PROJECT REPORT MT SUSHMA DESIGN OF A 150,000 t DOUBLE ACTING ICE CLASS TANKER OF SERVICE SPEED 15.0 KNOTS IN OPEN WATER AND 5.0 KNOTS IN SEVERE ICE CONDITION Thesis submitted in partial fulfillment of the Requirements for the Award of The Degree of Bachelor of Technology in Naval Architecture & Ship Building by VIMAL KUMAR DEPARTMENT OF SHIP TECHNOLOGY COCHIN UNIVERSITY OF SCIENCE & TECHNOLOGY COCHIN-682022 APRIL 2008
its suezmax ice class tanker of capacity 150000 t with speed 15 knots and astern speed 5 knots
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PROJECT REPORT
MMTT SSUUSSHHMMAA
DESIGN OF A 150,000 t DOUBLE ACTING ICE CLASS TANKER OF SERVICE SPEED 15.0 KNOTS IN OPEN WATER AND 5.0
KNOTS IN SEVERE ICE CONDITION
Thesis submitted in partial fulfillment of the Requirements for the Award of
The Degree of
Bachelor of Technology
in
Naval Architecture & Ship Building
by
VIMAL KUMAR
DEPARTMENT OF SHIP TECHNOLOGY COCHIN UNIVERSITY OF SCIENCE & TECHNOLOGY
COCHIN-682022 APRIL 2008
Certified that this is the bonafide record of the thesis submitted in partial
fulfillment of the requirements for the award of the degree of Bachelor in Technology
in
Naval Architecture & Ship Building
by
VIMAL KUMAR
DEPARTMENT OF SHIP TECHNOLOGY COCHIN UNIVERSITY OF SCIENCE & TECHNOLOGY
COCHIN-682022
Thesis Approved by Cdr P .G Sunil Kumar Department of Ship Technology Cochin University of Science & Technology, Kochi-22, Kerala
Thesis Accepted by Dr. Pyarilal S.K Reader and Head Department of Ship Technology Cochin University of Science & Technology, Kochi-22, Kerala
ACKNOWLEDGEMENT
I am deeply indebted to Cdr P.G Sunil Kumar, my guide and mentor for
his immeasurable help he lent me during the course of my project. I would like to
extend my thanks to all other faculty members of the department.
I am grateful to Mr. Muthukrishnan.A, and Mr. Shantanu Neema, my
class mates especially Mr. Sanjeev Kumar Singh, and Mr. Ujjawal Kumar Vidyarthi,,
with out whose help and assistance; my project would not have been completed. I take
this opportunity to thank all my juniors especially Mr. Ashish Kumar, Mr. Sachin
Kumar for helping me with the project.
Patience, understanding and constant prayers from my family played a
major role in completion of this thesis. The whole hearted cooperation, affection and
timely help of all my classmates are remembered with great appreciation and gratitude
Above all, I would like to thank Maa Durga for harbouring me safely thus
far
VIMAL KUMAR Batch XXIX
Dedicated to my family
AIM OF THE PROJECT
Aim of this project is to prepare a preliminary design of a Double Acting Ice
Class Tanker to meet the owner’s requirements given in the assignment sheet:
ASSIGNMENT SHEET
Cochin University of Science and Technology (CUSAT)
DEPT. OF SHIP TECHNOLOGY
Ship Design Project work Assignment sheet
Student Name : Vimal Kumar
Ship Type : Double Acting Tanker (Ice Class 1AS)
Deadweight : 150,000 t
Service speed (open water) : 15.0 Knots
Service speed (1.0 m thick Ice) : 5.0 Knots
Signature of Project guide
“Department of Ship technology, CUSAT, B.Tech (NA&SB), Batch – XXIX”
CONTENTS
Sl No: Chapter Page No:
1.0 INTRODUCTION 1
2.0 FIXING OF MAIN DIMENSIONS 7
3.0 HULL GEOMETRY 42
4.0 RESISTANCE AND POWERING 53
5.0 FINAL GENERAL ARRANGEMENT 77
6.0 DETAILED MASS ESTIMATION AND CAPACITY
CALCULATIONS 103
7.0 DETAILED TRIM & STABILITY CALCULATION 112
8.0 MIDSHIP SECTION DESIGN 164
9.0 OUTLINE SPECIFICATION 195
10.0 DESIGN SUMMARY AND CONCLUSION 201
“Department of Ship technology, CUSAT, B.Tech (NA&SB), Batch – XXIX”
LIST OF DRAWINGS Sl No: Chapter Drg No
1 LINES PLAN XXIX/01
2 BONJEAN CURVES XXIX/02
3 HYDROSTATIC CURVES XXIX/03
4 GENERAL ARRANGEMENT XXIX/04
5 MIDSHIP SECTION XXIX/05
“Department of Ship technology, CUSAT, B.Tech (NA&SB), Batch – XXIX”
LIST OF FIGURES
Chapter 1 Page No
Fig 1.1 Ice breaking capability of DAT 1 Chapter 2 Fig 2.1 Russian crude oil export pipelines 8 Fig 2.2 Typical GA 15 Fig 2.3 Power requirements of DAT 16 Fig 2.4 Graph of deadweight v/s length 21 Fig 2.5 Preliminary GZ curves 35 Chapter 3 Fig 3.1 Ice breaking tanker (hull form) 42
Chapter 4
Fig 4.1 Graph from guldhammer-harvald method of resistance calculation 58
Fig 4.2 Graph from Holltrop-Menon 1984 method of resistance calculation 59
Fig 4.3 Graph from BSRA method of resistance calculation 60
Fig 4.4 Graph to find KQ, J values for 4 bladed propeller 63 Fig 4.5 Power vs propeller speed 67 Fig 4.6 Azipod main dimensions 67 Fig 4.7 Propeller weight vs propeller diameter 68 Fig 4.8 Performance curves 70 Fig 4.9Graph showing Ice thickness (HICE) vs. VICE 76
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Fig 7.3 GZ Curve for fully loaded departure condition 150
Fig 7.4 GZ Curve for fully loaded arrival condition 154
Fig 7.5 GZ Curve for ballast departure condition 158
Fig 7.6 GZ Curve for ballast arrival condition 162
Chapter 8 Fig 8.1Typical midship section of a double skin Ice class Tanker 164 Fig. 8.2 Itemization of parts 167
Fig 8.3 Framing system 168
Fig 8.4 Side shell regions 182
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LIST OF TABLES Chapter 2 Page No Table 2.1 Principle dimensions estimated by ARCOP 13
Table 2.2 Double acting Tankers 14
Table 2.3 Ratio of main dimensions 19
Table 2.4 Results of first iteration 20
Table 2.5 Results of Iterations 21
Table 2.6 Results of final Iteration 22
Table 2.7 GZ at different angles of heel 34
Table 2.8 Initial stability check with IMO Requirements 35
Table 2.9 Final Dimensions 41
Chapter 3 Table 3.1 Offsets of standard BSRA waterlines 44 Table 3.2 Stem and stern offsets 45 Table 3.3 Faired offsets 46 Table 3.4 Area table 48 Table 3.5 Moment table 49 Table 3.6 Hydrostatic parameters 52 Chapter 4 Table 4.1 Total resistance by guldhammer - harvald Method 58
Table 4.2 Total resistance by Holltrop – Menon 1984 Method 59
Table 4.3 Total resistance by BSRA Method 60
“Department of Ship technology, CUSAT, B.Tech (NA&SB), Batch – XXIX”
Table 4.4 Model used for Extrapolation 62
Table 4.5 KQ, J values for 4 bladed propellers 62
Table 4.6 J, KQ Values from the Graph above 63
Table 4.7 n, PD and η0 for selected models 64
Table 4.8 Performance values 69
Table 4.9 t, c, xo and xm with varying r/R 74 Table 4.10 Ordinates of back 74 Table 4.11 Ordinates of face 75 Chapter 5
Table 5.1 Basic Frame Spacing 78 Table 5.2- Division of Compartments 82 Table 5.3 Compliment List 88 Chapter 6 Table 6.1 Capacity of cargo Tanks 105
Table 6.2 Capacity of Ballast Tanks 105
Table 6.3 Capacity of storage tanks 106
Table 6.4 Capacity of other tanks/compartments 106
Table 6.5 Determination of COG of Steel Mass 111
Table 6.6 Determination of COG of Machinery 111
Table 6.7 Determination of COG of Light Ship 112
“Department of Ship technology, CUSAT, B.Tech (NA&SB), Batch – XXIX”
Chapter 7
Table 7.1 Determination of X1 X2 K and s 118
Table 7.2 Windage area 119 Table 7.3 Down flooding and deck immersion angle 119 Table 7.4-7.12 Hydrostatic condition (Trimmed condition) 120-128 Table 7.13-7.21 KN Values (Trimmed condition) 129-133 Table 7.22-7.30 computation of IMO envelop (Trimmed condition) 137-141
Table 7.31 Determination of centre of gravity of cargo holds 143
Table 7.32 Determination of centre of gravity of ballast tanks 144
Table 7.33 Determination of centre of gravity of consumables 145
Table 7.34 Summary of all loading condition 163
Chapter 8 Table 8.1 Value of Ka 168
Table 8.2 Value of ho and h 169
Table 8.3 Value of a and b 170
Table 8.4 Value of c1 170
Table 8.5 Value of la 171
Table 8.6 Extension of ice strengthening at midship 171
Table 8.7 Vertical extension of ice strengthening 173
Table 8.8 Value of mo 174
Table 8.9 Determination of scantlings of side shell longitudinals 182
Table 8.10 Determination of inner hull and longitudinal bulkhead plating 184
Table 8.11 Determination of scantlings of CL longitudinal bulkhead 185 longitudinal and inner hull longitudinals.
Table 8.12 Section modulus calculation 190-194
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CHAPTER 1
INTRODUCTION
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1.1 Introduction
Earlier icebreakers used to assist ships navigating in the Arctic Region. Due to the inherent cost of this practice, ice breaking tankers and other concepts were developed. Routes were formulated accordingly through the Arctic Ocean depending on seasons and climatic conditions. The conventional ice breaking tankers had a bow somewhat similar to that of an icebreaker. The principle for breaking ice was to sit on the ice and break it by its own weight. However due to the modified bow form the efficiency of such tankers were vastly reduced in the open water regions. Thus another engineering solution was developed in the concept of Double Acting Tankers.
The double-acting concept is based on the idea that the vessel makes its path in heavy ice conditions the stern ahead, which will be possible through the use of electrical podded propulsion systems. Thus the stern and the propulsion units need to be dimensioned and need to be optimised for both conditions.
This arrangement offers good icebreaking capability with reduced power level and practically access to independent ice operation without compromising the open water performance of the ship. Experience has demonstrated a reduction in fuel consumption compared to conventional ships, which will be further enhanced through the pulling mode of the propeller.
Ice breaking capability of DAT in ahead and astern condition
Fig 1.1
Ice breaking capability of DAT [34]
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Advantage of ice class tanker (double acting)
a) Hull form can be optimized for all conditions. b) Total economy has improved. c) Improved Manoeuvrability. d) More freedom of design. e) Low Ice resistance (up to 50% in certain ice conditions) as well as low
power requirements (up to 40% less than conventional ice breaking tankers)
f) No need to stop propeller for reversing
The vessel is designed to follow the Double Acting principle and the hull form is designed accordingly. The vessel will be fitted with a bulbous bow. The bow shape is designed to be capable of operating in light ice conditions in Baltic Sea. The stern shape is of ice breaking type, planned to operate independently in the most severe ice conditions of the Baltic Sea. 1.2 Field search:
a) Ice conditions b) Ice properties c) Route selection d) Design basis development
The Baltic Sea:
Areas of northern Europe, including Baltic basin and the territory of Poland, were repeatedly covered by ice sheets. The Baltic Sea is a brackish inland sea, the largest body of brackish water in the world. It is about 1610 km long, an average of 193 km wide, and an average of 55 m deep. The maximum depth is 459 m. The surface area is about 377,000 km² and the periphery is about 8000 km of coastline. Ice conditions in Baltic Sea:
About 45% of surface area Of Baltic sea is covered by ice annually. The ice-
covered area during normal winter includes the Gulf of Bothnia, the Gulf of Finland, Gulf of Riga and Vainameri in the Estonian archipelago.
The thickness decreases when moving south. Freezing begins in the northern
coast of Gulf of Bothnia typically in early November, reaching the open waters of Bay of Bothnia, the northern basin of the Gulf of Bothnia, in early January. The Bothnian Sea, the basin south of it, freezes on average in late February. The Gulf of Finland and the Gulf of Riga freeze typically in late January.
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Severe (337,000 km2) Mild (122,000 km2) Average (206,000 km2)
The ice extent depends on whether the winter is mild, moderate or severe. Severe winters can ice the regions around Denmark and southern Sweden, and on rare cases the whole sea is frozen, Temperature Range:
In general ice forms in marine waters when temperatures are below zero on the Celsius grade, exact freezing temperature depending on the salinity of the water; more saline water freezes at lower temperatures. Because of this seawater freezes at.-0.20o C in the Bothnian. Minimum temperature observed in this region is - 20o C
Ice properties in Baltic Sea: The Baltic Sea is a brackish inland sea, the largest body of brackish water in
the world. Brackish water is water that is saltier than fresh water, but not as salty as sea water. It may result from mixing of seawater with fresh water, as in estuaries, or it may occur as in brackish fossil aquifers. Technically, brackish water contains between 0.5 and 30 grams of salt per liter. There are various types of ice defined by WMO (World Metrological Organization) in Baltic Sea are as follows:
New ice: A general term for recently formed ice which includes frazil ice, grease ice, slush and shuga. These types of ice are composed of ice crystals which are only weakly frozen together (if at all) and have a definite form only while they are afloat. • Frazil ice: Fine spicules or plates of ice, suspended in water. • Grease ice: A later stage of freezing than frazil ice when the crystals have coagulated to form a soupy layer on the surface. Grease ice reflects little light, giving the sea a matt appearance. • Slush: Snow which is saturated and mixed with water on land or ice surfaces, or as a viscous floating mass in water after a heavy snowfall.
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• Shuga: An accumulation of spongy white ice lumps, a few centimetres across; they are formed from grease ice or slush and sometimes from anchor ice rising to the surface. Nilas: A thin elastic crust of ice, easily bending on waves and swell and under pressure, thrusting in a pattern of interlocking 'fingers' (finger rafting). Has a matt surface and is up to 10 cm in thickness. Maybe subdivided into dark nilas and light nilas. • Dark nilas: Nilas which is under 5 cm in thickness and is very dark in colour. • Light Nilas: Nilas which is more than 5 cm in thickness and rather lighter in colour than dark nilas. • Ice rind: A brittle shiny crust of ice formed on a quiet surface by direct freezing or from grease ice, usually in water of low salinity. Thickness to about 5 cm. Easily broken by wind or swell, commonly breaking in rectangular pieces. Young ice: Ice in the transition stage between nilas and first-year ice, 10-30 cm in thickness. Maybe subdivided into grey ice and grey-white ice. • Grey ice: Young ice 10-15 cm thick. Less elastic than nilas and breaks on swell. Usually rafts under pressure. • Grey-white ice: Young ice 15-30 cm thick. Under pressure more likely to ridge than to raft. First-year ice: • Thin first-year ice/white ice: First-year ice 30-70 cm thick.
Thin first-year ice/white ice first stage: 30-50 cm thick. Thin first-year ice/white ice second stage: 50-70cm thick
• Medium first-year ice: First-year ice 70-120 cm thick. • Thick first-year ice: First-year ice over 120 cm thick. Old ice: Sea ice which has survived at least one summer's melt; typical thickness up to 3m or more. Most topographic features are smoother than on first-year ice. Maybe subdivided into second-year ice and multi-year ice. Second-year ice: Old ice which has survived only one summer's melts; typical thickness up to 2.5 m and sometimes more. Because it is thicker than first-year ice, it stands higher out of the water.
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In contrast to multi-year ice, summer melting produces a regular pattern of numerous small puddles. Bare patches and puddles are usually greenish-blue. • Multi-year ice: Old ice up to 3 m or more thick which has survived at least two summers' melts. Hummocks even smoother than in second-year ice and the ice are almost salt-free. Colour, where bare, is usually blue. Melt pattern consists of large interconnecting irregular puddles and a well-developed drainage system
The basic requirements set for the project are:
ICE CLASS: Finnish-Swedish 1A super
SIZE: ~ 150000 t dwt,
ICEBREAKING CAPABILITY: Baltic conditions
1.3 Type of Propulsion System:
Pod propulsion system without any rudder and shafting is normally employed for double acting tanker. It can generate thrust to arbitrary directions of 360 degrees. Utilizing this characteristic, double acting tanker (DAT) was built at Sumitomo Heavy Industries, Ltd. DAT is a double-bow tanker, which one bow is a bulbous bow and another is an ice breaking bow,
Bulbous bow can reduce resistance of the ship by about 15% from ordinary ice breaking ship with ice breaking bow (fuel economy 20%), and in addition during navigation on ice sea area, broken pieces of ice can be separated from hull by propeller flow and thus high ice breaking efficiency is expected Main Advantages of the Azipod Propulsion
• Excellent dynamic performance and maneuvering characteristics, ideal even in harsh arctic and offshore environments.
• Eliminates the need for long shaft lines, rudders, transverse stern thrusters, CP-propellers and reduction gears
• Combined with the power plant principle, it offers not only new dimensions to the design of machinery and cargo spaces, but also reduced levels of noise and vibration, less downtime, as well as increase safety and redundancy.
• Operational flexibility leads to lower fuel consumption, reduced maintenance costs, less exhaust emissions and increased redundancy with less installed power.
• The Azipod unit itself has a flexible design. It can be built for pushing or pulling, open water or ice conditions. The Azipod can be equipped with skewed propellers, with or without a nozzle.
• Excellent wake field due to improved hydrodynamics.
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1.4 Hull Strengthening:
Hull strengthening due to Ice Load is dependent on:
• Ice conditions. • Type of operation. • Ice classification Rules. • Direct Calculations. • Combined.(Ice class rules as reference)
1.5 Trade Route:
The trade route is decided to carry crude oil from Belokamenka (Murmansk Russia) to Rotterdam (Netherlands) via Baltic Sea. The ship will perform pendulum service between the two ports.
1.6 Classification:
The selection of classification depends on specific oceans and sea areas in the context of current and earlier commercial shipping developments for ice operation. For Baltic Sea region FSICR (Finnish - Swedish Ice Class Rules) 1A/1C, November ‘2004 (after amendments to the old rules) is used. The above selection of classification is done on the basis of:
• Requirements of Administrations • Area of operation (Ice level, Air/water temperature) • Chartered requirements, and • Future flexibility
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2.1 Preliminary Investigation:
The Baltic is as a export outlet for Russian crude/products and increasing its importance in Europe’s energy needs. The Republic of Russia, has become second largest oil producer after Saudi Arabia in world, Plans major energy infrastructure investments to keep up with increasing demand in European countries. The oil statistics of Russia:
Oil - production: 10.5 million barrels/day (2006 est.)
Oil - consumption: [26] 2.9 million barrels/day (2006 est.)
Oil - exports: 7.6 million barrels/day (2006 est.)
Oil imports from Russia to Europe have increased. Various European countries shares the Russian oil Export; like Netherlands 9.1%, Germany 8%, Ukraine 6.4%, Italy 6.2%, China 6%, US 5% etc.
Shipments in North Baltic:
• Export set to double in next 5 years. • Need of Ice Class Tankers up to Aframax/Suezmax size. • 100-150 million tons per year of oil transport is estimated for the future in the
arctic and far eastern areas of Russia.
The North Baltic, with a particular focus on the Port of Murmansk, is set to double its output in next five years. Presently 20% of all Russian oil export is finding its way to world market through the port of Murmansk. .The Russian Arctic region has oil reserves of about 100 Billion tons for the future which is 75% of total Russian oil reserves. MURMANSK PIPELINE PROJECT
In November 2002, four largest Russian oil companies signed an MoU on the development of an oil pipeline system via the sea bulk oil terminal in the area of Murmansk. The construction started in 2004 and is to be completed by 2008, when it will be put to operation. The yearly oil flow volume from the west Siberian – Murmansk oil pipeline is expected to be 80 million tons. One of the major driving factors behind the development of the terminal is the expected export growth, especially in the USA.
There has been two pipeline routes under consideration: Western Siberia – Ukhta – Murmansk (3600 km). Western Siberia – Usinsk – Murmansk via the White Sea (2500 km).
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Russian crude oil export pipelines
Fig 2.1 [26]
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CHAPTER 2
FIXING OF MAIN DIMENSIONS
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acting Ice Class Tanker Type of cargo : Crude oil Trade Route : Belokamenka vessel (Murmansk Russia) to
Rotterdam (Netherlands) Feature of trade : Pendulum Service Relevant Rules and Regulations: IMO, ILLC, SOLAS, MARPOL FSICR etc Dead weight : 150,000 t Service speed : 15 Kn (open water) and 5 Kn (1.0 m thick Ice) Classification : FSICR, LRS Radius of Action : 3800 Nautical Miles Shape of Hull : BSRA Shape of Stern : Form like the Bow of a normal Ice Breaker Shape of Stem : Bulbous bow is provided as per normal
tankers Before starting the design, the design problem is defined analyzing the different frontiers that will influence the entire design. System operational requirements include cargo and ballast pumping capabilities, speed, crude oil washing (COW) system, inert gas system (IGS), emissions, and possibly ballast water exchange in the future. All of these systems must work together in a safe manner, Constraints include:
a) Propulsion power b) Machinery c) Deckhouse volume d) Cargo block volume e) Deadweight f) tonnage g) Stores capacity
2.1.1.1 Hold Capacity
Hold capacity depends on stowage factor for crude oil, 1.13 to 1.24 m3/t 2.1.1.2 Engine Plant Space necessary for the engine plant and the mass of engine plant and the fitting of the podded thrusters are the deciding factors. Engine plant should be capable of providing power for propulsion as well as lighting, navigation, heating coils, heaters, steering gear etc. Engine room is located in the aft region. 2.1.1.3 Super structure & deck house Superstructures are usually arranged towards the ends. The forecastle is helpful in preventing the shipping of green water. Normal sheer is not given to the ship, for ease of construction.
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2.1.1.4 Shape of the hull, stern, stem The parameters describe the actual hull form with coefficients: Beam to Draft Ratio, Length to Beam Ratio, Block Coefficient, and Depth to Draft ratio. These allow the optimizer to choose a variety of ship shapes and size. The following are the some of the important points in relation with shaping the hull;
a) Minimization of Resistance , b) Interaction between hull and propeller, c) Favourable hull in connection with behaviour in both Ice and Open water. d) Favourable hull in connection with production e) Favourable hull related to stability.
Stern: As the stern part is to be capable of breaking the ice, it should be shaped like bow of an icebreaker with necessary arrangements to fit the Azipod. A bulbous bow is provided at aft in the vicinity of propeller.
Stem: The stem is as per the normal conventional tankers provided with a bulbous bow. Stem must be able to accommodate two bow thrusters.
2.1.1.5 Rules & Regulations Governing Double Hull Tanker Construction
The different rules and regulations governing double hull tanker construction are,
a) Classification Society Rules b) IMO Regulations c) International Convention for the Prevention of Pollution from Ships, it
includes • Annex I: Prevention of pollution by oil • Annex II: Control of pollution by noxious liquid substances • Annex III: Prevention of pollution by harmful substances in packaged
form • Annex IV: Prevention of pollution by sewage from ships • Annex VI: Prevention of Air Pollution from Ships
Most important factors to be incorporated are as follow. (i) Wing tanks
w = 0.5 + dwt/20000 m or 2 m whichever is lesser. The min value of w = 1 m
(ii) Double Bottom tanks At any cross section the depth of each double bottom tank space shall be such that the distance “h” between the bottom of cargo tanks and the moulded line of the bottom shell plating measured at right angles to the bottom shell plating is given by,
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h = B/15 or 2 m, whichever is lesser The min value is of “h” 1m.
(iii) The aggregate capacity of ballast tanks.
On crude oil tankers of 20,000t deadweight and above, the aggregate capacity of wing tanks, double bottom tanks, fore peak tanks and aft peak tanks shall not be less than the capacity of segregated ballast tanks required to meet the requirements
(iv) Ballast and cargo piping
Ballast piping and other piping such as sounding and vent piping shall not pass through cargo tanks.
The amendments also considerably reduced the amount of oil which can be discharged into the sea from ships (for example, following the cleaning of cargo tanks or from engine room bilges). Originally oil tankers were permitted to discharge oil or oily mixtures at the rate of 60 litres per nautical mile. The amendments reduced this to 30 litres. For non tankers of 400 grt and above the permitted oil content of the effluent which may be discharged into the sea is cut from 100 parts per million to 15 parts per million.
d) International Convention for the Safety of Life at Sea (SOLAS), 1974
The important parts of this convention are, • Chapter II-1 - Construction - Subdivision and stability, machinery and
electrical installations. • Chapter II-2 - Fire protection, fire detection and fire extinction • Chapter III - Life-saving appliances and arrangements • Chapter IV - Radio communications • Chapter V - Safety of navigation • Chapter IX - Management for the Safe Operation of Ships • Chapter X - Safety measures for high-speed craft • Chapter XI-2 - Special measures to enhance maritime security
e) International Convention on Load Lines, 1966 The important parts of this convention are,
• Chapter I - General • Chapter II - Conditions of assignment of freeboard • Chapter III - Freeboards • Chapter IV - Special requirements for ships assigned timber freeboards
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2.1.1.6 Trade routes
Vessel Belokamenka (Murmansk, Russia)
Belokamenka is an ULCC currently used as a storage tanker in the vicinity of Murmansk port. It has been fixed over there to overcome the draft restriction of Murmansk port. Different particulars of vessel have been provided below.
IMO NO : 7708314 Latitude: 69° 07'N, Longitude: 033° 16'E Flag ; Russian federation DNV ID : 11713 GT : 188728 NT : 125883 Capacity : 350000 Dwt Draft : 23 meters
Port of Rotterdam (Netherlands)
Code: NL0051, UNTAD Code: NLRTM
Latitude: 51° 54.100'N, Longitude: 004° 26.100'E
There are no restrictions regarding length and beam of the ship. Maximum
draft allowed is 22.55 m. Port of Rotterdam ideally located for the transshipment of cargo. The port of Rotterdam is well equipped for handling bulk and general cargoes, coal and ores, crude oil, agricultural products, chemicals, containers, cars, fruit, and refrigerated cargoes.
This ice class tanker is meant to operate between these two ports. It will
impart pendulum services between origin and destination ports
2.1.2 Evaluation of DAT
In order to evaluate the new concept DAT in a more realistic way, following factors has been considered.
(1) Size of vessel : Suezmax (2) Route : Baltic Sea (3) Main engine output : Based on charts or model tests (4) Ice conditions around the route : statistical data between 1999-2005
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The principal dimensions of DAT are almost the same as a conventional tanker because of its geometrical similarity with the conventional Tankers.
Principal dimensions of ice class tanker estimated by ARCOP
DWT (t) 63,000 90,000 120,000 LOA (m) 219.5 252.0 289.0 LBP (m) 202.0 228.0 268.0 B (m) 34.0 40.0 46.0 T (m) 13.0 14.0 15.0 D (m) 17.0 19.0 22.0 Power 14.5 18.0 22.0
Table 2.1 [22]
Principal dimensions as estimated by ARCOP 2.1.2.1 Principal particulars of the Tempera/Mastera: Ship type: Crude oil and oil product carrier LOA:. 252.00m LBP: 228.00 m Bm : 40.00 m Dm: 19.00 m TDesigned: 14.00 m TScantling: 14.50 m Speed: 13.5 knots in open water and 3 knots in 1 m thick Ice condition (Ice class 1AS) Propulsive power: 21MW Power: nominal output is 16 MW Size of the DAT influences by
• Limitations for the Draught • Icebreaking assistance • the Beam of the ship
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Some Ice class ships (DAT): [37] Above data shows:
• The Double Acting Tankers have more breadth than the conventional tankers of same deadweight.
• Beam of the DAT is more because of good Ice breaking capability; also the smaller length reduces the lightship weight by some amount and subsequent reduction in cost.
• For the same length of tankers, DAT is having more or less same deadweight as conventional tankers with more breadth for Suezmax size tankers because of the increased Engine plant mass and space for HFO and Stores and long operation time.
Sketches
Typical general arrangement of the vessel is given below. The sketches are not to the scale.
“D
Department of S
Ship technology
Fig Typic
gy, CUSAT, B.T
15
g 2.2 cal GA
Tech (NA&SB), Batch – XXIXX”
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2.2 First estimates of displacement/volume
Preliminary calculation of displacement is based on the displacement coefficient CD
CD = Deadweight/Displacement
For DAT, the value of CD is taken as 0.823 (Parent ship data).
Displacement = 150000/0.823 = 182260.02 t
2.3 Preliminary selection of main & auxiliary machinery
From empirical relation for calculating power delivered for conventional tanker. Power delivered, PD = (Δ0.567 × VT
Minimum required propulsion SMCR power demand (CP-propeller) for average-size tankers with Finnish-Swedish ice class notation (for FP-propeller add
+11%) [34]
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SMCR of engine considering FP Propeller =32000kw [34] Selected Engine
Type: 9TM620 Number: 3 Manufacture: STORK WARTSILA DIESEL CO. Holland [33] Rated output: 12,750KW Rated speed: 428rpm Consumption of heavy fuel oil: 174G/KWH +5% Consumption of lube oil: 1.3+0.3G/KWH Greatest weight/piece: 270T Auxiliary Machinery As an approximation the power of auxiliary engines is taken as 15 % of the main engine power.
15 % of main engine power = 0.15*12.75x3 = 5737 KW. [35]
2.4 First estimate of main dimensions and coefficients
The main dimensions have a decisive effect on the ship’s characteristics. It affects
Stability Hold capacity Hydro dynamic qualities such as resistance, manoeuvring, sea keeping Economic efficiency Initial cost
Determining the main dimensions, proportions and form coefficients is one of the most important phases of overall design.
Crude oil tankers are essentially slow speed ships carrying imperishable cargo. The shipment of crude oil over the last two decades has increased tremendously. Hence the need for economic optimality in design, capacity etc is necessitated.
2.4.1 Symbols list and their units Dwt - Dead weight (t) Δ - Displacement (t) LBP - Length between perpendiculars (m) V - Velocity (kn) g - Acceleration due to gravity (m/s2) B - Moulded breadth of the ship (m)
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D - Moulded depth of the ship (m) T - Draft of the ship (m) CB - Block coefficient of the ship Fn - Froude number PD - Power delivered (KW) ΔEP - Engine plant mass (t) ΔSE - Steel mass (t) Δou - Out fit mass (t) E - Lloyd’s equipment number
2.4.2 The stepwise procedure to find the length of a 150,000 ton DAT can be summarized as below:
• Find Range of length by Danckwardt formula for a conventional tanker of 150,000 ton.
• Estimate the Block coefficient. • Determination of B, T and D from the ratios (L/B, B/T and L/D) obtained from
the registered ice class ships ranging form 115,000 to 160,000 tonnes deadweight. The ratios must be chosen to provide more breadth than conventional tankers or L/B and L/D ratios should be comparable to Tempera/Mastera.
• Select the ratios. • Iterate the length found to satisfy the required deadweight.
Danckwardt formula:
LBP = (5.2 ±0.2-0.15×Δ×10-5)×Δ1/3
LBP = 267.98 m to 290.66 m [3]
Range of length selected:
From the lengths obtained by the above formulae a range of length is selected. The range is from 260 m to 290 m
2.4.2.1. Estimation of Block Coefficient (CB) CB = 0.975-(0.9×Fn) +- 0.02 Danckwardt Formula [4] Fn = V/√ (gL) [4]
CB corresponding to the length found above is thus calculated. Range of CB is from 0.817 to 0.857 Selected CB = 0.837
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2.4.2.2. Determination of B, T, D
B, T and D are calculated from the ratios (L/B, B/T, L/D) obtained from parent ships.
Ratio Range Taken L/B 5.27-5.94 5.40 B/D 1.799 -2.222 2.05 T/D 0.700 - 0.736 0.71
B/T 2.506 – 3.03 2.86
L/T 14.884 – 16.38 15.70
Fn 0.148 – 0.163 0.16
Table 2.3
Ratios of Main Dimensions
First Iteration Selected length is L = 260 m
Breadth We have the value of L/B = 5.40 B = 48.15 m
Draught We have the value of L/T = 15.70 T = 16.56 m
Depth We have the value of B/D = 2.05 D = 23.49 m
Displacement Δ = L.B.T.CB × 1.008 × 1.006
= 175958.6 t (1.006 is for skin correction) Equipment Number (E) E = L (B + T) + 0.85L (D-T) + 250
= 18605 Steel mass [2]
ΔSE = Δ7SE [1+0.5× (CB
8 – 0.7)] + 900 t (addition for Ice Class 1A) Δ7
SE = K.E1.36
(K= 0.029 to 0.035 for tankers with 1500 < E <40,000) E = 1500 – 40000 for tankers
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Take K = 0.035
Δ7SE = 22426.6
CB8 = Block Coefficient at 0.8D
= CB + (1- CB) (0.8D – T) /3T = 0.843
ΔSE = 24933.5 t
Out fit mass ΔOU = MOU× L × B + 100 t (approx additional weight for Helipad and helicopter) MOU = 0.24 [35]
ΔOU = 3104.44 t Delivered Power SMCR = 32000 KW [34] Engine Plant mass
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Similar iterations were done using the same procedure. Results are given in the table below
Table 2.5
Results of Iterations DWT V/S Length, a graph is plotted got from several iterations. The graph is given below. In X-axis length is plotted, Dwt in Y- axis
Hull form of the ship has a decisive effect on almost all the aspects of ship performance like:
a) Trim & stability b) Resistance c) Controllability d) Sea keeping
It also has to satisfy the requirements regarding displacement, volume and freeboard.
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2.5.1 Stem Design:
Stem is designed as per the conventional tankers with a bulbous bow. 2.5.2 Stern Design
Cruiser stern designed because of operation in ice, the vessel may encounter severe ice loads while moving aft. To distribute the ice loads, cruiser stern is more suitable. Because of its smooth curvature it is more suitable for running aft. 2.6 Preliminary General Arrangement
The allocation and dimensions of main spaces like length of cargo tanks, width of double skin and height of double bottom etc of double hull tankers are determined by the regulation 13 F MARPOL 73/78. Double hull is mandatory for tanker above 500grt.
The Mid Deck arrangement makes use of a horizontal subdivision (mid deck) of the cargo spaces so that the oil pressure is reduced to a level less than the hydrostatic pressure. As a result of this even if the hull is damaged the oil out flow will be considerably reduced.
Double hull construction makes use of wing tanks and double bottom spaces throughout the cargo region, so that even if the outer hull is damaged, oil out flow will not occur. Double hull construction is the modern trend.
2.6.1 Ballast Tanks or Spaces
According to regulations 13F and 13G of MARPOL 73/78, the entire cargo length should be protected by ballast tanks or spaces other than cargo and fuel oil tanks.
a) Wing Tanks or Spaces
Wing tanks or spaces should extend for the full length of ships side, from the top of the double bottom to the upper most deck, They should be arranged such that the cargo tanks are located in board of the moulded line of side shell plating nowhere less than the distance W at any cross section is measured at right angles to the side shell, as specified below. w = 0.5 + Δ / 20000 m = 9.61 m or, w = 2 m, which ever is the lesser.
The minimum value of w is 1m. w is taken as 3.0 m to satisfy the ballast requirements.
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b) Double Bottom Tanks or Spaces
At any cross section the depth of each double bottom tank or space is such that the distance h between the bottom of the cargo tanks and the moulded line of the bottom shell plating measured at right angles to the bottom shell plating is not less than specified below.
h = B /15 = 3.25 m OR h = 2 m, whichever is lesser
The minimum value of h is 1.0m Therefore h = 3.0 m to satisfy the ballast requirements. 2.7 Initial estimates of consumables, stores and cargo
Range = 3773 nm Speed = 15.0 Knot (open water) = 5.0 Knot (Most severe Ice conditions)
Max Hours of travel, H = 754.6 Hrs Hours in port = 48 Hrs No of officers = 21 No of crew = 23
2.7.1 Volume of heavy fuel oil (VHFO) Specific fuel consumption, SFC = 185 g / KWh. (Assumed for a slow speed large bore diesel engine) Brake power, PB = 32000 KW Mass of heavy fuel oil, MHFO = SFC × PB × H / 1000000 +20% (Allowance) = 5360 t Volume of HFO, VHFO = MHFO /0.90 = 5955 m3
2.7.2 Volume of diesel oil (VDO)
SFC = 220 g /KWh Power of auxiliary machinery, PAUX
= (1554 + 38.4 X1 – 0.269 X2 + 0.046X12 +16.21 X2
2
- 2.31X1.X2) 0.76 (H. SCHREIBER, HANSA 114 (1977) NO 23 P 2117)
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Mass of diesel oil, MDO = SFC × PAUX × H/1000000
= 1858 t Volume of diesel oil, VDO = MDO/0.95
= 1956 m3
2.7.3 Volume of lubricating oil (VLO) Mass of lube oil, MLO = 0.03 (MHFO + MDO)
= 216.6 t Volume of lube oil = 59/0.9 = 240.6 m3
2.7.4 Volume of fresh water, (VFW) Consumption of fresh water = 20 litres / person / day Mass of fresh water, M FW = 27.6 t Volume of fresh water, VFW = 27.6 m3
2.7.5 Volume of washing water (VWW)
Consumption 120 liters /person/ day for officers 60 liters /person/ day for crew Mass of washing water, MWW = 130.4 t Volume of washing water, VWW = 130.4 m3
2.7.6 Mass of crew and effects Assume 150 kg per officers and 120 kg per crew Mcrew = 150*21 + 23*120 = 5.91 t
2.7.7 Mass of Provision Assume 8 kg/officer/day and 6 kg/crew/day Mass of provision = 9.6 t Mass of stores & crew = MHFO + MDO + MLO + MFW + MWW + MCRW +MPRO
= 7609 t
2.7.8 Mass of Cargo
Mass of cargo, MCR = Dwt - Total mass of stores & crew
= 150491 – 7609
= 142882 t
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2.8 Checks on hold and tank capacity
The total capacity of the ship is the volume required for cargo plus the minimum volume required for ballast.
2.8.1 Volume of hold VHD = (VDD + VSH + VCA + VHT + VHS)-(VFP + VAP + VER + VDB
+ VTA + VSS + VCOF) Where: VHD = volume of hold VDD = volume up to upper deck VSH = volume of sheer VCA = volume of camber. VHT = volume of hatchway trunks VHS = volume of holds in superstructure VFP = volume of forepeak tank VAP = volume of aft peak tank VER = volume of engine VDB = volume of double bottom VTA = volume of tank in the hold VSS = volume of side tanks
Where C3 = 0.76CB + 0.273 = 0.909 ∴VCA = 0 m3 (Camber has not been considered)
(7) VCOF = LCOF ×B×D = 3471m3 (Length of Cofferdam taken as 3 m)
In segregated ballast tankers the ballast water is carried in the wing tanks and the double bottom tanks. Therefore the volume required for ballast water must be subtracted from the volume of hold, to get the actual volume available for the carriage of cargo.
2.9.2 Volume of Required Minimum Segregated Ballast Water
The minimum volume of ballast water that the vessel should carry is given by the MARPOL 73/78, Regulation 13.
Draft at aft, Ta = 0.7T (for full propeller immersion) = 11.725 m. Minimum draft, Tm = 2+0.02L = 7.26 m. Maximum trim by stern, tm = 0.015L
= 3.945 m. Draft at fore, T f = Ta–tm = 7.78 m.
Tmean = (Ta + Tf)/2 = 9.75 m. Mean draft, Tmean > Tm
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Ballast displacement, ΔB = (Tmin /T) (CW
/CB
)* Δ ∴ΔB = 73548 t Mass of ballast water = ΔB-ΔLS
= 41702 t Minimum volume of ballast water = 41702 /1.008 = 41371 m3
Available volume of ballast water
Total length of double bottom = LBP- LAP - LFP - LER - LCOF ≈ 196.88 m
Depth of double bottom = 3.0 m
Width of side skin = 3.0 m
Volume of double bottom = LDB*BDB*DDB*0.7
= 196.88*48.7*3*0.7
= 20135 m3 Total length of side skin = LBP- LAP - LFP - LER - LCOF ≈ 196.88m Width of side skin = 6 m Depth of side skin = 23.76 – 3 = 20.76 m Volume of side skin = 196.88*6*20.76*0.95 = 23297 m3 Total ballast volume available = Volume of double bottom + Volume of side skin + Volume of Aft peak tank = 20135 + 23297 + 1299 = 44731 m3 Available volume of ballast water is greater than the minimum required.
2.9.3 Volume of Cargo Required
Volume of Cargo required = (Mass of cargo, MCR)/0.85
= 142882/0.85 =168096 m3
2.9.4 Volume of Cargo Available
Volume of Cargo available = (VHOLD - VBALLAST)*0.98 The cargo hold is filled up to 98% of the capacity in order to account for the
Frictional resistance coefficient is calculated using the ITTC 1957 formula, CF =0.075/ (log10 Rn -2)2
Rn , Reynolds number = VLWL/ν V = 15.0 Knot = 7.716 m/s LWL = 270.8 m ν = 1.16*10-6 m2s-1 at T = 0 0C Rn = 18.01 * 108 CF, Frictional resistance = 0.00142 CT, Total resistance = 0.00142 +0.001745 = 3.165 x 10-3
2.10.3 Total resistance
RT = CT*1/2ρSV2 where S is wetted surface area and it is calculated by using the following formula
S = 1.7LWL T + ∇/T (Mumford’s Formula)
= 18513 m2
There fore total resistance
RT = 3.165 x 10-3*0.5*1.008*18513*(7.716)2
= 1758 KN
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RT (with allowance of 20 %) = 2109 PE = RT
V = 2109*7.716KW = 16279 KW PB = PE /( ηm x ηt x ηg x ηH ) η H = Hull efficiency (Twin screw ships)
= 0.9 ηm = Efficiency of motor
= 0.96 η t = Efficiency of transformer (ABB Finland)
= 0.97 η g = Efficiency of generator
= 0.96 η 0 = Efficiency of propeller = 0.76 (assumed) PB =26623 KW
2.11 Initial stability and Freeboard calculations
2.11.1 Freeboard Check (Practical Ship Design by DGM Watson)
Minimum freeboard is a statutory requirement for all vessels under the Merchant Shipping Act 1968. The freeboard assigned should be in accordance with the IMO Load line Convention Rules1966. The conventional tankers fall into IMO’s type A ship with regard to freeboard. It is observed that double hull tankers have excess freeboard. This is due to segregated ballast tank volume, which remains empty in the loaded condition. Thus higher freeboard is inevitable
Tabular freeboard (for type A ship) for L = 263 m is 3089 mm
(After interpolation from table given in Ship Design and Construction by Taggard)
This is the basic freeboard to which various corrections wherever applicable is applied
a) Correction for CB
When CB is greater than 0.68, the basic freeboard is multiplied by = (CBD +0.68)/1.36 = 1.116 Corrected freeboard = 3089 x 1.116 = 3447.32 mm
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b) Correction for Depth
Freeboard is increased by (D – L/15) R, where R is 250 for ships with L > 120m. R = 250, since L>120m Correction to be added
= (D-L/15)×R, since D>L/15
= (23.76-263/15)×250 = 1556.66 mm Corrected freeboard = 3447.32 + 1556.66 = 5003.98 mm
c) Correction for Superstructure
For lengths 125m and above, the standard height of superstructure is 2.3 m. the effective length of a superstructure of standard height can be taken as its length itself. Assuming standard height of superstructure for the ship, the length of superstructure is taken from a similar ship as 0.15 LBP and the length of forecastle is assumed to be 0.07 LBP Length of superstructure = 0.15 L Length of forecastle = 0.07L Effective length of superstructure = 0.15L + 0.07L = 0.22 L
When the effective length of superstructure and trunks of a ship is 1.0 L the basic freeboard shall be reduced by an amount 1070 mm (from table).
When the effective length of superstructure and trunks is less than 1.0 L the basic freeboard shall be reduced by an amount x % of 1070 mm Therefore Correction x =15.7% Therefore Correction factor to be added = 0.157*1070 = 167.99mm Corrected freeboard = 5003.98 – 167.99 = 4835.99 mm
d) Correction for Sheer
No sheer is given. So there is sheer deficiency and penalty for no sheer is to be applied.
Sheer Deficiency = (SAft+SFor’d)/16 SAft = 22.23L + 667 = 6513.5 mm SFor’d = 44.47×L+1334 = 13029.6 mm
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Sheer Deficiency (SD) = (SAft+SFor’d)/8×1/2 = (6513.5 +13029.6)/16 = 1221.4 mm Correction = SD {0.75- E/2L}; Where E is the effective length Of super structure = + 781.6 mm Correction for Ice thickness of 1000 mm = 8/9*(1.0) = 888.8 mm Corrected freeboard = 4835.99 + 781.6 + 888.8 = 6506.4 mm Available freeboard = 7010 mm
Hence the vessel has sufficient free board as per load line regulations 1966
e) Minimum Bow Height
Minimum bow height = 56*L (1-L/500)*(1.36/ (CB+0.68)) mm
(LRS PART 3, CHAPTER 3, SECTION 6)
= 6254 mm
A forecastle deck is 2.3 m high above main deck.
Available freeboard = 7010 mm
Total bow height = Available freeboard + 2300
= 9320 mm
Hence minimum bow height required is satisfied.
2.11.2 Preliminary Stability Check
Preliminary Stability check is done by Prohaska’s first approximate method (Transactions of the Institution of Naval Architects, 1947)
h* A non dimensional parameter referred to as residuary stability coefficient. GZ = h*BM+GMSinθ GM = KB+ BM- KG [14]
1). KB = T* (0.9-0.3*CM – 0.1*CB) [4] CM = 0.9+0.1* CB = 0.983 KB = 8.73 m
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2 (Normand’s Formula) CW = 0.95* CP + 0.17*(1-CP)1/3 [4] = 0.899 f (CW) = 0.815 BM = 11.47 m 3). KG = 0.58 D [3] = 13.78 m GM = 8.73 + 11.47 – 13.783 = 6.42 m GM/B = 6.42/48.7 = 0.131 [3] Required range of GM/B is 0.05 to 0.1; the calculated value is out of range. Hence roll period has to be checked for crew comfort.
For the given values of T/B and D/B h* is read for the six angles of heel Viz.15º, 30º, 45º, 60º, 75º, 90º.
Angle of Heel (θ) h* GM Sinθ BM x h* GZ (m)
0 0 0 0 0
15 0.009 1.66 0.103 1.763
30 0.09 3.21 1.03 4.24
45 -0.185 4.53 -2.12 2.41
60 -0.325 5.55 -3.72 1.83
75 -0.475 6.20 -5.44 0.76
90 -0.62 6.42 -7.11 -0.69
Table 2.7
GZ at different angles of heel
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The curve of intact stability is plotted and checked according to the guidelines set by IMO A. 749
30
0.8
7.2
6.4
5.6
4.8
4.0
3.2
2.4
1.6
ANGLE OF HEEL(deg)
RIG
HTI
NG
LEV
ER G
Z (m
)
807060402015105
8.0
50
Fig 2.5 Preliminary GZ curve
Description Requirement Available
Area under GZ curve upto 30° Should not be less than 0.055 m rad 1.021 m-rad
Area under GZ curve upto 40° Should not be less than 0.09 m rad 1.69 m-rad
Area under GZ between 30° & 40° Should not be less than 0.03 m rad .66 m-rad
Maximum righting lever, GZmax
Should be at least 0.2 m at angle of heel greater than 30° 4.26 m
Angle of GZmax Should occur at an angle greater than
30° 31.5o
Initial GM Should not be less than 0.15 m 6.42 m
Table 2.8
IMO Requirements The IMO conditions are satisfied.
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B
2.12 Flowchart of Design Process: The flowchart of design process given below is not standard flowchart of any
ship design process. The flowchart is prepared based on the direction given by the project coordinator and comply with the design guidelines given to us. FLOW CHART OF DESIGN
READ DEADWEIGHT, SPEED AND RANGE
CALCULATE THE MAIN DIMENSIONS
ESTIMATE DISPLACEMENT FROM – L x B x T x CB x ρSW x k
ESTIMATE LIGHT SHIP WEIGHT
DWT = DISPLACEMENT – LIGHTWEIGHT
A INPUT, DIMENSIONAL RATIOS FROM
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C
YES
FBD. ≥ REQUIRED FBD.
YES
DWT ≥ GIVEN DWT
A CHECK WITH IMO REQUIREMENTS
YES
A
A
B
NO
CALCULATE INITIAL STABILITY
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D
C
A STOWAGE FACTOR
WITHIN THE REQUIRED RANGE
YES
NO
ESTIMATE CAPACITY
PRELIMINARY GENERAL ARRANGEMENT
RESISTANCE AND POWERING
SELECTION OF MAIN ENGINE, POD AND AUXILIARY MACHINERY
DETAILED GENERAL ARRANGEMENT
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E
D
YES
CHECK FOR VOLUME
REQUIREMENTS
A CHECK WITH IMO CRITERIA
D
NO YES NO YES
DETAILED CAPACITY CALCULATION
DETAIL CALCULATION OF STABILITY AND TRIM FOR MOST SEVERE CONDITION
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E
CHECK WITH MIN CALCULATED
SECTION MODULUS
NO YES
MIDSHIP SECTION DESIGN
DESIGN SUMMARY AND CONCLUSION
STOP
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2.13 Final Main dimensions:
Considering all the requirements, the final dimensions are fixed and are shown in following table given below.
LBP 263.0 m
B 48.7 m
D 23.76 m
T 16.75 m
CB 0.838
Δse 25696 t
ΔOU 3174 t
ΔEP 2352 t
ΔLS 31846 t
DWT 150491t
Table 2.9
Final Dimensions
Hence the final dimensions of the ship are fixed. Now the next step is to generate the hull form that satisfies the above dimensions.
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CHAPTER 3
HULL GEOMETRY
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3. HULL GEOMETRY
3.1 Lines Design
After fixing main dimensions and coefficients the next step is to develop the lines plan of ship. Hull form of the ship has a decisive effect on almost all aspects of ship performance like:
a) Trim & stability b) Resistance c) Controllability d) Sea keeping
It also has to satisfy the requirements regarding displacement, volume and freeboard. Design of hull form using first principle should be tested in towing tank to determine its resistance and propulsion characteristics, which is beyond the scope of this project. Hence lines plan is designed using the standard data available.
Body plan of ice breaking tanker [34]
Fig 3.1
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A standard hull form has been selected from B.S.R.A (British Ship Research
Association) report no. 333.
Other advantages in choosing a BSRA standard hull forms are:
1) Development of lines by first principles involves a lot of trial and error and
quality of lines depends largely on experience. This can be avoided by selecting
a standard hull form.
2) Fairing of lines is minimized.
3) Standard lines are tested in towing tank and found satisfactory in resistance &
sea keeping qualities.
Standard lines give offsets for bulbous bow. So design of separate bulbous bow
not required.
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3.1.1 Design Procedure B.S.R.A presents waterline offsets for normal forms and bulbous bow forms on a
base of block coefficient. The offsets are presented in terms of the ratio (waterline
ordinate/full half breadth) for each of the standard B.S.R.A water lines as shown in table
3.1. Stn/ WL A B C D E F G H J K % of T 7.69 15.38 23.08 38.46 53.85 69.23 84.62 100 115.4 130.77Real WL 1.29 2.58 3.87 6.44 9.02 11.6 14.17 16.75 19.33 21.9
b) Stern Design Stern is designed with a O-type bulbous bow with assumed height of 4.5 m, the shape of bulb is given by iteration on AutoCAD after drawing the half breadth plan and cross checking of all three views until the design is not satisfactory. Also the Icebreaking stern is designed like a bow of an Icebreaker.
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c) Pod Dimensions Assumed pod diameter = 4.3 m (calculated from a scaled drawing with some geometrical assumptions, Actual diameter can only be decided after the final selection of the pod)
3.1.1 Final Lines
The offset values obtained by plotting body plan from BSRA Offsets. The station curves are extended up to the main deck / forecastle deck. Offsets at regular intervals of waterline are measured. The fairness is to be checked by drawing the half-breadth plan and profile plan.
The offsets so obtained are presented in table 3.2
WL spacing = 2.0 m LWL is 16.75 m above the base line. MDK is 23.76 m above the base line. STN spacing = 13.15 m. and STN 8 to STN 16 is parallel middle body = 105.2 m.
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3.2 BONJEANS AND HYDROSTATIC CURVES
3.2.1. Bonjean Calculations.
Bonjean calculation is calculation of sectional area and moment of each station up to each waterline about keel. This enables the calculation of displacement, LCB and VCB for any waterline for even keel.
The uses of Bonjean are: 1) Hydrostatic calculations 2) For floodable length calculations. 3) Launching calculations 4) Longitudinal strength calculations.
The calculations are done by MS-excel 2007 using Simpson’s and trapezoidal rules of integration. The results are given in the table 3.4 (area table) and table 3.5 (moment table).it has been checked with the help of SPAN software.
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3.2.2 Hydrostatic Calculations
Hydrostatic calculation is mandatory in the design phase of a ship for various drafts at different trim conditions. Any of hydrostatic particulars can be estimated with the table or graph obtained from hydrostatic calculation. The calculations are done with MS-Excel and the results are given in the table 3.5
List of formulae used. (Integration is performed using Simpson’s rule for port side and then doubled to get the total volume)
AWP = 2/3 h Σ f (A)
LCF =
IL = IФ – AWP x LCF2
IT = (2h/9)Σ f (IT)
TPC =
∇ = (h/3) Σ f (∇)
Δ = ∇ x 1.008 x 1.006
KB = (h/3) Σ f (MT)/∇
BMT =
BML =
MCT1cm =
KM = BM +KB
LCB = (h2/3) Σ f (ML)/∇
CB =
CM =
h × Σ f (M)
Σ f (A)
AWP × 1.008100
IT
∇ IL
∇
ΔxBML
100 LWL
∇
A ⊗BxT
LBP xBxT
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CW =
CP =
Hydrostatic parameters at designed load water are as below.
∇ = 180,113 m3 Δ = 182,643 t. KB = 8.73 m KMT = 20.36 m KML = 341.5 m IL = 59988798 m4 IT = 2095122 m4 TPC = 118.81 t MCT1cm = 2311.14 t-m LCF = -2.01m (Aft of midship) LCB = 4.79m (Fwd of midship) CB = 0.840 CP = 0.852 CW = 0.920 CM = 0.985 The value of CB and Displacement are approximately same and hence the lines design is satisfactory.
AWP
LxB
CB
CM
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WL/PROP
V Δ LCBФ LCFФ TPC IL IT KB BML KMT MCT1cm CB CW CM CP
NOTE 1) + means Fwd of midship Table 3.6 2) - ve means aft of midship HYDROSTATIC PROPERTIES
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CHAPTER 4
RESISTANCE AND POWERING
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4. RESISTANCE CALCULATION
4.1 Introduction
The resistance of a ship at a given speed is the force required to tow the ship at that speed in smooth water, considering no interference from towing ship. The resistance will be equal to the components of fluid forces acting parallel to the ship centreline.
The resistance of a DAT can be given by:
Total resistance RT (DAT) = R bare + R bow thrusters + R pod
4.1.2 Resistance Calculation of POD:
R pod can be calculated by using the equation: (from proceedings of 24th ITTC – Vol. III, Specialist committee on Azimuthing podded propulsion)
Rpod = Rbody + Rfin
Where,
R body = ½ ρV2 S body [C body (1+ k body) + ΔCF body]
R fin = ½ ρV2 S fin [C fin (1+ k fin) + ΔC Ffin]
The parameters of podded propulsion system can be assumed from the parent ship data. The approximate values are:
S body = 136.4 m2 (approx.)
Diameter of shaft = 1.0 m.
S fin = 8.4 m2 (approx.)
CF body = C fin = 0.001556 (from ITTC-57 line)
ΔCF body = ΔC fin =[105(ks/L)1/3 – 0.64] x 10-3 = 0.00358
(for ks = 0.015 m and L is the length of the ship)
K body = K fin = 0.7 (from VTT, Finland) The form factor, k, which is defined in pod setup and test location, is given only as qualitative information of the test results and the hull.
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R body = 24.81 KN
R fin = 1.52 KN
The sum of the separately measured nominal total resistance (bare hull + pod drag) compared to the directly measured total resistance deviate only approximately �2 % from each other. Thus it can be concluded that there are no significant pod - hull interaction despite the rather large sized pod units. (Source: VTT technical research center of Finland.)
Therefore,
R pod = R body + R fin = 26.33 KN (for V = 15.0 Knots)
For bare hull and bow thrusters resistance calculation, we can follow different methods of calculating resistance and assume the maximum of all to decide the powering requirements. The ship stern shape is considered to be normal, and the bow has a U-shape. Saltwater properties and the speed range are detailed in the vessel condition section of NAVCAD.
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The above data give resistance of bare hull and the resistance offered by one bow thrusters Hence the total resistance, for V =15 Knots (from Holltorp Menon - 1984 Method) RT (DAT) = Rbare + 2 x Rbow thrusters + Rpod For V = 15.0 knots (From Holltrop – Menon 1984 Method) RT (DAT) = 1637.15+ 2 x 12.43+ 26.33 KN = 1688.34 KN Total resistance by Guldhammer – Harvald Method:
From these three methods, Holltrop and Menon 1984 have the max value of resistance.
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4.2 Powering Calculation 4.2.1 Introduction
This deals with the selection of the main engine. The derivation of the engine power starts from resistance at service speed. A preliminary design of the podded machinery can be done which would deliver the required thrust. The selection of the pod is done on the basis of model test results carried out in the proceedings of 24th ITTC, Vol. – II (Special committee on Podded Propulsion). The Model tests were carried out for the Ice capable ships Mewis (2001) and Ukon et al (2003). The main engine is selected according to this parameter. Propeller design is done with the help of T-J and P-J charts. Wake fraction (w) w = 0.55CB-0.20 [36]
= 0.261
Thrust deduction factor (t) t = 1.25w [36]
= 0 .326 RT = 1688.34KN An allowance of 25% is provided to get service condition resistance. RT = 1688.34 *1.25 = 2110.5 KN
Thrust calculation
Required thrust = RT/ (1-t) = 3131.3 KN
Velocity of advance (VA)
VA = V (1-w)
= 15.0 × 0.5144(1-0.261) m/s
= 5.702 m/s
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Diameter of propeller
D = 2/3 T = 11.166 m T = draft D selected = 7.75 m (twin Azipod propeller) Td = √T/ρ/ (D × VA) In this case Td = (1/7.75× 5.7021) √(1565.65 /1.008) = 0.89
From Model results: (Model used for Extrapolation) (24th ITTC - Volume II)
Particulars Ukon et al. TU032 (VTT) Mewis
(AE/AO) 0.55 0.537 0.58 Diameter (mm) 200 200 215.15 Pitch Ratio 0.800 0.850 1.104 Boss Ratio 0.280 0.278 0.276 No. of Blades 4 4 4 Rotation direction Right Right Right
Table 4.4
Values of J, KQ are read off from T-J chart where the Td=0.89 line intersects the optimum efficiency line for optimizing n. This is done for AE/AO = 0.4, 0.55 and 0.70 Graphs are drawn with J and KQ versus AE/AO .Then the values of J and KQ for AE/AO = 0.55, 0.537 and 0.58 are found out for z = 4.
AE/A0 J KQ
0.4 0.47 0.0225
0.55 0.565 0.04
0.7 0.515 0.031
Table 4.5 KQ, J values for 4 bladed propellers
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4.2.2 Brake power calculation (for ahead running condition) PD = 15508.82 KW PB = PD / (η m x η t x η g) ηm = Efficiency of motor = 0.96 η t = Efficiency of transformer [28] = 0.97
η g = Efficiency of generator
= 0.96 PB = 15508.82/ (0.96x0.97x0.96)
= 17348.6 KW
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4.2.5 Engine selection
In order to utilize Azipod propulsion system, the ship should have electric power plants. Generator sets are connected to the main electric switchboard to distribute electric power for all power consumers onboard, including Azipod propulsion. In case of diesel electric power plant all the diesel engines can be of the same type as of the conventional vessel, which minimizes the spare parts inventories. The number of vulnerable auxiliary systems is reduced to a minimum. Diesel Engines Type: 9TM620 Number: 3 Manufacturer: STORK WARTSILA DIESEL CO. Holland [33] Rated output: 12,750KW Rated speed: 428rpm Consumption of heavy fuel oil: 174G/KWH +5% Consumption of lube oil: 1.3+0.3G/KWH Greatest weight/piece: 270T Generators Type: HSG 1600 S14 Number: 3 Rated capacity: 15,537 KVA Cos Factor: 0.8 Frequency: 50 HZ Rated current: 815A Rated voltage: 11KV Greatest weight/piece: 55T Rated speed: 429 rpm Rated output: 12.43 MW Transformers Number: 2 Type: STROD/BTRD. Rated voltage: 11KV/121KV Weight: 58T Auxiliary engines Type: SKU CUIN-1400N305, Model 1400 GQKA Number: 3 Manufacturer: Cummins Rated output: 1400 kW Rated capacity: 1400 kW (1750 kVA) 60 Hz or 1166.7 kW (1458.3 kVA) 50 Hz
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The engine is well suited for operation on low-quality fuels and intended to drive
the generator directly without any speed changing device. Normally generators are running at higher rpm, hence selected engine is medium speed engine using heavy fuel oil. This engine has been especially designed for such specific purpose only.
Brake power calculation (for ahead running condition) PB = 19125 KW η m = Efficiency of motor = 0.96 η t = Efficiency of transformer [28] = 0.97
η g = Efficiency of generator
= 0.96 PD = PB x (η m x η t x η g)
PD = 17096.8 KW 4.3 Selection of POD:
Power transmission and steering module is installed to the ship hull at a
convenient phase of ship construction. Pre-fabricated pod including strut and motor are delivered, installed and connected to the power and steering module separately on the most suitable phase only just before launching of the ship. The Azipod unit itself has a flexible design. It can be built for pushing or pulling in open water or in ice conditions.
PD = 17096.8 KW
Hence from Azipod performance curve, V25 type Azipod can be selected with special material requirements of Ice class operations.
Pod parameters are as follows
PD = 17096.8 KW RPM = 110
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Fig 4.5
Power (KW) Vs Propeller speed [28]
Fig 4.6
Azipod main dimension drawing [28]
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For V25 type (ABB) [Project [28]
A = 13500 mm B = 7050 mm C = 6500 mm D = 7750 mm (Assumed propeller diameter) E = 1600 mm F = 3355 mm G = 4900 mm H = 550 mm J = 2500 mm K = 2600 mm L = 6445 mm Tilt angle = 0o to 6o, Selected = 3o
Fig 4.7 [28] Weight of V25 Standard Azipod = Complete weight excluding propeller +
Weight of AZU (Azipod unit) + Weight of STU (Steering unit) + Weight of SRP (Slip ring unit) + Weight of CAU (cooling air unit) + Weight of HPY (Hydraulic power unit) + other ancillaries + weight of propeller [28]
= 315 + 175 + 85 + 4 + 10 + 5 + 8 + 60 = 662 tons
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4.4 Design of propeller to match the selected pod
PD = 17096.8 KW RPM = 1.833 VA = 5.7021 m/s PN = (n/ VA
Steps to get performance values for Wageningen B-Series propeller using P-J charts.
a) Find the point of intersection of PN = 1.22 line with the η optimum for PN constant
b) Read off J, where J = Advance coefficient c) Increase J by 6 %. d) At this J’=J(1.06), find the propeller characteristic where J’ meets e) For PN = 1.22 From J’ we can find the value of KT for given (AE/AO) = 0. 4 ,0.55
and 0.70after Interpolating the values of J’ and KT from the P-J charts
AE/Ao 0.4 0.55 0.70
J 0.385 0.408 0.43 J' (=J*1.06) 0.408 0.432 0.456
KT 0.158 0.175 0.208 P/D 0.68 0.75 0.77 D 7.635 7.204 6.836 T 1812.4 1591.6 1533.3
AE/Ao(min) 0.476 0.522 0.568 ηO 60.45 53.08 51.14
Table 4.8 Performance values
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Minimum blade area ratio to avoid capitation
(AE/A
O)
min = [((1.3 + 0.3Z) T) / ((P
atm + ρgh – P
V) D
2)]+ K [Auf’en Keller formula]
Where K = 0.1 for twin screw propellers Z = number of blades
h = height of LWL above shaft central line in meters P
atm = 101.366 kN/m2
PV
= 1.704 kN/m2
h = 8.0 m D = 7.75 m K = 0.1 for double screw propellers
ρ = 1.008 t/m3
g = acceleration due to gravity (9.81 m/s2)
=0.47 Performance curves
0.4 .55 .7
P/D D
AE/A
KTJ*
N
T
1 Kt 1cm=0.001
2 1cm=0.001
3 P/D 1cm=0.001
4 Ae/Ao 1cm=0.001
5 j* 1cm=0.002
6 T 1cm=2KN
1500
1700
1900
T(KN)
0.6
0.7
0.8
P/D
0.6
0.7
0.8
D(m) 0.5
0.6
0.7
no
0.4
0.5
0.6
Ae/Ao
0.1
0.2
0.3
kt
0.2
0.3
0.4
j*
00
N0
Fig 4.8
Performance curves
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Particulars of selected propellers D : 7.26 m Z : 4 AE/AO : 0.527 P/D : 0.742 T : 1612.56 KN ηO : 53.8 Material : Lloyd’s grade Cu 4 Manganese Aluminium Bronze Type : Wageningen B –series Fixed pitch Tensile strength N/mm2 minimum: 630N/mm2
Chemical composition of propeller and propeller blade castings
Sn 70-80%,
Pb-6%
Ni-0.05%,
Fe-1.-3%
Al- 5-9%,
Mn-8-20%
Zn -1%
4.5 Determination of ice torque [FSICR] Dimensions of propellers, shafting and gearing are determined by formulae taking into account the impact when a propeller blade hits ice. The ensuing load is hereinafter called the ice torque M. M = m D2 ton meters where: D = diameter of propeller in meters m = 2.15 for ice class IA Super = 1.60 (IA) = 1.33 (IB) = 1.22 (IC
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If the propeller is not fully submerged when the ship is in ballast condition, the ice torque for ice class IA is to be used for ice classes IB and IC.
M = 2.15X7.262 = 113.32 ton meters The elongation of the material used is not to be less than 19%, preferably less than 22% for a test piece length = 5 d and the value for the Charpy V-notch test is not to be less than 2.1 kpm at –10°C. Width c and thickness t of propeller blade sections are to be determined so that:
a) at the radius 0.25 D/2, for solid propellers
t = 23.85 cm
b) at the radius 0.35 D/2 for FP-propellers
t = 20.31 cm
c) at the radius 0.6 D/2
t = 13.06 cm
Where: c = length in cm of the expanded cylindrical section of the blade, at the radius in question t = the corresponding maximum blade thickness in cm H = propeller pitch in meters at the radius in question. = 5.386 (For controllable pitch propellers 0.7 H nominal is to be used.) Ps = shaft engine output according to 3.1, but expressed in horsepower [hp] = 22927.18hp n = propeller revolutions [rpm] = 110
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M = ice torque =113.32 ton meters Z = number of blades = 4 σ b = tensile strength in kp/mm2 of the material =31.5kp/mm2 The blade tip thickness t at the radius 1.0 D/2 is to be determined by the following Formulae: Ice Class IA Super
t = 43.49 mm Ice Classes IA, IB and IC
Where D and σb are as defined previously Other important aspects to be covered are as follow a) The thickness of other sections is governed by a smooth curve connecting the
above section thicknesses. b) Where the blade thickness derived is less than the class rule thickness, the latter
is to be used. c) The thickness of blade edges is not to be less than 50% of the derived tip
thickness t, measured at 1.25 t from the edge. For controllable pitch propellers this applies only to the leading edge.
d) The strength of mechanisms in the boss of a controllable pitch propeller is to be 1.5 times that of the blade when a load is applied at the radius 0.9 D/2 in the weakest direction of the blade.
Screw shaft The diameter of the screw shaft at the aft bearing is not to be less than:
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Where σb = tensile strength of the blade in kp/mm2 (49.0kp/mm2) ct2 = value derived =94667.3 σy = yield stress of the shaft in kp/mm2 (31.5kp/mm2)
CH = Hull condition coefficient = 1.33 (for new steel)
B = Beam of ship = 48.7 m
L = Length of ship at LWL = 272.5 m
T = Designed draft = 16.75 m
H = Thickness of Ice
t = Ice surface air temperature = taken as -10oC (most severe condition)
ψ = flare angle = 65 o
φ = buttock angle = 24o
σF = 270 KPa (for Baltic Ice)
R1 = Level Ice resistance at 1 m/s for rounded type icebreakers
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= 1154.05 KN (for H = 1.0 m, most severe Ice condition thickness)
Since, R α V2 For Designed Ice speed of 5.0 Knots in 1.0 m thick Ice
R = 1154.05 x VICE2
Required delivered power = R x VICE2 x 0.85 (assume 15% reduction for a DAT)
= 980.93 VICE2
ηH = (1-t)/(1-w)
= 0.912
PE = PT X ηH KW
= (1612.56X5.702X2) X 0.912 (Twin Azipod)
= 16771.3 KW
VICE (maximum) = (PE/980.93)1/3 = 2.576 m/s
VICE (Maximum) = 5.008 Knots
ASTERN SPEED IN KNOTS
0 . 4 0.6 0.8 1.0 1.2 1.4 1.6
5.06.07.08.0
THICKNESS OF ICE IN m
4.0
Fig 4.9 Ice thickness (HICE) vs. VICE
Hence for minimum Ice speed of 5 Knots is achievable with the selected model of Pod and the brake power calculation.
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CHAPTER 5
FINAL GENERAL ARRANGEMENT
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5. FINAL GENERAL ARRANGEMENT
5.1. Frame Spacing and Bulkhead Disposition 5.1.1 Introduction
The general Arrangement of a ship can be defined as the assignment of spaces for all the required functions and equipments, properly coordinated for location and access.
The requirements that must be met are, a) Volume requirements b) Adequate trim and stability c) Structural integrity d) Watertight subdivision and integrity e) Adequate access to spaces.
The volume below deck is subdivided into: a) Machinery space b) Cargo spaces c) Ballast spaces d) Pump room e) Slop Tank
5.1.2 Basic Hull Framing
The bottom shell, inner bottom, deck, side shell, inner hull bulkheads and longitudinal bulkheads are longitudinally framed. Transverse framing is adopted in fore peak region, aft peak region and machinery space region.
The different regions along with their rule spacing [LRS, Part 3, and Chapter 5, 6] are given below, a) Aft Ice breaking region: 500 mm (taken from trends in Russian Ice class 1A ships)
b) Aft of 0.05 L from AP
s = (470 + L / 0.6) = 908 mm (where L = 263 m) or 600 mm, whichever is the lesser. Taken s = 600 mm
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c) Between 0.05 L and 0.15 L from AP
s = (510 + L / 0.6) = 948 mm (where L = 263 m) or 850 mm, whichever is the lesser. Taken s = 850 mm
d) Forward of 0.05 L from FP s = (470 + L / 0.6) = 908 mm (where L = 263 m) or 600 mm, whichever is the lesser. Taken s = 600 mm e) Between 0.05 L & 0.2 L from FP s = (470 + L / 0.6) = 908 mm (where L = 263 m) or 700 mm, whichever is the lesser. Taken s = 700 mm
f) Rest of spaces, s = 850mm is adopted.
The maximum frame spacing as permitted by the rules has been calculated. The final frame spacing along the length in accordance with the rules is shown in the table.
Region Spacing (mm)
a 500 b 600 c 850 d 600 e 700
Rest o space 850
Table 5.1 Basic Frame Spacing
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Fig 5.1
Basic Frame Spacing
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5.1.3 Number and Disposition of Bulkheads
The disposition of transverse bulkheads is to comply with the requirements of LRS [LRS, Part3, Chapter 3&4], as applicable to ships with machinery located aft. Minimum number of bulkheads = 9 Number of bulkheads taken = 9 5.1.4 Forward Collision Bulkhead
For ships with bulbous bow [LRS, Part 3, Chapter 3, Section 4] and LL ≥ 200, the distance of collision bulkhead aft of fore end of LL in m is. 10 – f2 (minimum) 0.08 LL– f2 (maximum) Where:
LL = load line length, is to be taken as 96% of total length on WL at 85% of least moulded depth, or as the length from foreside of the stem to the AP on that WL, if that is greater f2 = G/2 or 0.015 LL m, whichever is the lesser G = projection of bulbous bow forward of fore end of LL in m = 4.56 m Here, LL = 270.65 m. G = 4.56 m. Whence f2 = 2.28 m. Minimum distance = 10 – f2 = 7.72 m. Maximum distance = 0.08 LL – f2 = 19.37 m.
Let’s take distance of fore peak bulkhead at a distance of 11.4 m from FP. 5.1.5 Aft Peak Bulkhead
All ships should have one aft peak bulkhead generally enclosing the stern tube and the rudderpost. As provided in the parent ship, aft peak bulkhead is provided at a distance of 12.6 m from AP.
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5.1.6.1 Length of Engine Room
The length of engine room is determined by the power and size of the engine, type and whether it is a slow-speed, medium-speed or high-speed engine. Main engine particulars: Type: 9TM620 Number: 3 Manufacturer: STORK WARTSILA DIESEL CO. Holland [33] Rated output: 12,750KW Rated speed: 428rpm
Considering the frame spacing and the information from built ships the length of engine room is fixed as 31.55 m. Length of pump room is 4.25m.
5.1.6.2 Cofferdams
Cofferdams are to be provided at the forward and aft ends of the oil cargo space. These cofferdams should be at least 760 mm in length and should cover the whole area of the bulkheads of the cargo space. Pump room has been incorporated as the aft cofferdam. The fore peak tank forms the forward cofferdam.
5.1.6.3 Slop Tank
According to LRS rule, slop tank should be provided with a minimum capacity of 3% of cargo carrying capacity.
3% of cargo carrying capacity = 3% of 150000 = 4500 t
Assuming a stowage factor of 1.2, 5400 m3 capacity is required for the slop tank, hence length of slop tank taken is 5.1m 5.1.7 Length of Cargo Tanks The structural configuration has been adopted with one centreline longitudinal bulkhead. For such a configuration the length of the hold [Part 4, Chapter 9] should not exceed, 10 m or (0.25 bi/B + 0.15) LL m, whichever is the greater.
Where bi = minimum distance from side shell to inner hull of tank measured inboard at right angles to the center line at load water line.
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Here bi = 3.0 m
LL = load line length, is to be taken as 96% of total length on WL at 85% of least moulded depth, or as the length from foreside of the stem to AP on that WL, if that is greater Therefore, LL = 270.65 m (0.25 bi / B + 0.15) LL= 44.76 m
According to the above mentioned restrictions the cargo region is divided into ten holds.(5 port and 5 stbd). For length of cargo tanks see table 5.2.
Component Frame Spacing (mm) Length (m)
Aft ballast tank -39-11 500 13.89
Pod room -11-21 500&600 18.1
A P tank 9-21 600 7.2
Engine room 21-59 600 & 850 31.55
Pump room 59-64 850 4.25
Slop tank 64-70 850 5.1
Cargo oil tank-1 70-114 850 37.4
Cargo oil tank-2 114-164 850 42.5
Cargo oil tank-3 164-209 850 38.25
Cargo oil tank-4 209-259 700&850 41.75
Cargo oil tank-5 259-314 600&700 38.2
Fore peak tank 314 to FE 500&600 19.9
Table 5.2 Division of Compartments
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5.2 GENERAL ARRANGEMENT 5.2.1 Introduction
The vessel has been designed as a twin screw diesel-electric driven (Podded Propulsion machinery) double skin segregated ballast crude oil tanker with machinery space and all accommodation including Navigation Bridge located aft. The vessel has a single continuous deck with forecastle deck and five tiers of deckhouse and has a bulbous bow at the stem and stern.
5.2.2 Hull Structure
The vessel is to be classed under LRS. All steel for hull construction is of ship building quality High tensile steel (DH32 or DH36) and grade of steel is in accordance with FSICR as par Ice Navigation requirements.
5.2.3 Framing
Details about major subdivision of cargo and ballast spaces are discussed in the above table 5.2. Longitudinal framing supported by transverse webs has been adopted in way of cargo region. Forward and aft ends have been framed transversely. Adequate changing systems from longitudinal to transverse framing have been provided to avoid abrupt discontinuities. Cargo hold region : Longitudinal framing in way of upper deck, side shell, inner bottom, longitudinal bulkhead and bottom Forepeak : Longitudinal except at fore part. Forecastle deck : Longitudinal except at fore part. Engine room : Longitudinal system in way of upper deck and side shell. Transverse system in double bottom Aft peak : Transverse system 5.2.4 Superstructure External bulkheads and decks of superstructure and deckhouse are of steel construction. Navigation bridge wings have been extended to the full breadth of the vessel. The wheel house is constructed in such a way to meet with the requirements to run the vessel ahead as well as astern. Funnel has sufficient height to prevent smoke nuisance at bridge wings and accommodation areas.
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5.2.5 Deck Machinery
Deck machinery has been arranged as shown in the general arrangement plan. Windlasses, mooring winches and hose handling cranes are of electro-hydraulic type. Each windlass provided with two declutch cable wire drums and two warping heads mounted on the shaft. Mooring winches are provided as shown in the general arrangement plan.
5.2.6 Pumps and Engines The ballast water is transferred by two electric powered pumps. There are also four tanks that hold drinking water & washing water .Two fire pump of capacity 300 m3/hr@4 bar running at 200 m3/[email protected] is provided which this can be used as bilge pump. Emergency fire pump has been provided in fwd .Cargo pump has been provided in pump room. Power is supplied by following Generators Type: SKU CUIN-1400N305, Model 1400 GQKA Number: 3 Manufacture: Cummins Rated output: 1400 kW Rated capacity: 1400 kW (1750 KVA) 60 Hz or 1166.7 kW (1458.3 KVA) 50 Hz Additionally two boiler of capacity 1400 KW has been provided for heating purpose.
5.2.7 Hose Handling Cranes
Hose handling cranes are provided on the upper deck for handling cargo oil hose. The installed crane has capacity 5-ton with the speed of 15m/minute, and have a radius of action (maximum 13 m and min 3.9m).additionally one provision crane of capacity 1-ton has been provided aft in port side near provision store.
5.2.8 Masts and Posts
One unstayed fore mast has been provided as shown in the general arrangement plan. One unstayed aft mast has been provided, fitted with Navigation lights; ladder and air horn.
5.2.9 Hatch Covers
One set of cargo oil tank hatch with neoprene rubber gasket has been provided for each cargo oil tank, fuel oil, bunker tank and slop tank as shown in the general arrangement plan. The hatches have been fitted at end of tanks. Oil tight or watertight manholes are provided for access to cargo tanks, double bottom tanks, peak tanks, cofferdam etc. The hatch is fitted with two vapour controlling valves. The hatch size should be of sufficient size to insert cargo sampling bottles.
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5.2.10 Doors
The sizes of doors fitted are of 850 mm wide. Heavy weather tight steel doors are to be provided at weather-exposed entrances. All doors are provided with stainless steel and nameplate.
5.2.11 Accommodation Ladders
Two accommodation ladders, one on each side, are provided on the upper deck as shown in the general arrangement plan. They are of the vertical self-stowing type. Material - Al alloy Width - 800 mm Length - Sufficient to reach 700 mm above WL at an angle of 50o. 5.2.12 Windows The sizes of windows fitted are: Windows: 400 x 600 mm in accommodation rooms 600 x 700 mm in public rooms
5.2.13 Guard Rails and Bulwark Guardrails have been provided in accordance with Lloyd’s Register [Part 3, Chapter 9]. Stanchions are provided at the boundaries of exposed freeboard. Guardrails are provided at super structure decks and first tier deckhouse. Height of Guardrails = 1 m Distance of first and second rail from bottom = 0.26 m Distance of second and third rail = 0.44 m Distance between third and top most rail = 0.30 m Bulwark of 1.0 m height is provided along the boundary of forecastle deck.
5.2.14 Foam Monitoring Platform
Foam monitoring platforms are provided on the upper deck for the installation of foam guns.
No. of foam monitoring platforms = 7 (on the main deck)
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5.2.15 Accommodation
The design of accommodation covers following aspects: 1. Crew accommodation aft. 2. All bulkheads should be of steel. If in contact with weather they have to be gas tight
and watertight. 3. Bulkheads connecting crew space with store, cargo spaced tanks etc should be
watertight, gastight. 4. Bulkheads connecting two galleys, sanitary space, laundry etc should be gastight
and watertight up to a certain height. 5. Floors to be properly covered. 6. Protection should be provided from following : a) Protection of crew against injury b) Protection of crew against weather c) Insulation from heat and cold d) Protection from moisture e) Protection from effluent originating in various compartments f) Protection from noise. 7. No direct opening between accommodation and stores. 8. Side scuttles can be opened in sleeping rooms, mess rooms, and recreation rooms. 9. Separate sleeping rooms for officers, petty officers, apprentices etc. 10. Mess room should be able to accommodate all officers at the same time. 11. Recreation room should accommodate one third of the officers.
5.2.16 Compliment Estimation Compliment is estimated as per the Indian regulations, i.e., Maritime Law of India. GRT = 84919 (Ref capacity calculation) 1) Deck officers including master For GRT > 1600 – 4 numbers. Additional 1 or 2 cadets are carried in larger vessels. 3 cadets are carried. 2) Radio Officer GRT > 500 – 1 number. 3) Deck ratings including petty officers GRT > 1500 – 10 numbers.
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4) Caterers For total crew up to 45 – 3 numbers. 5) Engineering officers including electrical engineer Over 3680 kW – 4 numbers. Additional 1 or 2 junior engineers are carried in higher-powered vessels 6) Engine ratings including petty officers Foreign going – 5 numbers. 7) Stewards For 6 officers - 1 numbers. For 10-12 officers- 2 numbers. Deck officers are: Captain Chief officer Second officer Third officer Radio officer Additional 1 or 2 cadets are carried in larger vessels. Engineering officers are: Chief engineer Second engineer Third engineer Fourth engineer Fifth engineer Electrical engineer
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Rank Deck Part Engine Part Other Part Total
Captain Class 1 1 2 4
Senior Class 1 1 - 2
Junior Class 2 4 1 3
Cadet 2 - 1 2
Petty Officers 1 2 1 3
Leading Crew 1 1 1 4
Crew Class 8 5 7 24
Table 5.3 Compliment List
Grand Total = 42
Single cabin accommodation has been provided for captain and other officers. And double berth accommodation for seamen. Accommodation for officers and crew is provided based on minimum area requirements.
The minimum stipulated areas are as follows: i) Captain and Chief Engineer : 30 m2 + bath 4 m2 or toilet 3 m2 ii) Chief Officer and 2nd Engineer : 14 m2 + toilet 3 m2 iii) Other Officers : 8 m2 + toilet iv) Captain’s office and Chief Engr’s office :7.5 m2 each v) Passages and Stairs : 40 % of sum of (i) to (iv) vi) Petty Officers’ and Crew cabin : 7 m2 single berth cabins vii) Passages and Stairs : 35 % of (vi)
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xii) General Stores : 125.4 m2 ( 0.09 m2 / person / day ) xiii) Refrigerated Stores : 56 m2 (0.04 m2 / person / day)
Area in excess of the minimum stipulated area is provided. The heights of various accommodation tiers are: A deck tier = 3.2 m B deck tier = 3.2 m C deck tier = 3.2 m D deck tier = 3.2 m Wheel house = 3.2 m
5.2.17 Anchoring Arrangements Anchor is selected as per LRS. [Part 3, Chapter 13] Equipment number = Δ2/3 + 2 B H + A / 10
Where H is the freeboard amidships plus sum of the heights of each tier of houses, in m
A is the profile area of hull and super structures above the summer load water line, in m2
B = 48.7 m Δ = 183376.12 t H = 25.01m A = 1843.63+439.92 = 2283.55 m2 E = 5879 From the table 13.7.2 in LRS [Part 3, Chapter 13] Equipment letter = A* Anchor type = Commercial standard stockless
No. Of anchors = 2 Mass of anchor, WA = 17800 kg Total mass of anchor = 17.8 x 2 = 35.6 t Total length of stud link cable, Lc = 742.5 m Diameter of stud link cable, dc = 102 mm (special grade of steel)
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5.2.17.1 Chain Locker Volume of chain locker = 0.6 Lcdc
2 ft3 [5] Where dc in inches and Lc in fathoms 1 fathom = 1.8288 m 1 inch = 0.0254 m Lc = 406.04 fathom dc = 4.0157 inch Volume required = 108.70 m3
A chain locker of rectangular shape of size 4x6x11 is provided on either side Width = 4.0 m
Depth = 11m (the depth is inclusive of the height of mud box.)
5.2.18 Navigation Lights
Navigational lights provided as follows 1) Masthead light - one on forward mast and one on navigational mast; visibility over an arc of horizon of 225°. 2) Side lights - Red light on port side and green light on starboard. Fitted on the sides of navigating bridge; visibility over an arc of horizon of 112.5°. 3) Anchor lights - All round white light at forward mast, visibility over an arc of horizon of 360°. 4) Stern light - White light at extreme aft having visibility over an arc of horizon of 225°. 5) NUC light - Red white and red light at aft navigating mast, visibility over an arc of horizon of360°. .
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Fig 5.2
Arc of light
5.2.19 Life Saving Appliances Life saving appliances provided as per SOLAS CHAPTER III. Lifeboat particulars should satisfy volume requirement for each person: Volume required per person = 0.283 m3. Total compliment = 42 Lifeboat chosen has following particulars: L = 8.5 m B = 2.97 m T = 1.25 m H = 8.58 m CB = 0.60 [5]
One totally enclosed free fall type, diesel engine driven lifeboats capable of 55 person’s capacity is provided on aft of the ship. The lifeboats are equipped with water spray fire protection system. Material of construction is GRP.
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Compliance list of life saving appliances a. Two inflatable life rafts of 25 person’s capacity each is provided on either side of
the ship. b. One life raft for 6 persons with hydrostatic release is installed on forward upper
deck behind forecastle deck. c. 55 life jackets have been provided. d. Eight life buoys are provided, four of which are fitted with self-igniting light e. 2 life jackets for child have been provided f. A line throwing apparatus in wheel house is provided. g. 2 two way portable VHF (CH16) is provided in wheel house. h. 12 parachute flare has been provided in wheelhouse. i. 4 EPIRB has been provided in wheelhouse and above deck. j. 2 SART has been provided in wheel house and adjacent space k. 4 WT set has been provided. l. 9 general alarm and P A System has been provided in different location in ships m. Training manual has been provided in wheel house, galley and other public places n. Operating instruction booklet is provided in each raft and boat. o. 9 muster lists has been provided in different public places in ship. p. 2 OMTL is provided in wheel house. q. 2 Embarkation ladder with light is provided in aft at MDK. r. Muster station has been provided at MDK in aft region. s. 55 immersion suits has been provided t. TPA has been provided according to approval of administrations
5.2.20 Fire Fighting Systems
Fire fighting systems are to be installed in accordance with SOLAS and fire fighting rules 1990.compliance list and calculation are as follows.
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SOLAS CHAPTER II-2
Construction – Fire Protection, Fire Detection and Extinction SOLAS CHAPTER II-2 PART-C (SUPPRESSION OF FIRE)
Fixed fire detection, fire alarm sys, manually operated call points should be
installed. Fire patrols shall provide an effective means of detecting and locating fire. Smoke detectors in accommodation spaces. installation of automatic and remote control systems in engine room Two-way portable radiotelephone apparatus Suitable arrangement shall be made to permit the release of smoke, in event of
fire, from protected space. Ship shall be subdivided by thermal and structural boundaries. Fire integrity of division shall be maintained at openings and penetrations Fixed fire fighting system should be installed. Fire extinguishing appliances should be readily available. Pipes and fire hydrants should be so placed that it can be easily coupled to fire
hoses, suitable drainage sys should be provided for fire main piping, isolation valve shall be installed for open deck fire main branch, hydrant should be so placed that it can be easily accessible and avoid the risk of damage to cargo.
The diameter of the fire main and water service pipes shall be sufficient for the effective distribution of the maximum required discharge from two-fire pump.
To separate the section of fire main within the machinery space, containing the fire main pump or pumps from rest of the fire main shall be fitted in easily accessible position outside machinery space.
Valve for each fire hydrant should be fitted to remove fire hoses. Isolation valves for tankers.
The following minimum Pressure shall be maintained at all hydrants
Passenger Ships : 4000 GT. and upward 0.40N/mm2. Under 4000 GT 0.30 N/mm2.
Cargo Ships.
6000 GT and upwards 0.27 N/mm2. Under 6000 GT 0.25 N/mm2
Max pressure at hydrant should not exceed that at which effective control of fire
hose is demonstrated
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Ship of 500 gross tonnages and above shall be provided with at least one
international shore connection. Above connection should be used on either side of the ship.
Fire pumps Passenger ship 4000 GT and upwards. at least 3 pumps Passenger ship less than 4000 GT at least 2 pumps Cargo ship of 1000 GT upwards at least 2 pumps Cargo ships have less than 1000 GT. at least 2 pumps Access to emergency fire pumps No direct access shall be permitted between machinery Space & space
containing emergency fire pump. (Door can be provided with air lock arrangement with self-closing doors).
Ventilation of emergency fire pump room. In addition, in cargo ships where other pumps, such as general service
pumps, bilge etc are fitted in a machinery space, arrangement shall be made to ensure that at least one of these pump should be capable to provide water to fire main at capacity and pressure required in above table.
Capacity of fire mains Capable of delivering for fire-fighting purpose at pressure specified above. Fire hoses and nozzle Fire hoses shall be non –perishable material approved by administration. fire
hose shall have a length of at least 10m,but not more than 25 m in machinery space,20 m in other spaces and open decks; and25m for open decks on ships with max breadth in excess of 30m.
Unless one hose and nozzle is provided for each hydrant in ship, there shall be complete interchange ability of hose couplings and nozzles.
Number and diameter of fire hoses Diameter of fire hose shall be to satisfaction to administration. Cargo ships 1000 GT and upwards fire hoses for every 30m of length of ship and
one spare no case less than five. Cargo ship less than 1000 GT hoses to be provided to satisfacti to
administration. Size and type of nozzles Nozzles standard size 12 mm, 16mm and 19 mm. Dia. Accommodation and
service spaces nozzle size 12mm to be used. Machinery space and exterior locations nozzle size greater than 19mm. should
not be used. it should obtain maximum possible discharge from two nozzle at pressure mentioned in table above.
Portable fire extinguisher It should comply with the requirement of the fire safety system code.
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Arrangements of fire extinguisher Accommodation spaces, service spaces and control stations shall be provided
with portable fire extinguisher of proper type and in sufficient in number to the satisfaction to administration.
Ship of 1000 gross tonnage and upwards shall carry at least five portable fire extinguishers. Portable fire extinguishers intended for use in any space shall be stowed near the entrance to the space.
Carbon dioxide fire extinguisher shall not be placed in accommodations spaces. In control station and other space containing electrical equipment necessary for
safety of ship, fire extinguisher shall be provided whose extinguishing media is neither electrically conductive nor harmful to the equipment and appliances.
Fire extinguisher shall be situated ready for use at easily visible place .it should be provided with device which indicates whether they have been used.
spare charges Spare charge shall be provided for 100%of the first ten extinguisher and 50%of
the remaining fire extinguisher. Capable of being recharged on board. Not more than sixty total spare charges are required.
Fixed fire extinguishing systems Fixed high expansion foam fire extinguishing system should comply the
provisions of the fire safety system code. Fixed pressure water-spraying fire extinguishing system should comply the
provisions of the fire safety system code. Fire extinguishing system using halon 1211,1301,and2402 and per fluorocarbon
shall be prohibited. Steam firefighting system is not permitted by administration in general, but if it
is permitted it shall be used in restricted area and it should complied the provisions of the fire safety system code
Closing appliances for fixed gas fire extinguishing systems. Where a fixed fire extinguishing system is used, opening which may admit air to,
or allow gas to escape from, a protected space shall be capable of being closed from outside the protected space.
Storage room for fire extinguishing media if it is stored outside a protected space, it should be stored in room behind the
forward collision bulkhead and not to be used for other purpose, entrance should be preferably from main deck, access doors should open outwards, closings should be gas tight. can be treated as fire control.
Water pumps for other fire extinguishing system Pumps, other than those serving the fire main, their source of power and
controls shall be installed outside the space or spaces protected by such systems and so arranged that fire in space will not put such system out of action.
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Machinery space containing oil fired boilers or oil fuel units Space containing oil fired boiler or oil fuel unit. Machinery space containing oil fired boiler or oil fuel unit shall be provided with
any of the fixed fire extinguishing system Additional fire extinguishing systems In each boiler room at least one set of portable foam applicator complying with
the provisions of the fire safety system code. There shall be at least two portable foam extinguishers in each firing space in
each boiler room There shall be receptacle containing at least 0.1m3 sand other approved
material in each firing space. an approved portable extinguisher may be substituted as an alternative..
At least one set of portable foam equipment complying with the provisions of the fire safety system code. One in each such space at least one 45 liters capacity or equivalent. Foam extinguisher system.
Machinery space containing internal combustion engine. Machinery space containing oil fired boiler or oil fuel unit shall be provided with
any of the fixed fire extinguishing system. Space containing flammable liquid Paint locker should be protected by: Carbon dioxide system, designed to give a
min volume of free gas equal to 40%of the gross volume, or Dry powder system, a water spraying or sprinkler sys.
It should be operated from outside the protected space. Flammable liquid locker shall be protected by an appropriate fire extinguishing arrangements.
Arrangements of fire extinguishing in cargo space. Fixed deck foam fire extinguishing systems. Protection of cargo pump room for tanker. Fire fighter outfits At least two fire fighter’s outfits should be provided. Should comply according to FSS Code. Two spare charges shall be provided for each breathing apparatus. Storage of fire fighter outfits Shall be kept ready for use easily accessible position Structure integrity The purpose is to maintain structural integrity of the ship, preventing partial loss
or whole collapse of the ship due to strength deterioration by heat. The hull, structural bulkhead, decks and deckhouse shall be constructed of steel
or other equivalent material.
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SOLAS CHAPTER II-2 PART-D (ESCAPE)
Notification to crew and passenger. General emergency alarm system should be provided. Means of Escape. Stairways and ladders shall be so arrange to provide from all accommodation
spaces service spaces, ready means of escape to embarkation deck. life raft ,life boat.
SOLAS CHAPTER II-2 PART-E (OPERATION REQUIREMENTS) Operational readiness and maintenance. Fire protection and fire fighting system shall be maintained ready to use. Fire protection and fire fighting system shall be properly tested and inspected. Instructions, onboard training and drills Fire safety operational booklet should be provided.
SOLAS CHAPTER II-2 PART-G (SPECIAL REQUIREMENTS) Helicopter facilities Helideck structure shall be adequate to protect the ship from the fire hazards. Two dry powder extinguishers having a total capacity of not less than 45 kg. Carbon dioxide extinguishers of a total capacity of not less than 18 kg or
equivalent. A suitable foam application system consisting of monitors or foam-making
branch pipes capable of delivering foam to all parts of the helideck in all weather conditions in which helicopters can operate
NO SMOKING’’ signs shall be displayed at appropriate locations;
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FIRE PUMP CAPACITY CALCULATIONS
Capacity of fire pump
Q = Cd2 where
C = 5 for ships required to be provided with more than one fire pump (excluding any
emergency fire pump) and C= 2.5 for ships required to be provided with only one fire
pump, and
d = 1+ 0.066 [√ L (B+D)] ⇒ 1+0.066√ 263.07 ( 48.7 +23.76 )] = 10.11
L = length of the ship in meters on the summer load water line from the foreside of the
Stem to the after side of the rudderpost. Where there is no rudderpost, the length is
measured from the foreside of the stem to the axis of the rudderstock if that be the
greater.
B = greatest moulded breadth of the ship in meters and
D = moulded depth of the ship in meters measured to the bulkhead deck amidships
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PRESSURE AT HIGHEST HYDRANT Pump Pressure at fire main, P1 (6.5bar)(650000N/ m2)
Specific gravity of the sea water (ρ) 1025 kg/m3
Capacity of fire pump, Q 200 m3/hr
Diameter of fire main, d1 0.15 m
Diameter of pipe at hydrant, d2 0.15 m
Cross-sectional area of fire main, A1 0.0177 m2
Cross-sectional area of pipe at hydrant, A2 0.0177 m2
Length of the pipe to hydrant, l 36 m
Velocity of water at fire main, V1 3.139 m/s
Velocity of water at hydrant, V2 = A1.V1 / A2 3.139 m/s
Applying Bernoulli’s equation at fire main and hydrant
P1 /ρ g + v12 / 2g + H1 = P2 /ρ g + v2
2 / 2g + H2 + Head losses
A. Loss of Head due to Height (H2 - H1)
Height of fire pump above base line (H1) 6.0 m
Height of highest fire hydrant above base line (H2) 39.78 m
Loss of Head due to Height (H2-H1) 33.78 m
B. Loss of Head due to Friction (4. f. l. v22/ d2. 2g)
Coefficient of friction 0.0033
Loss of head due to friction 1.59m
C. Loss of Head at the exit of Pipe (v22 / 2g)
Loss of Head 0.5 m
D. Loss of Head due to Bends, Valves and Pipe fittings
Loss of Head (considered 5% of loss of Head due to Friction) 0.08
P2 = (P1 /ρ g + v12 / 2g + H1 – v2
2 / 2g – H2 – Head losses)X (ρ g)
Pressure at highest hydrant (P2) 288513.76 N/m2
Required Pressure 270000 N/m2
Conclusion: Satisfactory
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PRESSURE AT FARTHEST HYDRANT
Pump Pressure at fire main, P1 (2.75 kg/cm2) 6.5 bar
Specific gravity of the sea water (ρ) 1025 kg/m3
Capacity of fire pump, Q 200 m3/hr
Diameter of fire main, d1 0.15 m
Diameter of pipe at hydrant, d2 0.15 m
Cross-sectional area of fire main, A1 0.0177 m2
Cross-sectional area of pipe at hydrant, A2 0.0177 m2
Length of the pipe to hydrant, l 236 m
Velocity of water at fire main, V1 3.139 m/s
Velocity of water at hydrant, V2 = A1.V1 / A2 3.139 m/s
Applying Bernoulli’s equation at fire main and hydrant
P1 /ρ g + v12 / 2g + H1 = P2 /ρ g + v2
2 / 2g + H2 + Head losses
E. Loss of Head due to Height (H2 - H1)
Height of fire pump above base line (H1) 6.0 m
Height of farthest fire hydrant above base line (H2) 20.76 m
Loss of Head due to Height (H2-H1) 14.76 m
F. Loss of Head due to Friction ( 4. f. l. v22/ d2. 2g)
Coefficient of friction 0.0033
Loss of head due to friction 10.43 m
G. Loss of Head at the exit of Pipe (v22 / 2g)
Loss of Head 0.5m
H. Loss of Head due to Bends, Valves and Pipe fittings
Loss of Head (considered 5% of loss of Head due to Friction) 0.52 m
P2 = (P1 /ρ g + v12 / 2g + H1 – v2
2 / 2g – H2 – Head losses)X (ρ g)
Pressure at farthest hydrant (P2) 386451.9 N/m2
Required Pressure 270000 N/m2
Conclusion: Satisfactory
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JET THROW CALCULATION
MS (Fire appliances) Rules 1990
Capacity of fire pump = 200 m3/hr
Dia. of nozzle = 19 mm
Cross-sectional area of nozzle = 2.8 x 10-4 m2
Length of the jet throw required = 12 m Jet velocity = 198.4 m/s
Percentage loss due to nozzling and air resistance = 30%
Net jet velocity = 138.8 m/s
Projectile Angle = 45˚
Velocity require at nozzle for 12 m throw
Using formula R = u2 Sin 2θ / g
Where
u = Velocity at the nozzle
θ = Projectile angle to get maximum range = 45˚
G= (acceleration due to gravity = 9.8 m/s2
R = Horizontal distance reached by the throw = 12 m.
i.e., u = √ R g / Sin 2θ = 10.84 m/s
Velocity of throw required = 10.84 m/s
Available jet Velocity = 138.4 m/s
Conclusion: Satisfactory
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CARBON DIOXIDE GAS CALCULATION Gross volume of engine room including pump room 21716.53 m3
40% of Gross volume of engine room including pump room 8686.612 m3
Gross volume of Azipod room 7714 m3
40% Gross volume of Azipod room 3085.6 m3
Addition of air receiver 18 m3 Gross volume for co2 protection 11790.2 m3
Gross volume of co2 required 11790.2 m3
Weight of Co2 required 11790.2 /0.56 =21053 kg (sp vol =0.56 m3/kg)
No of bottle of 45.5 kg required 21053/45.5 =463bottles
Department of Ship technology, CUSAT, B.Tech (NA&SB), Batch – XXIX”
CHAPTER 6
DETAILED CAPACITY CALCULATION AND
MASS ESTIMATION
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6. DETAILED CAPACITY CALCULATIONS
The capacity plan is to know the cargo volumes in holds and the disposition of tanks and their position of centre of gravities. The mass of crew and effects and water ballast necessary for the design are known. Knowing the density of the various liquids, the volume required is calculated. The hold capacity can be calculated by subtracting the sum of the wing tank capacity and double bottom volume from the total under deck capacity. With the capacity determined, it is possible to calculate the stowage factor. 6.1 Final estimates of consumables, stores and cargo
Range = 3800 nm Speed = 15.0 Knot (open water) = 5.0 Knot (Most severe Ice conditions)
∴Max Hours of travel, H = 760 Hrs (operation in most severe condition) Hours in port = 48 Hrs No of officers = 21 No of crew = 23
Volume of heavy fuel oil (VHFO) Specific fuel consumption, SFC = 182 g / KWh. (Assumed for a slow speed large bore diesel engine) Brake power, PB = 38250 KW Mass of heavy fuel oil, MHFO = SFC × PB × H / 1000000 +20% 20% allowance has been taken into account. = 6449 t Volume of HFO, VHFO = MHFO /0.90 = 7154 m3
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Mass of diesel oil, MDO = SFC × PAUX × H/1000000
= 747 t Volume of diesel oil, VDO = MDO/0.95 = 786 m3 Volume of boiler fuel oil (VBO) Boiler of capacity 2000KW is selected. Mass of boiler oil, VBO = SFC × P × H/1000000 SFC = 220 g /KWh
= 355 t Volume of boiler oil = 355/0.95 = 373 m3
Volume of lubricating oil (VLO) Mass of lube oil, MLO = 0.03 (MHFO + MDO +MBO)
= 216.6 t Volume of lube oil = 216.6/0.9 = 241 m3
Volume of fresh water, (VFW) Consumption of fresh water = 20 litres / person / day Mass of fresh water, M FW = 29.6 t Volume of fresh water, VFW = 29.6 m3
Volume of washing water (VWW)
Consumption 120 liters /person/ day for officers 60 liters /person/ day for crew Mass of washing water, MWW = 131.3 t Volume of washing water, VWW = 131.3 m3
6.2.1 Capacity Calculation with allocation of Spaces
The capacities of tanks/compartments are determined using the computer software AutoCAD 2007. The values are found by creating different regions, and the “mass prop” command. Tables 6.1, 6.2, 6.3 and 6.4 indicate the moulded capacities (exclusive of camber volume) of respective tanks/compartments along with their location and centres of gravity. In all the above tables LCG is measured from AP, VCG from base line and TCG from the centre line
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6.2.2 GROSS TONNAGE COMPUTATIONS
GROSS TONNAGE (GT) = K1 V
Where K1 = 0.2 + 0.02 log10 (V)
Where K1 = 0.2 + 0.02 log 10 (267133.34) = 0.3087
V = Total volume of all enclosed spaces of the ship in m3 = 275086.9 m3
GROSS TONNAGE (GT) = 84919
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6.2.3 NET TONNAGE COMPUTATIONS NET TONNAGE (NT) = K2 VC (4 d / 3 D )2 + K3 ( N1 + N2 / 10) In which formula a) The factor (4 d / 3 D)2 shall not be taken as greater than unity. b) The term K2 VC(4 d / 3 D )2 shall not be taken as less than "0.25 GT" ; c) "NT" should not be taken as less than "0.3 GT" VC, Total volume of cargo spaces =170160.17m3 (excluding slop tank volume) K2 = 0.2 + 0.02 * log10 (Vc) = 0.3046, D = Moulded depth amidships in metres. D = 23.76 m. d = Moulded draft amidships, d =16.75 m. K3 = 1.25 [(GT + 10000) / 10000] = 11.86 N1 = Number of passengers in cabins with not more than 8 berths. N2 = Number of other passengers. N1 + N2 = Total number of passengers the ship is permitted to carry as in the
ship’s Passenger certificates. When N1 + N2 is less than 13, N1 + N2 shall be taken as zero (no passengers hence zero) In the expression for Net Tonnage, K3 (N1 + N2 / 10) = 0 a) Since d = 16.75, the expression (4 d / 3 D )2 =0.8835 b) In the expression for Net Tonnage, K2 VC (4 d / 3 D )2 = 45792.5 > 0.25 GT ∴The term K2VC (4d / 3D) 2 is taken as 45792.5
c) NT = K2VC (4d / 3D) 2 + K3 (N1 + N2/10)
= 45792.5 + 0
= 45792.5 > 0.30 GT (24723.18)
∴Net Tonnage is taken as 45792.5
NET TONNAGE (NT) = 45793
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6.3 Final Mass Estimation
6.3.1 Introduction
At the initial stages of design, dimensions of superstructures and deckhouses were not known. Lightship mass was calculated by taking rough values or giving allowance for masses of these quantities. After designing the general arrangement plan, the lightship mass is estimated more accurately, using actual values wherever possible and empirical formulae when the actual mass is not known.
6.3.2 Procedure
The light ship mass is split up into various components and their masses are estimated using empirical formulae and summed up. Mathematically,
ΔLS = ΔSE + ΔWO + ΔEP,
Where, ΔSE = Steel mass ΔWO = Wood & outfit mass ΔEP = Engine plant mass
6.3.3 Steel Mass
ΔSE = Δ7SE [1+ 0.5 (CB
0.8 –0.7)] + 840 t (addition for Ice Class 1A, taken from parent ship)
Δ7SE = KE1.36
K = 0.029 –0.035 E = L (B + T) + 0.85L (D-T) + 250
= 19030.44 E = 1500 – 40000 for tankers Take K = 0.035 Δ7
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6.3.4 Wood and Outfit Mass ΔOU = Co× L × B + 100 t (approx additional weight for Helipad and helicopter)
Co =0.24 [35]
= 3173.9t
6.3.5 Engine Plant mass ΔEP = Weight of Main engine & generator + Weight of
transformer, frequency convertor &MSB + Weight of Pod + Weight of Auxiliary machinery (3*Cummins Model 1400 GQKA) + Weight of boiler& pump etc
= 975 + 174 + (662*2) + (3 x 60) + 150 = 2803 t Light ship weight = ΔSE + ΔOU + ΔEP, = 31694.8 t
6.4 Distribution of Masses to Find Centre of Gravity
LCG is measured from AP and VCG from keel.
6. 4.1 Steel Mass
Steel mass can be divided into mass of superstructure and that of continuous material. Volume of superstructure = 9472 m3
∴Mass of superstructure = 0.067 × 9472 = 634.6 t ∴Mass of continuous material = Mass of steel – Mass of super structure = 25717.9 – 634.6 = 25083.3 t
Mass of superstructure is assumed to act at its centroid (LCG = 36.89, VCG = 30.78) (Calculated by AutoCAD Drawing with some geometrical assumptions) COG of continuous material: VCG hull = 0.01D (46.6 + 0.135(0.81 – CB) (L/D) 2) + 0.008D(L/B – 6.5), L ≤ 120 m = 0.01D (46.6 + 0.135(0.81 –CB) (L/D) 2), 120 m < L [35] = 10.96 m
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The longitudinal position of the basic hull weight is assumed to be located at mid of length over all, as ship is highly strengthened in fwd and aft to meet with operational requirements. LCG hull = 125.6 m
LCG = 125.6 m from AP VCG = 10.96 m from keel
ITEM MASS(t) LCG from AP(m) VCG keel(m)
Super structure 634.6 36.89 30.78
Longitudinal continuous material 25083.3 125.6 10.96
TOTAL 25717.9 123.41 11.45 Table 6.5
Determination of COG of Steel Mass LCG of Steel mass = 123.41 m VCG of Steel mass = 11.45 m 6. 4.2 Engine plant mass
The engine plant mass is divided into propeller mass, propeller shaft mass, main engine mass, & remainder mass
Item Mass (t) LCG(m) VCG(m)
Main engine 975 21.27 7.00 Electric equipment 174 6.30 16.70 Pod and propeller 1324 0.00 7.93
Aux engine 180 33.90 6.50 Boiler and pump 150 34.00 8.00
Total 2803 11.79 8.06
Table 6.6 Determination of COG of machinery
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6. 4.3 Wood and outfit mass VCG = D + 1.25, L ≤ 125 m = D + 1.25 + 0.01(L-125), 125 < L ≤ 250 m [35] = D + 2.50, 250 m < L = 26.26m LCG = (25% Wo at LCGM, 37.5% at LCG dh, and 37.5% at amidships) [35]
LCG = 66.09 m
ITEM MASS(t) LCG from AP(m) VCG keel(m)
Steel 25717.9 125.6 11.45
Wood & Outfit 3173.9 66.09 26.26
Engine Plant 2803 11.79 8.06 TOTAL 31694.8 107.46 12.63
Table 6.7
Determination of COG of Light Ship
6.5 Required capacity: Volume of HFO, = 7154 m3
Volume of diesel oil, = 786 m3 Volume of boiler oil, = 373 m3
Volume of lube oil = 241 m3
Volume of fresh water, = 30 m3 Volume of washing water, = 131 m3
Volume of washing water = 168096 m3 Available capacity Cargo Capacity = 174294.17 m3
Ballast water Capacity = 50841.42m3
HFO tank Capacity = 7152.1 m3
DFO tank Capacity = 797.4 m3
Boiler fuel tank Capacity = 379.42 m3
LO tank Capacity = 247 m3
Capacity of FW tank = 32 m3
Capacity of washing water tank= 132.44 m3
All the available capacities of tanks is more than the required, hence the design
is satisfactory.
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CHAPTER 7 DETAILED TRIM AND
STABILITY CALCULATIONS
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7.1 TRANSVERSE STABILITY For small angles of inclination (heel) of the order of 4 or 5 degrees, the waterlines
before inclination and after inclination intersect at the same point on the vertical
centreline of the vessel, keeping the emerged and immersed volume of water equal.
The center of buoyancy has moved off the vessel’s centerline as the result of
inclination, and the lines along which the resultants of weight and buoyancy act are
separated by a distance, “GZ”, the righting arm. A vertical line through the centre of
buoyancy will intersect the original vertical through the centre of buoyancy, which is
in the vessel’s centreline plane, at a point “M” called the transverse metacentre. For
small angles of inclination, the point “M”, will remain practically stationary with respect
to the vessel’s centreline. The distance “GM", between the vessel’s centre of gravity
‘G’ and M’ when angle of heel is zero degrees, is the transverse metacentric height
(often called “Initial Stability” ) and is used as an index of stability for the preparation
of stability curves. The position of the transverse metacentre varies with the draft.
The transverse met centric position for small angles of inclination above the keel
point “K”, denoted as “KM".
The location of the metacentre has neither to do with the nature nor the distribution of
weights onboard. On the other hand, the vertical centre of gravity position above the
keel point “K”, denoted as “KG”, depends on the nature & distribution of oil, water
etc.
The centre of gravity of a vessel decreases directly when the positioning of weights is
lower and increases when positioning of weights is higher.
The transverse metacentric height is given by the relation:
GM = KMT – KG If the displacement of the vessel in the light condition is known, the position of centre
of gravity “KG” , can be calculated by taking the vertical moments (weight of the
item * centre of gravity of the item) of all items on board and dividing the sum of these
moments by the total weight, i.e., displacement. Corresponding to this displacement,
the draft is determined and the “KMT" value obtained from the Hydrostatic Curves or
tables.
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The motion of the liquid in a partially filled tank reduces the vessel’s stability
because, as the vessel is inclined, the centre of gravity of the liquid shifts towards
one side. This shift in the liquid causes the vessel’s centre of gravity to move towards
the lower side, reducing the righting arm and thus the stability is adversely affected
by the “free surface effect". The sum of the free surface moments of all liquid items in
tanks, not pressed full, is divided by the displacement of the vessel to obtain the Free
Surface Correction, described in page no. 21, denoted as “GG0 ". The new vertical
centre of gravity is denoted as “G” and its position above keel,”KG "is given by the
simple relation,
KGO =KG + GG0
The transverse metacentric height (corrected) is given by,
G0M = KMT -KG0 = GM - GG0
To maintain positive stability, the transverse metacentre must lie above the centre of
gravity i.e., the metacentric height must always be positive and its value must be able
to comply with statutory requirements.
7.2 LONGITUDINAL STABILITY
The longitudinal stability of a vessel usually poses no problem as the longitudinal
metacentric position is much higher than the center of gravity position The
longitudinal metacentre is similar to the transverse metacentre except that it involves
longitudinal inclinations. Since vessel is usually not symmetrical forward and aft, the
center of buoyancy at various even keel waterlines doesn’t always lie in a fixed
transverse plane, but may move forward and aft with changes in draft. For a given
even keel waterline, the longitudinal metacentre is defined as the intersection of a
vertical line through the center of buoyancy in the even keel position with a vertical
line through the position of the center of buoyancy after the vessel has been inclined
longitudinally through small angles.
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The longitudinal metacentre, like the transverse, is substantially fixed
with respect to the vessel for moderate angles of inclination if there is no abrupt
change in the shape of the vessel in the vicinity of waterline, and its distance above
the vessels center of gravity is called the longitudinal metacentric height.
DRAFTS AND TRIM: The draft “T”, corresponding to the displacement, obtained from the Hydrostatic
Curves or Tables, is the draft at the longitudinal centre of flotation, denoted as “LCF”.
The longitudinal centre of gravity “LCG” is obtained by dividing the net longitudinal
moment by the displacement. If the longitudinal centre of buoyancy “LCB” position
does not coincide with “LCG” position, the vessel will “trim“, i.e., the draft at the fore
peak of waterline “Tf " and the draft at the aft peak “T a " will not be equal. If the
“LCG” is forward of the “LCB”, the vessel will trim by forward and if the “LCB” is
forward of the “LCG” , the vessel will trim by aft.
The total trim, denoted as “t”, is given by:
t = T a - Tf = ((LCB – LCG) X Displacement ) / (100 X MCT1cm )
Positive “t” implies trim by aft & negative “t” implies trim by forward. The “LCB”,
“LCF”, and “MCT1cm" (moment to change trim by 1cm) are all obtained from the
Hydrostatic Tables
The drafts at the extreme ends of waterline are given by the algebraic relation:
Ta = T + t * LCF / LBP
Tf = T + t * (LCF-LWL) / LBP The position of “LCG” depends on whether the weights are placed more concentrated
in the forward or aft of the vessel, in which case the vessel will trim by forward or aft,
respectively. Hence, the distribution of cargo, oil, freshwater, etc. must be uniform to
keep the trim as little as possible and towards aft. It must be noted that if it is not
possible to avoid trim, then trim by aft is more recommendable than trim by forward.
In the departure condition the trim, if present, must be, as far as possible, by aft.
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7.3 WEATHER CRITERION ACCORDING TO IMO RES. A 749 (18) The ability of a ship to withstand the combined effects of beam wind & rolling should
be demonstrated for each standard condition of loading.
The ship is subjected to a steady wind pressure acting perpendicular to the ship’s
centreline which results in a steady wind heeling lever (lw1)
1. From the resultant angle of equilibrium (θ0), the ship is assumed to roll owing to
wave action to an angle of roll (θ1) to windward.
2. The ship is then subjected to a gust wind pressure which results in a gust wind
heeling lever (lw2)
3. Under these circumstances, area “ b” should be greater than or equal to area “a”.
4. Free surface effect should be accounted for in the standard conditions of loading.
θ
θ
θ θ
Fig 7.1 Weather criteria curves
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The angles are defined as follows:
θ0 = Angle of heel under action of steady wind.
θ1 = Angle of roll to windward due to wave action
θ2= Angle of down flooding ( θf ) or 50 degrees or θc , whichever is less
θf= Angle of heel at which openings in the hull, superstructures or
deckhouses which cannot be closed watertight,
θc= Angle of second intercept between wind heeling lever ( lw2 ) and GZ
curves.
The wind heeling levers lw1 and lw2 are constant values at all angles of inclinations
and should be calculated as follows:
lw1 = P * A * Z / (1000 * g * Δ (m)
lw2 = 1.5 * lw1
Where:
P = 504 N/m2
A = Projected lateral area of the portion of the ship above waterline in m2.
Z = Vertical distance from the centre of the projected lateral area (A) to the
centre of underwater lateral area or approximately to a point at one half
the draft in metres.
Δ = Displacement of the ship in tonnes.
g = Acceleration due to gravity (g = 9.81 m/s2)
The angle of roll (θ1) should be calculated as follows
θ1= 109 * k * X1 * X2 * √(r * s) (degrees)
Where,
X1, X2, k & s are factors given in tables 7.1 below.
k is a factor depending on type of bilge construction.
r = 0.73 + 0.6 OG/d
OG = distance between centre of gravity and the waterline in metres (+ ve if center
of gravity is above WL, -ve, if it is below)
d = mean draught of the ship (m)
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Rolling period T = 2CB / √ GM (s)
Where
C = 0.373 + 0.023 (B/d) - 0.043 (L / 100).
The symbols in the above tables and formula for the rolling period are defined as
follows:
L = waterline length of the ship (m)
B = moulded breadth of the ship (m)
d = mean moulded draft of the ship (m)
CB = block coefficient
Ak= total overall area of bilge keels, or area of the lateral projection of the
Values of factor k Ak × 100 / L × B 0.00 1.00 1.50 2.00 2.50 3.00 3.50 ≥ 4.00 K 1.00 0.98 0.95 0.88 0.79 0.74 0.72 0.70 Values of factor s T ≤ 6.00 7.00 8.00 12.00 14.00 16.00 18.00 ≥ 20.00S 0.100 0.098 0.093 0.065 0.053 0.044 0.038 0.035 (Intermediate values in tables should be obtained by linear interpolation)
Table 7.1 Table for X1, X2, K and s
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7.5 COMPUTATIONS OF IMO ENVELOP
1) The area under the righting lever (GZ) curve shall not be less than 0.055 m-radians upto an angle of heel of 30°.
i.e ∫30
0
GZ dθ = 0.055 m-rad.
But for an angle of θ, righting lever is given by GZ = KN – KG Sinθ
∫30
0
(KN – KG Sinθ) dθ = 0.055
∫30
0
KN dθ - ∫30
0
KG Sinθ dθ = 0.055
∫30
0
KN dθ - KG ∫30
0
KG Sinθ dθ = 0.055
KG = ∫ −30
0
055.0θdKN
∫30
0
θθ dSin
KG1 = ∫ −30
0
055.0θdKN m Condition (1)
1 – Cos30 (2) The area under the righting lever (GZ) curve shall not be less than 0.09 m-radians to an angle of either 40° or an angle of (θf) (Flooding angle) if that be less
∫40
0
GZ dθ = 0.09 m – radians (assuming Flooding angle (θf) is more than
40°) Similarly as above, we can arrive at
KG2 = ∫ −∂40
0
09.0θKN m Condition (2)
1 – Cos40
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COMPUTATIONS OF IMO ENVELOP The area under the righting lever (GZ) curve shall not be less than 0.03 m-radians between the angles of heel of 30° and 40° or between 30 and (θf) degrees, if it is less than 40 degrees Assuming (θf) (Flooding angle) is more than 40°
KG3 = ∫ −40
30
03.0θdKN m Condition (3)
Cos30 – Cos40 4) The maximum righting lever (GZ) shall be at least 0.2 metre at an angle of heel
equal to or greater than 30° i.e. GZ at 30° = 0.20m KG4 = KN30 – 0.20 Condition (4) Sin30 5) Maximum righting lever (GZ) should occur at an angle exceeding 30° but not less than 25° (say maximum righting lever (GZ) occur at 25°) ∂ (GZ) 25 = 0 ∂θ ∂ (KN – KG Sinθ) 25 = 0 ∂ θ ∂ KN 25 – KG∂ Sinθ) 25 = 0 ∂ θ ∂ θ KG = ∂ KN 1 ∂θ Cos25 KG5 = KN30 – KN20 1 Condition (5) 10 * π Cos25 180 6) The initial metacentric height shall be not less than 0.15 metre GM = 0.15 m KMT - KG = 0.15 m KG6 = KMT – 0.15 m
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7.8 DETAILED TRIM AND STABILITY CALCULATIONS
According to IMO A 749, a ship has to be examined for the following four loading conditions. 1) Ship in the fully loaded departure condition, with cargo homogeneously
distributed throughout all cargo spaces and with full stores and cargo. 2) Ship in the fully loaded arrival condition, with cargo homogeneously distributed
throughout all cargo spaces and with 10 % stores. 3) Ship in ballast departure condition, without cargo but with full stores and fuel. 4) Ship in ballast arrival condition, without cargo and with 10 % stores and fuel
remaining.
Trim calculations are based upon capacity and longitudinal position of centre of gravity. Apart from conditions stated above, the following conditions in MARPOL also have to be satisfied.
1) The moulded draught amidships(dm) in meters (without taking into consideration any ship’s deformation) shall not be less than: dm = 2.0 + 0.02L; dm = 6.58 m
2) The draughts at the forward and after perpendiculars shall correspond to those determined by the draught amidships (dm), in association with the trim by the stern of not greater than 0.015L.
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PROJECTED LATERAL WINDAGE AREA (A) 2280.95 m2 COG OF WINDAGE AREA ABOVE HALF DRAFT (Z) 13.69 m
STEADY WIND HEELING LEVER (lw1) 0.01 m
GUST WIND HEELING LEVER (lw2) 0.02 m
ANGLE OF HEEL DUE TO WIND (θ0) 0.16 degrees
ANGLE OF ROLL (θ1) 18.82 degrees
GUST WIND LEVER 2ND INTERCEPT (θc) 72.80 degrees
ADOPTED UPPER LIMIT FOR AREA (b) (θ2) 40.78 degrees
ANGLE OF DOWNFLOODING (θf) 40.78 degrees
ANGLE OF DECK EDGE IMMERSION (θd) 26.15 degrees NET AREA BELOW GUST WIND HEELING ARM "a" 0.36 m radians NET AREAABOVE GUST WIND HEELING ARM "b" 1.36 m radians
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PROJECTED LATERAL WINDAGE AREA (A) 4421.77 m2 COG OF WINDAGE AREA ABOVE HALF DRAFT (Z) 13.24 m
STEADY WIND HEELING LEVER (lw1) 0.03 m
GUST WIND HEELING LEVER (lw2) 0.05 m
ANGLE OF HEEL DUE TO WIND (θ0) 0.21 degrees
ANGLE OF ROLL (θ1) 17.48 degrees
GUST WIND LEVER 2ND INTERCEPT (θc) 99.06 degrees
ADOPTED UPPER LIMIT FOR AREA (b) (θ2) 50.00 degrees
ANGLE OF DOWNFLOODING (θf) 57.11 degrees
ANGLE OF DECK EDGE IMMERSION (θd) 31.81 degrees NET AREA BELOW GUST WIND HEELING ARM "a" 0.80 m radians NET AREA ABOVE GUST WIND HEELING ARM "b" 5.19 m radians
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CHAPTER 8
MIDSHIP SECTION DESIGN
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MIDSHIP SECTION
8.1 INTRODUCTION
Midship section design is in accordance with Ice class Rules given by Finnish Maritime Administration, Sept 2003 and the rules for classification of ships given by Lloyd’s Registrar of Shipping July 2002. Fig. 8.1 is a typical midship section of a double skin ice class tanker.
Figure 8.1
Typical midship section of a double skin Ice class Tanker
8.1.1. Definitions (1) L : Rule length, in m, is the distance, in meters, on the summer load water
line from the forward side of the stem to the after side of the rudderpost or to the center of the rudder stock, if there is no rudder post. L is neither to be less than 96% nor to be greater than 97% of the extreme length on the summer load water line.
97% of extreme length of LWL = 264.39 m (2) B : Breadth at amidships or greatest breadth, in meters. B = 48.7 m
(3) D : Depth is measured, in meters, at the middle of the length L, from top of the keel to top of the deck beam at side on the uppermost continuous deck. D = 23.76 m (4) T : T is the Maximum Ice Class draught of the ship, in m = 16.75 m (5) LPP : Distance in m on the summer LWL from foreside of the stem to after side of rudder post, or to the centre of the Podded unit, if there is no rudder post. LPP = 263.00 m
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(6) LPAR = Length of parallel midship body, in m (approx. 105.2 m) (7) CB : Block coefficient at draught T corresponding to summer waterline, based on rule length L and moulded breadth B. CB = 0.84 (8) hG = Ice thickness, in m, defined in the table given by FSICR (9) h = 0.35 m (10) Awf = Area of the waterline of the bow in m2. Awf = 3841 m2 (11) α = Angle of the waterline at B/4 = 70° (12) φ1 = Rake of the Ice breaking stern at the centreline = 24.2° (13) φ2 = Rake of the Ice breaking stern at B/4 = 24.5° (14) DP = Diameter of propeller = 7260 mm (15) HM = Thickness of the brash ice in mid channel, in m = 1.0 m (16) HB = Thickness of the brash ice layer displaced by the stern (17) ReH = Minimum yield stress, in N/mm2, of the material defined (18) LWL = Load Waterline, at fully loaded condition. (19) BWL = Ballast Waterline at Ballast condition. (20) b : The width of plating supported by the primary member or secondary member. (21) be : The effective width, in m, of end brackets. (22) bI : The minimum distance from side shell to the inner hull or outer longitudinal bulkhead measured inboard at right angles to the centre line at summer load water line, in m. (23) le : Effective length, in m, of the primary or secondary member, measured between effective span points. (24) ds : The distance, in m, between the cargo tank boundary and the moulded line of the side shell plating. (25) db : The distance, in m, between the bottom of the cargo tanks and the moulded line of the bottom shell plating measured at right angles to the bottom shell plating. (26) k : Higher tensile steel factors. For HT steels (Lloyd’s AH32, DH32 &
EH32), k = 0.78 (27) s : Spacing in mm of ordinary stiffeners or primary support as applicable.
(28) S : Overall span of frame, in m (29) t : Thickness of plating, in mm. (30) Z : Section modulus, in cm3, of the primary or secondary member, in
association with an effective width of attached plating. (31) RB : Bilge radius, in mm.
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(32) FD,FB : Local scantling reduction factor above neutral axis and below neutral axis
respectively. FD = 0.67, for plating and 0.75, for longitudinals FB = 0.67, for plating and 0.75, for longitudinals (33) dDB : Rule depth of center girder, in mm (34) SS : Span of the vertical web, in m (35) tW : Thickness of web, in mm (36) tB : Thickness of end bracket plating, in mm
8.1.2 Class Notation
Vessel is designed to be classed as ✠+100A1 Baltic service Ice class 1A Super Double Hull Oil Tanker ESP.’ ESP means Enhanced Survey Program. This is for Ice navigating tanker having integral cargo tanks for carriage of crude oil. Where the length of the ship is greater than 190m, the scantlings of the primary supporting structure are to be assessed by direct calculation and the Ship Right notations Structural Design Assessment (SDA), Fatigue Design Assessment (FDA) and Construction Monitory (CM) are mandatory.
8.1.3 Cargo Tank Boundary Requirements Minimum double side width (ds)
ds = 0.5 + (dwt/20,000) or ds = 2.0 m Whichever is lesser But ds should not be less than 1 m. ds = 0.5 + (150000/20,000) = 8.0 m Double side width is taken as 3.0 m to get the required ballast volume. ∴ ds = 3.0 m
Minimum double bottom depth (dB) dB = B/15 or dB = 2.0 m Whichever is lesser dB = 48.76/15 = 3.25 m A double bottom height of 3.0 m is provided to get the required ballast volume.
∴ dB = 3.0 m Structural configuration adopted has a single centreline longitudinal bulkhead. For length of cargo tanks and tank boundaries. [Refer General Arrangement Plan]
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8.1.4 Type of Framing System [LRS Part 4, Chapter 9, Section 1.3.10, 1.3.11]
The bottom shell, inner bottom and deck are longitudinally framed (for L > 75m). The side shell, inner hull bulkheads and long bulkheads are also longitudinally framed (L > 150m). When the side shell in long framed, the inner hull bulkhead is also to be framed longitudinally. Primary members are defined as girders, floors, transverses and other supporting members.
Values of Ka Ke = 1.60 RCH is the resistance in Newton of the ship in a channel with brash ice and a consolidated layer:
( ) ( )L
ABLTCHLCHCBHHCCCR wf
3
252FPAR4Fψ
2MF321CH ⎟
⎠⎞
⎜⎝⎛++++++= μC
Cμ = 0.15cosϕ2 + sinψsinα = 0.546 Cμ is to be taken equal or larger than 0.45 °≤=−⋅= 45if0Cand,115.2047.0C ψψ ψψ
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⎟⎠⎞
⎜⎝⎛=
αϕψ
sintanarctan 2 = 30.17o
ψC = 25.89 HF = 0.26 + (HMB) 0.5
= 7.2 m HM = 1.0 for ice classes IA and IA Super = 0.8 for ice class IB = 0.6 for ice class IC HM = 1.0 C1 and C2 take into account a consolidated upper layer of the brash ice and are to be taken as zero for ice classes IA, IB and IC. Given: C3 = 845 kg/ (m2s2) C4 = 42 kg/ (m2s2) C5 = 825 kg/s2
5 ≤ 3
2BLT
⎟⎠⎞
⎜⎝⎛ ≤ 20
P = 21.2 MW (approx) 8.2.4 Ice load Height of load area An ice-strengthened ship is assumed to operate in open sea conditions corresponding to a level ice thickness not exceeding ho. The design height (h) of the area actually under ice pressure at any particular point of time is, however, assumed to be only a fraction of the ice thickness. The values for ho and h are given in the following table. .
Table 8.2 Values of ho and h
8.2.5 Ice pressure The design ice pressure is determined by the formula: p = cd · c1 · ca · po [MPa], where
Ice Class ho [m] h [m] IA Super
IA IB IC
1.0 0.8 0.6 0.4
0.35 0.30 0.25 0.22
Ice Class ho [m] h [m] IA Super
IA IB IC
1.0 0.8 0.6 0.4
0.35 0.30 0.25 0.22
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cd = a factor which takes account of the influence of the size and engine output of the ship. It is calculated by the formula:
a and b are given in the following table: .
Table 8.3
Values of a and b Δ = the displacement of the ship at maximum ice class draught [t] = 183376.12 t P = the actual continuous engine output of the ship [kW] 38250 KW K = 83.75 a = 2 b = 286 c1 = a factor which takes account of the probability that the design ice pressure occurs in a certain region of the hull for the ice class in question. The value of c1 is given in the following table:
Table 8.4 Values of c1
1000b k acd
+⋅=
1000P k ⋅Δ
=
R e g i o n Forward Midship & Aft
a b
k ≤ 12 k > 12 k ≤ 12 k > 12 30 230
6 518
8 214
2 286
Ice Class R e g i o n Forward Midship Aft
IA Super IA IB IC
1.0 1.0 1.0 1.0
1.0 0.85 0.70 0.50
0.75 0.65 0.45 0.25
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c1 = 1 ca = a factor which takes account of the probability that the full length of the area under consideration will be under pressure at the same time. It is calculated by the formula:
0.6 minimum; 1.0 maximum;44
5-47=c aa
l
la shall be taken as follows: .
Table 8.5
Values of la po = the nominal ice pressure; the value 5.6 Mpa shall be used. 8.3 Calculations for Ice strengthened part 8.3.1 Vertical extension of Ice Belt The vertical extension of the ice belt shall be as follows: Ice Belt is from 7.00 m to 17.35 m above d ship’s depth from keel.
Table 8.6
Extension of Ice strengthening at midship
Structure Type of framing la [m] la [m] Ca [m] P Shell Transverse Frame spacing 0.35 1.028 2.612
Longitudinal Span of frame 4.25 0.585 1.486 Ice stringer Span of stringer 4.25 0.585 1.486 Web frame 2 ⋅ web frame spacing 8.5 0.102 0.260
Ice Class Above LWL [m]
Below BWL [m]
IA Super 0.6 0.75 IA 0.5 0.6 IB 0.4 0.5 IC 0.4 0.5
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8.3.2 Plate thickness in the ice belt For transverse framing the thickness of the shell plating shall be determined by the
For longitudinal framing the thickness of the shell plating shall be determined by the formula:
S = the frame spacing [m] pPL = 0.75 p [MPa] p = 1.88
1.0maximum;1.8)(h/s
4.23.1f 21 +−=
= 0.764
1h/swhen;(h/s)0.40.6f2 ≤+=
f2 = 1.4 - 0.4 (h/s); when 1≤ h/s < 1.8 = 1.0 h = 0.35
σy = yield stress of the material [N/mm2]
σy = 235 N/mm2 for normal-strength hull structural steel
σy = 315 N/mm2 or higher for high-strength hull structural steel If steels with different yield stress are used, the actual values may be substituted for the above ones if accepted by the classification society. tc = increment for abrasion and corrosion [mm]; normally tc shall be 2 mm t = 20.05 mm Taken t = 24 mm
[ ]mmtpf s 667 t cy
PL1 +⋅
=σ
[ ]mmtf
p s 667 t c2
PL +⋅
=yσ
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.
Table 8.7 Vertical extension of ice strengthening
The vertical extension of the ice strengthening of the framing shall be at least as Vertical extension of ice strengthening in framing is from 5.41 m to 18.55 m. 8.3.3 Transverse frames Section modulus The section modulus of a main or intermediate transverse frame shall be calculated
by the formula: p = ice pressure s = frame spacing [m] h = height of load area l = span of the frame [m]
[ ]36
t
cm10m
h s p Zy
lσ⋅⋅⋅⋅
=
Ice Class Region Above LWL [m]
Below BWL [m]
IA Super
From stem to 0.3L abaft it
1.2
To double bottom or below top of floors
Abaft 0.3L from
stem
1.2
1.6
midship 1.2 1.6 aft 1.2 1.2
IA, IB, IC
From stem to 0.3L abaft it
1.0
1.6
Abaft 0.3L from stem
1.0
1.3
Midship 1.0 1.3 Aft 1.0 1.0
Ice Class Region Above LWL [m]
Below BWL [m]
IA Super
From stem to 0.3L abaft it
1.2
To double bottom or below top of floors
Abaft 0.3L from
stem
1.2
1.6
midship 1.2 1.6 aft 1.2 1.2
IA, IB, IC
From stem to 0.3L abaft it
1.0
1.6
Abaft 0.3L from stem
1.0
1.3
Midship 1.0 1.3 Aft 1.0 1.0
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mt = l5h/-7
m7 o
σy = yield stress [N/mm2] mo = values are given in the following table: .
Table 8.8
Values of mo Z = 580.4 cm3 8.3.4 Longitudinal frames The section modulus of a longitudinal frame shall be calculated by the formula:
[ ]36
y
243 cm10m
hpff Z
σ⋅⋅⋅⋅⋅
=l
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The shear area of a longitudinal frame shall be:
This formula is valid only if the longitudinal frame is attached to supporting structure by brackets f3 = factor which takes account of the load distribution to adjacent frames f3 = (1 - 0.2 h/s) = 0.8. f4 = factor which takes account of the concentration of load to the point of support, f4 = 0.6 p = ice pressure h = height of load area s = frame spacing [m] l = span of frame [m] m = boundary condition factor; m = 13.3 for a continuous beam; where the
boundary conditions deviate significantly from those of a continuous beam, e.g. in an end field, a smaller boundary factor may be required.
σy = yield stress Z = 1076.5 cm3 A = 48.62 cm2 Scantling selected 330x15 HB Z = 1100 cm3 A = 65.9 cm2 8.3.5 Stringers within the ice belt The section modulus of a stringer situated within the ice belt (see 4.3.1) shall be calculated by the formula:
[ ]36
y
25 cm 10m
hpf Zσ⋅⋅⋅⋅
=l
The shear area shall be:
[ ]24
y
5 cm102
hpf3 Aσ
l⋅⋅⋅⋅=
[ ]24
y
3 cm102
hpf3 A
σl⋅⋅⋅⋅
=
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The product p ⋅ h shall not be taken as less than 0.30. f5 = factor which takes account of the distribution of load to the transverse
frames; to be taken as 0.9
σy = yield stress Z = 2153 cm3 A = 53.34 cm2 Wing tank girder has been provided in place of stringer. 8.3.6 Load on Web frames in Ice Belt The load transferred to a web frame from an ice stringer or from longitudinal framing shall be calculated by the formula: F = p ⋅ h ⋅ S [MN] The product p ⋅ h shall not be taken as less than 0.30 S = distance between web frames [m] F = 0.76 MN
8.4 Dimensions of non Ice strengthened parts:
8.4.1 Deck plating: [FSICR]
t = 20 mm
For Lloyd’s grade DH32, and for Russian Ice class LU4 or FMA Ice class 1A.
8.4.2 Sheer strake: [FSICR]
t = 20 mm
For Lloyd’s grade EH32, and for Russian Ice class LU4 or FMA Ice class 1A.
8.4.3 Side shell below Ice strengthening:
The greatest of the following is to be taken: t = 0.001s (0.059L1 + 7) √ FB/kL
= 11.81 mm
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But not less than
t = 0.0042 s√ hT1k s = spacing of shell longitudinals = 700 mm
hT1 = T + Cw m but need not be taken greater than 1.36T hT1 = 23.12 Cw = a wave head, in meters, 7.71 x 10–2Le–0,0044L Cw = 6.37 ∴ t = 12.48 mm
Selected t = 20 mm (Lloyd’s Grade DH32)
8.4.4 Bottom shell and bilge
t = 0.0052s hT2 = T + 0.5CW m but need not be taken greater than 1.2T = 19.93 FB = 0.67 (refer ‘DEFINITIONS’) k = 0.78 (refer ‘DEFINITIONS’) ∴ t = 10.27 mm Selected t = 18 mm (Lloyd’s Grade DH32)
8.4.5 Keel Plating
Keel plating should not be less than thickness of bottom shell + 2 mm
∴t = 20 mm,
But need not exceed t = 25 √ k = 22.08 mm Selected t = 22 mm
Width of keel plate is to be not less than 70B mm, but need not exceed 1800 mm and is to be not less than 750 mm. (LRS part 4, chapter1, and table 1.5.1)
70B = 3409 mm Selected w = 1800 mm
8.4.6 Inner bottom Plating t = t0 / √ 2-FB
t0 = 0.005s√ kh1
s = spacing of inner bottom longitudinal = 700mm k = 0.78
hT2k
1.8-FB√
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h = distance in m, from the plate in consideration to the highest point of the tank, excluding hatchway. R = 0.354 b1 = B/2 = 24.35 m h1 = 0.72 (h+Rb1) = 21.15 t0 = 14.22 mm t = 12.33 mm Selected = 14 mm (Lloyd’s Grade DH32)
8.5 Hull Framing [LRS Part 4, Chapter 9, Section 5]
8.5.1 Bottom Longitudinals
The section modulus of bottom longitudinals within the cargo tank region is not to be less than greater of the following: a) Z = 0.056kh1sle2F1FS cm3
K = 0.78 (Refer ‘DEFINITIONS’) h1 = (h0 + D1/8), but in no case be taken less than L1/56 m or
(0.00L1 + 0.7) m, whichever is greater & need not be taken greater than (0.75 D + D1/8), for bottom longitudinals.
= 19.82m h0 = distance in m, from the midpoint of span of stiffener to
highest point of tank, excluding hatchway. = 22 m D1 = 16 m (refer ‘DEFINITIONS’) s = spacing of bottom longitudinals = 700 mm le = effective span of longitudinals which are assumed to be supported by web frames spaced at 5s, where s is the basic frame spacing in midship region (850 mm ) not to be taken less than 1.5 m in double bottom and 2.5 m else where. le = 4.25 m F1 = Dc1/(25D-20h) = 0.133 c1 = 75/(225 – 150FB), at base line of ship. FB = 0.75 (refer ‘DEFINITIONS’)
∴c1 = 0.667
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h = distance of longitudinal below deck at side, in meters = 23.76 m D = 23.76 m (refer ‘DEFINITIONS’)
∴F1 = 0.133 FS = 1, at upper deck at side and at the base line.
∴Z = 1459.5 cm3
b) Z = 0.0051kh3sle2F2 cm3 k = 0.78 (refer ‘DEFINITIONS’) h3 = 75D+Rb1
b1 = 24.35 m R = (0.45+0.1 L/B)(0.54 – L/1270) = 0. 354 D1 = 16 m h3 = 26.44 m F2 = Dc2/ (3.18D-2.18h) = 0.785 c2 = 165/ (345-180FB) s = 700 mm le = 4.25 m
∴Z = 1044.8 cm3 Greater of the two is to be taken, i.e. Z = 1459.5 cm3
Selected 400 x 18 HB Z (Avail) = 1250 cm3 8.5.2 Deck Longitudinals (LRS, Part 4, Chapter 9.5.3.1)
The modulus of bottom longitudinals within the cargo tank region is not to be less than greater of the following: a) Z = 0.056kh1sl2eF1FS cm3
k = 0.78 (refer ‘DEFINITIONS’) h1 = (h0 + D1/8), but in no case be taken less than L1/56 m. h0 = 0 ( for deck longitudinals) D1 = 16 (h0 + D1/8) = 2 L1 = 190 L1/56 = 3.39 0.01L1 +0.7 = 2.6
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∴h1 = L1/56 = 3.39 s = 700 mm le = 4.25m F1 = Dc1 / (4D + 20h) h = 0 (for deck longitudinals) c1 = 60 / (225 – 165FD) at deck FD = 0.75 (refer ‘DEFINITIONS’) ∴ c1 = 0.595 ∴F1 = 0.148 Fs = 1, at upper deck at side and at baseline of ship ∴Z = 277.06 cm3
b) Z = 0.0051kh3sle2F2 cm3
R = 0.354 bi = B/2 = 24.35 m h3 = h0 + Rb1 = 8.62 m s = 700 mm le = 4.25m F2 = Dc2 / (D + 2.18h) c2 = 165 / (345 – 180FD) FD = 0.75 (refer ‘DEFINITIONS’) ∴c2 = 1.0 ∴F2 = 1.0 ∴Z = 433.5 cm3
Greatest of the two is to be taken, i.e. Z = 433.5 cm3
250 x 12 HB section is selected Z available = 500 cm3
8.5.3 Side Shell Longitudinals (LRS Part 4, Chapter 9. 5.3.1)
From standardization point of view the side shell is divided into longitudinal fields as shown in fig 8.4. Design of the longitudinals for each field is done using the information for the lowest longitudinal in each field. 8.5.4 Inner hull and CL bulkhead longitudinals The modulus of side shell longitudinals within the cargo tank region is not to be less than greater of the following: a) Z = 0.056kh1sle2F1Fs cm3
b) Z = 0.0051kh3sle2F2 cm3
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Where,
h1 = (h0 + D1/8), but in no case be taken less than L1/56 m or 0.01L1 +0.7 m whichever is the greater.
s = 700 mm
le = 4.25 m
k = 0.78
FD = 0.75
D1 = 16
L1 = 190 m
L1/56 = 3.39
h = distance of longitudinal below deck at side, in meters
h3 = h0 + Rb1
For side longitudinals above D/2,
F1 = Dc1 / (4D + 20h)
F2 = Dc2 / (D + 2.18h)
For side longitudinals below D/2,
F1 = Dc1/(25D-20h)
F2 = Dc2/(3.18D-2.18h)
c1 = 60 / (225 – 165FD) at deck
= 1.0 at D/2 = 75/ (225 – 150FB), at base line of ship
c2 = 165/ (345 – 180FB) at deck = 1.0 at D/2 = 165/ (345 – 180FD) at baseline of ship
“Department of Ship technology, CUSAT, B.Tech (NA&SB), Batch – XXIX”
Determination of scantlings of side shell longitudinals
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8.6 Inner Hull, Inner Bottom and Longitudinal Bulkheads
(LRS Part 4, Chapter 9, Section 6)
The inner hull, inner bottom and longitudinal bulkheads are longitudinally framed. The symbols used in this section are defined as follows:
b1 = the greatest distance in meters, from the centre of the plate panel or midpoint of the stiffener span, to the corners at top of the tank on either side.
c1 = 60 / (225 – 165FD) at deck = 1.0 at D/2 = 75/(225 – 150FB), at base line of ship c2 = 165/(345 – 180FB) at deck = 1.0 at D/2 = 165/(345 – 180FD) at baseline of ship h = load height, in meters measured vertically as follows: (a) for bulkhead plating the distance from a point one third of the height of the
plate panel above its lower edge to the highest point of the tank, excluding hatchway
(b) for bulkhead stiffeners or corrugations, the distance from the midpoint of span of the stiffener or corrugation to the highest point of the tank, excluding hatchway
h1 = (h + D1/8), but not less than 0.72 (h + Rb1) h2 = (h + D1/8), in meters, but in no case be taken less than L1/56 m or (0.01L1 + 0.7) m, whichever is greater h3 = distance of longitudinal below deck at side, in meters, but is not
to be less than 0 h4 = h + Rb1
h5 = h2 but is not to be less than 0.55h4 t0 = 0.005s √kh1
t1 = t0(0.84 + 0.16(tm/t0)2) tm = minimum value of t0 within 0.4D each side of mid depth of bulkhead
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8.6.1 Inner Hull Longitudinal Bulkhead Plating
For the determination of scantlings of longitudinal bulkhead plating and inner hull plating’s areas follows. (Refer fig 8.4)
Determination of Inner Hull and Longitudinal Bulkhead Plating
8.6.2 CL Longitudinal Bulk Head Longitudinals and Inner Hull Longitudinals
Inner hull and longitudinal bulkheads are to be longitudinally framed. The modulus of longitudinals is not to be less than greater of the following: (a) Z = 0.056kh2sl2eF1 cm3 (b) Z = 0.0051kh4sl2eF2 cm3
The inner hull and bulkhead plating is divided into various strakes for the determination of center line bulkhead longitudinals and inner hull longitudinals.
s = 700 mm le = 4.25m
“Department of Ship technology, CUSAT, B.Tech (NA&SB), Batch – XXIX”
Section HB HB HB Scantling 250 X 13 325 X 17 325 X 12
Table.8.11
Determination of scantlings of CL longitudinal bulkhead longitudinal and inner hull longitudinal
8.6.3 Inner Bottom Plating and Longitudinals
The inner bottom is to be longitudinally framed and the inner bottom plating thickness is to be
t = t0 / √ 2-FB
t0 = 0.005s√ kh1
s = spacing of inner bottom longitudinal = 700mm k = 0.78 h = distance in m, from the plate in consideration to the highest
point of the tank, excluding hatchway = 20.76 m R = 0.354 (refer previous sections) b1 = B/2 = 24.35 m h1 = 0.72 (h+Rb1) = 21.15 t0 = 14.21 mm
t = 12.32 mm Selected = 14 mm
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The modulus of longitudinals is not to be less than greater of the following: (a) Z = 0.056kh2sl2eF1 cm3
h = 19.38 m D1 = 16 m h2 = h + D1 / 8 = 22.76 m F1 = 0.078 ∴Z = 985.2 cm3
(b) Z = 0.0051kh4sl2eF2 cm3 h4 = h + Rb1 = 27.709m F2 = 0.316
∴Z = 440.67 cm3
Selected Z = 985.2 cm3.
Selected HB 330 x 13
Z available = 1000 cm3
8.7 Primary Members Supporting the Hull Longitudinal Framing 8.7.1 Centre girder (LRS Part 4, Section 9.3.3) (a) Minimum depth of centre girder
dDB = 28B + 205√ T mm dDB = 2202.6 mm dDB = 3000 mm Given 3.0 m.
(b) Minimum thickness of centre girder (LRS, Part 4.9.3.4) t = (0.008 dDB + 1) √ k = 22.07 mm Given thickness = 22 mm
8.7.2 Floors and Side Girders t = (0.007dDB + 1) √ k = 19.43 mm
But not to exceed 12√ k = 10.6 mm Given thickness = 10.6 mm
∴t = 16 mm
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8.7.3 Deck Transverses (LRS Part 4.10.2.8) Section modulus of deck transverses is not to be less than
Z = 53.75 (0.0269sL + 0.8) (ST + 1.83) k cm3
s = 4.25 m L = 229.8 m ST = span of transverse = 8.116 m ∴Z = 12871.3 cm3
Taken T section 1500 X 14 +600 X 20 is selected.
8.7.4 Vertical web on centreline longitudinal bulkhead Section modulus of vertical web is to be not less than
Z = K3shsSs2k (sm3)
K3 = 1.88, s = 4.25 hs = distance between the lower span point of the vertical web
and the moulded deckline at centreline, in meters = 20 m Ss = span of vertical web, in meters, and is to be measured between end span points. = 12.75 m ∴ Z = 18476.0 cm3
Taken T section 1250x 12+ 500x 18
8.8 Primary Members End Connections [LRS Part 3, Chapter 10, Section 3]
The following relations govern the scantlings of bracket:
(a + b) ≥ 2l
a ≥ 0.8 l
b ≥ 0.8 l l = 90 2 - 1 mm
Z
(14 + √ Z) √
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8.8.1 Bracket connecting deck transverse and inner hull
l = 90 2 - 1 mm Z = 12871.3 cm3
l = 90 {2 (√12871.3 / [14 + √ 12871.3]) – 1} = 1718.8 mm a ≥ 0.8l = 1375 mm b ≥ 0.8l = 1375 mm Given a = 2300 mm and b = 2000 mm t = thickness of web itself = 25 mm Flange breadth to be not less than bf = 40 (1 + Z / 1000) mm, but not less than 50mm = 40 (1 + 12871.3 / 1000) = 554 mm Taken 750 mm
8.8.2 Bracket connecting deck transverse and center line bulkhead web l = 90{ 2 - 1} mm Z = 14602 cm3 l = 90 {2 (√14602/ [14 + √ 14602]) – 1} = 1783.1 mm a ≥ 0.8l = 1426.5 mm b ≥ 0.8l = 1426.5 mm Given a = 2400 mm and b = 2000 mm t = thickness of web itself = 25 mm Flange breadth to be not less than bf = 40 (1 + Z / 1000) mm, but not less than 50mm = 40 (1 + 14602/ 1000) = 624.08 mm Taken 750 mm
Z
(14 + √ Z) √
Z
(14 + √ Z) √
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8.8.3 Bracket connecting centre line vertical web and inner bottom plating
l = 90{ 2 - 1} mm Z = 14602cm3 l = 90 {2 (√14602/ [14 + √ 14602]) – 1} = 1783.1 mm a ≥ 0.8l = 1426.5 mm b ≥ 0.8l = 1426.5 mm Given a = 2400 mm and b = 2000 mm t = thickness of web itself = 25 mm Flange breadth to be not less than bf = 40 (1 + Z / 1000) mm, but not less than 50mm = 40 (1 + 14602/ 1000) = 624.08 mm Taken 750 m
Z
(14 + √ Z) √
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Inner Hull Long 1 250 x 13 2 0.0084 23.06 0.1937 4.466814
2 250 x 13 2 0.0084 22.36 0.1878 4.199745
3 250 x 13 2 0.0084 21.66 0.1819 3.940907
4 250 x 13 2 0.0084 20.96 0.1761 3.690301
5 250 x 13 2 0.0084 20.26 0.1702 3.447928
6 250 x 13 2 0.0084 19.56 0.1643 3.213786
7 250 x 13 2 0.0084 18.86 0.1584 2.987877
8 325 x 12 2 0.0108 18.51 0.1999 3.700297
9 325 x 12 2 0.0108 18.16 0.1961 3.561684
10 325 x 12 2 0.0108 17.81 0.1923 3.425718
11 325 x 12 2 0.0108 17.46 0.1886 3.292397
12 325 x 12 2 0.0108 17.11 0.1848 3.161723
13 325 x 12 2 0.0108 16.76 0.181 3.033694
14 325 x 12 2 0.0108 16.41 0.1772 2.908311
15 325 x 12 2 0.0108 16.06 0.1734 2.785575
16 325 x 12 2 0.0108 15.71 0.1697 2.665484
17 325 x 12 2 0.0108 15.36 0.1659 2.54804
18 325 x 12 2 0.0108 15.01 0.1621 2.433241
19 325 x 12 2 0.0108 14.66 0.1583 2.321088
20 325 x 12 2 0.0108 14.31 0.1545 2.211582
21 325 x 12 2 0.0108 13.96 0.1508 2.104721
22 325 x 12 2 0.0108 13.61 0.147 2.000507
23 325 x 12 2 0.0108 13.26 0.1432 1.898938
24 325 x 12 2 0.0108 12.91 0.1394 1.800015
25 325 x 12 2 0.0108 12.56 0.1356 1.703739
26 325 x 12 2 0.0108 12.21 0.1319 1.610108
27 325 x 12 2 0.0108 11.86 0.1281 1.519124
28 325 x 12 2 0.0108 11.51 0.1243 1.430785
29 325 x 12 2 0.0108 11.16 0.1205 1.345092
30 325 x 12 2 0.0108 10.81 0.1167 1.262046
31 325 x 12 2 0.0108 10.46 0.113 1.181645
32 325 x 12 2 0.0108 10.11 0.1092 1.103891
33 325 x 12 2 0.0108 9.76 0.1054 1.028782
34 325 x 12 2 0.0108 9.41 0.1016 0.956319
35 325 x 12 2 0.0108 9.06 0.0978 0.886503
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36 325 x 12 2 0.0108 8.71 0.0941 0.819332
37 325 x 12 2 0.0108 8.36 0.0903 0.754808
38 325 x 12 2 0.0108 8.01 0.0865 0.692929
39 325 x 12 2 0.0108 7.66 0.0827 0.633696
40 325 x 12 2 0.0108 7.31 0.0789 0.57711
41 325 x 12 2 0.0108 6.96 0.0752 0.523169
42 325 x 12 2 0.0108 6.61 0.0714 0.471875
43 325 x 12 2 0.0108 6.26 0.0676 0.423226
44 325 x 17 2 0.0134 5.76 0.0772 0.44458
45 325 x 17 2 0.0134 5.26 0.0705 0.370746
46 325 x 17 2 0.0134 4.76 0.0638 0.303612
47 325 x 17 2 0.0134 4.26 0.0571 0.243178
48 325 x 17 2 0.0134 3.76 0.0504 0.189444
Bottom Longitudinals 400 x 18 64 0.64 0.2 0.128 0.0256 Inner Bottom Longls 330 x 13 50 0.32 2.85 0.912 2.5992 Side longitudinals 1 250 x 13 2 0.0084 23.06 0.1937 4.466814
2 250 x 13 2 0.0084 22.36 0.1878 4.199745
3 250 x 13 2 0.0084 21.66 0.1819 3.940907
4 250 x 13 2 0.0084 20.96 0.1761 3.690301
5 250 x 13 2 0.0084 20.26 0.1702 3.447928
6 250 x 13 2 0.0084 19.56 0.1643 3.213786
7 250 x 13 2 0.0084 18.86 0.1584 2.987877
8 330 x 15 2 0.0132 18.51 0.2443 4.522585
9 330 x 15 2 0.0132 18.16 0.2397 4.35317
10 330 x 15 2 0.0132 17.81 0.2351 4.186989
11 330 x 15 2 0.0132 17.46 0.2305 4.024041
12 330 x 15 2 0.0132 17.11 0.2259 3.864328
13 330 x 15 2 0.0132 16.76 0.2212 3.707848
14 330 x 15 2 0.0132 16.41 0.2166 3.554603
15 330 x 15 2 0.0132 16.06 0.212 3.404592
16 330 x 15 2 0.0132 15.71 0.2074 3.257814
17 330 x 15 2 0.0132 15.36 0.2028 3.114271
18 330 x 15 2 0.0132 15.01 0.1981 2.973961
19 330 x 15 2 0.0132 14.66 0.1935 2.836886
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20 330 x 15 2 0.0132 14.31 0.1889 2.703045
21 330 x 15 2 0.0132 13.96 0.1843 2.572437
22 330 x 15 2 0.0132 13.61 0.1797 2.445064
23 330 x 15 2 0.0132 13.26 0.175 2.320924
24 330 x 15 2 0.0132 12.91 0.1704 2.200019
25 330 x 15 2 0.0132 12.56 0.1658 2.082348
26 330 x 15 2 0.0132 12.21 0.1612 1.96791
27 330 x 15 2 0.0132 11.86 0.1566 1.856707
28 330 x 15 2 0.0132 11.51 0.1519 1.748737
29 330 x 15 2 0.0132 11.16 0.1473 1.644002
30 330 x 15 2 0.0132 10.81 0.1427 1.542501
31 330 x 15 2 0.0132 10.46 0.1381 1.444233
32 330 x 15 2 0.0132 10.11 0.1335 1.3492
33 330 x 15 2 0.0132 9.76 0.1288 1.2574
34 330 x 15 2 0.0132 9.41 0.1242 1.168835
35 330 x 15 2 0.0132 9.06 0.1196 1.083504
36 330 x 15 2 0.0132 8.71 0.115 1.001406
37 330 x 15 2 0.0132 8.36 0.1104 0.922543
38 330 x 15 2 0.0132 8.01 0.1057 0.846913
39 330 x 15 2 0.0132 7.66 0.1011 0.774518
40 330 x 15 2 0.0132 7.31 0.0965 0.705357
41 330 x 15 2 0.0132 6.96 0.0919 0.639429
42 330 x 15 2 0.0132 6.61 0.0873 0.576736
43 330 x 15 2 0.0132 6.26 0.0826 0.517276
44 340 x 13 2 0.012 5.56 0.0667 0.370963
45 340 x 13 2 0.012 4.86 0.0583 0.283435
46 340 x 13 2 0.012 4.16 0.0499 0.207667
47 340 x 13 2 0.012 3.46 0.0415 0.143659
48 340 x 13 2 0.012 2.76 0.0331 0.091411
49 340 x 13 2 0.012 2.06 0.0247 0.050923
50 340 x 13 2 0.012 1.36 0.0163 0.022195
51 340 x 13 2 0.012 0.66 0.0079 0.005227
CL Longl Bulkhead
1 250 x 13 1 0.0042 23.06 0.0969 2.233407
2 250 x 13 1 0.0042 22.36 0.0939 2.099872
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3 250 x 13 1 0.0042 21.66 0.091 1.970454
4 250 x 13 1 0.0042 20.96 0.088 1.845151
5 250 x 13 1 0.0042 20.26 0.0851 1.723964
6 250 x 13 1 0.0042 19.56 0.0822 1.606893
7 250 x 13 1 0.0042 18.86 0.0792 1.493938
8 325 x 12 1 0.0054 18.16 0.0981 1.780842
9 325 x 12 1 0.0054 17.46 0.0943 1.646199
10 325 x 12 1 0.0054 16.76 0.0905 1.516847
11 325 x 12 1 0.0054 16.06 0.0867 1.392787
12 325 x 12 1 0.0054 15.36 0.0829 1.27402
13 325 x 12 1 0.0054 14.66 0.0792 1.160544
14 325 x 12 1 0.0054 13.96 0.0754 1.052361
15 325 x 12 1 0.0054 13.26 0.0716 0.949469
16 325 x 12 1 0.0054 12.56 0.0678 0.851869
17 325 x 12 1 0.0054 11.86 0.064 0.759562
18 325 x 12 1 0.0054 11.16 0.0603 0.672546
19 325 x 12 1 0.0054 10.46 0.0565 0.590823
20 325 x 12 1 0.0054 9.76 0.0527 0.514391
21 325 x 12 1 0.0054 9.06 0.0489 0.443251
22 325 x 12 1 0.0054 8.36 0.0451 0.377404
23 325 x 12 1 0.0054 7.66 0.0414 0.316848
24 325 x 12 1 0.0054 6.96 0.0376 0.261585
25 325 x 12 1 0.0054 6.26 0.0338 0.211613
26 325 x 17 1 0.0067 5.56 0.0373 0.207121
27 325 x 17 1 0.0067 4.86 0.0326 0.158251
28 325 x 17 1 0.0067 4.16 0.0279 0.115948
29 325 x 17 1 0.0067 3.46 0.0232 0.08021 Total 30 7.75748 10.2374 79.416 1405.963 9.599469
Height of NA =10.237 m I ref =1415.56 m4 I NA =602.54 m4 Z deck = 44.44 m3 Z keel = 58.85 m3 Z Req = 43.31m3 Here ZDECK and ZKEEL are getting more than the minimum section modulus required. So the design is satisfactory.
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CHAPTER 9 OUTLINE SPECIFICATION
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9. OUTLINE SPECIFICATION
9.1. General 9.1.1. Main Particulars LOA - 290.5 m LBP - 263.0 m B (mld) - 48.7 m D (mld) - 23.76 m T (mld) - 16.75 m Ice draft (fully loaded) - 16.86 m CB - 0.840 Dead weight - 150,000 t Speed - 15.0 Knots Total Complement - 42 Range - 3800 nautical mile
9.1.2. Purpose
This double acting type double hull tanker is required to transport crude oil from Belokamenka vessel (Murmansk, Russia) to Rotterdam (Netherlands)
9.1.3. Description
The vessel is a twin screw, podded type propulsion, longitudinally framed, double hull vessel having a main deck, fore castle, superstructure and engine casing (aft), cranes etc. Main deck is the freeboard deck. The ship has nine watertight transverse bulkheads. A double bottom is arranged from the fore peak bulkhead to the aft peak bulkhead. The double bottom height is 3.0 m. Engine room and accommodation is arranged aft. Two deck cranes of 5t capacity are fitted on either side of the ship to facilitate easy cargo handling hose. Additionally one provision crane of capacity 1 tonne has been provided aft in port side.
There are ten holds to carry crude oil. The double bottom tanks beneath these holds and the wing tanks at the sides are used to carry ballast water. Towards the aft of cargo hold, a slop tank is provided to carry the sludge, which remains after the pumping out of cargo. Pump room is provided in between the slop tank and the engine room. A heavy fuel oil tank is provided in the forward region of the engine room. Forepeak tank is used for ballasting. Forepeak accommodates the chain locker also. Azipod room has been provided in aft region.
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9.1.4. Classification
The ships are classified under Lloyds Register of Shipping and FSICR.
Class notation: ✠+100A1double hull oil tanker Baltic service Ice class 1A Super.
9.1.5 Capacities Cargo Capacity = 174294.17 m3
Ballast water Capacity = 50841.42m3
HFO tank Capacity = 7152.1 m3
DFO tank Capacity = 797.4 m3
Boiler fuel tank Capacity = 379.42 m3
LO tank Capacity = 247 m3
Capacity of FW tank = 32 m3
Capacity of Waste water tank= 132.44 m3
9.1.6 Compliment Captain Class : 4 Senior Class : 2 Junior Class : 3 Cadet : 2 Petty Officers : 3 Leading crew : 4 Crew Class : 24 TOTAL : 42
9.2 Hull
The ship is made of Higher tensile steel (DH32 and DH36) and is of all welded construction. The wing tanks and double bottom constitute the double hull of the ship.
9.3 Life Saving Appliances
Life Saving Appliances Life saving appliances provided as per SOLAS requirements. Lifeboat particulars to be satisfied are:
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Volume required per person = 0.283 m3. Total compliment = 42 Lifeboat chosen has following particulars: L = 8.5 m B = 2.97 m T = 1.25 m H = 8.58 m CB = 0.60
One totally enclosed free fall type, diesel engine driven lifeboats each capable of 55 persons capacity is provided on aft of the ship. The lifeboats are equipped with water spray fire protection system. Material of construction is GRP.
COMPLIANCE LIST a. Two inflatable life rafts of 25 person’s capacity each is provided on either side of
the ship. b. One life raft for 6 persons with hydrostatic release is installed on forward upper
deck behind forecastle deck. c. 55 life jackets have been provided. d. Eight life buoys are provided, four of which are fitted with self-igniting light e. 2 life jackets for child have been provided f. A line throwing apparatus in wheel house is provided. g. 2 two way portable VHF (CH16) is provided in wheel house. h. 12 parachute flare has been provided in wheelhouse. i. 4 EPIRB has been provided in wheelhouse and above deck. j. 2 SART has been provided in wheel house and adjacent space k. 4 WT set has been provided. l. 9 general alarm and P A System has been provided in different location in ships m. Training manual has been provided in wheel house, galley and other public places n. Operating instruction booklet is provided in each raft and boat. o. 9 muster lists has been provided in different public places in ship. p. 2 OMTL is provided in wheel house.
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q. 2 Embarkation ladder with light is provided in aft at MDK. r. Muster station has been provided at MDK in aft region. s. 55 immersion suits has been provided t. TPA has been provided according to approval of administrations
9.4 Fire Extinguishing Appliances
Fire fighting systems are to be installed in accordance with SOLAS rules. Cargo oil tank deck spaces - Foam fire extinguishing system. Engine room and pump room - CO2 fire extinguishing system. Accommodation spaces, open deck engine room and pump room - Water hydrant system. Galley - Portable DCP fire extinguishers Paint store - Portable foam type fire extinguishers.
9.5 Ventilation and Air-conditioning
Mechanical ventilation is to be arranged for galley, provision store (dry), laundry, sanitary spaces, and pantries. Conditioned air to be supplied to all cabins as well as to the wheelhouse (spot cooling). Air conditioning installations to comprise an automatically controlled air-handling unit with filter, steam heater, cooler, and de-humidifier. One refrigerating plant, comprising one compressor with condenser etc for supply by a single duct system is provided. Outlets are to enable individual control of air. Engine room is to have mechanical ventilation. E.R control room is to have separate air conditioning unit.
9.6 Navigation and communication equipments
Wheel house is fitted with the following equipment:- Magnetic compass. Engine control and telegraphs. Revolution indicators. Steering wheel. Chart table with drawer for charts and navigational publication Voice pipes communication system. Locker with locking arrangement for navigational instruments. Navigational radar. Pod angle indicators.
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Navigational lights:
The ship has the following lights used for navigation. One masthead light forward. One masthead light aft. Two side lights (green is starboard side, red in port side). One stern light (white). Two anchor lights (white). Four all round lights (white). 3 NUC light (red white and red)
9.7 Propulsion
The vessel will be propelled by twin Azipod propeller driven by 3 generators directly coupled to 3 diesel engines separately. Diesel Engines Type: 9TM620 Number: 3 Manufacturer: STORK WARTSILA DIESEL CO. Holland Rated output: 12,750KW Rated speed: 428rpm Consumption of heavy fuel oil: 174G/KWH +5% Consumption of lube oil: 1.3+0.3G/KWH Greatest weight/piece: 270T Generators Type: HSG 1600 S14 Number: 3 Rated capacity: 15,537 KVA Cos Factor: 0.8 Frequency: 50 HZ Rated current: 815A Rated voltage: 11KV Greatest weight/piece: 55T Rated speed: 429 rpm Manufacturer: ABB, FINLAND Rated output: 12.43 MW Transformers Number: 2 Type: STROD/BTRD. Manufacturer: TAKAOKA ENGINEERING CO. LTD JAPAN Rated voltage: 11KV/121KV Weight: 58T
“Department of Ship technology, CUSAT, B.Tech (NA&SB), Batch – XXIX”
Propeller Particulars Type : Wageningen –B series D : 7.26 m Z : 4 AE/AO : 0.527 P/D : 0.742 T : 1612.56 KN η O : 53.8 Material : Lloyd’s grade Cu 4 Manganese Aluminium Bronze Tensile strength: 630 N/mm2
9.8 Anchoring Arrangement Anchor type = Commercial standard stockless No. Of anchors = 2 Mass of anchor, WA = 17800 kg Total length of stud link cable, Lc = 742.5 m Diameter of stud link cable, dc = 102 mm (special grade of steel)
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CHAPTER 10
DESIGN SUMMARY AND CONCLUSION
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10. DESIGN SUMMARY AND CONCLUSION
The entire project work done till preliminary design stage. Technical aspects were only considered and that too only up to the level of obtaining data from available literature. Economic aspects were not given due importance in all the places. In the real case importance is given to economic as well as technical aspects.
The design of a ice class tanker is highly dependent on the owner’s requirement routes and market trend. Draft restriction of the loading and unloading ports should be given due importance. The cargo compositions will very much influence the design. Crude oil with density ranging from 0.8 to 0.9 is available in Russia.
Hull form was designed using BSRA Charts, while aft has been designed using aft hull form of ice class tanker .The arrangement of the holds has been made to distribute the cargo evenly in its holds so as to reduce the cargo handling time. Maximum length of cargo holds, as specified by Lloyd’s Register of Shipping
The structural arrangement is made so as to obtain the maximum unobstructed space below the deck. The longitudinal in wing tank bulkhead protrude into wing tank so that it does not affect the crude oil stowage.
The general arrangement has been done keeping in mind all the major characteristics required for an ice class tanker.
The tanker has been examined for intact stability in all loading conditions and meets the IMO A.749 Righting Energy Criteria with a margin of safety. While doing the trim and the stability calculations, various centres of gravity are found using various empirical formulae. This may not be the actual centre of gravity and this can be calculated only after a detailed mass estimation for which the data is unavailable. Ice load has been considered according to IMO resolution.
The structural configuration of the double-bottom hull and cargo tanks results in an effective design that satisfies the owners’ requirements. The scantlings of the structural members are within accepted industry producibility limits. The stress distribution of the structure, although it requires further analysis, predicts a successful design. It is based on a parent hull form design that has good sea keeping abilities while allowing for 150,000 ton Dwt tank carrying capacity. A bulbous bow has been utilized to reduce wave making and viscous drag as well as increasing fuel efficiency while moving aft and forward.
The propulsion system within the ice class tanker incorporates a medium -speed diesel engine with diesel electric Podded propulsion for its cost efficiency, proven technology, and maintainability. The system also includes a four-blade fixed pitch propeller due to its optimal efficiency and minimal fuel rate.
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The engine, in conjunction with the propeller, produces ample power to propel the
ship efficiently and effectively. The propulsion system satisfies the requirements for endurance speed and range. Cargo systems utilize the most advanced equipment available for safe and efficient cargo handling. The cargo piping serves alternative pairs of tanks and is cross-connected for redundancy, allowing any tank to be serviced by any cargo pump. The cargo pumps facilitate the timely loading and unloading of the cargo. To eliminate the possibility of deck spills, the cargo is offloaded through discharge headers that run through the cargo tanks.
The ballast water system is completely segregated from the cargo system to prevent contamination of either system. The ballast water exchange system on the ship requires less operation and maintenance of auxiliary equipment. This system will meet future ballast water exchange requirements. Ballast pumps supply the means for ballasting the ship to ensure stability during the offloading procedures and unloaded voyages.
COW systems ensure the maximum cargo holding capacity and remove crude oil debris from the tanks. IGS is necessary for safe storage of cargo while in route and meets all requirements. Oil monitoring systems are utilized to ensure that water-oil mixtures are not discharged into the sea.
The design incorporates the efficient use of five decks. Central stairs and elevator, and various exterior entrances allow crew members to move freely through the entire deckhouse. Crew accommodations include individual staterooms, galleys, mess areas, and various rooms to provide an excellent crew living environment. The navigation deck provides outstanding visibility of the ship and surroundings, exceeding the visibility requirements.
Designed ship has 6.0 meter double side width and a 3.0 meter double bottom height to provide the most protection against collision and grounding. This also provides easy access to the tanks for inspection and maintenance which increases overall ship safety and life. All fuel tanks lube oil tanks, and waste oil tanks are contained within the 3.0 meter double side and 3.0 meter double bottom.
The machinery space design optimizes the space arrangements of various components of cargo, propulsion, and electrical equipment. The majority of the equipment surrounds the main engine. Components are positioned to work efficiently in performing their duty. Pumps interacting with cargo, ballast, and supply tanks are positioned within close proximity to their respective tanks. Other components are effectively positioned to provide control of propulsion and electrical systems. All equipment in the machinery space performs together in an efficient manner to meet the owner’s requirements.
As far as preliminary design is concerned, camber has not been considered, but there is need to provide camber in order to avoid accumulation of ice on deck.
Capacity of all tanks has been calculated using AUTOCAD. it can be optimized using 3-D modeling software. Camber volume also has to be incorporated.
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REFERENCES
1. MARPOL 73/78 ,International Convention on Marine Pollution,2003 2. Watson D.G.M, Gilfillan A.W; Some Ship Design Methods, RINA 1976. 3. Dankwardt, E ; 'Entwerfen Von Schiffen' 4. H.Schneekluth ; ‘Ship design for Efficiency and Economy’ 5. Taggart R; ‘Ship Design and Construction’, SNAME Publications, New York, 1980 6. Prohaska C. W.; ‘Results of Some Systematic Stability Calculations’,RINA 1947 7. Edward.V.Lewis; Principles of Naval Architecture Vol II 8. Gokaran and Ghose; ‘Basic ship propulsion’ 9. Derret. D R; Ship Stability for Masters and Mates 10. B.S.R.A Report No: 333 11. Rules and Regulations for Building and Classification of Steel Ships –Lloyds
Register of Shipping, July 2002 12. Harvald; Resistance and Propulsion of ships 13. Eyres D. J.; Ship Structures 14. Rawson and E.C.Tupper ; ‘Basic Ship Theory – Volume 2’,Longman ,1978 15. Mikko Niini; ‘Ice going ships and recent developments’ 16. Noriyuki Sasaki; ‘The first Double Acting Aframax Tanker in the world’, Sumitomo
Heavy Industries Ltd. 17. Lloyd’s Register Technical Notes on Cold Climate Navigation- Design and
operation Considerations 18. Reko Antti Suojanen; ‘Double Acting Ship concept and podded propulsion in Ice’,
Seminar on ice breaking and ice going ships 19. Sami Saarinen; ‘Design of Cargo vessels for Arctic’, Kvaerner Masa Yards, Arctic
Technology 20. Strengthening for Russian ICE Tanker. 21. www.ship-technology.com 22. www.arcop.fi 23. Proceedings of the 24th ITTC-Volume II and III, The specialist committee on
Azimuthing Podded Propulsion, Final Reports and Recommendations.
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24. Kimmo Juurmaa, Tom Mattsson and Goran Wilkman; ‘The development of the
new Double Acting Ships for Ice operation’, Kvaerner Masa Yards, Arctic Technology, Finland
25. www.distance.com 26. Ivan Ivanov; ‘Russia-Energy and Security’ 27. Growth Project GRD2-2000-30112 “ARCOP”, LRS and HUT 28. Project Guide for Azipod Propulsion System, ABB Marine and Turbo charging 29. Korin Strome; ‘Virginia Tech Shuttle Tanker’, Ocean Engineering Senior Design
Project 30. Amo Keinomen, Robin P Brown, Colin R Revill and Ian M Bayly; ‘Icebreaker
performance prediction’, SNAME 31. Calm water model tests for propulsive performance prediction, VTT Technical
research centre of Finland 32. IACS; ‘Requirements concerning Strength of Ships’ 33. www.wartsila.com 34. Propulsion trends in tankers (FSICR) 35. Michael G. Parsons PARAMETRIC DESIGN 36. FSICR Research Report No 53 37. Unicom Management Services, Cyprus