rlasuecjwith Army

Wa1943 SHEAVY PONTOON BRIDGE

FOR USE BY

IIECIIANIOAL TRANSPORT.

(PROVISIONAL.) ../

1914.

‘,‘- ,.\.,“

L 0 ON1!IUNTJID UNDER TITH AUTHORITY OF HIS MAJESTY’S STATIONERY OFFICH

fly lIARhfJSON SONS, 45-47, S~.M,IISTIN’S LLIE, W.V.,P!wsra~ssme OanueA~TO HIs MAjr4ry.

Tobe purchase4.eItherdirectlyorthron~hany l3ooksel!er,frontWYMAN AND SONS, LTI)., 29, ENEAMS DrJIL1)INOS, 1~ETrEMLAsie, E.C., and

M, ST. MARY STarEr,CAIWIFI’; orILM. STATIONERY OFFICE (Scorrism fiNANCE), 53, Fowrfl STaRE?,EDINISuRGII; or

11. PONSONIIY, Lw., 116, GRArroN STarE?, D~’Hit’(orfrom theAgenciesin theBritieii Coloniesaol Depen~iencie~.

the thsite4 States of America, the Continent of Enropoand Abroad ofT, FIShIER UNWIN, LocDoN, W.V.

Price Twopence.

for use by Ivleohauioal~ Trausport.

(PROVISIONAL.)

GENERAL INSTRUCTIONS.

1. Pending the issue of “Military Engineering, Part III(n),” the following provisional instructionsare issuedin regard.to the construction of a pontoon bridge suitable for use bymechanicaltransport.

2. These instructions replacethose dealingwith the heavybridge describedin “Military Engineering,Part III (1002),”pages141 to 143.

3. The heaviestvehicle which this bridge is designed tocarryis a light tractor weighing 7~tons, with S tons on tilerearaxle anda wheelbaseof 7’ 6”.

The width of the trackof the differentmechanicaltrunsport’vehicles which the bridge is required to carry, vary from aminimumof 5’ ‘2k” to a hnaXilflUIn of 7’. rFhe maximum turningradiusof thesevehiclesis 48’.

4. Thisbridge maybe usedin streamswith acurre~tup to 4milesper hour.

The time taken to make it is approximately twice thatrequiredfor a mediumbridgeof the samelength.

The details areshown in PlatesI and II.5. Each pier consistsof One complete pontoon. i.e. two

sectionsjoined together. The pontoonsare placed7’ 6” apartfrom centre to centre. Trestles when used will be placed at7’ 6” intervals.

6. The roadway is carried on 14 baulks, arranged asfollows;—

1. A groupof 6 plain baniksunder each wheel track.ii. Onebutton baulk outsideeachgroup.

Eachof the groups of baniks in (i) will l)e arrangedin twosets of three,separatedby the third pail’ of cleatsreckonedfromthecentreof the saddle-beam.

The outsidebaniks of eachgroup will be placed 3’ 6” fromthe centreof thesaddle-beams. The insidebaulksof eachgroupwill be ribands.

r2hebaulks in (ii) should be button baulks, as these rendertheroadwaymoresecureagainstshifting undera load(Plate 11).

(a 10847) Wt. 502—622 2000 4/14 H &S P. 13)208

3

If buttonbaulksare not available,plain baulksmust be used.Thesebaulkswill be placedsoas to comeundertheends of thechessesasdescribedfor mediumbridge.

The baulkswill be soplacedas to break joint in consecutive‘bays. This will necessitatethe useof 7 half baulks on eachendof thefloating portion of the bridge. Fourteenhalf baulks arebeingsuppliedto eachBridging Trainfor thispurpose.(PlatesIand11.)

If the floating portion of the bridge consistsof an oddnumber of bays, 2 half-button baulks,and 2 half ribands forwheel guides, will be required in addition. Until these arereceived,local arrangementsmust be made.

7. The roadwayis doublechessed,andthe chessesare laceddown to thehaulks with 1k” lashings,which are beingaddedtothe bridging train equipmentfor the purpose. (PlateII.)

8. Ftibandsareplacedaswheelguides3’ 9” from thecentreofthe bridge, thus giving a roadwayof 7’ 6” in the clear. Theyare held in position by 3 drop bolts each,which are droppedthroughholes bored through the ribands and chesses. Theseboltsare i-inch diameter,13 incheslong, with 1~inch cheeseheads,andstepsare being taken for eachpontoon and trestlewagon of the bridging train to carry 3 such bolts. tJntil~thesoare supplied,temporaryexpedientsmusthe used. Ribandsandchessesof future supplieswill tie bored with the necessaryholes;in themeantime,equipmentheldon chargemust be boredas follows ~vhierirequiredfor heavybridge

(a) Ribands—3holes ~“ diameter; one at the centre andoneat a distanceof ñ’ on eachside of the centre.

(b) Chesses—2holes 1~”x ~“ at a distanceof 3’ tog”from the centre of the chess, measured along itslongitudinal axis—the dimension1~”being iiieasnredacrossthe chess. (Plate I, fig. 2.)

At each shore end the wheel guides should be slightlysplayeduntil theyform a roadway10’ wide on theshore,sothatthedriving of vehicleson to the bridge may be facilitated.

Theequipmentof the bridging train is beingincreasedso asto carry enoughinat~rialto make125 yardsof this bridge.

9. The design of a suitable shore transom is underconsideration, but until issued, temporaryexpedientamust beused.

(n 10847) A2

4

DRILL FOR “FORMING’ UP” HEAVY BRIDG~I.

Forming L~TTEhi youn As for medium bridge.up in quick DETACUMENIStime. FROM ~

I’RONT.ARRANGE AND As for medium bridge.NUMIIER YOURI’ETACUMENTS.

i~ QUICK At the command’”FORM hEAVY BRIDGE” G.2.TIME FORM and G.3. bring up the shoretransom,and with

hEAVY theassistanceof G.6. andG.7. fix it in position.BRIDGE. 11.0. and his detachmentreceivethe pontoons

frotii the unpackingdivisions,and11.0. will mark,with chalk, the cleatsof thesaddlebeamsin whichthe baulks are to be placed. 11.0. directs twopontoonsto be brought up. 11.2. and 11.3. willsecurethesaddle-beamsto thebelayingcleatsonthe centralp~irtitionof the pontoon by ni~ansofa one-inchlashingpassedthrough No. 1 cleat,andtile hinged strapson the bow and stern tlmwarts~11.1. attachesthe warping hues to the secondhandlefrom the front of all successivepontoons.‘fiey are warped into position by the remnaining~numbersof H detachment.

1.6., 1.7., J.6.,J.7. place theshoreanchorsandbring the eiotsof thecablesto tuesecondpontoon.The remainderof I and J detachmentsform th&crews of the anchor boats. In each casethecommandertakesthesteeringoar. 1 and 3 pufl

NoTEs.

In making a heavybridgethe bridging party will consist ofthe same nutribers and will be organized into the samedetachmentsashas alreadybeendescribedfor medium bridge.Thedutiesof the detachmentswill be generallythe same.

‘I’he slowestpart of thework is placing the baulks, and thismnrust bedonecarefully, and cannot be hurried. Heavybridgeswill notbe madein double timefor this reason.

heavy bridge must be made either by “Forming up” or“Swinging,” but IU tile lattercasethe bridgemustbeconstructedfrom one endonly.

Cuts cannotbe formed: if required, the necessarylength ofbridgemustbe dismautled.

Iii orderto avoid confusion,all detail and executivewords ofconimnandwihi be given by theofficer in chargeof the bridge.

The sectionsareformedup in column of detachments,letteredandnumbered,and officersor non-commissionedofficersdetailedfor thedutiesof S.3.,S.4., S.5., or Cotnmandersof Nos.3, 4,or 5Bridge Section,as for mediumbridge.

S.3. takes post at the tail of the bridge, near to thesuperstructure,and, assistedby P.O., sees that the propermaterialis broughtup by the numbersdetailed.

S.4. takespostat time headof the bridgeand superintendstheplacing of time baulksin their propercleats.

S.5. superintends the work of the anchor boats and isresponsiblethat the saddle-beamsof the pontoons are correctlyplaced.lashed,amid markedbeforebeingbrought to the head oftime bridge. He will see that the joint of the saddle-beamisdirectly over the joint betweenthe two sectionsof thepontoon.

The, fixing of the shore transom may sometimes mean aconsiderable,amountof work, becausetheroadwayof thebridgemust be at sucha level that themechanicalroadtransportcanbedriven on to it safely. Tile two pontoonsfor the first two baysarethenplaced in position and the half baulks andbaulks fromthe shore-transomoutwardsare laid.

If a trestleis placed betweenthe bank and the first pontoonthe trestlemustbe regardedas the shore-transomfor purposesof the drill, and the subsequentarrangementof superstructure.Any superstructureshorewardsof this trestle,which projectsbeyondthe realshoretransom,must be beddedin the ground.

6

the starboardoars, and 2 and 4 the port oars.Nb. 5 takesa lifebuoy into tile boat with him~andhis dutiesareto receiveanchorsfrom 6 and7,.and cast and weigh them as required, assisted,whennecessary,by No. 1.

U.O. andUI get intotheouter(orNo.2) pontoon,.G.4. andU.S.get into time inner(or No. 1) pontoon..They hold the pontoonstogether. U.C. and UIreceivethe cablesof the shore anchorsfrom thenumbersof I andJdetachmentsand temporarilybelay.

1st bay. hALF BAULKS. G.2. andG.3. get into No. 1 pontoonwith G.4.and U.S. G.6. and G.7. get into No. 2 pontoonwitll G.0. and G.E. Thesenumbersof U detach-ment placethemselvesin their respectivepontoonsas follows

G.O.andG.4. onthe right, in the well of thepontoon,immediatelyoutsidetIle buttonbaniks.

G.1. and G.5. OR tile left, in tile well.immediatelyoutsidethebutton baniks.

G.13. in the well of the pontoon,on the rightof thecentreof tile saddle-beam.

G.7. in the well of thepontoon,OIL the left ofthe centreof time saddle-beam.

G.2. and G.3. stand partly on the ssddie-beamandpartly on thecentralpartition of thepontoon, G.2. on theright, G.3. on the left.

E detachmentbringup 7 half-baulks,amid,underthe directionof S.3., place and chock their shoreends, G.2., G.3., G.4., U.S. receiving the frontendsoftlmesellalf-baulksandplacing thornin theirpropercleats,steadyingthemthereuntil tile shoreendsare in position and chocked. G.4. and G.5.ame responsiblefor keeping the pontoon at theproperdistancefrom the shoretransom. In orderto avoid crowding E detachmentwork in tworauks; Nos. 7, 5, 3, and I forming time frontrank,Nos. 6, 4, and 2, the rear rank.

2nd bay. mm~ci~u~s. F.1., F.7., E.1., and E.7. bring up two buttonbaulks,P.2., P.3., P.S., F.6., E.2,, E.3.. E.5., andE.G. bring up four plain baulks, P.4 and E.4.bring up oneriband.

The numbers of F detachmentlead, andcorrespondingnumbersof time detachmentsworktogether.

S.4.placeshimself wherehe canbestsuperintendthe work.

NOTES.

P.2., P.3.,P.5., P.6., E.2., E.3., E.5., E.6.alwaysbring upplainbaulks. P.4.andE.4. alwaysbring up a riband.

WheneverF detachmentlead after the word “n~uI~ics,”P.1.,F.7.,E.I., and E.7. bring up buttonbaniks.

No buttonbaulksare brotight up wimen E detachmentleads.In order to avoid crowding, the baniks are brought U~iii tworanksat all times: the odd numbersforming the front rank,the

outerendsof thesebaulksand ribandsamereceivedby G.C., and 0.1., 0.6., and 0.7., whoplacethem in their propercleatsandchock them;0.2., 0.3.,0.4., and 0.5. assisting to guide timecentresof the bauiks into their proper cleatsofNo. 1 saddle-beam. Whentile outerendsof timefirst four baulks are chocked, the numnbers of Fdetaclmtnentpushout as necessary,and place theshoreends of the baulks, 5.4. being responsiblethat tile propercleatsare used. The rear mnkbaulks are then passedout and placed in theirproperpositions.

CIIE8SES. . 0.2. and 0.3. get up on to time baulks midprepareto lay chesses.

P.O.placeshimself at time chesspile and issues(ilesses.

P.1., 2, 3, 4, 5, 6, 7, E.1., 2, 3, 4, 5, 6, 7, andEU eachbring up one cimess. Time chessesarelaid double. The last chessis turned back overtile last pairof cliesses.

11.0. provides himself with a boatlmook, anddirectstimethird pontoonto bebroughtup. liegetsinto it, and from it superintendsits passageto tilebridgehead.

0.0., 0.1.,0.4.,0.5.,0.6., 0.7. eachmoveintothenextpontoon,0.2.and0.3. remainingstandingon thethwartsand saddle-beamafter laying thelast chess. These eight numbers preparetoreceivebaulks.

~cd bay. BAULKS. E.1., E.2..E.3., E.5., E.~.,E.7., P.1., P.2., F.3.,P.5., P.O., P.7. bring imp six plain baulks. E.4.andP.4.bring up one riband.

The numnbLrs of E dottchmemmt lead, a~dthebaulks no brought up mu two ranksasbefore

0.0., 0.1.. G.6., 0.7. receive the endsof theseImaulks amidplacetilem in timeir propercleats. 0.2.,0.3.,0.4., and0.5.,assistingatthesaddleof theirown pontoon.

9

NOTES.

even numbersthe rear rank. The even numbersoover theintervalsbetweentime odd numbers,thus

Front.

:c I ‘Io6 o4 o2

o6 o4

As soonas the officer in chargeseesthat the shoreendsof thebaulks are fixed, he gives the command “cmmnss~s,”whenchessingcan be completed for thefirst bay.—7feet.

F.C. alwaysstandsat the chesspile and issueschessea.E.C. alwayscarriesthe last chess.The chessesare broughtup 15 at a time andlaid double. The

last chessof theodd numberedbaysand thelast two chessesofthe evennumberedbays are turned back to leave the saddle-beamclear,asin mediumbridge.

10

Whenthe outerendsof the first four baulksarechocked,the numbersof F detachmentpush outasnecessaryandplacethe baulks in the cleats ofNo. 1 pontoon. S.4.is responsiblethat theendsofthe baulksare placed in their propercleats. Theremainingbaulksof therearrankarethen placed.

orniss~s. 0.2. and G.3.get up on to thebaulksand laythe lastchessof the previousbay.

11.0. getsinto the fourth pontoonandguides itto the headof time bridge.

0.0.,0.1.,0.4., 0.5.,0.6., 0.7. eachmove intothe next pontoon; 0.0., 0.1.,0.4.,G.S. dealingwith the cablesin theirrespectivepontoonsas maybe necessary.

PCgoesto the chesspile. The numbersof FandF detachmentsas previouslydetailedbring upa chesseach. The first chessis laid on top ofthe lastchessof the previousbay, the remainderof the chessesare laid double. Time last twocimessesareturnedback.

4th bay. BAULJtS. P.1., F.7., E.1., E.7. bring up two buttonbaulks.

P.2., P.3., P.S., F.6.,E.2., E.3., E.S., E.G., bringup four plain baulks. P.4.and E.4. bring up oneriband.

The numbersof F detachmentlead.cnass~s. 0.2. and0.3.getupon tothe baulkaandlay the

lasttwo chessesof the previousbay.The chessnumbersas before detailedbring up

the chesses, and the last chessof this bay isturnedback.

110 brings upthe fifth pontoon,and G0,~0.1.,0.4.,0.5., 0.6.,G.7.move,asbeforedetailed.

5th bay. BAULKS. Ri., E.2., E.3., E.5., E.G., E.7., P.1., P.2.,P.3.,P.S.,F.6., P.7., bring up six plain baulks. E.4.andF.4. bring up oneriband.

The numbersof F detachment lead.CIII~SSES. 0.2. and0.3.get up on to the baulks and lay

the last chessof the previous bay. r1~lmo chessnumbersactasdetailedfor the third bay. TImelasttwo chessesof thisbayare turnedback.

11.0. brings up the sixth pontoon and 0.0.,0.1., 0.4.,0.5.,0.6.,0.7.move asbeforedetailed.

6th bay. RAULK$. P.1., E.1., F.7., E.7. bring up button baulks.P.2.,P.3.,P.S.,P.O.,E.2.,E.3.,E.5., E.G. bring up

four plain baulks. P.4. and E.4. bring up oneriband.

Thenumbersof F detachmentlead.CUESSES. 0.2. and (1.3. get up ontothebaulksandlay the

11

NOTES.

As soonas the officer in chargeseesthat the ends of bauiksate fixed, he gives the command “OIIESSES,” when chessing canbe donefor the secondhay.

12

lasttwo chessesof the previous bay. The chessnumbersactas detailedfor the secondbay. Timelast chessof thisbay is turnedback.

H.O.bringsuptimeseventhpontoonand0.0.,0.1.,0.4.,0.5.,0.6., 0.7. move as beforedetailed.

Succeed- As soonas six bays havebeen chessed,11.4.,ing bays. 11.5., 11.6., 11.7. bring up ribands for wheel-

guides,fix them with dropbolts,~nd beginlacingthe chessestothe buttonbaulks...~ 11.2.,11.3. keepup the supplyof pontoonsto the headof thebridge.

COMFLETIi 11.0., 11.1., 11.2., 11.~.will fix the landing bayBRIDGE. transom, and either E or F detachment,

whichevershould lead, bring up the half baulksnecessaryfor the landing bay. If half buttonbaulksare required,they will be brought up byNos. 1 and 7.

I andJ detachmentsare now spare,and willmoor their anchorboats.

O detachment, on the completion of thechessingof the bay,will completelaying ribandsan(I lacing chesses.

13

NOTES.

The construction of the bridgeis continuedina similarmanner,the numbers lacing down the chessesand placing the wheel-guides,working six baysbehind theheadof the bridge.

LAcING cmIEssEs.—The chessesare laced iii the followingmanner:—Startingwith a timberhitch round the button baulk,the runningendof the lashingis takenover the top surfaceofthefirst pairof chesses,then passeddown betweenthe first andsecondpair of chesseson the insideof the button baulk. It isthenbroughtup on theoutsideof thebanlkoverthetopsurfaceofthe secondpair of chesses,andpasseddownbetweenthesecondand third pairof chessesandso on. It is most important thatthe turns should be strainedas taut as possible, in order topreventany movementof the chessesunderthe load.

The bridgebeing completedat the landing bay, all numbersfall in andhelp to carry wheelguidesor lace down chesses.

7

fl~H H

Note:— Bau/ks etc. marked >- at Second

6 5 4

DIAGRAM TO SHOWARRANGEMENTOF BAULKS ON SADDLE OF SHORE ENDAND TWO FIRST PONTOONSOF HEAVY BRIDGE.

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~g. E.RIBANDS AS V~HEELGUIDES HELD

BY 3 BOLTS DROPPED THRO’ HOLES.

Riband

Chess.

‘3?/ ~‘2 Cheese hesd.

Note: Special Ha/I6~ci/ksmust be used betweenthe shore or Trestle, and the nearest Pontoon.

7I2O/~o3/359.9. ~Y5 & L. /e./~

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0~00

Plat~IT.

• HEAvY PONTOON BRIDGE FOR MECHANICALIRANSPORT(showing arrangement of baulks and chessi~g) -

~,-Doub/e chessi~14~ - —

— A ___ = ~— — -— —

- _i_~_

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