fm 5-212 medium girder bridge

8/14/2019 fm 5-212 medium girder bridge

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Field ManualNo. 5-212

FM 5-212Headquarters

Department of the ArmyWashin gton, D C, 7 Febru ary 1989

MEDIUM GIRDER BRIDGE

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DISTRIBUTION RESTRICTION: Approved for public release; distribution is unlimited.


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PREFACE

This pu blication contains am endments to Technical Manuals (TMs) 5-5420-272-72, Operator andOrganizational Maintenance Manual for Medium Girder Bridge (MGB) and 5-5420-272-72-7, Operator andOrganization/ Maintenance Manual Link Reinforcement Set for the Medium Girder Bridge (MGB).TheseTMs are being updated to correspond with information contained in this field manual. This publicationdescribes design, recon reports, safety rules; and building, boom, and delaunch tables for the MGB.

The Bridging Branch, Department of Military Engineering, US Army Engineer School, has developed thisdesign package with significant Input from Fairey Engineering, Ltd., The Royal School of MilitaryEngineering (United Kingdom) and countless Engineer Officer Basic/ Adva nced N oncommissioned officerCourse students attending resident instruction at Fort Belvoir.

The purpose of this publication is to standardize procedures and make the design process easy tounderstand. (Abbreviations for MGB design are included In the glossary.) No longer will engineers have tocount boxes and squares on scaled pap er to employ the MGB.

The prop onent of this pu blication Is the US Arm y Engineer School, Subm it chan ges for imp roving th ispublication on DA Form 2028 (Recommended Changes to Publications and Blank Forms), and forward it toCommandant, US Army Engineer School, ATTN: ATSE-Z-BTD-P, Fort Belvoir, VA 22060-5291.

Unless otherwise stated, whenever the masculine gender is used, both men and women are included.

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Chapter 1

Medium Girder Bridge Components

The medium girder bridge (MGB) is lightweight,

hand-built, bridging equipment, it can be built invarious configurations to provide a full range ofbridging capability for use both in the forwardbattle area and in the comm un ications zone.Speed of erection by few sold iers is its majorcharacteristic.

The MGB parts are fabricated from a speciallydeveloped zinc, magnesium, and aluminum alloy(DGFVE 232A). This enables a lightweigh t, highstrength bridge to be built. All except three partsweigh under 200 kg. Most parts can be handledeasily by four soldiers. The three heavier parts,

used in limited quan tities. are six-man load s.The MGB is a tw o-girder, d eck bridge. The two

longitudinal girders, with deck units between,provide a 4.0m wide roadway. Girders of toppanels can form a shallow, single-storyconfigur ation. This type of bridge is u sed for shortspans that will carry light loads. A heavierdouble-story configuration using top panels andtriangular bottom panels is used for heavy loads

or longer spans. Single-story bridges can be

constructed by 9 to 17 soldiers. The normalbuilding p arty for dou ble-story bridges is 25soldiers.

The bridge can be supported on unp reparedand uneven ground without grillages. It isconstructed on one roller beam for single-storyconstruction; two roller beams, 4.6m apart, fordou ble-story construction; and on th ree rollerbeams when constructing a double-story bridgeover 12 bays long. The end s of the roller beamsare supported on base plates and each can beadjusted in height. No leveling or other

prep aration of the groun d is required. Single-spanbridges are launched using a centrally mountedlaunching nose (Figure 1).

A third configuration using th e linkreinforcement set (LRS) is constructed w hen along, high class type of bridge is required. TheLRS deepens the gird er and transfers the loadthroughou t the length of the bridge. This type of

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construction requ ires a building p arty of 34soldiers, and is built on three roller beams.

ADVANTAGES OF THE MGB/LRSLightweight no component requires more

than six soldiers to lift or carry.

Easy to assemb le components have specialalignment aids built into them.

Minimal m aintenance very little lubricationrequire.

Air transportable in either standard palletloads or in partially assembled bridgeconfigurations.

Compatibility all US components will fitMGBs in use by allies, except for launching nosecross girder (LNCG) posts.

DISADVANTAG ES OF THE M GB/LRSLength - Maximum length is 49.7m.

Military Load Class (MLC) - MLC is 60,not 70.

MAJOR PARTS (See Figure 2).

Top panel. End taper panel.

Bankseat beam . Ramps US (long)

Bottom panel.and UK (short).

Deck unit.Junction panel.

ALLOCATION/CAPABILITIESAn MGB company (corps level) is issued four

bridge sets, two erection sets, and two linkreinforcement sets. These are divided betweentwo platoons.

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COMPONENT LISTSBridge Set

Item description and quantity

Bag, equipment 8

Basket, equipm ent 14

Beam assembly, bankseat 7Brace, sway 19

Clip, retainer 94

Curb assembly 42

Deck 74

Guide assembly, marker 24

Panel assembly, end taper 5

Panel assembly, bottom 26

Panel assemb ly, jun ction 5

Panel assembly, top 34

Pin, bracing 68

Pin, panel 92

Pin, panel, headless -5

Ramp assembly, short 29

Ramp assembly, long 15

Bridge Erection Set Item description and quantity

Adap ter, pu sh bar 2Bag, equipm ent 2

Bar, carrying 46

Bar assembly, launching 2


Beam assembly, roller 4

Cable, extractor 1

Clip, retainer 56

Girder assembly, launching 2

Girder, cross fram e 3

Girder, longitudinal* 3

Girder, pu sh bar 2

Handle, carrying 46

Jack, bridge, 15-ton 7

MGB pallet, truck mounted 13

Rear bumper assembly 13

Lug, tie-down, steel 104

Stray assembly, 5,000-pound capacity 52

Strap assembly, 10,000-pound capacity 117

Tie-down, cargo, 10,000-pound 26

MGB pa llet, trailer mou nted 12

Adapter, pallet 12

Bracket adapter, with hardware 48

Rear bumper assembly 12Strap assembly, 5,000-pound capacity 28

Strap assembly, 10,000-pound capacity 108

Tie-down, cargo, 10,000-pound 48

Nose assem bly, launching 8

Nose, light, front 5

Nose, light, rear 5

Panel erection aid 3

Pedestal assem bly, adjustable, MKI 2

Pedestal, building 7

Pin, anchorage** 10

Pin, bracing 8

Pin, launching nose 23

Pin, panel 20

Plate, base, DS 6

Plate, base, SS 7

Post assembly, jacking 4

Bracket, lifting 4

Post, launching nose 2

Roller assembly, land ing 4* Issued in some sets though not required.** Transfer from link reinforcement set.[Items with separate national stock numbers (NSNs) that together with other item(s) in brackets comprise

an assembly.

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Roller assembly, launching 2 Rear bumper assembly 1

Seat, building frame, jack 5 Strap assem bly, 5,000-poun d capacity 4

Support assembly, ad ju stable 6 Strap assembly, 10,000-pound capacity 9

Supp ort assembly, fixed 7 Tie-down, cargo, 10,000-pound 4

Supp ort, jacking 5 Nose assembly, launching 6

Sling, steel, wire 1 Pedestal assembly, adjustable, MKII 2

Link Reinforcement Set Pin, anchorage* 10 Item description and quantity

Anchor assembly 4

Antiflutter tackle 5

Bag, equipment 2

Bar assem bly, launching 2


Bearer, footwalk 10Bracket, jacking 2

*

Capsill, bridging 1

Clip, retainer 150

Davit post assem bly 2

Footwalk, bridge 4

Hammer, hand, nylon 4

Jack, bridge, 20-ton 2

Link, launching, tw o-tier 3

Link, reinforcing, long 20

Link, reinforcing, short 4

MGB pallet, truck mounted -

Rear bumper assembly 1

Lug, tie-dow n, steel 8

Pin, bracing 22

Pin, capsill 3

Pin, launching 40

Post, footwalk 10

Post-tensioning assembly 4

Puller assembly, tirfor, T-35 2

Roller assembly, rocking 2Rope, guard 4

Seat, building fram e, jack 2

Tackle, light 20

Wrench, ratchet, 3/ 4-inch 2

Expendable Supplies and Materials(per bridge set)

Item description and unit of issue

Grease, autom otive lb can

Oil, lubr icating, GP, MIL-L-7870A gal canCoating compound, metal retreatment

can1 Primer coating, p henolic resin gal can

Enamel, alkyd, camouflage forest greencan

Strap assem bly, 5,000-poun d capacity 4 Enamel, lustreless, white gal can

Strap assembly, 10,000-pound capacity 9 Walkway compou nd, OD gal can

Tie-down, cargo, 10,000-pound 2 Cleaning solvent gal can

gal

gal

MGB pallet, trailer mou nted - 1 Lumber, softwood, 3 x 8 x 14 40 each

Adapter, pallet 1 required. Cut into lengths to obtain:144 pieces 3 x 8 x 36Bracket, adapter, with hardware 1 4 pieces 3 x 8 x 84

Transfer to bridge erection set.[Items with separate NSNs that together with other item(s) in brackets comprise an assembly.

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MG B DESIGN

STEP 1. Measure th e angle ofrepose (AR) gap. This stepis comm on to all length sand configurations.

Select a b ridge centerline.The centerline should extend froma point app roximately 15.2m onthe far bank to a pointapproximately 45.7m on the nearbank. This will ensure tha t thereis space on the far bank forvehicle egress and sp ace on thenear ban k for the R distance ofany brid ge length. There shou ldbe sufficient clear area extending

out 3.0m on both sides of thecenterline for its full length toallow for bridge construction.

Determine the location of firmground on the near and far banks.

(1) For the field method ofdetermining firm grou nd , assumethe AR of the soil to be 45degrees.

(2) At the edge of firm groundon the near bank, place the Apeg. At the edge of firm groundon the far bank, place the A peg.

The distance between th e twopegs is know n as the AR gap.Keep in m ind that th e MGB mu stnot bear on the ground at eitherend for more than 2.1 m (SS) or2.3m (DS), regardless of itslength.

If actual slope of bank doesnot exceed 45 degreeshorizontal, place A and A' pegsas shown in a or b below.

If actual slope of bank doesexceed 45 degrees from thehorizon tal, place A and A pegs adistance H from the toe of slopewhich is equal to the height of thebank measu red from the toe ofslope to the top of the gap, asshown in c below.

NOTE: Gaps below are show nwith one prepared and one

unprepared abutment. Actualsites may be any combination ofexamples shown.

c. Measure the d istance from

the edge of firm grou nd on th enear ban k (A' peg locatlon) to theedge of firm grou nd on the farbank (A peg location) using oneof the methods described below.This distance is know n as the A Rgap.

(1) Triangulation m ethod .

(2) A string line with a weightattached thrown across the gapan d measured while beingretrieved.

(3) If in a relatively secure areaand site cond itions allow, a tapemeasure should be used.

d. Select the typ e of bridge tobe built, based on resourcesavailable, the MLC desired , andthe AR gap.

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Chapter 2

M G B 4-12 BAY SS D ESIG N

STEP 1. Measure the AR gap (see page 5).

STEP 2. Select a bridge.Using column (a) ofTable 1 or 2, (shown on

page 7) choose a bridge length wh ose AR gaprange brackets the AR gap m easured . Alway sselect the smallest range possible to avoidwasting assets. For example, if the AR gapmea sured 9.5m, choose the AR gap range of 7.4mto 9.8m, even though the range of 9.2m to 11.6malso meets the criteria. Read the bay configurationcolumn (c), and check the MLC of the bridgecolumn (d) to ensure that it meets what isspecified by the tasking authority.

STEP 3. Read the bridge length column (b).

STEP 4. Read and note the R distance column (f).

STEP 5. Read and note the nose configurationcolumn (e).

STEP 6. Identify key construction points asfollows:

F peg Designates the approximate location ofthe far bank bankseat beam. Initially placed 0.9mfrom A peg on far bank.

RB peg Designates the position of the rollerbeam (RB). It may be located in on e of tw odifferent positions depend ing up on launch m ethodused , push launch (4 through 8 bays) or jacklaunch (4 through 12 bays).

NOTE: Push launches are to be performed only inan actual wartime bridge operation. Pushlaunches are no longer performed for trainingor demon stration pu rposes.

Push launch - The d istance to the RB peg iscalculated by using the position of the A peg onthe near bank, the brid ge length (L), AR gap,

minimum bearing requirement (0.9m), and theapp roximate distance the bridge falls in front ofthe roller beam (0.23 m). This distance is X.

X = (bridge length + 0.23m) - (AR gap +0.9m)

NOTE: To adhere to minimum / maximum bearingrules without having to dig out or pack up und erthe end of bridge, you must ensure that the RBpeg is placed between 1.113m and 2.33m fromthe A peg.

Jack launch -The d istance to the RB peg is

calculated by using the position of A peg on thenear bank, the bridge length, AR gap, minimumbearing requirement (0.9m), and the approximatedistance required behind the roller beam to attach

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the jacks (0.23m). This distance is X. O peg Marks the clear distance behind theX = (bridge length - 0.23m) - (AR gap + 0.9m) roller beam required to construct the bridge. It is

NOTE: To adhere to minimum/ maximum bearingpositioned by measuring the R distance, Table 1or 2, column (f), behind the RB peg.

rules without having to dig out or p ack up und er Adjust the position of the F peg, if required, andthe end of bridge, you must ensure that the RB determine the final position of the bridge on thepeg is p laced betw een 0.67m and 1.87m from the

near bank (F peg).A peg.

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N O TES: (These notes apply to both Table 1 an dTable 2.)

1.

2.

.

4.

An extra 0.075m of clearance can be obta inedby lifting on the nose to remove the pin sag.Where levels are estimated , this should not betaken into accoun t du ring design but left to

compensate for any errors in calculating thevalue of H (for SS 4 through 8 bays).

An extra 0.6m of clearance can be obtained bylifting on the nose to remove the pin sag (for SS9 through 12 bays).

Any additional packing under the RB willincrease the vertical interval N by three timesthe thickness of the packing. For example, if thepacking is 0.075m thick, N w ill be increased by0.225m.

The table incorporates an allowance to ensu rethat the nose clears the landing roller (LR) whenit is positioned 0.230m in fron t of poin t F.Bearing Check. The minimum/ maximum

bearings for-any SS bridge u p to an d includ ing 12bays are shown in Table 3.

To calculate the a ctual locations of the F and Fpegs, the following procedur e is used:Near bank bearing =bridge length - (AR gap + 0.9m) where

Bridge length is obtained from column (b) ofTable 1 or 2.

The AR gap was measured by you in the firststep of this design procedure.

An assum ption of 0.9m is made at this point inthe calculation sequence because we knowthat this is the minimu m acceptable bearing

allowable on the far bank.If the near bank bearing is within acceptable

limits, you do not have to ad just the p osition of theF peg. Its final p osition will be the initial value th atyou assumed of 0.9m from the A peg. The F pegwill be located at a d istance equal to the n ear

bank bearing measured from the A peg on nearbank.

If the near bank bearing is greater than themaximum allowable (2.1m), you must do one ofthe following:

Move the F peg further away from its present

assum ed location to a point wh ere the amoun t ofbearing on the near bank is less than or equal to2.1m, and greater than or equal to 0.9m. This willallow the F peg to be placed at a suitabledistance from the A peg. The RB peg m ust bemoved toward the gap the same d istance the Fpeg is moved away from the gap. This will alsomove the O peg towards the gap.

Dig out the soil from the near bank until themaximum allowable bearing is not exceeded.

Crib up un der the end of bridge up on

completion.Physically locate the key constru ction points on

the groun d a nd take elevations relative to the RBpeg.

Locate O, RB, F, F, A, and A pegs. Estimateelevations of F and O p egs relative to the RB peg.A positive value ind icates a point higher th an theRB peg an d a negative value indicates a valuelower th an th e RB peg. The RB peg w ill alwa ys be0.0 elevation. Place the elevations on the baselineas shown in Figur e 3.

Push launch:X = (L + 0.23m) - (AR gap + 0.9m)

Jack launch:X = (L- 0.23m) - (AR gap + 0.9m)

Check bearing to make sure you have not mad ea mistake.

Bearing FB + AR gap + Bearing NB = L

The critical points a nd definitions u sed inplanning, designing, construction and launchingof single-span MGB areas shown in Figure 4.

STEP 7. Slope check.Ensure that the difference in elevation between

the F and F peg does not exceed one-tenth of thetotal bridge length. If it does, you will have to cribup , und ertake a m ajor construction project, orchoose another centerline.



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STEP 8. Calculate the far ban k height (H ) relativeto a baseline drawn through the ground levelat the RB and O pegs as follows:

H = HtF +[HtO x (L A0.23)] + 0.23 if push launchR distance -0.23 if jack lau nch

STEP 9. Launch design:4 through 8 bays:

RB pa cking. From Table 1 (page 7), columns (i)and (j), choose a n ose lift N wh ich is greater thanH. If none is available, add itional packing will berequired u nder the d eck unit (DU) (Table 1 andnote 3 on p age 8).

From column (i) an d (j) or by calculation,determine the amou nt of packing required for thenose lift (N) required.

9 through 12 bays:

Choose an LNCG setting from Table 2, columns(g), (h), (i), (j), (k), or (l) to give a n ose lift Ngreater than H.

If N is not gr eater than H, see note 3 (page 8) toincrease N by add itional packing.

STEP 10. Loads required. From Table 4,determine the tru ck and trailer loads requiredfor the bridge.

STEP 11. From Table 5, extract the followinginformation:Construction time

Manpower requirements

STEP 12. Final design:Bays

LNCG setting

Packing required

Bearing : NB FB

Truck and trailer loads

Manpower required

Time to construct



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CHAPTER 3

M G B 1-12 BAY D S D ESIG N

STEP 1. Measure the A R gap (see page 5).STEP 2. Select a bridge.

Using column (a) ofTable 6, on page 12,choose a bridge length wh ose AR gap r angebrackets the AR gap m easured . Always select thesmallest range possible to avoid w asting assets.For example, if the AR gap measured 16.2m,choose the AR gap range of 14.0m to 16.3m, eventhough the range of 15.8m to 18.1m also meetsthe criteria. Read the bay configuration column(c), and check the MLC of the bridge column (d)to ensure that it meets what is specified by the

tasking authority.STEP 3. Read the bridge length column (b).

STEP 4. Read and note the R distance column (f).

STEP 5. Read and note the nose constructioncolumn (e).

STEP 6. Identify key construction points.These points are constant for any DS bridgeconstruction u p to and includ ing 2E + 12 bays(Figure 5).

F peg - Designates the approximate location ofthe far ba nk bankseat beam . Initially placed 0.9mfrom A peg on far bank.

FRB peg - Designates the position of the frontroller beam (FRB). It is placed 0.9m from the Apeg on the near bank as measured to thecenterline of the roller beam.

RRB peg - designates the position of the rearroller beam (RRB). It is p laced 4.6m from the FRB(measured to .

O peg - Marks the clear distance behind th efront roller beam requ ired to construct the bridge.It is positioned by measuring the R distance, Table6, column (f), behind the FRB peg.

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Bearing Check. The minimum/ maximumbearings for any DS bridge up to and including 2E+ 12 bays are sh own in Table 7.

To calculate the actua l locations of the F and Fpegs, the following procedu re is used:

Near bank bearing =bridge length - (AR gap + 0.9m) where

Bridge length is obtained from column (b) ofTable 6.


An assumption of 0.9m is made at this point inthe calculation sequence because we knowthat this is the minimum acceptable bearingallowed on the far bank.

If the near bank bearing is within acceptablelimits, you do n ot have to ad just the p osition of theF peg. Its final position will be the initial value thatyou assumed of 0.9m from the A peg. The F pegwill be located at a d istance equal to the n ear bankbearing measu red from the A peg on th e nearbank.

If the near ban k bearing is greater than themaximum allowable (2.3m), you must do one ofthe following:

Move the F peg further away from its presentlocation to a point w here the amou nt of bearing onthe near bank is less than or equal to 2.3m, and

greater than or equal to 1.4m. This will allow theF peg to be p laced a t a suitable distance from theA peg.

Crib up the near bank end of bridge to wherethe maximu m allowable bearing is not exceeded.


Physically locate the key construction points(Figure 6) on the ground and take elevationsrelative to the FRB.

Locate O, RRB, F, FRB, A, A, and F pegs on

the groun d along the centerline of the bridge.Estimate elevations of F, RRB, and O p egs

relative to the FRB peg. Positive value ind icatesthat a point is above the FRB peg and a negativevalue ind icates that a p oint is below th e FRB peg.The FRB peg will always be 0.0 elevation.

Place the key construction point elevations anddistances on the baseline below (Figure 6).

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STEP 7. Slope check.Ensure that the difference in elevation between

the F and F pegs d oes not exceed on e-tenth ofthe total bridge length. If it does, you are eithergoing to have to crib up , un dertake a m ajorconstruction project, or choose anothercenterline. Note that th e elevation of the F pegcannot be lower than the elevation of the FRB orthe bridge will not receive full bearing. In thesecases, the normal procedure is to crib up or fill inun til the elevation of the F peg is at least as highas the FRB. Otherwise, you would have to removethe soil next to the ba nk to the level of the F peg,This rule also applies to the F peg.

STEP 8.Calculate the far bank height (H), near bank tail

clearance (G) relative to the baseline, and the

distance of water below a line joining FRB and F(C) using these formulas:H= HtF + H tRRB X (L - 0.5)

4.6G = H tO - Ht RRB x R distance

4.6C = HtW L - Ht F x W d istance

(L - 0.5)

STEP 9.RULE 1If both bank heights are greater than 0.6m

above the waterline, go to RULE 2. See Table 6,pag e 12.

If either or both bank heights are less than

0.6m from the waterline, choose an LN CG settingfrom colum n (h), (i), or (j) so that C is greaterthan D to avoid immersion in water, and go toRULE 2.

If C is greater than D, go to RULE 2.

If C is not greater than D and the water is notflowing, go to RULE 2.

If C is not greater than D and immersion inwater is less than 0.3m and th e current speed isless than 5 meters p er second (reps), it is notessential to adjust the LNCG setting. Therefore, go

to RULE 2.If C is not greater than D and the current speed

is greater than 5 mps, another site must bechosen.

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STEP 10.RULE 2Using the LNCG settings from RULE 1, choose a

setting from column (l), (m), or (n) (whichever isallowable from RULE 1 ) which gives an N greaterthan H. If none of the choices meet the criterion,choose the highest value available.

Check to see if the T value from colum n (k)isgreater than G. If N is not greater than H, or if Tis not greater than G, proceed to RULE 3.

If N is greater than H and T is greater than G, theLNCG setting chosen has adequate nose lift andthe brid ge selected h as ad equate tail clearance.

STEP 11.RULE 3Raise both the FRB and RRB by 0.69m to

increase nose clearance (N) and tail clearance (T).

N RULE 3 = N RULE 2 + 0.69m

T RULE 3 = Value obtained from column (p).

If N RULE 3 is not greater than H and TRULE 3 is greater than G, proceed to RULE 4a,

colum n (q)

If N RULE 3 is greater than H and T RULE3 is not greater than G, proceed to RULE 4b,column (r).

If N RULE 3 is greater than H and T RULE 3 isgreater than G, the bridge has adequate nose andtail clearance for launching.

STEP 12. RULE 4aLowering the RRB. If there is ample tall

clearance, some increase in N can be obtained bykeeping the FRB in its highest position andlowering the RRB to its lowest p osition. Themathematical equation for this process is shown

under column (q).N RULE 4a = N RULE 3 + Value N calculatedfrom the equation shown under column (q).

T RULE 4a = T RULE 3

STEP 13.RULE 4bLowering the FRB. If there is ample nose

clearance, some increase in T can be obtained bykeeping the RRB in its highest position andlowering the FRB to its lowest p osition. Themathematical equation for this process is shown

under column (r).T RULE 4b = T RULE 3 + Value T calculated fromthe equation shown und er column (r).

N RULE 4b = N RULE 3

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CHAPTER 4

M G B 13-22 BAYS WITH O UT LRS(where water level or any obstructions are

at least 2.7m below bank heights)

STEP 1. Measu re the AR gap (see page 5). 34.1m to 36.4m also meets the criteria. Read thebay configuration column (c). Check the MLC of

STEP 2. Select a bridge. the bridge colum n (d) to ensure that it meets whatUsing column (a) of Table 10, choose a bridge is specified by the tasking authority.

whose AR gap range brackets the AR gapmeasu red. Always select the sm allest range STEP 3. Read the bridge length column (b).possible to avoid wasting assets. For examp le, ifthe AR gap m easured 34.2m, choose the AR gap STEP 4. Read th e R distance colum n (f).range of 32.3m to 34.6m, even thou gh th e range of

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STEP 5. Read and note the nose constructioncolumn (e).

STEP 6. Identify key construction points.These are constant for any DS bridge

construction 13 through 22 bays withou t LRS(Figu re 7).

F peg Designates the approximate locationof the far ban k end of bridge. It is initially p laced0.9. from A p eg on far ban k.

CRB pe g Designates the location of thecapsill roller beam. It is placed 0.9m from the Apeg on n ear bank as measured to the centerline ofthe capsill roller beam.

FRB peg Designates the location of the frontroller beam. It is placed 9.1m from the CRB peg tothe centerline of the front roller beam.

RRB peg Designates the location of the rearroller beam. It is placed 4.6m from the the FRB

peg (measured centerline to centerline).O peg Marks the clear distance behind the

capsill roller beam required to construct thebridge. It is positioned by measuring the Rdistance, Table 10, column (f), behind the CRBpeg.

Bearing Check. The minimum/ maximumbearings for any DS bridge 2E + 13 throu gh 2E +

22 bays are shown in Table 11.To calculate the actua l locations of the F and F

pegs, the following procedu re is used:

Near bank bearing =bridge length - (AR gap + 0.9m) where

Bridge length is obtained from colum n (b) ofTable 10.


An assumption of 0.9m is made at this point in

the calculation sequence because we knowthat this is the m inimum acceptable bearingallowed on the far bank.

If the near bank bearing is within acceptablelimits, you do not hav e to ad just the position of theF peg. Its final position will be the initial value thatyou assumed of 0.9m from the A peg. The F peg

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will be located at a distance equal to the near bankbearing measured from the A peg on the nearbank.

If the near ban k bearing is greater than the

maximum allowable (2.3m), you m ust d o one ofthe following:

Move the F peg further away from its presentassumed location to a point where the amou nt ofbearing on near bank is less than or equal to2.3m , and greater than or equal to 1.4m . This w illallow the F peg to be p laced at a suitable distancefrom the A peg.

Crib up the near bank end of bridge until themaximum allowable bearing is not exceeded.


Physically locate the key construction points(Figure 8) on the ground and take elevationsrelative to the CRB peg.

Locate the O, RRB, FRB, CRB, F, A, A, and Fpegs on the ground along the centerline of thebridge.

Estim ate elevations of F, RRB, and O p egsrelative to the CRB. A positive value indicates thata point is above the CRB and a negative valueindicates that it is below thealways be 0.0 elevation.

Place the key constructionthe baseline below, Figure 8.

STEP 7. Slope check.

CRB. The CRB will

point elevations on

Ensure th at the d ifference in elevation betweenthe F and F pegs does not exceed one-tenth ofthe total bridge length , if it does, you w ill have tocrib up, u nd ertake a m ajor construction pr oject, orchoose another site. Note tha t the elevation of theF peg cannot be lower than the elevation of theCRB peg or the bridge will not receive full bearing.In these cases, the norm al procedu re is to crib u p

or fill in until the elevation of the F peg is at leastas high as the CRB peg. Otherwise, you wouldhave to remove the soil next to the bank to thelevel of the F peg. This same ru le app lies to the Fpeg.

MG B 13-22 Bays Withou t LRS 19


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FM 5-212

STEP 8.Calculate the far bank height (H) and the near bank tall clearance (G) relative to the baseline using these

formulas:H = HtF + HtRRB x (L - 0.5)

13.7G = H tO - H tRRB x R distance

13.7

STEP 9.RULE 1Use an LNCG setting to give adequate nose

clearance (N) and tall clearance (T). See Table 10,pag e 17.

Choose a setting from column (h),(i), or (j)which gives an N greater than H. If none of thehree choices meet the criteria, choose th e highest

value available.

Check to see if the T value from colum n (g)isgreater th an G.

If N is not greater than H, proceed to RULE 2,or if T is not greater than G, proceed to RULE 2.

If N is greater than H and T is greater than G,the LNCG setting chosen has ad equate noseclearance and the bridge selected has adequateail clearance.

STEP 10. RULE 2Raise both the capsill roller beam (CRB) and

rear roller beam (RRB) by 0.253m to increasenose clearance (N) an d tail clearance (T).

N RULE 2 = Value obtained from colum n (k).

T RULE 2 = Value obtained from column (l).

If N RULE 2 is not greater than H and T RULE 2is greater than G, proceed to RULE 3a.

If N RULE 2 is greater than H and T RULE 2 isnot greater than G, proceed to RULE 3b.

If N RULE 2 is greater than H and T RULE 2 isgreater than G, the bridge has ad equate noseand tail clearance for laun ching.

STEP 11. RULE 3

Lowering the RRB. If there is ample tallclearance, some increase in N can be obtained bykeeping the CRB in its highest position andlower lng th e RRB to its lowest p osition. Themath ematical equation for this p rocess is shownunder column (m).

N RULE 3a = N RULE 2 + Value N calculatedfrom the equation shown u nder column (m).

STEP 12.RULE 3bLowering the CRB. If there is ample nose

clearance, some increase in T can be obtained bykeeping the RRB in its highest position andlower ing th e CRB to its lowest p osition. Themath ematical equation for this p rocess is shownunder column (n).

T RULE 3b = T RULE 2 + Value calculatedfrom the equation shown und er colum n (n).

20 MGB 13-22 Bays Wi thout LRS


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STEP 13. Loads required. STEP 15. Final design:From Table 12, determine the the tru ck and 2E +

trailer loads required for the bridge. LNCG setting

bays

STEP 14. From Table 13, extract the following CRB settinginformation:

Construction time RRB setting

Manpower requirements Bearing: NB FB


Manpower required

Time to construct

MG B 13-22 Bays Without LRS 21


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CHAPTER 5

M G B 13-22 BAYS WITH LRS(where water level or any obstructions

are at least 3.7m below bank heights)

STEP 1. Measure the AR gap (see page 5).

STEP 2. Select a bridge.Using colum n (a) ofTable 14, choose a bridge

whose AR gap range brackets the AR gapmeasu red. Alway s select the smallest rangepossible to avoid wasting assets. For example, ifthe AR gap measured 40.2m, choose the AR gaprange of 37.8m to 40.5m even though the range of

39.8m to 42.4m also meets the criteria. Read thebay configuration column (c). Check the MLC ofthe bridge column (d) to ensure that it meets whatis specified by the tasking au thority.

STEP 3. Read the bridge length column (b).

STEP 4. Read the R d istance column (f).

STEP 5. Read the nose construction colum n (e).

STEP 6. Identify key construction points.

These are constant for any DS bridgeconstruction 13 through 22 bays with LRS(Figure 9).

F peg Designates the approximate locationof the far ban k end of bridge. It is initially placedthe d istance shown und er far bank minimumcolumn, Table 15, from the AR peg on the farbank.

CRB peg Designates the location of theCRB. It is placed 2.7m from the A peg on the nearbank as measured to the centerline of the CRB.

FRB peg Designates th e location of the FRB.It is placed 9.1 m from the CRB peg to thecenterline of the FRB.

RRB peg Designates t he location o f the RRB.It is placed 4.6m from th e FRB peg (m easuredcenterline to centerline).

O peg Marks the clear distance behind theCRB required to construct the bridge. It ispositioned by m easuring the R d istance, Table 14,column (f) behind the CRB peg.

22 MGB 13-22 Bays Wi th LRS


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Bearing Check. The minimum/ maximumbearings for any D S bridg e 2E + 13 through 2E +22 bays are show n in Table 15.

To calculate the actu al locations of the F an d Fpegs, the following procedu re is used:

Near bank bearing =bridge length - (AR gap + far bank bearing)where

Bridge length is obtained from colum n (b) ofTable 14.


Far bank bearing is obtained from theappropriate column in Table 15.

If the near bank bearing is within acceptablelimits, you do n ot have to ad just the p osition of theF peg. Its final p osition w ill be the initial valueobtained from Table 15 as measu red from the A

MGB 13-22 Bays With LRS 23


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peg. The F peg w ill be located at a d istance equalto the near bank bearing measured from the Apeg on the near bank.

If the near ban k bearing is greater than themaximum allowable (2.3m), you m ust d o one of

the following:Move the F peg further away from its present

location to a point where the amoun t of bearingon near bank is less than or equ al to 2.3m andgreater than or equal to the value given in Table15 for minimum bearing.

Crib up the near bank end of bridge to wherethe maximum allowable bearing is not exceeded.

Dig out the soil from the near bank until themaximum allowable bearing is not exceeded .

Physically locate the key construction points

(Figure 10) on the ground and take elevationsrelative to the CRB peg. Locate the O, RRB, FRB,F, A, A, and F pegs on the grou nd along the

bridge centerline. Estimate elevations of F, RRB,and O pegs r elative to the CRB peg. A positivevalue ind icates a point is above the CRB peg an da negative value indicates it is below the CRB peg.The CRB peg will always be 0.0 elevation. Placekey construction point elevations on the baseline

(Figu re 10).

STEP 7. Slope check.Ensure th at the d ifference in elevation between

the F and F peg does not exceed one-twentieth ofthe total bridge length . If it does, you w ill have tocrib up, undertake a major construction project, orchoose another site. Note that the elevation of theF peg cannot be lower th an the elevation of theCRB peg or the brid ge will not receive full bearing.In these cases, the normal procedure is to crib upor fill in u ntil th e elevation o f the F peg is at leastas high as the CRB peg. Otherwise, you w ould

have to remove soil next to the bank, level with theF peg. This same rule applies to the F peg.

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STEP 8.Calculate the far bank height (H), and the near bank tall clearance (G) relative to the baseline.

H = HtF + H tRRB x (L - 0.5) G = HtO - HtRRB x R distance13.7 13.7

STEP 9. RULE 1Use the LNCG setting to give adequate nose

clearance (N) and tail clearance (T). See Table 14,pag e 23.

Choose a setting from column (h), (i), or (j)which gives an N greater th an H. If none of thethree choices meet the criteria, choose the highestvalue available.

Check to see if the va lue from colum n (g) isgreater than G.

If N is not greater than H or if T is not greaterthan G, pro ceed to RULE 2.

If N is greater than H and T is greater than G,the LNCG setting chosen has ad equate noseclearance and the bridge selected has adequatetail clearance.

STEP 10.RULE 2Lowering the RRB. If there is ample tail

clearance, some increase in N can be obtained by

keeping the CRB in its highest position andlower ing th e RRB to its lowest position. See Table14, column (k), for values.

STEP 11. Loads required.From Table 16, determine the truck and trailer

loads required for the bridge.

MG B 13-22 Bays With LRS 25


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STEP 12. From Table 17, extract the followinginformation:

Construction time


STEP 13. Final d esign:2E +

LNCG setting

CRB setting

RRB setting

Bearing: NB FB

bays


Manpower required

Time to construct

26 MGB 13-22 Bays With LRS


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CHAPTER 6

MGB DESIGN(all measurements

PRO FORMAare in meters)

SS 4 Throu gh 12 BaysGrid

Recon Officer

Map Ref

Unit MLC

1. Measure AR gap A to A

NOTE: Use Tables 18 or 19 (page 28) to obtainthe answ ers to the following:

2. Select bridge

3. Bridge length

4. R distance

5. Nose constru ction

6. Key construction points, dim ensions, andelevations. Calculate the distance from th eRB to th e A peg (X), wh ere

Push launch:X = (bridge length + 0.23m)

- (AR gap + 0.9m)Jack launch:X = (L- 0.23m) - (AR gap + 0.9m)

MG B Design Pro Forma 27


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28 MG B Design Pro Forma


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7. Slope check.Ensure that the difference in elevation between

the F and F peg does not exceed one-tenth of theactual bridge length . If it does, you will have to cribup, undertake a major construction project, or find

another centerline.

8. Calculate H:for push launch H = HtF + [HtO x (L + 0.23)]

R distancefor jack launch H = HtF + [HtO x (L - 0.23)]

R distance

9. Launch d esign:

10. Loads required.From Table 20, determine the truck and trailer


11. From Table 21, extract the followinginformation:

Construction time


12. Final design:Bays

LNCG setting

Packing required

Bearing: NB FB


Manpower required

Time to constru ct



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Grid

DS 2E + 1 Through 2E + 12 Bays

Recon Officer

Map Ref

Unit

1. Measure AR Gap A to A

NOTE: Use Table 22 to obtain the answers to thefollowing:

2. Select bridge

MLC

3. Bridge length

4. R distance

5. Nose construction

6. Key construction points, dimensions, andelevations (as shown below).


the F and F pegs d oes not exceed one-tenth ofthe total bridg e length. If it does, you w ill have tocrib up, undertake a major construction project, orfind another centerline.

8. Calculate C, H, and G:C = HtW L - HtF x W d istance

(L - 0.5)

H = HtF + HtRRB x (L - 0.5)4.6

G = H tO - H tRRB x R distance4.6

9.RULE 1. (if both bank heights > 0.6m, go toRULE 2.)

Choose an LNCG setting that ensures depth ofC > depth of D.

LNCG settings permitted

10.RULE 2. LNCG setting to give N > H andT >G.

Choose an LNCG setting so that N > H.

LNCG setting chosen

NOTE: The setting chosen cannot be lower thanthat chosen in RULE 1.if N H and/ or T G, go to RULE 3

11.RULE 3. Raise the FRB and RRB by 0.69mN RULE 3 = N RULE 2 + 0.69m N =

Check N Rule 3 > H Yes/ No

Check T > G Yes/ No colum n (p) T =

If Yes, design is OK.

if N RULE 3 H, go to RULE 4a.

if T RULE 3 G, go to RULE 4b.



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12.RULE 4a. Lower RRB 16. Final design:N RULE 4a = N RULE 3 + answ er to 2E + bayscolumn (q). Check N > H LNCG setting

13.RULE 4b. Lower FRB FRB setting

T RULE 4b = T RULE 3 + an swer to RRB settingcolumn (r). Check T > GBearing: NB FB



loads required for the bridge. Manpower required

15. From Table 24, extract the followingTime to construct

information:Construction time




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D S 2E + 13 Thro u gh 2E + 22 BaysWithout LRS

(wh ere water level or any obstru ctionsare at least 2.7m b elow b ank heigh ts)

Grid 1. Measure AR gap A to A

Recon Officer NOTE: Use Table 25 to obtain the answers to the

Map Ref following:

Unit 2. Select bridge. 2E + bays

MLC3. Bridge length

4. R distance

5. Nose construction



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6. Key construction points, dimensions, andelevations.


the F and F pegs does not exceed one-tenth ofthe total bridge length. If it does, you w ill hav e tocrib up , und ertake a ma jor construction pr oject, orfind another site.

8. Calculate H and G:H=

G=

HtF + HtRRB x (L - 0.5)13.7

HtO - HtRRB x R distance13.7

9.RULE 1. LNCG setting to give N > H and T> G.Choose an LNCG setting so that N > H.LNCG setting chosenThen check If T > GIf N > H and / or T > G, go to RULE 2.

10.RULE 2. Raise the CRB and RRB by 0.253mCheck N > H Yes/ No column (k)Check T > G Yes/ No colum n (l)If Yes, design is OK.If N H, go to RULE 3a.If T G, go to RULE 3b.

11.RULE 3a. Lower RRBN RULE 3a = N RULE 2 + answer tocolumn (m) Check N > H

12.RULE 3b. Lower CRBT RULE 3b = T RULE 2 + answ er tocolum n (n) Check T > G





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Construction time


15. Final design:2E +

LNCG setting

CRB setting

RRB setting

Bearing: NB FB


Manpower required

Time to construct

bays



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D S 2E + 13 Thr ou gh 2E + 22 BaysWith LRS

(where w ater level or any ob structionsare at least 3.7m b elow b ank heigh ts)

GridRecon Officer

Map Ref

Unit

MLC

1. Measure AR gap A to A

NOTE: Use Table 28 to obtain the answers to thefollowing:

2. Select a bridge

3. Bridge length

4. R distance

5. Nose constru ction



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6. Key construction points, dimensions, andelevations.


the F and F peg does not exceed one-twentieth ofthe total bridge length . If it does, you w ill have tocrib u p, un dertak e a ma jor construction p roject, orfind another centerline.

8. Calculate H and GH = HtF + HtRRB x (L - 0.5)

13.7

G = HtO - HtRRB x R distance13.7

9.RULE 1. LNCG setting to give N > H and T > G.Choose an LNCG setting to give N > H.

If N H, go to RULE 2. If T G, choose anothersite, or prepare to d ig out und er NB end of bridge

prior to launch.

10.RULE 2. Lower RRBN Ru le 2 = N RULE 1 + answer to

column (k) Check N > H





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Construction time


13. Final design:2E + bays

LNCG setting

CRB setting

RRB settingBearing: NB FB


Manpower required

Time to construct

V Distance. The V distance, for delaunchingpu rposes, is the distance from th e FRB/ CRB to theLRP for DS bridges requiring a launching n ose.The V d istance must never exceed the distance

given in Table 31. Exceeding the V distance mayresult in failure of the launching nose.



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Appen dix A

Safety Rules (for all

Rule

1. Do not throw tie-down straps across loads orvehicles when strapping or unstrapping loads.

2. Do not drop, throw, or shove components offloads or vehicles.

3. Always check all tie-down straps p rior tocrane-lifting pallets onto vehicles.

4. Check tightness of tie-down straps during

5.

6.

7.

8.

9.

convoy rest stops.

Do not drop pallets without rubber bumpers.

Do not pu t fingers or hand s into pin holes orbetween comp onents being m oved.

Ensure that all members of work p arty are fullyaware of action to take place prior to start ofaction.

Do not use any type of metal object to drivepins or shoot bolts. If a pin or shoot bolt has tobe driven, use a rubber/ nylon-faced ham mer ora block of wood.

Do not use carrying bars on bridge duringbooming procedures. USE HANDS ONLY ONBRIDGE.

10. Do not p osition yourself between girders du ringbooming of bridge. STAY OUTSID E OFGIRDERS.

11. Do not release roller locks until bridge is beingheld by manpower or vehicle.

12. Do not try to boom a brid ge larger than 2E + 8bays by man pow er. Always u se a 5-ton truck(loaded). If any doubt exists as to the ability ofwork party to boom by hand, USE A TRUCK.

13. Do not engage roller locks while bridge ismoving over rollers.

MGBs)

Reason

To prevent injury to personnel and damage toequipment.




To prevent damage to equipment.

To prevent injury to p ersonnel.


To prevent damage to equipment.

To prevent injury to personnel and damage topersonnel.

To prevent injury to personnel.



Roller locks will break, or bridge will skewover rollers.

App end ix A 41


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Rule Reason4. Ensure that all roller locks are engaged before To prevent injury to personnel and damage to

disconnecting vehicle from bridge. equipment.

5. Ensur e that jack seat is alwa ys positioned on To prevent injury to personnel and damage tosup por t pins or cap sill pins in holes 1, 2, or 3 equipment.from bottom of adjustable sup port. NEVERUSE HO LES 4, 5, OR 6 FOR JACK SEAT.

6. Monitor the jack-up of roller beams and / orcapsill to ensure that they are not jacked toohigh. The fixed p ins mu st never get w ithin2.5cm (1 inch) of the top of the ad justa blesupp ort vertical posts.


7. Ensure that a ll personnel are clear of the bridge To prevent injury to personn el.during booming/ launching/relaunching.

8. Ensure that the push vehicle is centered over To prevent dam age to equipm ent. Bridgebridge centerline and is in line with the bridge will skew over rollersthroughout the boom/ launch/ delaunch.

9. A lw ays u se a loaded veh icle (LRD load ) to To incr ease veh icle t raction.boom/ launch/ delaunch all DS bridges.

0. Always use the access holes in the side of the To prevent serious injury to p ersonnel.LRP to op erate the jack. Keep hand s and feet

clear of the LRP base wh en op erating th e jack.1. Ensure that the jack heads are p roperly seated To prevent damage to equipment.

in jack hoods prior to ap plying load to th e jack.

2. Ensure th at the jacks are prop erly placed for To prevent injury to personnel and damage tothe bridge that is being raised/ lowered. equipment.

3. Monitor jacking operation to ensure that the To prevent injury to personnel and damage tobridge is lowered/ raised as evenly as possible. equipment.

4. Use CG and boom m arkers in correct position Improp erly placed m arkers can result in bridgeat all times. tipping d own at the heavy end.

5. Never jack the near end of bridge if the far end LR and LRP are not equipped with a lock; br idge isis up on th e LR or LRP. free to roll.

42 Appendix A


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Rule26. Put lock pins in pan el, bracing, and nose pins

as identified below :

a. Bracing p ins - ALLb . Nose pins - ALLc. Panel pins ALL, except where bottompan el conn ects to top pan el. Shoot bolt jawtraps ridge on p in against panel.d . Head less panel pins - ALL, both ends of pin.Be especially wa tchful with the p ins in theLNCG and p osts.

27. Ensure that sup port p ins are fully seated in theadjustable supports.

28. Put lock pins in supp ort pins if bridge to beconstructed is 2E + 13 or larger.

29. During launching, the LRP mu st be placed atthe given (or higher) LZ nu mber w hen thepublished CG is over the roller which is nearestthe gap.

30. When delaun ching, check the V distance toensure that it does not exceed the V distancegiven in Table 31, page 39.

31. Jack on far bank on ly when n ear bank end ison locked rollers and PUSH BAR isDISCONN ECTED from BRIDGE.

ReasonPins can vibrate out at certain stages of

construction or as traffic crosses.

Jack seat bears on pin taper an d p ushes pin ou t.

To prevent pins from vibrating out.

Launching equipment w ill be overloaded .

Launching equipment w ill be overloaded .

Vertical movem ent is limited w hen vehicle isconnected.a. Jacking up un der n ose as it crosses far ban kmay buckle light n ose, overload nose crossgirder, or over-compress push bar.b . Jacking down may over tension push bar.Launch equipmen t will be overloaded .

Appen dix A 43


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Append ix B

MGB BUILDING, BOOM,AND DELAUNCH TABLES

This app end ix prov ides the MGB user w ith a complete set of building, boom ,and delaunch tables required to construct/ disassemble any length of MGB onthe various types of sites that may be encountered . It is limited to the bridgelengths that can be constructed with US Army MGB sets. It does not provideinstructions for MGBs constructed on piers or on floating sup ports.

It is strongly advised th at only experien ced u sers attemp t to use th isappen dix. Personn el new to the MG B must useTM 5-5420-272-72 for MGBan d TM 5-5420-212-12-1 for MGB with Link Reinforcement Set.

LIST O F TABLES PAGETable 33.Building and boom table 4through 8 bay single-story - normal site. . . . . . . . . . . . . . . . . . . . 45

Table 34.Delaunch table 4 through 8 baysingle-story - normal site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Table 35.Building and boom table 9 through 12bay single-story - norm al site . . . . . . . . . . . . . . . . . . . . . . . . 47

Table 36.Delaun ch table 9 throu gh 12 baysing le-story - norm al site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Table 37.Building and boom table 9 through 12bay sing le-story - restr icted site . . . . . . . . . . . . . . . . . . . . . . . . 49

Table 38.Delaunch table 9 through 12 bay

single-story- restricted site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50Table 39.Building and boom table 2E + 1through 2E + 12 bay double-story -norma l site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Table 40. Delaunch tab le 2E + 1 through2E + 12 bay dou ble-story- norm al site -near bank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Table 41.Delaunch table 2E + 1 through2E + 12 bay d ouble-story norm al site -original far bank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Table 42.Building and boom table 2E + 1through 2E + 12 bay double-story -restricted site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Table 43.Delaunch table 2E + 1 through2E + 12 bay dou ble-story restricted site -near bank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

PAGETable 44.Delaunch table 2E + 1 through2E + 12 bay double-story- restricted site -orig ina l far bank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Table 45.Building and boom table 2E + 13throu gh 2E + 22 bay d oub le-story (wo/ LRS) -normal site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

Table 46.Delaunch table 2E + 13 through2E + 22 bay d oub le-story (wo/ LRS) -normal site - near bank . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

Table 47.Delaunch table 2E + 13 through2E + 22 bay d ouble-story (wo/ LRS) -norm al site - original far bank . . . . . . . . . . . . . . . . . . .65

Table 48.Building and boom table 2E + 13throu gh 2E + 22 bay d ouble-story (w o/ LRS) -restricted site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

Table 49.Delaunch table 2E + 13 through2E + 22 bay d ouble-story (wo/ LRS) -restricted sitenear bank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

Table 50. Delaunch table 2E + 13 through2E + 22 bay d oub le-story (wo/ LRS) -restricted site original far bank . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

Table 51.Building and boom table 2E + 13throu gh 2E + 22 bay doub le-story (w/ LRS)

no rm al site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Table 52.Delaunch table 2E + 13 through2E + 22 bay d oub le-story (w/ LRS) - norma l sitenear bank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

44 Appendix B


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App end ix B 45


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46 Appendix B


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Appendix B 47


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48 Appen dix B


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App end ix B 49


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0 Appendix B


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App end ix B 51


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52 App end ix B


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Appendix B 5


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54 Appendix B


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Appendix B 55


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58 Appen dix B


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Append ix C

COUNTERWEIGHTS FOR MGBs

74 Appendix C


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GLOSSARY

ABBREVIATIONS, DEFINITIONS, ACRONYMS,AND BREVITY CODES

A Indicates edge of gap, far bank.

A Indicates edge of gap, near bank.

AA Anchor assembly.

AA(L) Long link of an chor assembly.

AA(S) Short link of anchor assem bly.

AF Antiflutter tackle.

AR Angle of repose w hich is marked on sitewith A (far bank) and A (near bank) pegs.

AR Gap - The distance from the ed ge of firmground (A) on the near bank to the edge of firmground (A) on the far bank.

BES Bridge erection set .

Boom M arker Carrying bar (painted orange)which marks th e position of the next booming orlaunching point.

BP Building pedestal (SS only), baseplate (SSand DS)

b rg bridge

BSB Bankseat beam.

C Distance of wat er below line joining FRB andF at distance W from FRB (negative). Fine for upto 2E + 12 bays. For 2E + 13 through 2E + 22bays DS bridges, a CRB is required.

CG Marker Carrying bar (painted blue) whichmarks the center of gravity of the bridge duringconstruction.

cm centimeter

cntr counter

conf configuration

const construction

CRB Capsill roller beam . This type of rollerbeam must be used for 2E + 13 through 2E + 22bays DS bridges with or without LRS.

Centerline.

D Deflection of bridge during launch in relationto line joining FRB and F pegs.

d el delaunch

dist distance

D S Double-story bridge construction.

DU Deck unit.

E End of bridge.

elev elevation

F Final position of the far end of bridge asmarked w ith the F peg.

F Final position of the near end of bridge asmarked with the F peg.

FB Far ban k

FRB Front roller beam.

G Distance between O p eg and baseline.

ga l gallon

H Far bank height at F peg, relative to thebaseline.

H t Height.

k g kilogram

L Length of bridge.

LAU Launch.

lb pound

lgth length

LLN Light launching nose.

LNCG Launching nose cross girder,

LN H Launching n ose heavy.

LR Land ing roller. Used by itself for 4 throu gh 8bays of SS. Used in LRP for all other bridgelengths.

LRD Long ramp and deck pallet. This is lastpallet to be off-loaded on a bridge site. Should beloaded onto p ush v ehicle to maintain a prop ercounterweight.

Glossary 77


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LRP Landing roller ped estal (MK I for 2E + 1through 2E + 12 bays DS, MK II for 2E + 13through 2E + 22 bays DS with or without LRS).

LRS Link reinforcemen t set.

LT Light tackle.

LZ Land ing zone.

m meter

max maximum

MGB med ium girder bridge

min minimum

MLC Military load class.

mps meters per second

N Nose tip height above baseline.

N 1 Laun ching n ose heavy, one story high.N 2 Launching nose heavy, two stories high.

N B Near bank

NCQ noncommissioned officer

N SN national stock num ber

O Distance R from RB (single-story), FRB(double-story), and CRB (double-story with orwithout LRS) as marked w ith the O peg.

PT Post-tensioning assembly.

R Maximum distance to the rear of the bridgeduring construction (excluding push bar andvehicle).

RB Roller beam.

rcvr recover

rem remove

RRB Rear roller beam.

spec special

SS Single-story bridge construction.

T Height of near bank end of bridge in relationto baseline.

thru through

TM technical manu al

V For relaunching purposes, the maximumallowable d istance between the FRB or CRB tothe LRP for bridges requ iring a launching n ose.

W Distance of end taper panel from FRB formaximum deflection.

WL Waterline.

wt weight

1LL One long reinforcing link.

1SL One short reinforcing link.

6N1, 7N1, and 8N 1 Types of single-story noseconstruction. The first nu mber show s the nu mberof heavy nose sections u sed. The N1 mean s

single-story nose.6N1 + 3N2 Type of doub le-story noseconstruction. The 6N1 is explained above. The3N2 means th at three h eavy nose sections areused in second story. The N2 means double-storynose.

2 + 3 + or 8 throu gh 10 Describes nu mberof bays to be added or removed. The 2 + 3 +means add second and third bays, or removethird and second bays if numbers reversed, 3 +2+. Similarly, the 8 through 10 means add bays 8through 10, or remove bays 10 through 8, if

reversed.Boom to Movement of bridge until panel pointgiven is over RB (for SS) or RRB (for DS).

Laun ch to Movement of bridge un til pan elpoint given is over RB, FRB, or CRB.

3D, 8D, 20D, 27D + 6C, and 37D + 6C Counterweight codes giving the number of deckunits and curbs used.

(4p0), (2p4), and (Bp3) Examples of the waythat the center of gravity (CG) is shown.

SYMBOLSis greater than is less than

is greater than or equal to is less than or equal to

is not greater than

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REFERENCES

REQUIRED PUBLICATIONSRequired publications are sources that users

must read in order to und erstand or to complywith this publication.

Technical Manuals (TMs)5-5420-212-12 Operator and Organizational

Maintenance Manual for M edium Girder Bridge(MGB)

5-5420-212-12-1 Operator and OrganizationalMaintenance Manual Link R einforcement Set forthe Medium Girder Bridge

RELATED PUBLICATIONSRelated publications are sources of additional

information. They are not requ ired in ord er tounderstand this publication.

Military Engineering Volume III, Part III, MediumGirder Bridge, Army Code No 71133, British A rmy.This pu blication is av ailable from the Pu blicationsSection, Headquarters, Royal School of MilitaryEngineering, Brompton Barracks, Chatham, Kent,England, ME3 8NQ .

U. S. GOVERNMENT PRINTING OFFICE 1989/627-027/80150

References 79


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By ord er of the Secretary of the A rmyFM 5-212

7 FEBRUARY 1989

CARL E. VUON OGeneral, United States Army

Chief of Staff

Official

WILLIAM J. MEEHAN II

Brigadier General, United States ArmyThe Adjutant General

Distribution:Active A rmy, USAR and AR N G: To be d istributed in accordan ce w ith DA Form 12-25A,requirements for TM 5-5420-212-12, Operator and Organizational Maintenance Manual forMedium Girder Bridge, (Qty rqr block no. 292).


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