator lights on the upper panel. An identicalswitch is located on the lower right side of thepanel and provides the same function.

There are no supply or exhaust fanindicators in FIRE ZONE 1.

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Located at the lower center of the upperpanel is a push-button switch labeled ALARMACKNOWLEDGE. An alarm condition is dis-played by a flashing indicator accompaniedby an audible alarm. Depressing the ALARMACKNOWLEDGE push button silences the audiblealarm and causes the flashing indicator toilluminate steadily. The indicator extinguisheswhen the alarm condition clears.

The next two push-button switches provide fortesting of the annunciator. The switches arelabeled HORN TEST and BELL TEST. Depressingthe HORN TEST push button sounds the horn,while depressing the BELL TEST push buttonsounds the bell. Associated with these pushbuttons is a volume control potentiometer thatthe operator can use to adjust the volume of theaudible alarm.

The only control feature on the top panel islocated on the lower right side. It is labeled FIREZONE DOOR RELEASE. When this push buttonis depressed, the console sends out a signal to closethe fire boundary smoketight doors. This functionprevents the spread of smoke throughout the shipduring fires.

DCC LOWER PANEL

The lower panel of the DCC, shown in figure9-27, monitors and controls the ship’s firemainsystem. This panel has a complete mimic of themajor piping of the firemain. Some of thecapabilities available from this panel include thefollowing:

Fire pump on/off control (five pumps)

Control of major isolation valves (20valves)

AFFF proportioner activation indication

Minor isolation valve indication

Figure 9-27.—DCC lower panel.

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Firemain pressure indication (two meters)

Fire pump power status

During this discussion, refer to figure 9-27.The indicators and controls on the lower panelwill be discussed from left to right and top tobottom.

The first indicator on this panel is asplit-legend status indicator labeled OPEN andCLOSED (A). The top portion of the indicatorilluminates green to indicate that the associatedmotor-operated valve is open. The bottomportion of the indicator illuminates white toindicate the valve is closed. Associated with eachsplit-legend status indicator is a split-legendcontrol push button labeled OPEN and CLOSE.It controls the motor-operated valve. For quickvisual identification, the OPEN/CLOSE pushbuttons and valve position indicators for the threeZEBRA condition loop valves are each high-lighted with dashed lined boxes. The secondindicator is labeled AFFF PROPN ACTIVATION(B). It is an alarm indicator that illuminates toindicate the corresponding AFFF valve isactivated. This alarm is energized in conjunctionwith the corresponding alarm on the miscellaneousfire fighting section of the upper panel. Locatedin the center of the DCC lower panel are twovertical reading meters labeled ZEBRA-UPPERLOOP PRESSURE and ZEBRA-LOWER LOOPPRESSURE (C). These meters reflect firemainpressure measured by transducers at the indicatedlocations. The meters are scaled from 0 to 300psig.

The next section of the lower panel monitorsand controls the fire pumps. It contains threepush-button indicators. There are five identicalsets of push buttons on this panel, one for eachfire pump (D). The first control push-buttonindicator is labeled FIRE PUMP 4 RUN. Itilluminates green to indicate the fire pump isrunning. There are five fire pump run controlpush buttons located on the lower panel. The split-legend indicator control push button is labeledPOWER AVAIL and LOCAL LOCKOUT. Thetop portion of the indicator illuminates to reflectthe status of power availability to the fire pump.The lower portion of the indicator illuminates toindicate the fire pump controller is in localcontrol and remote operation of the pump is notavailable. The second control push-buttonindicator, labeled FIRE PUMP 4 STOP,illuminates red to indicate the fire pump isstopped. There are five fire pump stop control

push buttons located on the lower panel. At theinlet of each fire pump is a split-legend indicatorlabeled OPEN and CLOSED (E). This indicatordisplays the position of the fire pump suctionvalve. The top portion of the indicator illuminatesgreen to indicate the valve is open. The bottomportion of the valve illuminates white to indicatethe valve is closed. There are five indicators onthe DCC lower panel. Located at the lower rightof the panel is a toggle switch labeled LAMPTEST (F). It provides for testing the indicatorson the lower panel.

Operation of the fiiemain system is fairly easy.You can start or stop pumps by depressing eitherthe pump run or pump stop push button. Thesepush buttons also serve as indicators of pumpstatus. The motor-operated isolation valves havesplit-type indicators to display their status. A split-legend push button is also provided to allowoperation of the valves.

During general quarters, condition ZEBRA,the firemain is segregated into two loops. Inthis mode, three motor-operated valves must beclosed. This provides for an upper and a lowerloop. The upper loop is fed by fire pumps 3 and4. The lower loop is fed by pumps 1, 2, and 5.Since the firemain pressure may be differentbetween the loops, two pressure meters areprovided; one is for the upper loop and one forthe lower loop.

BELL AND DATA LOGGERS

Two automatic loggers are located in the CCSto provide printed copies of plant conditions.These automatic loggers are the data logger andbell logger. Both of the printers are identical indesign and operation. The difference is in theinformation the printer is commanded to print.

DATA LOGGER

The data logger (fig. 9-28) provides a hardcopy printout of selected monitor points. Theprintout is initiated automatically once everyhour; however, an automatic/demand controlpermits the operator to demand a printout of datawhen it is needed. If a fault alarm occurs, the datalogger prints out the parameter that caused thealarm. The data logger gives the time in secondsand identifies the monitored sensor.

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Figure 9-29.—Bell logger with sample printout.

Figure 9-28.—Data logger with sample printout.

BELL LOGGER

The bell logger (fig. 9-29) provides anautomatic printout each hour or when any of thefollowing events occur:

The propeller rpm or pitch is changed bymore than 5 percent.

A bell logger printout is demanded by thePCC operator.

The EOT is changed.

The controlling station has been changed(bridge or PCC).

The bell logger prints out the following infor-mation on a 72-column preprinted page:

Time

Month

Day

Order

Station

Pitch (angle of controllable pitch propeller)

rpm

Shaft revolutions

DAMAGE CONTROL CONSOLEFOR DDG-51 CLASS SHIPS

The DCC on the DDG-51 class ship is a three-bay console with access to the componentsmounted in the enclosure through front and rearhinged access doors. The DCC is located in CCS.

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Figure 9-30.—Damage control console (DDG-51).

Figure 9-30 is an overall view of the console.The following paragraphs provide a physicaldescription of the DCC.

The DCC is a single structural enclosure withthree sections designated as A1, A2, and A3. Thefront console has vertical and sloping panelsfor mounting controls and displays and a worksurface that supports a plasma display keyboard.Accessible from the rear of the Al section are apower supply, a fuse panel, and a tone generatorassembly with a speaker and a buzzer. The A2section has another power supply and a powercontrol panel that are accessible from the rear.Accessible from the rear of the A3 section is thepanel distributor swing-frame that holds all of thestandard electronic modules (SEMs). The frontpanels of the console are hinged at the topso the panels can be raised to reach the plasmadisplay assemblies and the other panel-mountedcomponents.

The DCC provides centralized control andmonitoring of the damage control equipment onthe DDG-51 class ship from the CCS. A backupconsole for the DCC is the repair station console(RSC), which is also a part of the machinerycontrol system (MCS). The RSC is located in

repair station 2 and will automatically switch theprimary damage control location between theDCC and the RSC when certain failures areidentified in the DCC. The RSC will be discussedlater in this chapter.

Damage control status signals are receivedfrom peripheral devices that monitor for fire,smoke, intrusion, firemain valve position, andfiremain pump status. Command signals are sentfrom the DCC control panels to the firemainpumps, firemain valves, washdown counter-measure (WDCM) panel, and vertical launchsprinkler system.

VERTICAL PANEL

The vertical panel of the DCC consists of aconsole test section, two plasma display units, andthe firemain control panel.

Console Test Section

The first section of the DCC, labeledCONSOLE, is located at the upper left of theconsole. It contains two push-button indicators,a rotary potentiometer, and two indicator LEDs.The two push buttons, under the headingAUDIBLE ALARMS TEST, are labeled HORN

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and BUZZER. When depressed, these pushbuttons sound the horn and buzzer. The rotarypotentiometer, labeled VOLUME, adjusts thevolume of the horn and- buzzer. The first LEDis labeled TEMP HIGH. It illuminates yellow toindicate the temperature of the console hasexceeded the preset limit. The second LED,labeled UPS IN USE, illuminates red to indicatethe DCC is on UPS.

Plasma Display Section

Located toward the center of the vertical panelare two plasma displays. All plasma display units

in the MCS are identical. A detailed descriptionof the plasma display was presented in chapter7 of this TRAMAN.

Firemain Panel

The firemain panel (fig. 9-31) has a completemimic of the major piping of the firemain. Thepanel is divided into the following four fire zones:

FIRE ZONE 1 - Frame 0 to frame 126,

FIRE ZONE 2 - Frame 126 to frame 254,

FIRE ZONE 3 - Frame 254 to frame 370,and

FIRE ZONE 4 - Frame 370 to frame 466.

The firemain panel provides controls tooperate fire pumps No. 1, No. 3, and No. 5, thefiremain valves, and the washdown countermeasurevalves. This panel also provides indicators to show

Figure 9-31.—Firemain panel.

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the position of the firemain valves, the status offire pumps No. 1, No. 3, and No. 5, and thepressure of the port and starboard firemainrisers.

The DCC firemain panel displays the four firezones. During the discussion of this panel, onlyFIRE ZONE 1 will be described. The other firezones are similar. Their differences will be pointedout during the discussion.

The first section of the FIREMAIN panelmonitors and controls three fire pumps and theirassociated discharge valves. It contains four push-button indicators and two LEDs. There are threeidentical sets of these indicators and controls onthis panel, one for each fire pump (A). The firstLED indicator on the firemain panel is labeledREADY. It illuminates green to indicate the firepump is aligned for operation. A fire pump isready for operation when its motor controller isin remote, and its discharge valve and its seasuction valve are fully open. The first control pushbutton is labeled ON. When depressed, this pushbutton starts the fire pump and illuminates greento show the fire pump is running. The secondcontrol push button is labeled OFF. Whendepressed, this push button stops the fire pumpand illuminates white to show the fire pump isstopped. The second LED indicator, labeledDISCH PRESS LOW, illuminates yellow toindicate the fire pump discharge pressure is belowthe preset limit. The third control push button islabeled OPEN. When depressed, it opens the firepump discharge valve and illuminates green toindicate the valve is open. The fourth control pushbutton is labeled CLOSE. When depressed, itcloses the fire pump discharge valve andilluminates red to indicate the valve is closed.Located below the fire pump controls are twocontrol push buttons labeled OPEN and CLOSE(B). There are 40 identical sets of these pushbuttons on the firemain panel. These pushbuttons control the various firemain valves of thesystem and function the same as the fire pumpdischarge valves. Located at the center of FIREZONE 1 is a vertical reading meter labeled STBDPRESS (C). This meter continuously monitors thepressure of the starboard firemain loop. Anidentical meter, labeled PORT PRESS, is used tomonitor the port firemain loop. The meter for theport loop is located at the center of FIRE ZONE4. Associated with each vertical reading meter isan LED labeled PRESS LOW. It is located at thebottom of the firemain pressure meters. This LEDilluminates yellow to indicate a low firemainpressure in the firemain loop.

SLOPING PANEL

The sloping panel of the DCC contains thecontrols and indicators for WDCM control, thealarm acknowledge push button, the lamp testpush button, and the fire pump panel.

Washdown CountermeasureControl Section

This section is used to select which station hascontrol of the WDCM valves. This sectioncontains two control push buttons under theheading WDCM CONTROL. The first controlpush button is labeled BRIDGE. It transferscontrol of the WDCM group 1 through group4 valves to the bridge control unit (BCU). Itilluminates green to show the BCU has controlof the valves. The second control push button,labeled CTL CONT STA, transfers control of theWDCM group 1 through group 4 valves to theDCC. It illuminates orange to show the DCC hascontrol of the valves. The LED in this section islabeled RPR STA CSL IN CONTROL. Itilluminates yellow to indicate the RSC hascontrol of the firemain valves, the fire pumps, andthe WDCM valves.

Alarm Acknowledge

The alarm acknowledge push button is labeledALARM ACK. Depressing the ALARM ACKpush button silences the audible alarm and causesthe flashing indicator to illuminate steadily. Theindicator extinguishes when the alarm conditionclears.

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Lamp Test

The next push button, located at the lowercenter of the sloping panel, is labeled LAMPTEST. Depressing this push button illuminates allthe lights on the console. The operator uses thispush button to determine which light bulbsneed replacing. Releasing the LAMP TEST pushbutton completes the test and extinguishes thelamps.

Fire Pump Panel

The fire pump panel (fig. 9-32) is locateddirectly below the firemain panel. It contains thecontrols and indicators for fire pumps No. 2, No.4, and No. 6. This panel is also divided into fourfire zones. The controls and indicators on thispanel function identically to those discussed onthe firemain panel.

Figure 9-33.—Repair station console.Plasma Display Keyboard

The final section of the DCC contains theplasma display keyboard. All plasma displaykeyboards in the MCS are identical. A detaileddescription of the plasma display keyboard waspresented in chapter 7.

REPAIR STATION CONSOLE

The RSC on the DDG-51 class ship is a two-bay console with access to the components

mounted in the enclosure through front andrear hinged access doors. Figure 9-33 is anoverall view of the console. The followingparagraphs provide a physical description ofthe RSC.

The RSC is a single structural enclosurewith two sections designated as A1 and A2.The front console has vertical and slopingpanels for mounting controls and displaysand a work surface that supports a plasma

Figure 9-32.—Fire pump panel.

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display keyboard. Accessible from the rearof the Al section are a power supply forthe plasma display and a tone generatorassembly with a speaker and a buzzer. Thefront of the Al section has the mountingfor the plasma display, the AN/UYK-44 main-tenance panel, two power supplies, a batterycharger, and a power/fuse panel. The A2section has two battery assemblies, a transformer,the AN/UYK-44 SEMs, and a bubble memory.The front panels of the console are hingedat the top so the panels can be raised toreach the plasma display assemblies and theother panel-mounted components.

The RSC provides centralized control ofthe damage control equipment and serves asthe primary control station when the DCCis not available. The RSC is a backup consolefor the DCC and automatically switches theprimary damage control location between theDCC and the RSC when certain failures areidentified in the DCC. The RSC is located inrepair station 2.

VERTICAL PANEL

The vertical panel of the RSC consists of aconsole section, a control section, a plasmadisplay unit, and the firemain panel.

Console Section

The first section of the RSC, labeledCONSOLE, is located at the upper left ofthe console. It contains a push-button indicator,a rotary potentiometer, two indicator LEDs,and three fuse holders. The push button,under the heading AUDIBLE ALARM TEST,is labeled HORN. When depressed, this pushbutton sounds the horn. The rotary poten-tiometer, labeled VOLUME, adjusts the volumeof the horn. The first LED is labeled TEMPHIGH. It illuminates yellow to indicate thetemperature of the console has exceeded thepreset limit. The second LED, labeled UPSIN USE, illuminates red to indicate the RSCis on UPS. The first fuse holder is labeledSPARE F03B125VAS. It houses a spare fusefor the console. The next two fuse holdersare under the heading EXHAUST FANS 115VACFUSES. They are labeled LEFT GROUP and

RIGHT GROUP. These fuses protect the exhaustfan circuits.

Control Section

This section contains two control push buttonsused to transfer damage control functions betweenthe DCC and the RSC. The first push button islabeled CTL CONT STA. It illuminates to showthe DCC has control of the firemain valves andfire pumps. The second push button, labeled RPRSTA CSL, illuminates to show the RSC hascontrol of the firemain valves and fire pumps.

Plasma Display Section

Located toward the center of the vertical panelis a plasma display unit. All plasma display unitsin the MCS are identical. A detailed descriptionof the plasma display was presented in chapter 7.

Firemain Panel

The firemain panel has a complete mimic ofthe major piping of the firemain. (Refer tofig. 9-34.) This panel is similar to the firemainpanel on the DCC. Only the fire pumps can becontrolled and monitored from this panel.

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SLOPING PANEL Power Control Panel

The sloping panel of the RSC contains the The power control panel, shown in figure 9-35,power control panel, the firemain valve panel, and distributes electrical power to various componentsthe bubble memory system. of the RSC. The panel consists of 2 rotary snap

Figure 9-34.—Firemain panel.

Figure 9-35.—Power control panel.

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switches, 12 fuse holders, and 3 test points. Thepower control panel is located on left side of thesloping panel.

The first rotary snap switch is labeled 115VACMAIN/155 VDC BAT (A). The positions of theswitch are labeled OFF and ON/AUTO. In theOFF position, no power is applied to the RSC.In the ON/AUTO position, 115 volts ac is appliedto the RSC. This switch position also enables theUPS circuitry. In the event normal power is lost,the 155-volts dc UPS is supplied to the RSC. Thesecond rotary snap switch is labeled HEATER(B). The positions of the switch are labeled ONand OFF. This switch controls the power to theconsole heater.

The right-hand side of the POWER CONTROLPANEL is occupied by 12 fuse holders (C). Thefirst two fuse holders, labeled HEATER andHEATER RELAY, are the dual-cartridge type.They hold the 5-amp fuses that serve to protectthe heater and the heater relay circuits. The threefuse holders, located under the heading FANS,are single-cartridge, twist-type fuse holders. Theyhold the 5-amp fuses that protect the fans of theAN/UYK-44 computer, the transformer, and theinput/output multiplexer. The fuse holder, labeledAUDIBLE ALARM, holds the 5-amp fuse thatprotects the audible alarm circuit. The three fuseholders, under the heading 1 AMP, contain aspare 1-amp fuse, a 1-amp fuse for the self-testcircuit, and a 1-amp fuse for the indicating switchcircuit. Next, there are two spare 5-amp fuse

holders. The last fuse holder on this panel islabeled PLASMA. It holds the 5-amp fuse thatprotects the plasma display circuits. Locatedbelow the fuse holder section are three test points(D). The first test point on the power control panelis labeled RTN. This is the return test point usedwith the self-test relay test points. The next twotest points are located under the heading SELFTEST RELAYS. These test points provide fortesting the self-test relays.

Firemain Valve Panel

The firemain valve panel, shown in figure9-36, contains a digital indicator, four push-button indicators, and a numerical keypad. Thefiremain valves can be opened or closed from theRSC using the controls on the firemain valvepanel. The seven-digit valve number is addressedusing the keypad, and the selected valve isdisplayed on the digital indicator. Once selected,the appropriate push button is used to open orclose the valve.

The digital indicator (A) consists of three sec-tions labeled LEVEL, FRAME, and ATHWART.This indicator displays the seven-digit valvenumber of the selected valve to be controlled.

ALARM ACKNOWLEDGE.—The alarmacknowledge push button (B) is labeled ALARMACK. Depressing the ALARM ACK push buttonsilences the audible alarm and causes the flashing

Figure 9-36.—Firemain valve panel.

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indicator to illuminate steady. The indicatorextinguishes when the alarm condition hascleared.

NUMERICAL KEYPAD.—The numericalkeypad (C) is used to select the firemain valve tobe controlled. As the keys are pressed, thecorresponding digits are displayed on the digitalindicator.

VALVE CONTROLS.—The valve controlpush buttons (D) are labeled OPEN and CLOSE.Once a valid valve number is entered intothe digital display, an automatic display ofthe valve position results on the associatedopen and close push buttons. An invalid numberwill cause the level display on the digitalindicator to flash and OPEN or CLOSE willnot light. Depressing the OPEN or CLOSE pushbutton causes the valve to cycle to the desired posi-tion. The appropriate OPEN/CLOSE push but-ton illuminates to show the position of the valve.

LAMP TEST.—Depressing the LAMP TESTpush button (E) illuminates all the lights on theRSC. This allows the operator to determine whichbulbs need replacement. Releasing the LAMPTEST push button completes the test andextinguishes the lamps.

Bubble Memory Section

Located on the right side of the slopingpanel is the bubble memory system. A detaileddescription of the bubble memory system waspresented in chapter 7.

Plasma Display Keyboard

The final section of the DCC contains theplasma display keyboard. All plasma displaykeyboards in the MCS are identical. A detaileddescription of the plasma display keyboard waspresented in chapter 7.

DATA MULTIPLEX SYSTEM

The ship’s propulsion plant, electric plant, anddamage control system are considered to beassociated equipment of the MCS. The data

multiplex system (DMS), however, is functionallyintegrated with the MCS where all consolesdepend upon the DMS for input data and for acommunications link.

DMS SYSTEM

The DMS is a general-purpose, user-oriented,electronic information transfer system thatprovides data transfer for the major systemsaboard the DDG-51 class ship. The DMS conveysdata from shipboard subsystems such as naviga-tion, damage control, and machinery control.Instead of using conventional multiple hard-wired signal cables unique to each majorsystem, the DMS sends the signals over general-purpose multiplex cables. These cables areinstalled at locations in the ship that allowcontinued DMS operation even when theship is damaged during combat conditions. Theredundancy that is designed into the DMSsystem reduces the chance that data transferswill be lost because of a single-point failure.The DMS interfaces with the MCS consolesto provide console-to-console communications.The DMS also provides control and statusof equipment in the machinery plant, includingdamage control equipment.

DMS INTERFACES

Six consoles in the MCS have AN/UYK-44computers that interface with the DMS network.They are the SCU-1, SCU-2, PACC, EPCC,RSC, and EOOW/logging consoles. Theseinterfaces are dual channel with a primaryand alternate channel. Each channel has itsown cable that connects between the con-sole and the input-output unit (IOU) of theDMS.

There are two interfaces of MCS equipmentthat are not computer interfaces. The panels inthe SCC and the WDCM panel connect to aninput-output module in the DMS IOU. Thecommunication protocol for this type of interfaceis different from that of the AN/UYK-44computer.

The DMS provides the means of transferringinformation between consoles, for collecting dataon the operating machinery monitored by theMCS, and for controlling equipment remotely

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Figure 9-37.—DDG-51 DMS configuration.

from the consoles. (See fig. 9-37.) The DMSfunctionally connects the MCS equipmenttogether by data message transfers. This reducesthe number of cables that would otherwise berequired to achieve the same compatibility.

DMS CONFIGURATION

Figure 9-37 shows the DDG-51 class DMSconfiguration. The configuration shown has 29IOUs, 9 remote multiplexers (RMs), 5 areamultiplexers (AMs), 5 traffic controllers (TCs),and 1 maintenance group (MG) contained in twoenclosures. The IOUs that interface with the MCSare shaded in figure 9-37.

The TCs operate independently of each otherto provide orderly control of access to the primarybusses. The AMs provide the interface for thegroups of RMs so channel access offers from theTCs are matched with the service requests fromthe RMs. The AMs issue service offers to the RMsso they can start message transfer. The RMs

perform the primary control functions associatedwith starting message transfers when requested bythe IOUs and responding to message transferrequests. The RMs also perform primary controlfunctions associated with formatting messages fortransmission and processing messages receivedfrom other RMs or AMs. The IOUs interface withuser devices and the local RMs to provide user-to-user communication paths. The IOU convertsthe input user signals to the DMS signal formatand converts the digital data from the DMS tosignals that are compatible with interfacing userdevice.

DMS TO MCS COMMUNICATIONS

Figure 9-38 is a block diagram of the deviceson the DMS bus that communicate with the MCSequipment. There are three categories ofcommunications used with MCS, each with itsown protocol. They are computer-to-computer(smart-to-smart), computer-to-non-computer

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Figure 9-38.—DMS/MCS communication paths.

peripheral (smart-to-dumb), and non-computerperipheral-to-computer (dumb-to-smart).

DMS COMMUNICATION TEST

The two communication channels that inter-face the DMS with the consoles are verified bysending test messages from one channel to theother and then reversing the transmitting channeland the receiving channel. All test messages mustresult in a positive acknowledgement. A negativeacknowledgement, a time-out, or an errordetected in the transmission results in a testfailed message.

SUMMARY

This chapter should have provided you witha basic understanding of the indicators andcontrols of the auxiliary equipment and consolesof gas turbine-powered ships. Most GSEs andGSMs assigned to a gas turbine-powered ship willstand watches at one time or another in the CCS.For this reason, you should be familiar with thecapabilities of the CCS consoles and auxiliary

equipment. The GSEs are also responsible formaintenance of the consoles. Although theseconsoles are relatively trouble-free, you shouldbecome familiar with their internal operation.

While this chapter was written to familiarizeyou with the consoles in the CCS of DD-963,CG-47, FFG-7, and DDG-51 class ships, theinformation in this chapter is not sufficient foroperational or troubleshooting purposes. Thismaterial provides you with enough knowledge tobegin qualifying on CCS watches, in addition toyour using the PQS applicable to the watchstation you are learning.

The knowledge you have gained by readingthis chapter should also provide you with enoughinformation to help a qualified technician in therepair of this important equipment. Only technicalmanuals can give you the in-depth procedures asto how to troubleshoot and repair the CCSequipment. Never try to work on this equipmentwithout the proper manuals. The GSE 1 & CTRAMAN also provides general information ontroubleshooting techniques and repair procedures.

Like all other material in this manual,this chapter was written to provide you with

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a basis upon which to start your qualifications In no way is this material meant to be a one-at watch stations on your ship. Your knowledge stop source for qualifying as a watch stander. Youof this material should help you to advance should use the EOSS, the PQS, ship informationin rate and make you more valuable to the books, and the applicable technical manuals forNavy. this process.

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APPENDIX I

GLOSSARY

ADIABATIC—To occur without loss or gainof heat by the substance concerned.

AERODYNAMICS—A branch of dynamicsthat deals with the motion of air and other gaseousfluids and the forces acting on bodies in motionrelative to such fluids.

ALARM ACKNOWLEDGE—A push buttonthat must be depressed to silence an alarm.

ALLOY—Any composition metal producedby the mixing of two or more metals or elements.

ALTERNATING CURRENT (ac)—An elec-trical current that constantly changes amplitudeand polarity at regular intervals.

AMBIENT TEMPERATURE—The surroundingtemperature, such as the air temperature thatsurrounds a conductor in a compartment or pieceof equipment.

AMBIENT PRESSURE—The surroundingpressure, such as the air pressure that surroundsa conductor in a compartment or piece ofequipment.

AMPERE (amp)—A unit of electrical currentor rate of flow of electrons. One volt across 1 ohmof resistance causes a current flow of 1 ampere.

ANALOG SIGNAL—A measurable quantitythat is continuously variable throughout a givenrange and that is representative of a physicalquantity.

ANALOG-TO-DIGITAL CONVERSION(A/D or ADC)—A conversion that takes ananalog in the form of electrical voltage orcurrent and produces a digital output.

ANNULAR—In the form of or forming aring.

ANTI-ICING —A system for preventingbuildup of ice on the gas turbine intake systems.

ATMOSPHERE—A unit of measure equal to14.696 psi or 29.92 inches of mercury (1 atmos-phere = 14.696 psi).

ATMOSPHERIC PRESSURE—The pressureof air at sea level, about 14.7 psi.

AUTOMATIC PARALLELING DEVICE(APD)—The APD automatically parallels anytwo generators when an auto parallel commandis initiated by the EPCC.

AUXILIARY CONTROL CONSOLE (ACC)—The console in CCS used to monitor the auxiliarysystems on FFG-class ships.

AXIAL FLOW—Air flow parallel to the axisof the compressor rotor.

BABBITT—A white alloy of tin, lead,copper, and antimony that is used for liningbearings.

BAFFLE—A plate, wall, or screen used todeflect, check, or otherwise regulate the flow ofa gas, liquid, sound waves, and so forth.

BATTERY—A device for converting chemicalenergy into electrical energy.

BLEED AIR—Air bled off the compressorstages of the GTEs. See BLEED AIR SYSTEM.

BLEED AIR SYSTEM—This system uses asits source compressed air extracted from thecompressor stage of each GTE or GTG. It is usedfor anti-icing, prairie air, masker air, and LP gasturbine starting for both the GTEs and GTGs.

BLOW-IN DOORS—Doors located on thehigh hat assembly designed to open by solenoid-operated latch mechanisms if the inlet airflowbecomes too restricted for normal engineoperation.

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BORESCOPE —A small periscope (instru-ment) used to visually inspect internal enginecomponents.

BRIDGE CONTROL UNIT (BCU)—Theconsole located on the bridge of the DDG-51 classship that has equipment for operator control ofship’s speed and direction.

BUS TIE BREAKER (BTB)—A device usedto connect one main switchboard to another mainswitchboard.

BUS—An uninsulated power conductor (a baror wire) usually found in a switchboard.

CALIBRATION—( 1) The operation of makingan adjustment or marking a scale so that thereadings of an instrument conform to an acceptedstandard. (2) The checking of reading by com-parison with an accepted standard

CANTILEVER —A horizontal structuralmember supported only by one end.

CASUALTY—An event or series of events inprogress during which equipment damage and/orpersonnel injury has already occurred. The natureand speed of these events are such that proper andcorrect procedural steps will only serve to limitequipment damage and/or personnel injury.

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CENTRAL CONTROL STATION (CCS)—The main operating station from which a majorityof the engineering plant machinery can becontrolled and monitored.

CENTRAL INFORMATION SYSTEM EQUIP-MENT (CISE)—Located in CCS and is part ofthe PAMISE. It includes the general-purposedigital computer (ECU), S/CE No. 1, andsupporting equipment.

CENTRIFUGAL FORCE—That force thattends to drive a thing or parts of a thing outwardfrom a center of rotation.

CIRCUIT BREAKER (CB)—A device usedto energize/de-energize an electrical circuit andfor interrupting the circuit when the currentbecomes excessive.

CLASSIFICATION—A method of identifyingand sorting various equipment and materials. Forexample: (1) check valve—swing check valve, stopcheck valve; (2) valve—solenoid valve, manualvalve.

CLUTCH/BRAKE ASSEMBLY—a clutch/brake assembly for each GTE is mounted on theMRG housing to couple or decouple either or bothengines to the drive train, to stop and hold thepower turbine, and for shaft braking.

COALESCE—To grow together, unite, orfuse, as uniting small liquid particles into largedroplets. This principle is used to remove waterfrom fuel in the filter/separator.

COHESION—The force that causes moleculesthat are brought close together to stick together.

COMBUSTION CYCLE—The process thatincludes compression of air, burning of compressedair/fuel mixture, expansion of gases, and removalof gases.

COMPRESSOR INLET TEMPERATURE(CIT or T2)—The temperature of the air enteringthe gas turbine compressor (GTE) as measuredat the front frame; one of the parameters usedfor calculating engine power output (torque) andscheduling combustion fuel flow and VSV angle.

COMPRESSOR DISCHARGE PRESSURE(CDP)—Compressor discharge pressure is sensedby a pressure tap on the compressor dischargestatic pressure sensing line to the MFC and pipedto a base-mounted transducer on the GTE.

COMPRESSOR INLET TOTAL PRESSURE(Pt 2)—The pressure sensed by a total pressureprobe mounted in the GTE compressor frontframe.

COMPRESSOR—The component of a GTEthat compresses the air.

CONCENTRIC —Having a common axis orformed about the same axis.

CONDUCTION—The transfer of heatthrough matter by communication of kineticenergy from particle to particle rather than by aflow of heated material.

CONTROLLABLE REVERSIBLE PITCH(CRP) PROPELLER—A propeller whose bladepitch can be varied to control the amount of thrustin both the ahead and astern directions. (Knownas controllable pitch propeller (CPP) on FFG-classships.)

CURRENT—The movement of electrons pasta reference point. The passage of electronsthrough a conductor. It is measured in amperes.

DAMAGE CONTROL CONSOLE (DCC)—This console is located in CCS and providesmonitoring for hazardous conditions (fire, highbilge levels, and so forth). It also monitors theship’s firemain and can control the fire pumps.

DATA MULTIPLEX SYSTEM (DMS)—Ageneral-purpose information transfer system thatprovides data transfer for most of the majorsystems aboard the DDG-51 class ship.

DEAERATOR—A device that removes airfrom oil (for example, the lube oil storage andconditioning assembly (LOSCA) tank whichseparates air from the scavenge oil).

DEMAND DISPLAY INDICATOR (DDI)—Anumerical display that is used to read values ofparameters within the engineering plant.

DEMISTERS—A moisture removal device(GTE intake system) that separates water fromair.

DENSITY—The quantity of matter containedin a body.

DIFFERENTIAL PRESSURE—The differencebetween two pressures measured with respect toa common basis.

DIFFUSER —A device for reducing the velocityand increasing the static pressure of a mediumpassing through a system.

DIGITAL-TO-ANALOG CONVERSION (D/Aor DAC)—A conversion that produces an analogoutput in the form of voltage of current from adigital input.

DIRECT CURRENT—An essentially constantvalue electric current that flows in one direction.

DROOP MODE—This mode is normally usedonly for paralleling with shore power. This modeprovides a varying frequency for any varying load.Droop mode inhibits the load sharing circuitry.

EDUCTOR —A mixing tube (jet pump) thatis used as a liquid pump to dewater bilges andtanks. A GTE exhaust nozzle creates an eductoreffect to remove air from the enclosure.

ELECTRIC PLANT CONTROL ELEC-TRONICS ENCLOSURE (EPCEE)—The EPCEEis part of the EPCE. It contains power suppliesthat provide the various operating voltage requiredby the EPCC on the CG- and DD-class ships.

ELECTRIC PLANT CONTROL CONSOLE(EPCC)—This console contains the controls andindicators used to remotely operate and monitorthe generators and the electrical distributionsystem.

ELECTRIC PLANT CONTROL EQUIP-MENT (EPCE)—The EPCE provides centralizedremote control of the GTGS and electricaldistribution equipment. The EPCE includes theEPCC and EPCEE and is located in CCS.

ELECTRONIC GOVERNOR (EC)—A systemthat uses an electronic control unit with an electro-hydraulic governor actuator (EGA) to control andregulate engine speed.

EMERGENCY —An event or series of eventsin progress which will cause damage to equipmentunless immediate, timely, and correct proceduralsteps are taken.

ENGINEERING CONTROL AND SURVEIL-LANCE SYSTEM (ECSS)—An automatic elec-tronic control and monitoring system using analogand digital circuitry to control the propulsion andelectric plant. The ECSS consists of the EPCE,PAMCE, PAMISE, PLOE, and SCE on the CG-and DD-class ships.

ENGINEERING OPERATIONAL SEQUENC-ING SYSTEM (EOSS)—A two-part system ofoperating instructions bound in books for eachwatch station. It provides detailed operatingprocedures (EOP) and casualty control procedures(EOCC) for the propulsion plant.

ENGINE ORDER TELEGRAPH (EOT)—A non-voice communication system providedbetween the command station (pilot house), CCS,and the main engine room.

EXECUTIVE CONTROL UNIT (ECU)—Acomputer (part of PAMISE) that is the nucleusof the information center of the ECSS. The ECUgathers data information from the ship’s propul-sion, auxiliary, and electric plant equipment.

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EXPANSION—The increase in volume of thegases in a turbine after combustion by which thegases continue to turn the rotor while expendingpart of its internal energy and losing in pressureand temperature.

FEEDBACK—A value derived from a con-trolled function and returned to the controllingfunction.

FEEDWATER —Distilled water made inevaporators for use in boilers. Feedwater is morepure than drinking (potable) water.

FERROUS—Refers to metals having iron asthe base metal.

FILTER—(l) A device that removes insolublecontaminants from the fluid power system. (2) Adevice through which gas or liquid is passed; dirt,dust, and other impurities are removed by theseparating action.

FREE STANDING ELECTRONIC ENCLO-SURE (FSEE)—The FSEE provides the supportingelectronic and engine control interface betweenthe GTE and the control consoles. One FSEE islocated in each MER.

FREQUENCY—The number of cycles (as inan alternating electrical current) completed persecond.

FRICTION —Resistance to the relative motionof one body sliding, rolling, or flowing overanother with which it has contact.

FUEL SYSTEM CONTROL CONSOLE(FSCC)—Located in CCS and is the centralstation for monitoring and control of the fuel filland transfer system.

FUEL OIL SYSTEM—This system providesa continuous supply of clean fuel to the GTEs.

FULL POWER—The condition in which bothengines (GTEs) in one engine room are engagedand driving the reduction gear and propeller shaft.

GAS GENERATOR (GG)—The gas-producingsection of any GTE. It usually has a compressor,a combustor, a high-pressure turbine, an accessorydrive system, and controls and accessories.

GAS TURBINE ENGINE (GTE)—A GTEconsists of a compressor, a combustor, a turbine,and an accessory drive system. Many variationsof GTEs exist.

GAS GENERATOR SPEED (NG G)—Thespeed sensed by a magnetic pickup on the transfergearbox of the GTE.

GAS TURBINE GENERATOR SET (GTGS)—The GTGS has a GTE, a reduction gearbox, anda generator.

GENERATOR BREAKER (GB)—The GB isused to connect a generator to its main switchboard.

GOVERNOR CONTROL UNIT (GCU)—Astatic GCU is supplied for each GTGS consistingof a static exciter/voltage regulator assembly, fieldrectifier assembly, motor-driven rheostat, and modeselect rotary switch. It controls the output voltageof the generator.

HEADER—A piping manifold that connectsseveral sublines to a major pipeline.

HEAD TANK—A tank located higher thanother system components to provide a positivepressure to a system by gravity.

HERTZ (Hz)—A unit of frequency equal to onecycle per second.

HIGH HAT ASSEMBLY—A removable housingover the main engine air intake ducts that containsthe moisture separation system (demisters), inletlouvers, and blow-in doors.

HORSEPOWER (hp)—A standard unit ofpower that equals 550 foot pounds of work persecond.

HUMIDITY—The weight of water vapor ingrains per cubic foot of air.

HYDRAULIC—Conveyed, operated, ormoved by water or other liquid in motion.

HYDRAULIC OIL POWER MODULE(HOPM)—A component located near the MRGto deliver control oil and high pressure (HP) oilto an oil distribution box for distribution to thepropeller hub and activation of the pitch controlrod within the shaft.

IMPELLER—A blade or series of blades ofa rotor that imparts motion.

INERTIA —Any change in motion beingmeasured by the acceleration of the center ofmass.

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INFORMATION CONTROL CONSOLE(ICC)—Part of the ECU. ICC No. 1 is used toprogram and run the computer. ICC No. 2 is thetape reader and is used to input the program intothe ECU.

INLET GUIDE VANE (IGV)—The variablevanes ahead of the first stage of compressor bladesof a GTE. Their function is to guide the inlet airinto the GTE compressor at the optimum angle.

ISOCHRONOUS MODE—This mode isnormally used for generator operation. This modeprovides a constant frequency for all loadconditions. When two (or more) generators areoperated in parallel, the isochronous mode alsoprovides equal load sharing between units.

JOULES—Unit of energy. The work donewhen the point of application of 1 newton isdisplaced a distance of 1 meter in the directionof force.

JP-5—The primary type of fuel used forhelicopters and small boats. The emergency sourceof fuel for the GTEs and GTGs.

KILOWATT —A unit of electrical powerequal to 1000 watts. (A watt is a unit of powerequal to the rate of work represented by acurrent of 1 ampere under a pressure of 1 volt.)

KINETIC ENERGY—Energy in motion.

LABYRINTH/HONEYCOMB SEAL—Thisseal combines a rotating element and ahoneycomb stationary element to form an air seal.Used in GTEs to maintain close tolerances overa large temperature range.

LABYRINTH/WINDBACK SEAL—This sealcombines a rotating element with a smoothsurface stationary element to form an oil seal. Thewindback is a coarse thread on the rotatingelement of the oil seal which uses screw action(windback) to force any oil that might leak acrossthe seal back into the sump.

LIQUID FUEL VALVE (LFV)—This valvemeters the required amount of fuel for all engineoperating conditions for the Allison 501-K17GTE.

LOAD SHEDDING—Protects a generatorfrom overloading by automatically droppingpreselected loads when generator output reaches100 percent.

LOCAL OPERATING PANEL (LOP)—TheLOP is the local operating station for GTEs onthe FFG-class ships. It is located in the MER andis used primarily for maintenance.

LUBE OIL STORAGE AND CONDITION-ING ASSEMBLY (LOSCA)—The LOSCA ismounted remotely from the GTE and is a unitwith a lube oil storage tank, a heat exchanger, ascavenge oil duplex filter, and a scavenge oilcheck valve (all mounted on a common base). Itsfunction is to provide the GTE with an adequatesupply of cool, clean lube oil.

MACHINERY CONTROL SYSTEM (MCS)—Provides centralized and remote monitoring andcontrol of propulsion, electrical, auxiliary, anddamage control systems of the DDG-51 class ship.

MAIN REDUCTION GEAR (MRG)—Alocked train, double-reduction gear designed toreduce the rpm output of the GTE and drive thepropeller shaft.

MAIN FUEL CONTROL (MFC)—A hydro-mechanical device on the propulsion GTE thatcontrols NGG, schedules acceleration fuel flow,deceleration fuel flow, and stator vane anglefor stall-free, optimum performance over theoperating range of the GTE.

MASKER AIR SYSTEM—This systemdisguises the sound signature of the ship and alterstransmission of machinery noise to the water byemitting air from small holes in the emitter ringson the ship’s hull.

MASS—The measure of the quantity ofmatter contained in a body.

METALLURGY—The science dealing withthe structure and properties of metals and alloys,and the processes by which they are obtained fromore and adapted to the use of man.

MICRON—A unit of length equal to onemillionth of a meter.

MIL—A unit of length equal to onethousandth of an inch.

NAVY STANDARD DAY—Parametersmeeting the following requirements: sea level,barometric pressure of 29.92 inches of mercury,humidity of 0.00 inch of mercury, and atemperature of 59°F.

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NOZZLE—A taper or restriction used tospeed up or direct the flow of gas or liquid.

OIL DISTRIBUTION (OD) BOX—This boxis located at the forward end of each MRGassembly. It directs HP oil from the HOPM tothe propeller hub through the shaft bore. The ODbox also establishes propeller pitch by usingcontrol oil from the HOPM to position the valverod, which extends through the shaft to the hub.

ORIFICE—A circular opening in a flowpassage that creates a flow restriction.

PARAMETER —A variable, such as temper-ature, pressure, flow rate, voltage, current, orfrequency that may be indicated, monitored,checked, or sensed in any way during operationor testing.

PERMANENT MAGNET ALTERNATOR(PMA)—The PMA is mounted on the generatorshaft extension of each GTGS and supplies speedsensing and power to the EG. The PMA alsosupplies initial generator excitation.

PHOTOELECTRIC—Electricity produced bythe action of light.

PITCH—A term applied to the distance apropeller will advance during one revolution.

PLENUM CHAMBER—An enclosed spacein which the pressure of the air is greater than theoutside atmosphere.

POTENTIOMETER—A variable resistanceunit having a rotating contact arm that can be setat any desired point along the resistance element.

POWER TURBINE INLET TOTAL PRES-SURE (Pt 5 . 4)—The pressure sensed by pressureprobes located in the GTE turbine midframe andpiped to a transducer on the bottom of the GTM.

POWER TURBINE INLET GAS TEMPER-ATURE (T5.4)—The temperature sensed bythermocouples installed in the GTE midframe.

POWER TURBINE SPEED (Np t)—Thespeed sensed by magnetic pickups in the GTEturbine rear frame.

POWER LEVEL ANGLE (PLA)—A rotaryactuator mounted on the side of the GTE fuel

pump and its output shaft lever. It is mechanicallyconnected to the MFC power lever. The PLAactuator supplies the torque to position the MFCpower lever at the commanded rate.

POWER TURBINE (PT)—The GTE turbinethat converts the GG exhaust into energy andtransmits the resulting rotational force via theattached output shaft.

POWER TAKEOFF (PTO)—The drive shaftbetween the GTGS GTE and the reduction gear.It transfers power from the GTE to the reductiongear to drive the generator.

PRAIRIE AIR SYSTEM—This system emitscooled bleed air from small holes along the leadingedge of the propeller blades. The resulting airbubbles disturb the thrashing sound so identifica-tion of the type of ship through sonar detectionbecomes unreliable.

PRESSURE—Force per unit of area, usuallyexpressed as psi.

PRIME MOVER—( 1) The source of motion—as a GTE, (2) the source of mechanical power usedto drive a pump, or compressor, (3) or rotor ofa generator.

PROPELLER—A propulsive device consistingof a boss or hub carrying two or more radialblades. (Also called a screw.)

PROPULSION AUXILIARY CONTROLCONSOLE (PACC)—This console is located inCCS and is part of the PAMCE. It contains theelectronic equipment capable of controlling andmonitoring both propulsion plants and auxiliaryequipment on a CG- or DD-class ship. (Alsoknown as PACC on the DDG-51 class ship butnot a part of PAMCE.)

PROPULSION AND AUXILIARY MACHIN-ERY CONTROL EQUIPMENT (PAMCE)—This equipment is located in CCS, is part of theECSS, and includes the PACC and PACEE. Thisequipment provides centralized control andmonitoring of both main propulsion plants andauxiliary machinery on a CG- or DD-class ship.

PROPULSION AND AUXILIARY MACHIN-ERY INFORMATION SYSTEM EQUIPMENT(PAMISE)—This equipment is located in CCSand is part of the ECSS. This equipment receives,

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evaluates, and logs the engineering plant perform-ance, status, and alarm state. The PAMISEcontains the CISE and S/CE No. 1 on a CG- orDD-class ship.

PROPULSION CONTROL CONSOLE (PCC)—This is the main engine control console in CCSon an FFG-class ship. It is used for starting,stopping, and controlling the GTEs and propellershaft.

PROPULSION LOCAL CONTROL CON-SOLE (PLCC)—The PLCC is located in eachengine room and is part of the PLOE. It hascontrols and indicators necessary for operator’scontrol of one main propulsion plant and itssupporting auxiliaries on a CG- or DD-class ship.

PROPULSION LOCAL OPERATING EQUIP-MENT (PLOE)—The PLOE is located in eachengine room and is part of the ECSS. It includesthe PLCC and PLCEE. The PLOE provides forlocal control and monitoring of the main pro-pulsion GTE and the associated auxiliary equip-ment on a CG- or DD-class ship.

PUMP—( 1) A device that converts mechanicalenergy into fluid energy. (2) A device that raises,transfers, or compresses fluids or gases.

RADIALLY—Developing uniformly arounda central axis.

REPAIR STATION CONSOLE (RSC)—Provides centralized control of the damagecontrol equipment on DDG-51 class ships. TheRSC serves as the primary control station whenthe DCC is not available.

RESISTANCE TEMPERATURE DETECTOR(RTD)—A temperature sensor that works on theprinciple that as temperature increases, theconductive material exposed to this temperatureincreases electrical resistance.

RESISTOR —A device possessing the propertyof electrical resistance.

RHEOSTAT —A variable resistor having onefixed and one moveable terminal.

ROTOR—A rotating wheel or group ofwheels in a turbine.

SALIENT POLE GENERATOR—A generatorwhose field poles are bolted to the rotor, asopposed to a generator whose field poles areformed by imbedding field windings in the slotsof a solid rotor.

SCAVENGE PUMP—A pump used to removeoil from a sump and return it to the oil supplytank.

SENSOR—The part of an instrument thatfirst takes energy from the measured medium toproduce a condition representing the value of themeasured variable.

SHAFT CONTROL UNIT (SCU)—The SCUis located in each engine room. It has controls andindicators necessary for operator control of onemain propulsion plant and its supportingauxiliaries on a DDG-51 class ship.

SHIP CONTROL CONSOLE (SCC)—Thisconsole is located on the bridge of CG- and DD-class ships. It has equipment for operatorcontrol of ship’s speed and direction.

SHIP’S SERVICE DIESEL GENERATOR(SSDG)—The SSDG is the main source of elec-trical power for a ship. It uses a diesel engine asthe prime mover for the generator.

SHIP’S SERVICE GAS TURBINE GENER-ATOR (SSGTG)—The SSGTG is the main sourceof electrical power for a ship. It uses a GTE asthe prime mover for the generator.

SIGNAL CONDITIONING ENCLOSURE(S/CE)—Part of the PAMISE and provides themajor input interface between the propulsionplant machinery and the ECSS control consoles.The S/CE accepts inputs from the plantmachinery and outputs normalized signals to theECSS control consoles. Also has alarm detectionand alarm output circuitry. One S/CE is locatedin each engine room and one is a part of the CISE(located in CCS).

SOLENOID—A coil of wire in the form ofa long cylinder that resembles a bar magnet. Whencurrent flows in the wire, a movable core is drawninto the coil.

SPLIT PLANT—The condition in whichonly one engine in an engine room is driving thereduction gear/propulsion shaft.

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STALL—An inherent characteristic of all gasturbine compressors to varying degrees and undercertain operating conditions. It occurs wheneverthe relationship between air pressure, velocity, andcompressor rotational speed is altered so that theeffective angle of attack of the compressor bladesbecomes excessive, causing the blades to stall.

STATOR—The body of stationary blades ornozzles of a turbine.

SUMMARY ALARM—An indicator at aconsole that indicates to an operator that one ofseveral abnormal conditions has occurred on acertain piece of equipment.

SYNCHRO SELF-SHIFTING (SSS) CLUTCH—The SSS clutch is a fully automatic, free-wheeldevice that transmits power through gear-toothedelements.

TACHOMETER—An instrument used tomeasure the speed of rotation of a device.

TEMPERATURE—The quantitative measureof the relative hotness or coldness of an object.

THERMAL ENERGY—The potential andkinetic energy of particles of a body which canbe evolved as heat.

THERMOCOUPLE —(1) a bimetallic devicecapable of producing an emf roughly proportionalto temperature differences on its hot and coldjunction ends. (2) A junction of two dissimilarmetals that produces a voltage when the junctionis heated.

THERMODYNAMICS—A branch of dynamicsthat deals with the applied forces caused by theapplication of heat.

THRUST BEARING—Bearing that limits theaxial (longitudinal) movement of the shaft.

THRUST—The forward directed reactionforce produced by a high-speed jet of air dis-charged rearward from a nozzle or orifice.

TOLERANCE—The allowable deviationfrom a specification or standard.

TORQUE—A force or combination of forcesthat produces or tends to produce a twisting orrotary motion.

TRANSDUCER —(l) A device that convertsa mechanical input signal into an electricaloutput signal. (2) Generally, a device thatconverts energy from one form into another,always retaining the characteristic amplitudevariations of the energy converted.

TRANSFORMER—A device composed oftwo or more coils, linked by magnetic linesof force, used to step up or step down an acvoltage.

TURBINE OVERTEMPERATURE PRO-TECTION SYSTEM (TOPS)—A system used ona CG- or DD-class ship to protect a survivinggenerator from overload if another generatorfails.

TURBINE INLET TEMPERATURE (TIT)—The GTGS turbine inlet temperature on theAllison 501-K17. (Known as T5.4 for an LM2500GTE.)

ULTRAVIOLET (UV) SENSOR—A devicethat senses the presence of fire in the GTE andGTG enclosure and generates an electrical signalthat is sent to the ECSS.

UNINTERRUPTIBLE POWER SUPPLY(UPS) SYSTEM—Critical ship control systemshave a UPS as an emergency power source.The UPS is used to maintain operationsduring any interruption of the normal powersource.

VACUUM—Pressure less than atmosphericpressure.

VARIABLE STATOR VANE (VSV)—Acompressor stator vane that is mechanically variedto provide optimum, stall-free compressor per-formance over a wide operating range.

VELOCITY —The rate of motion in aparticular direction. The velocity of fluid flow isusually measured in feet per second.

VENTURI—A device that depends for opera-tion upon the fact that as the velocity of flow ofair increases in the throat the pressure decreases.

VISCOSITY —The internal resistance of afluid which tends to prevent it from flowing.

VOLT—A unit of electrical potential.

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VOLTAGE—An electric potential difference,expressed in volts.

VOLUME—The amount of space that matteroccupies.

WASTE HEAT BOILER (WHB)—Eachwaste heat boiler is associated with a GTGS anduses the hot exhaust gases to convert feedwaterto steam for various ship’s services on CG-, DD-or CG- and DD- class ships.

WATT—A unit of electric power equal to theVORTEX—That which resembles a whirlwind rate of work represented by a current of 1 ampere

or whirlpool. under a pressure of 1 volt.

AI-9

APPENDIX II

ABBREVIATIONS AND ACRONYMS

This appendix is a listing of the abbreviations and acronyms used in thistext. Although this is an extensive listing, it is not an all-inclusive list of ab-breviations and acronyms used by the Gas Turbine Systems Technicians. TheGSE3/GSM3, NAVEDTRA 10563, volume 1, also has an appendix II withabbreviations and acronyms used in the text. However, this list will help forma basis for your qualification under the PQS system and allow for rapidaccess to terms used by Gas Turbine Systems Technicians.

A

A/C—air conditioning

ACC—auxiliary control console

ADC—analog-to-digital converter

AFFF—aqueous film forming foam

AGB—accessory gearbox

AM—area multiplexers

AMR—auxiliary machinery room

APD—automatic paralleling device

ASROC—antisubmarine rocket

ASW—antisubmarine warfare

B

BCU—bridge control unit

BLISS—boundary layer infrared suppressionsystem

BTB—bus tie breaker

C

CB—circuit breaker

CBR—chemical, biological, radiation

CCS—central control station

CDP—compressor discharge pressure

CHT—collecting, holding and transfer

CISE—central information system equipment

CIT—compressor inlet temperature

CO2—carbon dioxide

CODAG—combined diesel and gas

CODOG—combined diesel or gas

COGOG—combined gas or gas

COSAG—combined steam and gas

CPU—central processing unit

CRP—controllable reversible pitch

CT—current transformer

D

DAC—digital-to-analog converter

DCC—damage control console

DDI—demand display indicator

DFM—diesel fuel, marine

DMS—data multiplex system

DVM—digital voltmeter

AII-1

E

ECSS—Engineering Control and SurveillanceSystem

ECU—electronic control unit

EG—electrohydraulic (electric) governor

EHGA—electrohydraulic governor actuator

EMI—electromagnetic interference

EOOW—engineering officer of the watch

EOSS—Engineering Operational SequencingSystem

EOT—engine order telegraph

EPCC—electric plant control console

EPCE—electric plant control equipment

EPCEE—electric plant control electronicsenclosure

EPM—equivalent parts per million

F

FO—fuel oil

FOD—foreign object damage

FSCC—fuel system control console

FSEE—free standing electronic enclosure

ft3/min—cubic feet per minute

G

GB—generator circuit breaker

GCU—governor control unit

GG—gas generator

GMLS—guided missile launching system

GMT—greenwich mean time

gpm—gallons per minute

GSE—Gas Turbine Systems Technician (Elec-trical)

GSM—Gas Turbine Systems Technician(Mechanical)

GSs—Gas Turbine Systems Technicians

GT—gas turbine

GTE—gas turbine engine

GTG—gas turbine generator

GTGSs—gas turbine generator sets

GTM—gas turbine module

H

HF—high-frequency

HP—high-pressure

hp—horsepower

HSS—high-signal select

HVAC—heating, ventilation, and air con-ditioning

I

ICC—information center console

IGV—inlet guide vane

in.H2O—inches of water

IOU—input-output units

IR—infrared

K

KOH—potassium hydroxide

AII-2

L NOAP—Navy Oil Analysis Program

lb/min—pounds per minute Np t—power turbine speed

lb/set—pounds per second NRTC—nonresident training course

LCAC—landing craft, air cushion

LED—light-emitting diode

LFV—liquid fuel valve

LO—lube oil

O

OD box—oil distribution box

OOD—officer of the deck

LOCOP—local operating control panel

LOP—local operating panel

LOSCA—lube oil storage and conditioningassembly

P

PACC—propulsion and auxilary control con-sole

LOSIP—local operating station instrumentpanel

LP—low-pressure

PAMCE—propulsion and auxiliary machinerycontrol equipment

PAMISE—propulsion and auxiliary machineryinformation system equipment

LSS—low-signal select

lube—lubricating

LVDT—linear variable-displacement trans-former

PCB—printed circuit board

PCC—propulsion control console

PCS—propulsion control system

PG—patrol combatant

M

MCS—machinery control system

MER—main engine room

PKP—potable potassium bicarbonate

PLA—power lever angle

MFC—main fuel control

MG—maintenance group

MPU—magnetic pickup unit

MRC—maintenance requirement card

MRG—main reduction gear

PLCC—propulsion local control console

PLOE—propulsion local operating equipment

PMA—permanent-magnet alternator

PMS—Planned Maintenance System

PQS—Personnel Qualification Standard

N

N1—speed voltage

Ngg—gas generator speed

Ps 3 —compressor discharge static pressure

PSEA—power supply enclosure assembly

psia—pounds per square inch absolute

AII-3

psid—pounds per square inch differential

psig—pounds per square inch gauge

PT—power turbine

Pt2 —compressor inlet total pressure

Pt 5 . 4—power turbine inlet total pressure

PTO—power take-off

PWB—printed wiring board

R

RC—resistive capacitive

RFI—radio-frequency interference

RM—remote multiplexers

rpm—rotations per minute

RSC—repair station console

RTD—resistance temperature detector

RTE—resistance temperature element

S

SKE—signal conditioning enclosure

SAC—starting air compressor

SCCP—self-cleaning centrifugal purifier

scfm—standard cubic feet per minute

SCS—supervisory control status

SEM—standard electronic module

SHP—shaft horsepower

SPM—speed phase matching

srpm—shaft rpm

SS—ship’s service

SSAS—ship’s service air system

SSDG—ship’s service diesel generator

SSGTGS—ship’s service gas turbine generatorset

SWBD—switchboard

T

T2—compressor inlet temperature

T5.4—power turbine inlet gas temperature

TC—traffic controllers

TGB—transfer gearbox

TIT—turbine inlet temperature

TOPS—turbine overtemperature (overload)protection system

TRAMAN—training manual

U

UPS—uninterruptible power supply

UV—ultraviolet

V

VERTREP—vertical replenishment

VSV—variable stator vane

W

WDCM—washdown countermeasure

WHB—waste heat boiler

X

xdcr—transducer

AII-4

INDEX

A

Abbreviations and acronyms, AII-1 to AII-4ACC, auxiliary control console, 9-28 to 9-42

lower panel, 9-37 to 9-42distilling plants section, 9-40drainage system section, 9-41 to 9-42fill valves section, 9-40lamp test, 9-39masker, prairie/fin stabilizer, and

bleed air systems section, 9-38potable water system section, 9-37saltwater service system section, 9-40sewage disposal system section, 9-39

top panel, 9-29 to 9-30CONSOLE POWER STATUS sec-

tion, 9-30DAMAGE CONTROL section, 9-29PARAMETERS section, 9-29

vertical panel, 9-30 to 9-37air-conditioning plants section, 9-36alarm acknowledge, 9-35chilled water circulating system section,

9-32compressed air plants section, 9-34fuel filling, transfer, and purification

system section, 9-31lamp tests, 9-33machinery space ventilation fans,

9-30main engines starting air system

section, 9-34processor generated alarm, 9-35ship’s stores refrigeration plants sec-

tion, 9-36 to 9-37waste heat water circulating systems

section, 9-33Accessary drive system, 1-28Adiabatic compression, 1-9Aegis pumps section, 5-25Air cond plants section, 8-51Air cond section, 5-24Air control section, 5-25 to 5-26Air intake system, 2-9 to 2-14

Air start system, 3-29Air systems, 1-27Alarm ACK section, 5-32Alarm test panel, 5-46 to 5-47Alternating current generator and voltage

regulator, 3-39 to 3-46Anti-icing air system, 4-18 to 4-20Anti-icing system, 2-14Aqueous film forming foam system, 4-27Auto parallel section, 8-15 to 8-16Auxiliary cooling system, 4-26Auxiliary equipment and consoles, 9-1 to 9-60

auxiliary control console, 9-28 to 9-42lower panel, 9-37 to 9-42top panel, 9-29 to 9-30vertical panel, 9-30 to 9-37

bell and data loggers, 9-48 to 9-49bell logger, 9-49data logger, 9-48

damage control console for DD-963/993and CG-47 class ships, 9-21 to 9-28

design and components, 9-21 to 9-26operation, 9-27 to 9-28

damage control console for DDG-51 classships, 9-49 to 9-53

sloping panel, 9-52 to 9-53vertical panel, 9-50 to 9-52damage control console for the FFG-7

class ships, 9-42 to 9-48lower panel, 9-47 to 9-48upper panel, 9-42 to 9-47

data multiplex system, 9-57 to 9-59communication test, 9-59configuration, 9-58DMS to MCS communications, 9-58interfaces, 9-57system, 9-57

INDEX-1

Auxiliary equipment and consoles—Continuedfuel system control equipment, 9-9 to 9-21

control console, 9-9 to 9-17fuel oil transfer local panels, 9-17 to 9-19JP-5 local control panel, 9-19 to 9-20operation, 9-20 to 9-21

propulsion and auxiliary machinery infor-mation system equipment, 9-1 to 9-9

bell and data loggers, 9-7 to 9-9central information system equip-

ment, 9-2 to 9-5signal conditioning equipment, 9-5 to

9-7repair station console, 9-53 to 9-57

sloping panel, 9-55 to 9-57vertical panel, 9-54

summary, 9-59 to 9-60Axial-flow compressors, 1-11 to 1-16

B

Ballast system, 4-23 to 4-24Bell and data loggers, 9-48 to 9-49

bell logger, 9-49data logger, 9-48

Bellmouth and bulletnose, 2-19Bleed air control panel, 5-34 to 5-35Bleed air start system, 4-17 to 4-18Bleed air system, 2-46, 3-20 to 3-21, 4-17 to

4-21Blow-in and blow-out panels, 3-4 to 3-5Blow-in doors, 2-13 to 2-14Bus tie & SWBD section, 8-8Bus tie & SWBD voltage select section, 8-13

C

CG, and DD anti-icing system, 4-18 to4-19

CG, and DD cooling system, 2-17 to2-18

CG, and DD inlet duct systems, 2-10 to2-13

CG, and DD low-pressure air system,4-21 to 4-22

CG, and DD masker air system, 4-20to 4-21

CG, and DD seawater sysems, 4-25CG, and DD steam distribution system,

4-26CG exhaust duct system, 2-15 to 2-16Centrifugal compressor, 1-10 to 1-11Chilled water section, 5-25

Circuit breaker switches/indicators, 8-8 to8-10

CO2 system, 3-10 to 3-11Combat dry air section, 5-25Combustion chamber design, classification by,

1-16 to 1-19annular chamber, 1-16 to 1-18can chamber, 1-16can-annular chamber, 1-18 to 1-19

Compressor cleanliness, effect of, 1-10Compressor type, classification by, 1-10 to

1-16Compressed air systems, 4-21 to 4-23Compressor inlet temperature/compressor dis-

charge pressure sensor, 3-26Compressor inlet temperature sensor, 2-38Console power status/console/vital power

feeder circuit breaker status panel (A-3),8-31 to 8-33

Control console, electric plant (CG-class ships), 8-17 to 8-26

Control console, electric plant (DD-classships), 8-1 to 8-17

Control console, electric plant (DDG-51-classship), 8-44 to 8-53

Control console, electric plant (FFG-classships), 8-27 to 8-44

CRP section, 5-3 to 5-4

D

Damage control console for DD-963/993 andCG-47 class ships, 9-21 to 9-28

design and components, 9-21 to 9-26operator’s panels (front of console),

9-21 to 9-26rear panel (back of console), 9-26

operation, 9-27 to 9-28normal securing, 9-28power application, 9-28self tests, 9-28

Data multiplex system, 9-57 to 9-59DMS communication test, 9-59

DMS configuration, 9-58DMS interfaces, 9-57

DMS system, 9-57DMS to MCS communications, 9-58DCC, damage control console for DDG-51

class ships, 9-49 to 9-53sloping panel, 9-52 to 9-53

alarm acknowledge, 9-52fire pump panel, 9-53lamp test, 9-53plasma display keyboard, 9-53

INDEX-2

DCC, damage control console for DDG-51 Electrical plant operation—Continuedclass ships—Conrinued

vertical panel, 9-50 to 9-52console test section, 9-50fireman panel, 9-51plasma display section, 9-51 to 9-52

DCC, damage control console for the FFG-7class ships, 9-42 to 9-48

lower panel, 9-47 to 9-48upper panel, 9-42 to 9-47

alarm and detection section, 9-45miscellaneous fire fighting section,

9-44power monitoring section, 9-42 to

9-44ventilation system, 9-46 to 9-47

DD exhaust duct systems, 2-15DDG-51, machinery control system, 7-1, 7-2Demands panel, 6-7Demister panels, 2-13Distilling section, 5-24Distribution panel (A-2), 8-51 to 8-53Drainage and ballast systems, 4-23 to 4-24Droop mode, 3-32

E

Eductors, 2-15Electrical plant operation, 8-1 to 8-53

electric plant control console (CG-class ships), 8-17 to 8-26

400-Hz alarm/status panel, 8-19 to8-21

400-Hz alarm/status indicator sec-tion, 8-20 to 8-21

400-Hz ground detect section,8-21

meter section, 8-21400-Hz MIMIC panel, 8-25 to 8-26

converter control section, 8-25 to8-26

mimic section, 8-25alarm/status panel, 8-17 to 8-19

alarm acknowledge, 8-19alarm/status indicator section,

8-17 to 8-19demand display section, 8-19emergency power section, 8-19generator and gas turbine lube

oil meters section, 8-19synchronizing indication section,

8-19

INDEX-3

electric plant control console (CG-class ships)—Continued

generator status panel, 8-19MIMIC panel, 8-21system control panel, 8-21 to 8-24

electric plant control console (DD-classships), 8-1 to 8-17

alarm /status panel, 8-1 to 8-6alarm acknowledge, 8-6alarm/status section, 8-1 to 8-4emergency power section, 8-4gas turbine generators demand

display section, 8-5 to 8-6load shedding switch/indicator,

8-5main switchboard ground detect

section, 8-5switchboard section, 8-4synchronizing lights section, 8-5

generator status panel, 8-6 to 8-8bus tie & SWBD section, 8-8generators section, 8-6shore power section, 8-7 to 8-8

load centers, 8-16MIMIC panel, 8-8 to 8-11

circuit breaker switches/indicators,8-8 to 8-10

gas turbine start mode selector,8-10

generators sections, 8-10miscellaneous indicators, 8-10 to

8-11system configuration, 8-16 to 8-17

emergency configurations, 8-17nonstandard plant configura-

tions, 8-16 to 8-17standard parallel-plant configura-

tions, 8-16standard split-plant configura-

tions, 8-16system control panel, 8-11 to 8-16

auto parallel section, 8-15 to8-16

bus tie & SWBD voltage selectsection, 8-13

generators section, 8-11 to 8-13logic self test section, 8-15MALF section, 8-14 to 8-15power section, 8-14synchro control section, 8-13 to

8-14system section, 8-14test section, 8-15

turbine overload protection system, 8-16

Electrical plant operation—Continuedelectric plant control console (DDG-51-

class ship), 8-44 to 8-53distribution panel (A-2), 8-51 to 8-53

air cond plants section, 8-51alarm acknowledge section, 8-51gas turbine section, 8-52lamp test section, 8-51load shedding section, 8-52shore power section, 8-51 to

8-52start air section, 8-52switchboard section, 8-51synchronization section, 8-52 to

8-53output monitor panel (A-1), 8-47 to 8-50

console section, 8-47plasma display section, 8-48power generation and distribution

section, 8-48 to 8-49summary alarms section, 8-47synchronization section, 8-49 to

8-50system output section, 8-49

electric plant control console (FFG-classships), 8-27 to 8-44

console power status/console/vitalpower feeder circuit breaker statuspanel (A-3), 8-31 to 8-33

console power status section,8-32 to 8-33

console section, 8-33vital power feeder circuit breaker

status section, 8-33engine fuel systems panel (Al), 8-27

to 8-28shore power/generators panel (A-9),

8-43generators section, 8-44shore power section, 8-43 to 8-44

SSDG output and distribution panel(A-5), 8-33 to 8-37

alarm acknowledge and processorgenerated alarm section, 8-37

governor control section, 8-36meter section, 8-36voltage regulator control section,

8-36SSDG output and distribution panel

(A-8), 8-40 to 8-43circuit breaker control and switch-

board control sections, 8-42 to8-43

engine starting and stopping sec-tion, 8-41 to 8-42

Electrical plant operation—Continuedelectric plant control console (FFG-class

ships)—Continued

EngineEngineEngineEngineEngineEngineEngineEngineEngineEngine

1-10EngineEngine

SSDG panel (A-4), 8-33SSDG panel (A-7), 8-37 to 8-40

exhaust temperature section,8-40

jacket cooling water system sec-tion, 8-40

seawater system section, 8-40supervisory control status/synchroniza-

tion/paralleling/parameters panel(A-2), 8-28 to 8-31

paralleling section, 8-30 to 8-31parameters section, 8-31supervisory control status sec-

tion, 8-28 to 8-29synchronization section, 8-30

system output monitor/ground statustest/generator 4 panel (A-6), 8-37

audible test switches and rheostatsection, 8-37

generator 4 section, 8-37ground status test section, 8-37system output monitor section,

8-37fuel system, 3-21 to 3-25instrumentation, 2-47 to 2-48No. 1 demands panel, 5-32 to 5-34No. 1 panel, 5-17No. 2 demands panel, 5-26 to 5-30room No. 2 panel, 5-2 to 5-9order telegraph (EOT) panel, 5-30order telegraph section, 5-32panel, 6-9 to 6-15performance, factors affecting, 1-9 to

start panels, 6-4 to 6-7systems, 2-33 to 2-47

Engineering auxiliary and support systems, 4-1to 4-27

bleed air system, 4-17 to 4-21anti-icing air system, 4-18 to 4-20

CG, and DD anti-icingsystem, 4-18 to 4-19

FFG anti-icing system, 4-19 to4-20

bleed air start system, 4-17 to 4-18masker air system, 4-20 to 4-21

CG, and DD masker airsystem, 4-20 to 4-21

FFG masker air system, 4-21prairie air system, 4-21

INDEX-4

Engineering auxiliary and support systems—Continued

compressed air systems, 4-21 to 4-23CG, and DD high-pressure air

system, 4-22CG, and DD low-pressure air

system, 4-21 to 4-22FFG high-pressure air system, 4-22

to 4-23FFG low-pressure air system, 4-22

drainage and ballast systems, 4-23 to 4-24ballast system, 4-23 to 4-24main drainage system, 4-23secondary drainage system, 4-23

fire-extinguishing systems, 4-27aqueous film forming foam system,

4-27fixed flooding CO2 system, 4-27Halon 1301 fire-extinguishing system,

4-27firemain system, 4-24fuel systems, 4-11 to 4-17

JP-5 system, 4-16 to 4-17naval distillate system, 4-11 to 4-16

fuel oil fill and transfer system,4-11 to 5-15

fuel and service system, 4-15 to4-16

lube oil fill, transfer, and purificationsystem, 4-4 to 4-7

lube oil purifiers, 4-5 to 4-7purification of lube oil, 4-5 to

4-6sampling of lube oil, 4-6 to 4-7

storage and settling tanks, 4-4 to 4-5lube oil system fundamentals, 4-1 to 4-4

friction and lubrication, 4-1 to 4-2lubricating oils, 4-2 to 4-4

classification of lube oils, 4-2 to4-3

properties of lube oil, 4-3 to 4-4main lube oil system, 4-7 to 4-11

system components, 4-7 to 4-10header, 4-10lube oil cooler, 4-9lube oil filter, 4-10lube oil pumps, 4-8 to 4-9lube oil sump, 4-7temperature regulating valve, 4-9unloading valve, 4-9

system lube oil flow, 4-7system monitoring, 4-10 to 4-11

Engineering auxiliary and support systems—Continued

seawater service system, 4-24 to 4-26CG, and DD seawater systems

4-25FFG seawater systems, 4-25 to 4-26

auxiliary cooling system, 4-26main propulsion reducting gear

cooling system, 4-25SSDG cooling system, 4-25 to

4-26steam and waste heat systems, 4-26

CG, and DD steam distribu-tion system, 4-26

FFG waste heat distribution system,4-26

EOOW/LU, Engineering Officer of theWatch/Logging Unit, 7-1 to 7-8

keyboard control section, 7-7 to 7-8arrow/home keys, 7-8function keys, 7-8standard keys, 7-8

panel assembly A1, 7-3 to 7-6AN/USH-26 section, 7-4 to 7-6bubble memory section, 7-4fuse assembly section, 7-3

panel assembly A2, 7-6 to 7-7console section, 7-6plasma display section, 7-6printer section, 7-6 to 7-7

EOT panel, 5-44Exhaust systems, 2-14 to 2-16

FFG anti-icing system, 4-19 to 4-20FFG cooling system, 2-18FFG exhaust duct system, 2-16FFG high-pressure air system, 4-22 to 4-23FFG inlet duct system, 2-13 to 2-14FFG low-pressure air system, 4-22FFG seawater systems, 4-25 to 4-26FFG waste heat distribution system, 4-26

F

Filter, high pressure, 3-25Filter, low-pressure, 3-24 to 3-25Fire detection and extinguishing systems, 2-7

to 2-9, 3-7CG-, and DD-class ships, 2-8 to

2-9FFG-class ship, 2-9fire detection and extinguishing systems,

3-7

INDEX-5

Fire-extinguishing systems, 4-27Firemain system, 4-24Fixed flooding CO2 system, 4-27400-Hz alarm/status panel, 8-19 to 8-21400-Hz MIMIC panel, 8-25 to 8-26Free standing electronic enclosure, 2-48 to

2-58Fresh water section, 5-22FSEE circuitry tests, 2-56 to 2-57Fuel and speed-governing system, 2-34 to 2-46Full manifold drain valve, 3-26Fuel manifold system, 2-37Fuel nozzles, 2-37 to 2-38Fuel oil fill and transfer system, 4-11 to 4-15Fuel oil service system panel, 6-15 to 6-16Fuel oil section, 5-4 to 5-6Fuel oil system, 1-28Fuel pump, 3-24Fuel pump and filter, 2-34 to 2-36Fuel shutdown valves, 2-37Fuel shutoff valve, 3-26Fuel system control equipment, 9-9 to 9-21

control console, 9-9 to 9-17

fuel

calibration panel, 9-16card cage, 9-15fuel oil fill and transfer control

panel, 9-10 to 9-12fuel oil fill section, 9-12fuel oil transfer section, 9-12, 9-13fuse and circuit breaker panel, 9-16JP-5 control panel, 9-14 to 9-14power supplies, 9-17relay panel assembly, 9-16oil transfer local panels, 9-17 to 9-19

calibrate panel, 9-18 to 9-19card 9-18cage,power distribution panel, 9-18power supplies, 9-18

JP-5 local control panel, 9-19 to 9-20calibrate panel, 9-20card 9-19cage,operator’s panel, 9-19power distribution panel, 9-20power supplies, 9-19

operation, 9-20 to 9-21normal securing, 9-21power application, 9-20self-tests, 9-20

Fuel systems, 4-11 to 4-17Fuse and status panels, 6-3 to 6-4

G

Gas generator assembly, 2-18 to 2-30Gas turbine engine assembly, 2-18 to 2-33Gas turbine engine fundamentals, 1-1 to 1-35

gas turbine engine auxiliary systems, 1-26to 1-31

accessory drive system, 1-28air systems, 1-27

primary airflow, 1-27secondary airflow, 1-27 to 1-28

fuel oil system, 1-28lubrication system, 1-28 to 1-31

lubrication system subsystems,1-29 to 1-30

oil seals, 1-30 to 1-31spark igniter system, 1-32 to 1-33starting systems, 1-31 to 1-32

Gas turbine generators demand display sec-tion, 8-5 to 8-6

Gas turbine generator set module componentsand systems, 3-4 to 3-11

Gas turbine start mode selector, 8-10Gear lube oil panel, 6-16 to 6-18Generator and gas turbine lube oil meters sec-

tion, 8-19Generator assembly, 3-39 to 3-41Generator lube oil system, 3-40Generator space heater, 3-40Generator status panel, 8-6 to 8-8Generator temperature monitoring, 3-41Glossary, AI-1 to AI-9Governor control unit, 3-36GTE assembly, 3-11 to 3-18GTE starting and stopping, 6-26 to 6-27GTGS fire stop and CO2 system, 3-10 to 3-11GTGS LOCOP model 104, 3-46 to 3-49GTGS LOCOP model 139, 3-49 to 3-52GTM 2A manual start section, 5-15 to 5-16GRM 2A section, 5-12GTM 1B manual start section, 5-17GTM 1 B section, 5-15GTM 2B start/GTM 2B stop section, 5-29GTM 2

gas turbine engine theory, 1-4 to 1-10B section, 5-6 to 5-8

adiabatic compression, 1-9basic GTE operation theory, 1-5 to 1-7convergent-divergent process, 1-7 to 1-8factors affecting engine performance,

1-9 to 1-10effect of ambient temperature, 1-9

to 1-10effect of compressor cleanliness, 1-10

open, semiclosed, and closed cycles, 1-5theoretical cycles, 1-4 to 1-5

INDEX-6

GTM 2 B section—Continuedhistory and background, 1-1 to 1-4

advantages and disadvantages, 1-3 to1-4

future trends, 1-4twentieth-century development, 1-2 to

1-3American development, 1-2marine gas turbine engine, 1-2 to

1-3types of gas turbine engines, 1-10 to 1-26

classification by combustion chamberdesign, 1-16 to 1-19

annular chamber, 1-16 to 1-18can chamber, 1-16can-annular chamber, 1-18 to

1-19classification by compressor type,

1-10 to 1-16axial-flow compressors, 1-11 to

1-16centrifugal compressor, 1-10 to

1-11classification by type of shafting, 1-19

to 1-20main bearings, 1-26turbine assemblies, 1-20 to 1-26

gas generator turbine, 1-20 to 1-24power turbines, 1-25 to 1-26

H

Halon 1301 fire-extinguishing system, 4-27High hat assembly, 2-11 to 2-12High-speed flexible coupling shaft, 2-32 to

2-33

I

Ignition exciter, 3-19Ignition system, 2-44 to 2-46Infrared suppression, 2-15Intake, cooling, and exhaust systems, 3-7 to

3-9Intake monitoring and control, 2-14IR SUPPR section, 5-17Isochronous mode, 3-32

J

Jacket cooling water system section, 8-40JP-5 system, 4-16 to 4-17

L

Lamp test section, 8-51LM2500 gas turbine engine, 2-1 to 2-58

air intake system, 2-9 to 2-14CG, and DD inlet duct systems,

2-10 to 2-13ducting, 2-12 to 2-13high hat assembly, 2-11 to 2-12overall flow description, 2-11

FFG inlet duct system, 2-13 to 2-14anti-icing system, 2-14blow-in doors, 2-13 to 2-14demister panels, 2-13intake monitoring and control,

2-14base/enclosure assembly, 2-2 to 2-9

base assembly, 2-4 to 2-5enclosure, 2-5 to 2-7

heater, 2-6 to 2-7lighting, 2-5 to 2-6

fire detection and extinguishing sys-tems, 2-7 to 2-9

CG-, and DD-class ships,2-8 to 2-9

FFG-class ship, 2-9engine instrumentation, 2-47 to 2-48engine systems, 2-33 to 2-47

fuel and speed-governing system,2-34 to 2-40

compressor inlet temperaturesensor, 2-38

fuel manifold system, 2-37fuel nozzles, 2-37 to 2-38fuel pump and filter, 2-34 to 2-36fuel shutdown valves, 2-37main fuel control, 2-36power lever angle rotary actuator,

2-39 to 2-40pressurizing valve, 2-36 to 2-37purge valve, 2-37variable stator vane actuators, 2-39variable stator vanes, 2-38 to 2-39

ignition system, 2-44 to 2-46balance piston air, 2-47

bleed air system, 2-46eighth-stage air, 2-46ignition exciters, 2-45ignition leads, 2-46ninth-stage air, 2-46 to 2-47sixteenth-stage air, 2-47spark igniters, 2-45thirteenth-stage air, 2-47

INDEX-7

LM2500 gas turbine engine—Continuedengine systems—Continued

water wash system, 2-46start air system, 2-33 to 2-34

starter, 2-34starter air valve, 2-34

synthetic lube oil system, 2-40 to 2-44lube oil flow, 2-44lube oil system components, 2-41

to 2-43exhaust systems, 2-14 to 2-16CG exhaust duct system, 2-15 to 2-16

DD exhaust duct systems, 2-15eductors, 2-15infrared suppression, 2-15silencers, 2-15

FFG exhaust duct system, 2-16free standing electronic enclosure, 2-48 to 2-58

gas turbine engine assembly, 2-18 to 2-33

start/stop sequences, 2-57torque computer, 2-50

gas generator assembly, 2-18 to 2-30accessory drive section, 2-29 to 2-30bellmouth and bulletnose, 2-19combustor section, 2-24compressor section, 2-19 to 2-24high-pressure turbine section,2-25 to 2-29

FSEE circuitry tests, 2-56 to 2-57overspeed switch control, 2-50PLA actuator electronics, 2-53 to 2-56

PLA actuator drive, 2-54PLA actuator theory of operation,

2-55 to 2-56protective functions, 2-54 to 2-55servomotor, 2-53slider potentiometer, 2-53tachometer, 2-53 to 2-54

power supply, 2-51 to 2-53CG, and DD FSEE power

distribution, 2-51 to 2-53FFG FSEE power distribution,

2-51signal conditioning electronics, 2-49

to 2-50

high-speed flexible coupling shaft,2-32 to 2-33

power turbine/low-pressure section,2-30 to 2-32

rotor, 2-31stator, 2-31 to 2-32

module cooling systems, 2-17 to 2-18CG, and DD cooling system,

2-17 to 2-18FFG cooling system, 2-18

Load centers, 8-16Load shedding switch/indicator, 8-5Local operating control panel, 3-46 to 3-52Local operating panel, 6-27 to 6-36Local operating station instrument panel, 6-29

enclosure section, 6-29fuel system section, 6-29gas generator section, 6-29lube oil section, 6-29power turbine section, 6-29throttle section, 6-29

Logic self test section, 8-15LOP bottom panel, 6-36LOP fuse panel, 6-36LOP status panel, 6-35LOP top panel, 6-29 to 6-35

enclosure section, 6-32 to 6-33engine lube oil section, 6-34fuel section, 6-33gas generator section, 6-33power turbine and output section, 6-34 to

6-35seawater cooling supply pressure and

reduction gear lube oil remote bearingpressure meters, 6-34

start/stop section, 6-33vibration section, 6-34

Lube oil cooler, 4-9Lube oil fill, transfer, and purification

system, 4-4 to 4-7Lube oil filter, 4-10Lube oil fundamentals, 4-1 to 4-4Lube oil pump, 4-7Lube oil, purification of, 4-5 to 4-6Lube oil, sampling of, 4-6 to 4-7Lube oil section, 5-9Lube oil system, 3-26 to 3-29Lube oil system, main, 4-7 to 4-11Lubrication system, 1-28 to 1-31

M

Machinery control system for DDG-classships, 7-1 to 7-23

DDG-51, machinery control system, 7-1,7-2

EOOW/LU, 7-1 to 7-8keyboard control section, 7-7 to 7-8panel assembly A1, 7-3 to 7-6panel assembly A2, 7-6 to 7-7

INDEX-8

Machinery control system for DDG-classships—Continued

PACC, 7-8 to 7-17plasma display keyboard panel (A3),

7-17propulsion monitor panel (Al), 7-9

to 7-13thrust/auxiliary panel (A2), 7-14 to

7-17shaft control unit, 7-18 to 7-23

horizontal keyboard panel, 7-23propulsion monitor panel (Al), 7-18thrust auxiliary panel (A2), 7-19,

7-23Main bearings, 1-26Main fuel control, 2-36Main seawater cooling panel, 6-8 to 6-9MALF section, 8-14 to 8-15Malfunction section, 5-28Marine gas turbine engine, 1-2 to 1-3Masker air system, 4-20 to 4-21MIMIC panel, 5-9 to 5-17Module cooling systems, 2-17 to 2-18

N

Naval distillate system, 4-11 to 4-16

P

PACC and PLCC for DD- and CG-classships, 5-1 to 5-48

propulsion and auxiliary control console,5-1 to 5-47

bleed air control panel, 5-34 to 5-35groups and auxiliary demands

section, 5-35port and starboard engine room

sections, 5-34engine No. 1 demands panel, 5-32 to

5-34engine No. 1 panel, 5-17engine No. 2 demands panel, 5-26 to

5-302B emergency controls section,

5-28GTM 2B start/GTM 2B stop sec-

tion, 5-19 to 5-30malfunction section, 5-28port shaft propulsion demands

section, 5-26 to 5-28test section, 5-28 to 5-29

PACC and PLCC for DD- and CG-classships—Continued

propulsion and auxiliary control console—Continued

engine order telegraph (EOT) panel,5-30

engine order telegraph section, 5-32alarm ACK section, 5-32throttle transfer section, 5-32

engine room No. 2 panel, 5-2 to 5-9CRP section, 5-3 to 5-4fuel oil section, 5-4 to 5-6GTM 2 B section, 5-6 to 5-8lube oil section, 5-9RDCN gear LUBO section, 5-2

integrated throttle control panel, 5-35to 5-37

MIMIC panel, 5-9 to 5-17GTM 2A manual start section,

5-15 to 5-16GTM 2A section, 5-12GTM 1B manual start section,

5-17GRM 1B section, 5-15lower center section, 5-16main center section, 5-12 to 5-15PLA and VIBRATION meters

and MRG mimic section, 5-15PACC auxiliary/bleed air panel, 5-17

to 5-26aegis pumps section, 5-25air cond section, 5-24air control section, 5-25 to 5-26chilled water section, 5-25combat dry air section, 5-25distilling section, 5-24fresh water section, 5-22HP air section, 5-22 to 5-23IR SUPPR section, 5-17REFRD section, 5-23seawater section, 5-21 to 5-22sewage and sewage/waste sec-

tions, 5-23SS air section, 5-24 to 5-25steam header press section, 5-21waste HT BLR section, 5-17 to

5-21port manual throttle section, 5-30 to

5-32

INDEX-9

PACC and PLCC for DD- and CG-classships—Continued

propulsion local control console, 5-37 to5-47

alarm test panel, 5-46 to 5-47GTM A section, 5-46malfunction section, 5-47power section, 5-46test section, 5-46

EOT panel, 5-44alarm acknowledge section, 5-44engine order telegraph section,

5-44 to 5-45GTM A panel, 5-41 to 5-42

CRP section, 5-42GTM A section, 5-42lube oil section, 5-42

GTM A/B panel, 5-40 to 5-41GTM B panel, 5-38

emergency controls section, 5-39fuel oil section, 5-38 to 5-39GTM B section, 5-39

PLA and pitch control levers, 5-47self test panel, 5-42 to 5-44

GTM B section, 5-43 to 5-44start/stop self test section, 5-43

PACC, propulsion and auxiliary control console,7-8 to 7-17

plasma display keyboard panel (A3), 7-17propulsion monitor panel (Al), 7-9 to

7-13console section, 7-9 to 7-10plasma display section, 7-11propulsion section, 7-11 to 7-13

thrust/auxiliary panel (A2), 7-14 to 7-17console section, 7-16control location section, 7-17independent aux section, 7-14programmed control lever section,

7-17propulsion auxiliaries section, 7-14 to

7-16thrust setting section, 7-16

PAMISE, propulsion and auxiliary machineryinformation system equipment, 9-1 to 9-9

bell and data loggers, 9-7 to 9-9central information system equipment,

9-2 to 9-5ECU test panel, 9-5executive control unit, 9-2monitor and control panel, 9-2 to 9-5

signal conditioning equipment, 9-5 to 9-7CALIBRATION section, 9-6MALFUNCTION section, 9-7

PCC and LOP for FFG-class ships, 6-1 to6-37

local operating panel, 6-27 to 6-36local operating station instrument

panel, 6-29enclosure section, 6-29fuel system section, 6-29gas generator section, 6-29lube oil section, 6-29power turbine section, 6-29throttle section, 6-29

LOP bottom panel, 6-36LOP fuse panel, 6-36LOP status panel, 6-35LOP top panel, 6-29 to 6-35

enclosure section, 6-32 to 6-33engine lube oil section, 6-34fuel section, 6-33gas generator section, 6-33power turbine and output sec-

tion, 6-34 to 6-35seawater cooling supply pressure

and reduction gear lube oilremote bearing pressure meters,6-34start/stop section, 6-33

vibration section, 6-34propulsion control sole, 6-2 to 6-27

GTE starting and stopping, 6-26 to6-27

PCC control modes, 6-25 to 6-27programmed control mode, 6-25

to 6-26remote manual mode, 6-26

PCC conntrols and indicators, 6-2 to6-25

demands panel, 6-7engine panel, 6-9 to 6-15engine start panels, 6-4 to 6-7fuse and status panels, 6-3 to 6-4fuel oil service system panel, 6-15

to 6-16gear lube oil panel, 6-16 to 6-18main seawater cooling panel, 6-8

to 6-9operational adjustments panel, 6-24

to 6-25propulsion control panel, 6-19

PLA actuator electronics, 2-53 to 2-56Plasma display section, 8-48Potentiometer, motor-operated, 3-32Power lever angle rotary actuator, 2-39 to

2-40Power supply, 2-51 to 2-53Power take-off assembly, 3-30 to 3-31

INDEX-10

Power turbines, 1-25 to 1-26Power turbine/low-pressure section, 2-30 to

2-32Prairie air system, 4-21Pressure relief valve, 3-25Pressurizing valve, 2-36 to 2-37Purge valve, 2-37

Ship’s service gas turbine generator sets, 3-1to 3-52

alternating current generator and voltageregulator, 3-39 to 3-46

generator assembly, 3-39 to 3-41generator lube oil system, 3-40generator space heater, 3-40

Q

Oil seals, 1-30 to 1-31Oils, classification of lube, 4-2 to 4-3Oils, lubricating, 4-2 to 4-4Operational adjustments panel, 6-24 to 6-25Overspeed switch control, 2-50

R

RDCN gear LUBO section, 5-2Reduction gear and lube oil system, GTGS,

3-30References, AIII-1 to AIII-4REFRO section, 5-23Repair station console, 9-53 to 9-57

sloping panel, 9-55 to 9-57bubble memory section, 9-57fireman valve panel, 9-56plasma display keyboard, 9-57power control panel, 9-55

vertical panel, 9-54console section, 9-54control sectikon, 9-54firemain panel, 9-54plasma display, 9-54

S

SCU, shaft control unit, 7-18 to 7-23horizontal keyboard panel, 7-23propulsion monitor panel (A1), 7-18thrust auxiliary panel (A2), 7-19, 7-23

Seawater section, 5-21 to 5-22Seawater service system, 4-24 to 4-26Seawater system section, 8-40Self test panel, 5-42 to 5-44Servomotor, 2-53Sewage and sewage/waste sections, 5-23Shafting, classification by type of, 1-19 to

1-20

generator temperature monitoring,3-41

voltage regulation, 3-41 to 3-46model 104 voltage regulation, 3-41

to 3-43model 139 voltage regulation, 3-44

to 3-46engine instrumentationk 3-31 to 3-46

speed pickup, 3-31thermocouple, 3-31vibration transducer, 3-31

engine systems, 3-18 to 3-29air start system, 3-29

air starter motor, 3-29high-pressure air start system,

3-29low-pressure air start system,

3-29bleed air system, 3-20 to 3-21

fifth- and tenth-stage bleed air,3-21

fourteenth-stage bleed air, 3-20to 3-21

engine fuel system, 3-21 to 3-26compressor inlettemperature/compressor discharge

pressure sensor, 3-26electrohydraulic governor actuator,

3-25 to 3-26fuel manifold drain valve, 3-26fuel pump, 3-24fuel shutoff valve, 3-26high-pressure filter, 3-25low-pressure filter, 3-24 to 3-25model 104 fuel system flow path,

3-21 to 3-24model 139 fuel system flow path,

3-24model 104 liquid fuel valve, 3-25model 139 liquid fule valve, 3-25models 104 and 139 flow divider

fuel manifold, and fuel nozzles,3-26

pressure relief valve, 3-25start limit control valve, 3-26

INDEX-11

INDEX-12

Ship’s service gas turbine generator sets—Con-tinued

engine systems—Continuedignition system, 3-19

ignition exciter, 3-19spark igniters, 3-19

lube oil system, 3-26 to 3-29external scavenge pump, 3-28main pressure and scavenge oil

pump, 3-28oil filter, 3-28turbine scavenge pump, 3-28vent system, 3-28

gas turbine generator set module com-ponents and systems, 3-4 to 3-11

base, 3-4enclosure, 3-4 to 3-6

blow-in and blow-out panels, 3-4to 3-5

module cooling air flow and temper-ature monitoring, 3-5 to 3-6

fire detection and extinguishing systems,3-7

GTGS fire stop and CO2 system,3-10 to 3-11

CO2 system, 3-10 to 3-11model 104 fire stop logic, 3-10model 139 fire stop logic, 3-10

intake, cooling, and exhaust systems,3-7 to 3-9

exhaust duct system, 3-9intake duct, 3-8module cooling system, 3-8 to 3-9

seawater service system, 3-11water wash system, 3-6 to 3-7

general description of the generator set,3-1 to 3-4

GTE assembly, 3-11 to 3-18accessory drive section, 3-18air intake, 3-12 to 3-15combustion section, 3-16compressor section, 3-15turbine section, 3-17 to 3-18

GTGS reduction gear and luke oil system,3-30

local operating control panel, 3-46 to 3-52model 104 LOCOP, 3-46 to 3-49

turbine start/stop sequencing,3-48

turbine temperature and speedcontrol box, 3-48 to 3-49

model 139 GTGS LOCOP, 3-49 to3-52

Ship’s service gas turbine generator sets—Con-tinued

power take-off assembly, 3-30 tp 3-31housing, 3-31power take-off shaft and adapter, 3-30

to 3-31speed governing system, 3-31 to 3-39

model 104 governor system, 3-32 to3-35

electrohydraulic governor actuator,3-34 to 3-35

electronic control unit, 3-32 to3-34

motor-operated potentiometer,3-32

model 139 governor system, 3-35 to3-39

electronic fuel control unit, 3-36to 3-39

governor control unit, 3-36operating modes, 3-32

droop mode, 3-32isochronous mode, 3-32

Shore power/generators panel (A-9), 8-43Shore power section, 8-7 to 8-8Signal conditioning electronics, 2-49 to 2-50Silencers, 2-15Slider patentiometer, 2-53Spark igniter system, 1-32 to 1-33SS air section, 5-24 to 5-25SSDG cooling system, 4-25 to 4-26SSDG output and distribution panel (A-5), 8-33

to 8-37SSDG output and distribution panel (A-8), 8-40

to 8-43SSDG panel (A-4), 8-33SSDG panel (A-7), 8-37 to 8-40Start air system, 2-33 to 2-34Starting systems, 1-31 to 1-32Steam and waste heat systems, 4-26Steam header press section, 5-21Storage and settling tanks, 4-4 to 4-5Supervisory-control status/synchronization/

paralleling/parameters panel (A-2), 8-29 to8-3 1)

Switchboard ground detect section, main, 8-5Switchboard section, 8-51Synchro control section, 8-13 to 8-14Synthetic lube oil system, 2-40 to 2-44System output monitor/ground status test/

generator 4 panel (A-6), 8-37

T

Tachometer, 2-53 to 2-54

Temperature regulating valve, 4-9

Test section, 5-28 to 5-29

Thermocouple, 3-31

Throttle transfer section, 5-32

Torque computer, 2-50

Turbine assemblies, 1-20 to 1-26

Turbine overload protection system,8-16

U

Unloading valve, 4-9

V

Variable stator vanes, 2-38 to 2-39Vibration transducer, 3-31Voltage regulation, 3-41 to 3-46

W

Waste HT BLR section, 5-17 to 5-21Water wash system, 2-46, 3-6 to 3-7

INDEX-13