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THEWORLDSGREATTANKS

From1916tothePresentDay

ROGERFORD

Thisdigitaleditionfirstpublishedin2012

PublishedbyAmberBooksLtd

7477WhiteLionStreetLondonN19PFUnitedKingdom

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Copyright2012AmberBooksLtd

ISBN:9781909160019

Allrightsreserved.Withtheexceptionofquotingbriefpassagesforthepurposeofreviewnopartofthispublicationmaybereproducedwithoutpriorwrittenpermissionfromthepublisher.Theinformationinthisbookistrueandcompletetothebestofourknowledge.

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orspecificdetails.

Contents1:ADifficultBirth

2:TheTankBetweenTheTwoWorldWars

3:BlitzkriegAndBeyond-TheTanksofWorldWarII

4:TanksInTransition,FromPotsdamToVietnam

5:TheModernTank

CHAPTER1

ADIFFICULTBIRTHInSeptemberof1916,asthefirstBritishtankslurchedponderouslytowardstheGermantrenches,anewchapterinthehistoryofwarfarewasopened.Fewcouldhaveimaginedtheimpacttheseungainlymachinesweredestinedtohaveontwentieth-centurywarfare.

Thereseemednowaytobreakthedeadlock.Theterrainbetweentheopposingarmiesfacing one another and across the battlefields of eastern and northernFrancewas oftenvirtuallyimpassable,eventomenonfoot;andevenbeforetherustingthicketsofbarbedwireandthedefensivefirefrommachinegunsweretakenintoconsideration.Unprotectedmentriedtocrossthisdesolatenomansland,stopped,stuckanddied.Novehiclestoodachanceofcrossing,even ifbysomemiracle itcouldbemade immuneto themachinegun rounds and the howitzer shells that turnedmudbaths into charnel houses.And stillWorldWarIgroundon

Whenwar broke out inAugust 1914, therewas very little in theway ofmechanicaltransport tobefoundoneitherside.Draughthorses, inhugenumbers,providedmostofthe motive power, all the way from the rear echelons almost to the fighting frontsthemselvesandhorsesstoodevenlesschanceinno-manslandthanmendid.Butthereweremotorisedtractors,bothwithinternalcombustionenginesandwithsteamengines,topullveryheavyloads,suchasthebiggestartillerypieces.Someoftheformertypewerefittedwithcontinuoustracksinplaceofwheels.Theydidntoftencomewithin10milesoftheactualfighting,butthepresenceofthesetractorsintherearechelons,whereconditionsunderfootwereoftenlittlebetterthanatthefront,setsomepeoplethinking.

SWINTONSVEHICLESIn1912,anAustralianengineerandprofessionalinventornamedLancelotdeMolehad

sentadesignforanarmouredtrackedvehicletotheBritishWarOffice.Hewasignored.Now,withtheworldatwar,aservingBritishofficer,Lieutenant-ColonelErnestSwinton,putforwardsomethingsimilar.Insteadofadesignstartingfromscratch,though,Swintonsuggested utilising theHolt caterpillar tractor, then just coming into service as a primemoverwiththeartillery.Suitablyarmouredandarmedwithguns,suchavehiclecouldactas a mobile machine gun destroyer. Swinton at the time Deputy Secretary of theCommitteeofImperialDefencehadseenatfirsthandwhatarmouredfightingvehicles(AFVs)coulddo.HehadbeenbrieflywithCommanderCharlesSamsonsRoyalNavalAirService(RNAS)squadroninFranceintheroleofofficialeyewitness,theonlyformofwar correspondent then permitted to visit thewar zone. Samsons squadron rescueddownedairmenandcarriedoutgroundreconnaissancemissions,atfirstusingtouringcarsthey had armoured themselves, and later in vehicles armed and armoured by theAdmiralty.SwintonhadalsoworkedalongsideSirIanHamiltonontheofficialreportonthe Russo-Japanese War and thus had seen exactly what machine guns could achieve

againstmassedinfantry.

Swinton made his suggestion in the form of a memorandum to Lieutenant-ColonelMauriceHankey,thecommitteessecretary.HankeypassedituptotheImperialGeneralStaffand to itsunenthusiasticchief,LordKitchener.There, for themomentat least, thesuggestion stalled. Hankey, however, had been convinced. He next wrote a longmemorandum to Winston Churchill, who as First Lord of the Admiralty had been infavourofsendingarmouredcars toFranceandBelgiumandhadbeen impressedby thevehiclessuccess.ChurchillrespondedbyconvincingPrimeMinisterAsquithtoputheavypressureontheWarOfficetoreconsider.TheWarOfficedecidedtogivetheHolttractoratrial before senior officials over a prepared obstacle course on the artillery ranges atShoeburyness.Thedayof the trial17February1915 itwas rainingheavilyand thegroundwas sodden. Itwas a fair test, in fact, except that theunarmoured andunarmedHolttractorwascalledupontonegotiatethecoursetowingatruckladenwith2.5tonnesof sandbags.The loadwas supposed to represent theweight the vehiclewould have tocarrywhenarmedandarmoured,and the tractor found it impossible topull thisburdenovertrenches.Thereisagreatdealofdifferencebetweenaloadaboardavehicleandonebeingtowedbehind,especiallyundersuchconditions,butthatcountedfornothing.Intheopinion of theWarOffice committee, the vehicle had failed the trial and the ideawasimpracticalandworthyofnofurtherconsideration.

ThecommitteecountedwithoutChurchillsdetermination,however.SomuchthebetteriftheArmywasnotinterestedhewouldmakesurethattheNavyretainedtheinitiative.Churchill convened what he called the Admiralty Landships Committee to look onceagainatmechanisationonthebattlefield.Chairmanshipofthecommitteewasgiventoanundeniable expert of his own, Sir Eustace Tennyson dEyncourt, Director of NavalConstruction.Thecommitteessecretarywastobeanenthusiasticamateur,aCitybankernamedAlbertStern.

THELINCOLNMACHINEAfter a series of false starts and unsuccessful attempts to employ commercially

available tracked vehicles, a small design team was formed. It was placed under theleadershipofthemanagingdirectoroftractionenginemanufacturersFowlersofLincoln,SirWilliamTritton,withnavalengineerturnedcarmakerWalterWilsonashisdeputy.Atthe same time, sensible new performance criteria, developed by Swinton and basedrealisticallyonconditionsatthefightingfront,wereadopted.Anynewvehiclewouldnowhavetoproveitselfcapableofclimbinga1.5m(5ft)parapetwitha45-degreeslopeandcrossinga2.5m(8ft)trench.

Construction of the No 1 Lincoln Machine or the Tritton Machine, as it wassometimescalledcommencedon11August1915,andthevehiclewasfirsttestedon10September. Thiswas nomean engineering feat, but it soon became clear that the tracksystem used, from a Bullock tractor imported from the United States, was entirelyinadequate, in terms of both endurance and performance, for a vehicle of this size andweight.Thedesignerswentback to thedrawingboard,and itwasTrittonwhocameupwiththeanswer.Hesuggestedasystemofarticulatedmetalshoesrivetedtolinksthathadaninternalliptoengagerunnersinthetrackframe.Thisarrangementwouldpreventthe

tracks dropping away from the guide rollers when unsupported, as they were whencrossing a trench. The systemwas fitted to a rebuilt No 1 LincolnMachine known asLittle Willie, which could then span a 1.5m (5ft) trench and scale a 1.4m (4ft 6in)parapet.

THETRITTON-WILSONBut this improvedversionwasalreadyobsolescent, forWilsonhadhadan inspiration

evenbeforetheoriginalvehiclewasfinished.AttheSeptembertrial,hehadproducedawoodenmock-upofanewconceptthathebelievedwouldcomemuchclosertomeetingSwintons criteria.Swintonhimself agreed. Itwas clear that bigwheels scaledparapetsbetter than tracks did. However, Wilson realised that he could improve the trackedvehicles climbingability ifhecould increase theverticaldistancebetween the forwardandrearwardtrackrunsandproject theupper trackrunforwards.Bydoingthis,Wilsonensured that the trackat the frontof thevehicle ran inanarcmuchgreater indiameterthanthatofanywheelevercontemplated.Infact,theeffectivearedescribedbythetrackof his prototype was equivalent to that of a wheel some 18m (60ft) in diameter. Thedistinctive lozenge, or rhomboidal, shape of the secondTritton-Wilson vehicle,with itstracksrunningaroundthefullheightofthehull,hascometotypifythearmouredvehiclesofWorldWarI,althoughitwasbynomeanstheonlylayoutemployed.

The specification for a new prototype embodying Wilsons improved scheme wasaccepted at a meeting of the Landships Committee held on 29 September 1915, anddetaileddesignworkbeganimmediately.ThevehiclevariouslycalledBigWillie,theCentipede, the Wilson Machine and eventually Mother emerged from Fostersworkshopson26January1916.Thenewmachinewas9.9m(32ft6in)long,includingitsrear-mountedsteering/stabilisingwheels,2.4m(8ft)high,4.25m(14ft)wide,includingthedetachablesponsons,andweighedinatmorethan28tonnes.ThemainarmamentwastwoHotchkissL/40six-poundergunsinsidesponsons.Themachinehadarmour10mm(.4in)thickonthefrontfaceand8mm(.375in)thickonthesidesandboastedatopspeedofjustover5.5km/h(3.5mph).Ithadarangeontheroadof40km.(24miles)onafull227-litre(60USgallon)tank,couldclimba25percentgradient,surmountaverticalobstacle1.4m(4ft6in)highandcrossa3.3m(11ft)trench.Steeringwaseffectedbypreventingonetrackortheotherfromturningbymeansofagearboxbetweeneachtransversedriveshaftandthechainthatconnecteditwiththedrivewheelsattheveryrear.Toturnthevehicle,thegearbox inquestionwasput intoneutral.When themanoeuvrehadbeenaccomplished,thegearboxwasputbackintogearagain.Allthistookthecoordinatedactionsoffourmen the commander and the driver in the forward cupola and the twogearmen.Since theinterior of the tank was far too noisy to permit speech to be heard (the engine wasunsilenced),thecommandersinstructionstothegearmenintherearcouldbepassedonlybyhandsignalorbybangingontheenginecoverwithahammerinapredeterminedcode.Small course changes could be made by use of the exposed rear wheels in idealconditions,althoughtheirrealpurposewastoimprovestabilityandenhancethevehiclestrench-crossing performance. Not surprisingly, the rear wheels proved to be veryvulnerableinbattleandwereremovedfromNovember1916onwards.Atapinch,thetankcommandercouldtosomeextentsteerthroughthebrakes,whichhecontrolled,althoughtheeffortrequiredwasalmostsuperhuman.Eventhoughthevehiclewasproceedingonly

atwalkingpace,itwasnoeasyjobtokeepthevehiclepointingintherightdirection,evenunderthebestconditions.Inbattleitwastoprovetobenexttoimpossible.

KITCHENERSDOUBTSAftersuccessfultrialsinearly1916,anofficialorderwasplacedforjust40units.While

prepared to agree, albeit reluctantly, that the vehicle under test performed adequately,Kitchenerwasstill farfromconvincedthatarmouredvehicles(prettymechanical toys,he called them) had any real tactical merit whatsoever. Minister of Munitions DavidLloyd-George, on the other hand, saw the armoured vehicle as a way of breaking themachinegunsstrangleholdon thebattlefield,andwasprepared togive it thebenefitofthedoubt.Bydint of considerablepolitical acumen,Lloyd-Georgemanaged toget theLandships Committee absorbed into his ministry. In fact, at Swintons suggestion, theLandshipsCommitteehadbecometheTankSupplyCommittee,inanattempttokeepthevery existence of the new weapon secret. The official story was that mobile watercontainerswerebeingbuiltforuseinthedesertsofMesopotamia(inwhatisnowIraq).Thenamestuck,andheavy, trackedarmouredvehicleshavebeenknown, inEnglish,astanks ever since. Within just a few days of the committees absorption into Lloyd-Georgesministry,theorderforwhatwasnowofficiallyknownastheTankMarkI(MkI)was increased to100, and subsequently to150.The first tanks cameoff theproductionlinesinthelastweekofJune.

With the technicalproblems ifnotsolved, thenat leastaddressed,Swinton turnedhisthoughtstoexactlyhowthetanksshouldoperateonthebattlefield.InMarch1916,hehadbeennamedasheadof theunitwhichwastooperate themachinestheArmouredCarSection,MotorMachineGunService.

MACHINE-GUNCARRIERSSwintonsoriginalconceptofthetankasamachinegundestroyerstillstood,butnow

hebegantoquestionitsabilitytodefenditselfWouldthefourless-than-perfectclip-fedHotchkissmachinegunsoriginallyspecifiedasdefensivearmamentbeenoughtodriveoffcounterattacking infantry, orwould determined enemy troops be able to press home anassault,disablethetankanddestroyitatleisure?Indeed,twoofthesemachinegunsweretobemannedonlyinextremecircumstances,bythesecondmembersofthesix-pounderscrews.Swintonknewhecouldnot take thechance,and inApril1916he requested thathalf the tanks should be equipped with paired .303in Vickers Class C belt-fed, water-cooledmachineguns,arguablythebestoftheirkindintheworldatthetime.TheVickersmachinegunsweretoreplacethesix-poundergunsinslightlymodifiedsponsons,andthefemaletanksthatresultedwereearmarkedtoaccompanythesix-pounder-armedmalesintobattleanddefendthemagainstinfantryassault.Histermsstuck,anduntilafterWorldWar1,Britishtanksweredividedintomaleandfemaletypesaccordingtotheirarmament.In 1918, theywere joined by so-called hermaphrodites, tankswith onemale and onefemalesponson.

FRENCHDEVELOPMENTSWithGermanyhavingexaminedandrejectedtheconceptofarmouredfightingvehicles

in1914,theonlynationbesidesBritainlookingtodevelopsuchmachinesearlyinthewar

was France. InMay 1915, Schneider, Francesmain heavy armsmanufacturer, orderedtwo Holt tractors from the United States and began experimenting with them. In mid-December 1915, Schneider invited the political head of Frances Department ofInventions, Jules-Louis Breton, to a demonstration of a BabyHolt 45 horsepower (lip)tractor fittedwithabox-likearmouredbody.Themachinewas theworkofSchneiderschief engineer,work of Schneiders chief engineer,EugneBrilli, and although itwasveryclearlyunderpowered,BretoncameawayconvincedthatithadsomemeritandwroteafavourablereporttostaffofficersatGrandQuartierGnral(GQG).

Within a fewdays, newsof aguardedly favourable response toBretons report camebackfromthecommanderin-chief,GeneralJosephJoffre.On20December,Brilliestartedworkonwhatwas tobecome theSchneiderchardassaut (CA).Hiscollaboratoron theprojectwasJean-BaptisteEstienne,whowasinchargeofexperimentalworkonarmouredvehicles.Designingthevehicletookthepairsixdays,andon21February1916anarmedandarmouredprototypeusingtheexistingHolttracksystemwasdemonstratedinfrontofthe French commander-in-chief. Four days after that, a contract was signed for theproductionof400vehicles.However,itwastobewelloverayearbeforeSchneiderCA-1s,astheyweredesignated,hadbeendeliveredinsufficientnumbersforthemtobereadyandabletogointobattle.TheSchneidercharshadpointed,boat-likebows,withanangledgirder to cut or force down wire entanglements. As in the case of the first Britishprototype, however, the performance and endurance of the French vehicles tracks designedforamuchlightervehicleprovedtobeverypoor.ButunliketheBritish,theFrench did nothing about that deficiency, and for that reason above all others the first-generation French vehicles proved unbattleworthy. The Schneider chars dassaut werewell-enougharmed,withashort-barrelledversionofthejustlyfamous75mmquick-firinggun, but theweaponwasmounted in an embrasure to the right of the driving position.Thisplacementgave it avery limited fieldof fire fromdeadahead throughabout60degreestotheright-handsideonly.

CA-1ARMAMENTDefensivefirewasprovidedbytwo8mmHotchkissmachinegunslike thosefitted to

theBritishtanks.Thechardassautwasparticularlyvulnerabletocatchingfire,thankstoitspetrolcontainerbeingmountedhighenoughtofeedtheenginescarburettorbygravity,andthevehicleearnedthenicknamemobilecrematoriumasaresult.Twomorepowerfulversions,theCA-2andCA-3,reachedthedesignstage,andtheCA-2,withitsembrasuregunreplacedbya47mmcannoninarotatingroofturret,actuallyappearedinprototypeform.TheCA-1firstsawactionatBerry-au-Bacon16April1917.Of132tanks,57weredestroyed, largelyasa resultof theirarmourbeingvulnerable to theGermanK-Patronerifleround.

THESTCHAMONDEvenbefore itwent intoproduction, theSchneider char dassaut had a rival theSt

Chamond.Thiswasaheavier, thoughsimilarlyarmed,vehicle,namedafter the towninwhich it was produced by the Compagnie des Forges et Acieries de la Marine etHomecourt (FAMH). Designed by Colonel Rimailho of the French Armys vehicleprocurement section, the Service Technique Automobile (STA), the St Chamond, too,

employedtheinadequateHolttracksystem,butwithaveryimportantdifference.TheStChamondstracksweredrivenbyindividualelectricmotors,andsincethepowertoeachtrackcouldbecontrolledbyarheostat,steeringwasmuchsimplified.Inthisrespect,theStChamondwas a longway ahead of its time.Had the electricmotors been powerfulenough to overcome the handicap of the vehicles hugeweight, the StChamondmightwellhavebeenmoresuccessful.Asitwas.thevehiclewasbadlyunderpowered,andthis,plusthedesignofits22-tonnebody,whichhadexcessiveoverhangsatbothfrontandrear,almostguaranteedthattheStChamondwouldbogdownatthefirstobstacle.Whenitdid,thedriverwouldpromptlyburnouttheelectricmotorsinafutileattempttoextricatehistank. As in the case of the Schneider char, it was more than a year before significantdeliveries of the St Chamondweremade because of the heavy demands already beingmadeonFrancesdepletedindustry.TheStChamondwassooneclipsedbythetwo-manFT-17,alighttankproducedbyRenault in1917.Ofthe16StChamondsthatfirstwentintobattle, atMouledeLaffauxon5May1917, all but oneditched in the first lineofGermantrenchesandwerelost.NomoreStChamondswereproduced,andbyearly1918,thefewthatremainedhadbeenrelegatedtotrainingduties,muchtothereliefofthemenwhocrewedthem.

THESOMME,15SEPTEMBER1916ThefirstBritishtanksdesignatedasHisMajestysLandshipslefttheBristolChannel

portofAvonmouthforLeHavreinmid-August1916,justafterthesecondanniversaryofthestartofthewar.Bythen,thedeathtollontheWesternFront,withtheattritionbattlesoftheSommeandVerdunwelladvanced,alreadystoodatwelloveramillionmen.Bytheend of the month, there were 50 operational vehicles at Yvrench, where the camp toreceive them had been set up. As early as February 1916, when the tank was still acompletely unknown force, the British commander in France, Sir Douglas Haig, hadvoicedhisapprovalofproposalsfortacticaldeploymentthatSwintonhadputforwardinamemorandum.Inthisdocument,Swintonadvocatedthat tanksshouldbekeptoutof thelineofbattleuntilasufficientnumberhadbeenassembledforamassedassault.Bymid-summer,withplansforahugeattackontheSommeatanadvancedstage,Haigrevisedhisopinion, and orders began to emanate from his headquarters calling for tanks to beincludedintheorderofbattleastheybecameavailable.Theyweretobemovedintothecombat zone itself in an attempt to change the course of an offensive battle that hadboggeddowninthefaceofdefensivepositionsayearandmoreinthemaking.

Some 49 tanks reached the 15km-wide (nine-mile) sector between Thiepval andComblesintimetojoininthethirdphaseoftheSommeoffensivescheduledtobeginon15September.Here,asoneoftheBritishcorpscommanders,SirHenryRawlinson,notedatthetime,TheChief[Haig]isanxioustohaveagamblewithalltheavailabletroopswith theobjectiveofbreakingdown theGerman lineandgetting through toBapaume.The tankswere not to operate all together, butwere immediately distributed piecemealacrossthebattleline.Duringthenightsof13and14September,thevehiclesweremovedup to their jumping-off points under conditions of great secrecy and even greaterdifficulty. Driving at night was a hazardous business at best; under the prevailingconditionsitwasanightmare.

Intotal,just36oftheavailable49tankswereinpositionby5a.m.on15September.

One tank,D1, under the commandofCaptainH.W.Mortimer andwith two companiesfrom the 6thBattalion, theKingsOwnYorkshire Light Infantry, in support, was soondespatched to deal with a particularly troublesome fortified machine gun nest nearDelville Wood. D1 achieved its objective handsomely and became the first trackedarmoured vehicle ever to go into action but was almost immediately disabled by anartilleryshellandtooknofurtherpartintheaction.Mostoftheremainingtankswaitedintheirallottedpositionsforanhourand20minutes,untilthemomentdesignatedasH-Hourarrived.Asthepreparatorybarragelifted,andtheinfantrymenlaunchedthemselvesoverthe top of their defensive parapets and began their straggling death march across no-mans land,anewnoisecameto thebattlefield therumbleof tracksandtheroarofengines.Thesoundwasdeafeningatclosequartersbutoftengotlostfromfurtherawayinthegeneralcacophony.Becauseofthis,thefirstmostinfantrymenoneithersideknewofthenewweaponswastheirsuddenappearance,trundlingoutofthesmokeandmistlikemonsters, rearing to cross obstacles, crashing down on barbedwire andmen alike andweavingdangerouslyfromsidetosideasthecrewsbattledtomaintainacourseacrosstheunevenground.Slowlybutinexorablythetanksgroundforward,leadingtheserriedlinesof infantrymen,while small arms firebouncedoff their toughened skins, and their ownmachinegunsandsix-poundersspatoutinretribution.Tankswerenotinvincible,perhaps,but certainly a decisive step in the right direction ameans, at last, of destroying thehated,deadlymachinegunnests.

CREWCONDITIONSInsidethevehicles,thecrewshadaratherdifferentperspective.TheinteriorofaTank

MkIwascrowdedandconfused.Crammedintotheconfinedspacewereeightmenandtheirpersonalkit,rudimentaryprotectiveclothing(includingplatearmourandchain-mailface masks) and rations, the engine and gearbox, together with the 227-litre (60 USgallon)fueltank.Therewerealsotheweaponsandammunition336six-pounderroundsand6272 roundsof8mmmachinegunammunition in thecaseof themale tanks; some33,000roundsofmachinegunammunitionin8mmand.303incalibresinthecaseofthefemales.Eachtankalsocarrieddrumsoflubricatingoilandgrease,about90litres(24USgallons)ofdrinkingwater,abasketofcarrierpigeons,signallinglampsandflags,acrudefieldtelephoneandadrumcarryingseveralhundredmetresoftelephonecable,aswellasspares for the guns and for the engine. Nothing was lashed down, and the awkward,arhythmicmovement(likeatorpedo-boatinastorm,asoneex-navalcrewmandescribedit) set it all in confused motion and threatened the crewmen with broken bones andcracked heads.Working conditionswere truly appalling. Therewas no silencing of themachinery, nor any meaningful form of ventilation or cooling. Within 10 minutes ofstartingoff, thetemperatureinsideaMk1wasuptoover40degreesCelsius,eveninanorth European winter, while the noise from engine and transmission left each manisolated in a cocoon of total deafness. At the same time, the lurching, unpredictablemotionspilledcrewmenabouttheinteriorofthevehicleliketwigsinamillrace,andtheexhaust fumes from the engine and thewaste gases from themachinegun and artilleryammunitionexpendedintheill-ventilatedinteriorsoonmadebreathingitselfdifficult.

FIRSTSUCCESSES

Almostagainsttheodds,andatconsiderablecost,theearlytanksprovedthemselvestobe effective in the limited tactical role allotted to them. Many a German infantrymanbrokeandranfromthefrontlinedefencesatthesightofthem,andmanymorewereshotdownorGerman infantrymanbroke and ran from the frontline defences at the sight ofthem, and many more were shot down or crushed, while the hitherto impregnablehardeneddefensivepositionsprovedvulnerabletothecombinationofarmouredvehiclesandinfantrymaninclosesupport.Oftheseventanksthatleftthestartlinetogetherinthecentre of XV Corpss sector (the largest number of tanks deployed together on 15September)fourwereknockedout,butthethreesurvivorspushedontotheobjectivethevillageofFlers,almost2km(onemile)behindwhathadbeentheGermanfrontline.Theretheychalkedupthefirstimportantsuccessforthenewweaponwiththebattlejusttwoandahalfhoursold.Inall,thepushof15SeptembersawtheBritishlinethrustforwardbyalmost 2km (1.2 miles) across a front more than 9km (six miles) wide. The daysachievements included thecaptureof threevillages thathadbeenverystronglyfortifiedindeedagreatergainthananymadeinasingledayduringtheentireSommeoffensiveuptothattime.

Still the realworth of the newweaponwasbynomeans clear.The tanks detractorscouldalwayseffectivelyargue that thegainsmadebetweenAlbertandBapaumewouldhavebeenmadeanyway,whetherthearmouredvehicleshadtakenpartinthebattleornot.Thetankssupporters,ontheotherhand,couldnotpointtoanysinglesignificantincidentto gainsay them. Haig, however, was by now a definite enthusiast and requested theconstructionofafurther1000tanks.

One hundred and fifty were completed as Mk Is; 50 more were built as Mk IIs(basicallythiswastheoriginaldesignwithanenlargedroofhatchwitharaisedcoaming,and improved traction); and a similar number were constructed asMk IIIs (with theirarmourimprovedtothestandardoftheMkIVs).Thebulkoftheorder,though,wasmadeupofMkIVs.

THEBRITISHMKIVTheMkIV tanksdiffered fromtheMkIschiefly in theirarmourandarmament.The

powerplantwasunchanged,althoughthepetrol tankthatfeditwasenlargedandmovedoutsidethevehicletoanarmouredpositionbetweentherearhorns.Maletanksretainedtheirsix-pounderHotchkissquick-firingguns,butthehandiershort-barrelledL/23versionwas substituted for theL/40. TheirHotchkissmachine gunswere exchanged forLewisgunsin.303incalibre,andtwomoremachinegunswereaddedintherearportionofeachsponson.ThefemaletanksVickersClassCmachinegunswerealsoexchangedforLewisguns. The Lewis guns were soon found to be unsuitable, however, since the maletanksgun slits had to bemuch larger than before. The gunscooling system also drewpetrolfumesintothetank,pollutingtheatmosphereevenmorethanever.TheLewisgunswerereplacedbymodifiedHotchkisses.Infemaletanksthisallowedsmallersponsonstobefitted,withescapehatchesincorporatedbelowthem.Thedesignofthemalesponsonswasimproved,too, inanattempttolimit their tendencytodigtheircornersintounevenground.

THEMKIVSARMOUR

TheMkIVsarmourwasupgradedtoathicknessof16mm(.625in)atthefront,whileelsewhereitwaseither12.5mm(.5in)or8mm(.375in)thick.Theupgradewasnecessaryto protect the vehicles against the German tungsten-cored K- Patrone 7.92mm rifleammunition,whichwascapableofpenetratingtheskinofaMkIorMkIItank.Theothersignificant feature of the new tank (although it was not added until after the attack onMessineson7June1917)wasthesetofpairedupperrailsthatranfromfronttorearandsupportedtheunditchingbeam.Thiswasastouttimberbaulkthatcouldbechainedtothetracksandusedtohelpthevehicleclimboutofdeepmud.Inall,some1200MkIVswereto be produced, in the ratio of three female versions to twomales, and they started toarriveinFranceinApril1917.

THESIEGRIEDLINEMeanwhile,however,inMarch,theGermanHighCommandmuchtothesurpriseof

theBritishandFrenchhadpulleditstroopsbacktotheSiegfriedLinefromthepositionstheyhadheldsincetheRacetotheSeaofAugust1914.TheSiegfriedLine(whichtheBritishcalledtheHindenburgLine)wasaseriesofin-depthdefensivepositionsthatmadethoseontheSommefront lookpuny.Haigdeterminedtolaunchanoffensivetotest thenewdefensivelineandinearlyAprilattackednearArras,atthepointwheretheoldlinejoined the new.All the tanks available 34Mk Is and 26Mk IIs were pressed intoaction.Onceagaintheyweredistributedpiecemealandsentinafteraprolongedartillerybarrage.

Some tanks managed to make significant contributions to the offensive. On Day 1,tankshelpedcapturethefortifiedvillagesofNeuville-VitasseandTilloy,forexample,andonDay2, three tanks took thehitherto impregnablestrongpointofManchy-le-Preux. Ingeneral, though, itwas theSommeall over again.Most tankswere immobilised, eitherbecomingboggeddowninshell-torntrenchesorknockedoutbyclose-rangeartilleryfire.OnDay3,the4thAustralianDivisionwassentintotheassaultnearBullecourt,supportedby11of its12allotted tanks.TheGermanfieldartillerywaswaitingfor themindepth,andduringthenightof10April,athickcoveringofsnowhadfallen.Asthetanksmovedout into the emptiness of no-mans-land, they stuck out like training targets against thewhiteness. Nine of the 11 succumbed to artillery fire as they ground their slow waytowards their first-line objectives, and the remaining two were later captured. TheAustralianinfantrytheyweretosupportlosthugenumbersofofficersandmen2250outof3000inonebrigadealone.AlthoughitsucceededinbreakingintotheSiegfriedLine,the offensivewas unable to consolidate andwas soon driven out again.And therewasworsetocome

Asspringturnedtosummer,theBritishGeneralStaffturneditsattentionnorthwardstothecountrysidearoundYpres -already thesceneof twoclashesofepicproportionsandnow set to be the site of another. The battle began on 7 June 1917 at Messines andcontinuedthroughAugust,September,Octoberandthefirst10daysofNovembertotheeastandnorthofYpres.TheattackatMessines,whereMkIVtankswentintoactionforthefirsttime,wasasuccess,thankslargelytothestringof19hugemines,monthsinthediggingandpackedwithover400 tonnesofexplosive,whichweredetonatedunder theGerman lines just before H-Hour. The tanks gave valuable support to the assaultinginfantry,particularlyinMessinesvillageitself.Ofthe40thatstartedthebattle,25reached

thelimitoftheirobjective.AtYpres,though,itwasanothermatter.Morethan200MkIVtankswerecommittedtothethirdbattleofYpresorPasschendaele,asitisoftencalled.One after another, they sank into themorass ofmud churned up by shellfire andweredestroyed,batteredintooblivionbyartillery.Alongsidethem,tensupontensofthousandsof infantrymenmet the same fate. Eventually, after 14weeks of fighting, the offensivepetered out, with a bare 6.5km (four miles) of muddy ground won at a cost of over400,000casualties.

CRITICSOFTHETANKThe tanks disastrous performance atYpres seemed to lend undeniableweight to the

wordsofoneseniorArmycommander,whosaid:One,tanksareunabletonegotiatebadground;two,thegroundonabattlefieldwillalwaysbebad;three,thereforetanksarenogood on a battlefield. Senior tank officers, on the other hand,while knowing, perhapsbetter than anyone, the tanks limitations, also knew that properly used, and underfavourableconditions,armourwasabattlewinner.TheyweretobegiventheirchancethatwinteratCambrai.

CAMBRAI,20NOVEMBER1917On 13October 1917,Haig gave the go-ahead for the preliminary planning stages of

whatwastobeknownasOperationGYtheassaultatCambrai.Withinaweekthedateoftheattackhadbeenfixedfor20November,andthemassivetaskofplanninglogisticsand assembling supplies got under way. The plan called for the commitment of everyavailableup-to-datetanktheninexistence.Aswellas376fightingtanks,theBritishtankforce of three brigades mustered 18 supply and gun-carrying tanks and three wirelesstanks. A further 32 tanks were equipped with towing gear and grapnels to clear pathsthroughthewireforthecavalryunitsthatweretofollowthemintobattle.Twomoretankscarriedbridgingmaterials,andonecarriedadrumoftelephonecable.Thisamountedtoagrandtotalof474armouredvehicles.

Before the assault could go ahead, ameans needed to be thought of to get the tanksacrossthetrenchesoftheSiegfriedLine,whichwerewiderthanaMkIVcouldnormallyspan.Firstofall,modificationstothebasicMkIVdesignweresuggested,buttheyprovedunworkable.Eventually a really quite simplemethodwas devised.Each tankwould gointo battle carrying a bundle of brushwoodon its deck.At around2 tonnes each, thesebundles or fascines, as they were properly known were actually extremelysubstantial,beingcomposedof the trunksofsaplingsandsmall treesup toabout10cm(4in) in diameter. Each finished fascinemeasured 1.4m (4ft 6in) in diameter andmorethan3m (10ft) long and could bear theweight of a fully laden tank.Thebundleswereloadedontotheupperdeckrailsofthefrontlinetanks,fromwhichtheycouldbereleasedby a catch from inside the vehicle to roll down the front face of the tank and into thetrench.

Since there was no question of recovering and redeploying the fascines afterwards,considerablecarewentintoplanningexactlywhereandhowtheywouldbeplacedforthegreatesteffect.

EARLYTANKTACTICS

Itwasdecidedthetanksweretoworkingroupsofthree.Thefirsttankwastoadvanceto the enemy frontline trench, turn to the left and run parallelwith it, suppressing anydefensiveactivitywithitsmachineguns.Thetwofollowingtankswouldthenhaveaclearrun to a predetermined position on the trench, where the second tank would dump itsfascineandcross,followedbyitsfellow,andmakefortheseconddefensiveline.Itwouldthenturnleftinturnandworkdownthetrench,whilethethirdtankcrossedandcontinuedon towards the third defensive line.Here itwould provide suppressive fire for the firsttank,whichwouldbythenhavecomeupfrombehindtodumpitsfascineandcrossinitsturn.Thisarrangement,simplethoughitsounds,wasmorecomplexthanthebattletacticsofthedaynormallycalledfor,especiallyconsideringthepresenceofsupportinginfantryin addition to the tanks. In the event, though, the plan went well, except in the 51st(Highland)Division,whosecommander,Major-GeneralG.M.Harper,insistedthatthe70frontlinetankssupportinghisdivisionwouldturnright,notleft,duringthetrench-crossingmanoeuvres, and that they would be deployed in groups of four, not three. A furtherinstructionthathisinfantrymenweretodeployinlineabreastbycompany,some100m(330ft) behind the tanks, rather than by platoon in single file immediately behind eachvehicleresultednotonlyintheunnecessarydeathsofmanyofHarpersownmen,butalsocausedproblemsacrosstheentirebattlefield.

Comparedwiththoseofaninfantrycorps,thetankforcesneedsforwhatwastohavebeenashortbattlewerequitemeagre.Theyrequired775,500litres(205,000USgallons)ofpetrol,34tonnesofgrease,500,000roundsofsix-pounderammunitionandfivemillionroundsofmachinegunammunition,plusthemensrations.Bringingallthismaterialandthe474vehiclesthemselvesquickly,smoothlyandinconditionsofgreatsecrecyuptothenarrow,10km-wide(sixmiles)sectorofthefrontfromwhichtheyweretooperatewasnoteasy.Muchoftherailwaysystemintherearechelonwasstillinoperation,anditwasbyusingthisthatthetanksandtheirsuppliesweremovedupfromthedispersalandtrainingareasnearthecoast.Themovewasaccomplishedontime,andthebuild-upcontinuedinsecret on the night of 18 November. At 6.20 a.m. on 20 November, the attack waslaunchedasplanned.

GERMANYSTANKSThe firstGerman tank saw the lightofday inprototype form inApril 1917andwas

acceptedforproductionon14Mayas theSturmpanzerwagenA7V.Further testingwenton throughout the summer and showed the vehicles design to be deeply flawed. Inparticular,thetracksystemhadinsufficientriseatthefront,andthetwin100hpDaimlerengines were hard pushed to perform in a vehicle with an all-upweight of 33 tonnes,whichincludedacrewof18men,fuelandsupplies,andammunitionforasingle57mmgunandsixmachineguns.ThefirstfullyarmouredA7Vwasdeliveredon1October,anddespite its shortcomings, an order for 100 was placed with Daimler on 1 December,delivery to take place by the following spring in time for the planned offensive. In all,however, 35 atmost hadbeendelivered to theWehrmacht by the followingNovember,plusafurther30withmildsteelbodiesandnoarmament,foruseassupplyvehicles.TheA7VtankwentintoactionforthefirsttimeatStQuentinon21March1918andprovedlargely useless, except in bolsteringGermanmorale.About amonth later, on 24April,nearVillersBretonneux,thefirsttank-versus-tankengagementsawoneA7Vdriveofftwo

BritishfemaleMkIVsbeforeitwasknockedoutbyamale,whichthenengagedtwomoreA7Vs,knockingoutoneofthemanddrivingofftheother.

It was clear that no amount of modification would turn the A7V into a successfulfightingmachine,andthedesignteamturnedinsteadtoproducingplansforavehicleverysimilarindeedtotheBritishtanks.ThisvehiclewastheA7V/U,withanoveralllengthof8.5m(almost28ft)andafightingweightof40tonnes.Aprototypewasproduced,buttoolatetogointoproduction.LiketheoriginalA7Vtank,theA7V/Uwasrathermoreheavilyarmoured than itsBritish counterparts,with plate between 10 and 30mm (.4 and 1.2in)thick. There is said to have been considerable variation in the quality of German tankarmourat thistime,andcertainly, theearliervehicleswereconstructedofsuchplatesofarmour as were available, some small, some large. Those built up out of small platesections,which naturally needed vast numbers of rivets to hold them together, sufferedbadlyfromsplash,asthesprawlingeffectofeffectivefirewasknown.Germanywasalsoresponsible for planning one of the biggest, heaviest tanks ever proposed the giantGrosskampfwagen orK-Wagen,whichwould perhaps have exceeded 150 tonnes all-upweightinfightingorder.Crewedby22men,andarmedwithfour77mmgunsandsevenmachineguns, theK-Wagenwas tohave runon four roller-type trackspoweredby two650hp Daimler-Benz aero engines.Work had begun on two prototypes before the warended, but neither was anything like complete at the armistice, and both weresubsequentlybrokenupforscrap.

THEHEAVYTANKAs it developed during World War I, the heavy tank changed the character of the

conflictmoreandmore.Theheavytankcanfairlybesaidtohavebeenthedecisivefactoronland,andcertainly,hadawiderangeofinterlinkedeventsnotbroughtGermanytoitskneeswhen itdid, itwouldhavebeenonhugenumbersofheavy tanks that theAlliesprogress through the German positions would have depended, as plans for the aborted1919offensiveshow.Butthesteelmonstersstillhadtheircritics.Andtheircriticismsofthe tanks poormanoeuvrability and sluggishness, above all had both foundation andvalidity.If,thankstothetank,thedaysofstaticwarfareweredone,andmobilitywastobecomeofparamountimportanceoncemore,thentherehadtobeamodernsubstituteforthecavalryofold,whoserolehadbeenexpungedbytheinventionofthemachinegun.Inthiswaywas born the concept of the cavalry, or exploitation, tank. Itwas tracked toallow it mobility over terrain that would defeat wheeled vehicles, but it was smaller,lighterandaboveallfasterthantheheavytankandabletodevelopabreakthroughmorerapidlythanthedefendinginfantrycouldretireorregroup.

CAVALRYTANKSAsearlyas1916,WilliamTrittondesignedalighttankthathecalledtheChaser,which

heenvisagedbeingusedinthecavalrysupportandliaisonroles.TheChaserfirstraninFebruary1917,andits trialsweregenerallysuccessful.InJune,anorderwasplacedfor200MkAMediumTanks,deliveriescommencingfourmonthslater.TheChasersdesignwasquitedifferentfromthatoftheheavytanks.Tostartwith, thetrackswereunsprungandlowslung,withacomparativelysmallrise,althoughtheywerelongenoughtoallowthetanktocrossa2.1m(7ft)trench.Betweenthetracks,forward,wereplacedtwo45hp

Taylorfour-cylinderengines,eachwithitsownclutchandgearboxandeachdrivingonetrack. The steeringwheelwas linked directly to the throttles turning it increased thepower to one engine and reduced it to the other. This solution to the problems ofdifferentialcontrolwassimple,butmadethetankdevilishlydifficulttodrive,evenatslowspeeds.Totherearwasthecrewcompartment,forthreeorfourmen,witharaised,fixedbarbettemountingthreeorfourmachineguns.Thetanksarmourwasrivetedsteelplate,512.5mm(.25in) in thickness,and in fightingorder,with5400roundsofammunitionand318litres(84USgallons)offuelaboard,thevehicleweighedslightlymorethan14tonnes. Nonetheless, it could manage 13.5km/h (8.5mph) on the road, and bycontemporarystandards,thatwasfastindeed.However,withnoformofsuspensionatall,the rideat that speedmusthavebeen rough to say the least.TheMkA tankdevelopedfromtheChaser,andwidelyknownastheWhippet,itwentintoactionforthefirsttimeatColincampson26March1918.Butitwas8August,atAmiens,beforetheWhippetfirstshoweditspotential,whenaforceof96MkAsofthe3rdTankBrigadewasdeployedinsupportofthe(stillhorseborne)CavalryCorps.Thankstothestill-prevalenttendencytoemploytankspiecemeal,theresultswereinconclusive,butthereweresufficientgroundstobelievethathadthetanksbeenemployedenmasse,amajorbreakthroughwouldhavebeenpossible.Asitwas,wherethelighttanksdidpenetrate,theywereeffective.

FRANCE,AGAINIn France, Jean-Baptiste Estienne, in conjunction with Renault, came up with what

becameknownastheFT17.Itweighedjustunder7tonnes,hadatwo-mancrewandwasarmed with either a single Hotchkiss machine gun (the char mitrailleuse version) or ashort-barrelledPuteaux37mmcannon(thecharcanonversion)inaturretwith360-degreetraverse.Thetanksweightwaskeptdownbydoingawaywithaconventionalchassisandattaching themajorcomponents to the6-16mm(.25.6in)armouredbody instead,usingthemonocoqueconstructionprinciplelaterusedforvirtuallyallpassengercarsandlightvehicles. The FT17s tracks had an exaggerated idlerwheel at the front to increase thetrackriseandimprovethetanksclimbingability.Beingonly5m(16ft6in)long,theFT17wasunable tocrossa trenchmore than1.8m(6ft)wide. Its35hpRenaultpetrol enginegaveitatopspeedofunder8km/h(5mph),anditsrange,on100litres(26USgallons),wasonly35km(22miles).

TheRenaultFTinfluenced twoof its foreignusersItalyand theUSAenoughforthembothtoproducetanksoftheirownbasedonthesamebasicconcept.ItalysversionwastheTipo3000,which,althoughitdidnotcomeintoserviceuntil1923,certainlyhaditsoriginsinWorldWarI.TheTipo3000wasanadvanceddesign,wellsuitedtoItalysrequirements.ItsucceededtheFIATTipo2000,anabsolutegiantofaheavytank,withacrewof10andarmedwithone65mmshort-barrelledgun,one14mmmachinegunandnofewerthanseven6.5mmmachineguns.TheTipo2000sbestfeaturewasprobablyitstop-mountedturret,with360-degreetraverseandelevationbetween10and75degrees.Thetanks1520mm(.6.8in)armourgaveitanall-upweightof40tonnes,whichmeantthatevenwitha240hpFIATaeroengine,itcouldattainnomorethan6km/h(4mph).

CHAPTER2

THETANKBETWEENTHETWOWORLDWARSAlthoughtankdevelopmentcontinuedapaceinEuropeandtheUSAintheaftermathofWorldWarI,onlytheGermanHighCommandembracedtheconceptofarmouredwarfare.Elsewherethetankwasseenprimarilyasaninfantrysupportweapon.

Primitive though the tanks of 1918 were by later standards, the advances inperformance that armoured fighting vehicles had made in the first three years of theirexistencewereconsiderable.Nevertheless,withWorldWarIover,thefutureofthetankwas far from certain. It had proved outrageously expensive to develop, produce andoperate,anditstillhadenemiesinhighplaces.Woulditcoulditsurvive?

INTERWARUNCERTAINTYBy 1919, the armoured corps of Britain and France were facing the threat of

disbandment. Traditionalists maintained that their own particular arm, be it infantry,artilleryorevencavalry,wasstillthemostimportant,hadclearlywonthewarjustendedandthereforehadtobenurturedat theexpenseofallothers.Indeed,thefollowingyear,the US Armys armoured corps actually was disbanded. The problem was that thetankershadfewmenofrealinfluenceintheirranks,andasaresulttheywereexcludedas a class from the highest levels of decision-making and policy-setting. There wasanotherfactor,too.AgainstthewidespreadhorroratwhathadhappenedinWorldWarI,therewas littlehopeof raising the sortofbudgetnecessary todevelopnew enginesofwarsuchastanks.Inthisclimate,theonlywayforthetanksadherentstokeepthepotsimmeringwastoworkwithsuchmaterialasalreadyexisted.TheUSArmyfollowedthiscourse, assemblingMkVIII Liberty tanks from components manufactured before theoriginalprogrammewascancelledattheendofthewarandusingthemasthebasisforamedium tank force.TheFrench, for their part, perseveredwith theirRenault FTs, eventhough they were technically obsolescent. The FTs pointed the way forward in onerespect.Theirarmamentwasmountedinaturretthatcouldrotatethrough360degreesandwassetabovethereturnrunofthetracks,makingthegunnerentirelyindependentofthedriver at last. Although there have been tanks with hull-mounted main guns producedsince, the flexibility of action provided by a rotating turret becamewidely accepted asessential.

BRITAINSLIGHTTANKMKIThefirstBritishArmytankwitharotatingturrettogointoproductionwastheVickers

Medium.Officiallydesignated theLightTankMk Iwhen itwasdelivered in1924, the

Mediumwasalso thefirstBritish tankwithsprungsuspensionand thefirstwithanair-cooledengine.DerivativesofthedesigncontinuedtobetheBritishArmysmainstayforthenexttwodecades.Weighinginatunder12tonnes,thankstoits7mm(.25in)armour,theMediumhadacrewoffiveandwasarmedwitha47mmthree-pounderQFgunplusfourHotchkissandtwowater-cooledVickersClassCmachineguns.Thevehicles90hpArmstrong-Siddeleyenginegave it a roadspeedof24km/h (15mph),although it is saidthatunofficialenginemodificationsinlaterversionsboostedthat to40km/h(25mph).A327-litre(86USgallon)fueltankgavetheMediumarangeof195km(120miles).Only27oftheoriginalMkIswereeverbuilt.LatermodelsMkIAs,MkIIsandMkIIAshadprogressivelyupgradedarmourandanimprovedversionoftheQFgun,whichgaveslightlygreatermuzzlevelocityandthereforeslightlybetterpenetrationofenemyarmour.In all, around 160 Mediums, in their various guises, were built, and they stayed infrontline service with the Royal Tank Corps until the late 1930s. Vickers sold a smallnumberofMkIIAstothefledglingSovietUnionastheEnglishWorkman.PerhapsthemostsignificantfeatureincorporatedduringtheMediumsdevelopmentwastheco-axialmachinegunmount,incapableofmovementindependentofthemaingun,whichwastobecomeanestablishedfeatureofvirtuallyeverytankthatcameafterit.

BIGGERANDBETTERWhile the firstMediumMk IIs were rolling out of the Vickers factory in 1925, the

companywasturningitsattentiontoamuchbigger tank,designedtobeable tooperatewithout support andknown as the Independent.The Independent orAlEl, as itwaslaterdesignatedwascomparableinsizeandweightwiththeMkVheavytanksstillinservice. It was 7.75m (25.4ft) long andweighed over 32 tonnes, combat-ready, largelythankstoits13-29mm.51.14in)armour.Ithadacrewofeight,aturret-mountedthree-poundergunandfourVickersCmachinegunsinstubby,cylindricalsubsidiaryturretsateachcornerofthemainturretmount.Thetanksair-cooledArmstrong-Siddeley350hpV-12enginegaveitatopspeedof32km/h(20mph).However,inthecourseofanevaluationprogrammethatlastedsomenineyears,theA1E1coveredjust1015km(630miles)onitstracks,foratotalcostinexcessof150,000.Andintheend,theArmydidnotbuyit.

The A1E1 was followed by the A6 and A7 prototypes, neither of which reachedproductionbecauseofthelengthoftimeittooktocorrectbasicdesignfaults.Bythetimethey were perfected, it had become clear that quite different types of tank from thegeneral-purposemediumwereneededtofilldifferentroles.Light,fastcruisertankswererequiredformobileoperations,andmoreheavilyarmouredinfantrytanks,notasfastbutwithbetterobstacle-crossingcapabilities,wereneededforuseintheoriginalclosesupportrole. The first British cruiser tank, the Cruiser Tank Mk I, was designed by Sir JohnCardenofVickers-Armstrong in1934.With itscrewofsix,a fullammunition loadand327litres(86USgallons)offuelforthe9.6-litre,150hpAECpetrolengine,thetanksall-upweightwasaround13tonnes.Itwentintoproductionin1937,andatotalof125werebuiltintwobasictypes.Therewasthecavalrytank,witha40mmtwo-poundermaingun,whichhadgreaterpenetratingpower than theearlier three-pounder, anda close supporttank,with a 3.7in howitzer.Bothvariants also carried threeVickersmachineguns, onemountedco-axiallywiththemaingunandelevatingandtraversingwithit,theothertwoin subsidiary cylindrical turrets flanking the driverscab and capable of traversing

through120degreestoeachsidefromtheaheadposition.Thesubsidiaryturretsproduceddangerous shot-traps between themselves and the rest of the tanks superstructure,reducing the chances of incoming rounds bouncing off.The new tankhad a number ofinteresting features. The most ingenious was what became known as Cardens BrightIdeasuspension.Thetwobogiespersideweremadeupofonelarger-diameterroller,atfrontorback,andtwosmaller-diameterrollers,allofthemrubber-covered,oncoil-springsuspension.TheCruiserMkIalsohadahydraulicallypoweredturrettraverse.

VICKERSHEAVYInparallelwiththeA9tank,astheCruiserMkIwasdesignated,Vickersalsotookon

thedevelopment of a heavier version, to theA10 specification,which called for 30mm(1.2in)ofarmour.TheCruiserMkIIwasessentiallythesametankastheMkI,withthesame main armament of either two-pounder gun or 3.7in howitzer, but with plates ofadditionalarmourattachedtothehull,thefirsttimeappliquarmourhadbeenusedonaBritish tank. Even with the removal of the two subsidiary turrets, the all-up weightincreased to14 tonnes, andwith the sameAECType179engine, thishad theeffectofcuttingthetankstopspeedto26km/h(16mph)anditsendurancebyathird.Uparmouredasitwas,bythetimetheA10appearedin1938itwasclearthatitdidnothaveadequateprotectionforthecloseinfantrysupportrole,whereitcouldbeexpectedtoencounteranti-tank guns at short range. Its operational description was therefore changed to that ofheavy cruiser, even though no such classification had actually existed until then andtherewasabsolutelynotacticalrequirementforsuchavehicle.Theentirecruiserconceptcalled for a tank fast enough and agile enough to run away from anything it could nothandle,andthattheCruiserMkIIcouldnotdo.

THECRUISERMKIllIn 1936, with Cruiser Mk I production just about to start, the General Staff issued

another specification, A13, for a similarly armoured cruiser tank to be fitted with asuspensionsystemdevelopedbyWalterChristieintheUnitedStates.AprototypeofwhatwastobecometheCruiserMkIIIwascompletedthefollowingyear.Fromtheoutset, itwasclearthatthistankhadimpressiveperformance,bothonandofftheroad,thanksbothtotherevolutionarysuspensionsystemandtoits350hpengine,thelong-livedLibertyinamodified form.Despitebeing1.5 tonnesheavier than theMk1, theMk IIIspower-to-weight ratio was more than twice as great, and it was capable of 48km/h (30mph),althoughwithreducedrange.Itmountedthesameturretasthetwoearliercruiserdesigns,butdispensedwiththehull-mountedmachinegun,thusbringingdownthecrewingleveltofourmen.However,its14mm(.5in)armourprovedwoefullyinadequateincombatinFranceandNorthAfricain1940and1941,asGermanarmouredformationssmashedtheirwaywest.

Just as theA10 tankwasbasically anuparmouredA9, so thenextheavycruiser, theA13MkIIICruiserTankMkVCovenanter,wasessentiallyaCruiserMkIIIwithextraarmourboltedon,although itdidhaveamoremodernpowerplant,a300hp flat12unitspecially designed by Meadows. To give it its due, the Covenanter was a stop-gapmeasure,commissionedwhentheA14andA16prototypesprovedunworkableandhadtobeabandoned. Itwasordered off thedrawingboard,without aprototypehavingbeen

builtand testedfirst.Nonetheless,noCovenantereversawcombat.The tanksenduringproblem was its engine, which always overheated, no matter how many modificationswere made to it. Another major defect lay in its complicated, difficult-to-maintaincompressed-air assistance for steering and gear-changing. Even so, almost 1800Covenanterswerecompleted,and themajorityofBritishandEmpireWorldWarII tankcrewsdidtheirbasictraininginthem.

THETANKETTECONCEPTBesidesmedium tanks, theBritishArmy also had small, light tanks, conceived very

much on the Renault FT model, and even so-called tankettes, smaller still and moreproperlyregardedasmachineguncarriers.ThetanketteconceptowedagooddealtoJean-BaptisteEstiennesworkindevelopingtheRenaultFTsinthelatterpartofWorldWarI,butwasprobablythebrainchildofColonelHenryKarslake.Hesawthelittlecarsbothasreconnaissance vehicles and as the mechanised equivalent of the old cavalry screen,protectingmedium tanks as theymanoeuvred.HediscussedhisnotionwithLieutenant-ColonelGiffardMartel, who saw greater possibilities in the tankette amachine-gun-armed armoured vehicle small enough and cheap enough to be used in large numbersduringtheinfantryassaultphasetogiveclosesupportingfiretothemenastheyadvanced.Martelbuilt aprototypevehiclehimselfandoffered it to theWarOffice forevaluation.WiththeassistanceofPhilipJohnson,withwhomhehadservedinFrance,hecompletedahalf-track, steered by a pair of wheels at the rear, and with the driver/operator seatedroughlyamidships,behindtheengine,inwhatwouldeventuallybeanarmoured,open-topbox.He handed it over to theTank andTrackedTransport Experimental Establishment(TTTEE)andawaitedresults.TheWarOfficeguardedlyapprovedMartelslightvehicleandeventuallyplacedorderswithMorrisMotorsforeightMorris-Martelmachinesinbothone-andtwo-manversions.Thetanketteconceptwasonitsway.

TEETHINGPROBLEMSTheMorris-Martelreceivedquitealotofpublicity,whichbroughtittotheattentionof

John(laterSirJohn)Carden.Cardenhadalreadyproducedandsoldbothalightcarandalightaircraft,theexcellentFlyingFlea,andby1925wasinvolvedwithanotherex-ArmyServiceCorpsofficer,VivianLoyd,inagaragebusinessinwestLondon.Carden,too,hadturnedhis attentions to thedesignof avery small tank, and inMarch1926delivered aprototypetrackedvehicletoTTTEEforevaluation.Aftermodification,theCarden-LoydcarrierwasacceptedandevolvedintotheUniversalCarrier(betterknownastheBrenGunCarrier).Itformedthebasis,atleastconceptually,forafamilyoflighttanks,startingwiththe prototype A3E1, built at the Royal Ordnance Factory in 1926. The A3E l used astandard bus engine from AEC, a four-speed gearbox, the by-now standard Rackham.steeringclutches,andsimple,cast-steeltrackshoes.Itweighedalittleover6tonneswithits 12.7mm (.5in) armour plate and couldmanage 26km/h (16mph). Its three-man crewconsistedofadriverandtwomachinegunners,whocommunicatedbymeansofadevicecalledtheLaryngaphoneaformofthroatmicrophonewhichwasdesignedtoexcludeextraneous noise but which also translated the human voice into a flat croak that wasbarely comprehensible. Thus, therewas noway the crew could act in concert, and thedriverwashamperedbyhavingpoorvisiontothefrontandtohisrightandnoneatallto

hisleft,thedrivingpositionbeingalongsidetheforwardturret.Inthecircumstances,itishardlysurprisingthatnothingfurtherwasheardoftheA3E1afteritarrivedatTTTEEfortrialsinthespringof1926.

Itwas twoyearsbefore thenext falteringstepwas taken, in theshapeof theCarden-LoydMkVII Carrier, or the A4E1. The vehicle put up for trials showed considerablepromise,althoughCardenhadgonetoofarintryingtogiveitanultra-lowprofileitwasbarely1.2m(4ft)inheightandhadcrampedboththedrivingpositionandtheturretintheprocess.Boththedriverandgunner(theonlycrewmembers)foundtheA4E1almostimpossible. When the design was translated into a preproduction version, the fightingcompartmentwasconsiderablydeepened,whicheasedbothmenspositionsconsiderably.Late in 1928, theWarOffice placed orders for four Light TankMk Is, and distributedthemtoRoyalTankCorpsunitsforevaluation.Theyneverenteredservice,buttheyweresufficientlywellreceivedformoreorderstobeplacedwithVickers-Armstrong,whichhadbynowacquiredCarden-Loyd.

BRITISHLIGHTTANKSOrders for16LightTanksMkIAwereplacedat theendof1930,and thesevehicles

reached operational units the following year asLightTankMk IIs. The addition of thecrewmens personal gear and radio sets, and the batteries to power them, increased thevehicles weight to well above the 3.5 tonnes originally specified. Happily, the tanksappearancecoincidedwiththedevelopmentofanewtypeofarmourplatethatwassome20per cent lighter than the old homogenous armour for the samedegree of protection.This Cemented Tank Armour (CMT) was immediately specified for all further BritishlighttanksuptotheVickersMkVI,whichenteredservicein1936.

ThelighttanksintheseriesMkI-IIIwereaprogression,andthelastwasrecognisablyadevelopmentofthefirst.TheMkIVwasashortervehicleoverall,butintechnicaltermsitsmostsignificantfeaturewasitsmonocoqueconstruction.TheMkVintroducedatwo-manturret,withroomforbothcommanderandamachinegunner,armedwithaVickers.5inguntosupplementthesingle.303inMk4Bfittedtotheearliervehicles.BythetimetheMkVIwasputintoproduction,in1936,theentirelighttankconcepthadcomeofage,andbythebeginningofWorldWarII, inSeptember1939, theBritishArmyhada lighttankforcesome1000vehiclesstrong.Unfortunately,bythattimedevelopmentselsewherehadrenderedtheselittle4.5-tonnetanks,withtheir15mm(.6in)ofarmourandtheirlightarmament,completelyobsolescent,andwherevertheysawactionoverthenextfewyears,inEurope,NorthAfricaandtheMiddleEast,theysufferedheavylosses.ThereweretwomoreBritish light tanks, theMkVII Tetrarchand theMarkVIII HarryHopkins, theformerproduced in 1938, the latter in 1941.Neitherwasproduced in largenumbers orsawmuchoperationaluse.Theirtrackscouldbeflexedtonegotiategentlecurves,whilesharper turnswereaccomplishedby thestandarddeclutch/brake-and-skidmanoeuvre. Inasmuchastheywereconsiderablybetterarmedthanearlierlighttanks,havingthesametwo-poundergun found in themedium tanksof theday, theMkVIIandMkVIIIweresomethingofanimprovement.Nonetheless,theywerestillsohopelesslyunderarmouredas to be vulnerable to even second-string anti-tank (AT) weapons such as the GermanPanzerbuscheanti-tankrifles.

INFANTRYTANKSVickers-Armstrong produced for export two other light tanks based on the original

Carden-Loyddesigns.ThemoresuccessfuldesignofthetwowastheSix-TonTankMkE,whichwasavailableintwoforms.Onehadpaired,side-by-sideturrets,eachcontainingamachinegun;theotherhadasingleturretmountinga47mmthree-pounderQFgunandaco-axialmachinegun.TheSix-Tonsold toadozencountriesandwas to influence lighttankdesigninPoland,theUSAandtheUSSR,wherederivativesthe7TP,theT1andtheT-26,respectivelyweredevelopedandmanufacturedpartlyunderlicence.Thesecondofthe export tankswas a derivative of theBritishMk IV, and between 1933 and 1936 itattractedordersfrommanyoverseasnations.

BeforehisuntimelydeathinanaircrashinDecember1935,JohnCardenalsoplayedapartinthedevelopmentoftheinfantrytank,evenifhiscontributionwas,ultimately,tobelargelysetaside.In1934,GeneralSirHughElles,theformercommandingofficeroftheTankCorpsandnowMasterGeneraloftheOrdnance,issuedadirectiveforanewbreedof tank designed to offer close support to assaulting infantry. Primarily, the tankwouldhavetobeinvulnerabletothebestandmosteffectiveATweaponsthenavailableandhavegoodrough-groundperformance.BythetimeCardenwasapproachedinOctober1935toundertaketheactualdesignofthevehicletotheAllspecification,ithadbeendecidedthatthetankwouldbeaheavilyarmouredsmallvehicle,armedonlywithmachinegunsandproduced in large numbers. Carden was briefed accordingly, and the project wasdevelopedunderthecodenameMatilda.Thenamestuck,notjustfortheproject,butforthetankthatresultedandthengottransferredtoitssuccessor.TheInfantryTankMkIwas clearly designed to a fixed price, and showed it. It met Elless basic criteria wellenough,andwith60mm(2.36in)offrontalarmourwasimpervioustoabsolutelyanything,exceptperhapsaheavyartilleryshellatcloserange.Butthesevererestrictiononthecostof the finished articlemeant that it rolledout of theVickers factory as a two-man tankcapableofabout11km/h(7mph),withatrackandsuspensionsystemthatwasabsolutelyinadequate, and carryingone .303inVickersmachine gun in its turret. From the outset,those in theknowquestioned the tanksultimateeffectivenessandbeganacampaign togetthenewvehiclereplacedevenbeforeitenteredservice.Eventually,itwasdecidedtolimitproductionof the InfantryTankMkI to just139units, andspecificationA12wasissuedtotheVulcanFoundryCoforwhathadbythenbecomeknownasMatildaSenior.The result was as much a success as the original Matilda had been a failure. It wasprobablythebesttankofitskindintheworldatthetime.

THEMATILDASpecificationA12 leanedheavilyon the lessons learned in theA7project. Indeed the

tank inquestionhad thesamepowerplant twin87hpAECdieselsandrunninggear,alongwiththesamemainarmamentandaverysimilarturrettothatfoundintheA7E3.Inorder toprotect its four-mancrew fromanti-tankguns at close range, theA12s frontalarmourwas78mm(3in)thick,diminishingto13mm(.5in)inlessvulnerableareas.Asaresult, the tanks all-upweightwas almost 27 tonnes,making it the heaviest armouredvehicle contemplated inBritain since the abortedMkVIII. In all, almost 3000 InfantryTankMkIIMatildaswerecompleted,inavarietyofdifferentformsandtypes,includinga

mineclearancevariant.Newtypesofdieselengines improvedthepower-to-weightratiosomewhat,buteveninitsfinalform,withpaired95hpLeylandengines,theMkIIMatildacouldstillmanagenomore than24km/h(15mph)on the road,although its rangewasarespectable260km(160miles).

France,havingsharedwithBritainthedistinctionofbringingarmouredvehiclestothebattlefield, faced similar problems to its ally in determining a direction for thedevelopment of the new weapon after the war was over. In 1921, a developmentprogrammecalling for two typesof tank a charde rupture (breakthrough tank) andachar de bataille (battle tank) was formulated under the guidance of Jean-BaptisteEstienne,nowageneral.Theancestryofthebreakthroughtankthatensued,theCharFCM2C,canbetracedbackto1916,bywhichtimeitwasalreadyclearthattheSchneiderandStChamond tanks thengoing intoproductionwouldnotbeup to the taskdemandedofthem. Forges et Chantier de la Mediterrane (FCM) of Toulon was commissioned toproduceacharlourd(heavytank),andproducedtwoprototypesofthe40-tonneChar1A,built to a rhomboidal design, one with mechanical and one with electro-mechanicaltransmission.FCMalsobuiltasimilarChar1B,witha105mmguninplaceofthelighter75mm. weapon, the main armament being located in a top-mounted turret with 270-degree traverse. Neither version ever came to production, but the Jammy and Sabatierdesign formed the basis for the electro-mechanical 2C, which was a monster by anystretchoftheimagination.Itwasthebiggest,heaviest tankeverbuilt,weighinginat70tonnesandmeasuringalmost10.5m(34ft)longand4m(13ft)high.Itcarriedacrewof12or 13 men, yet it was armed with just one 75mm gun and four 8mm machine guns,althoughwithfrontalarmour45mm(1.75in)thick,taperingoffto13mm(.5in)elsewhere,itwasproofagainstanythingitwaslikelytoencounteronabattlefieldbesidesadirecthitfromheavyartilleryfiringarmour-piercingrounds.Of3002Csprojectedfortheplanned1919 offensive, only 10 had been started and just one delivered - by the time of thearmistice,whereupon theorder for furtherunitswascancelled.The lastof the10 tanksstartedwas delivered in 1922, and the type stayed in service right up until June 1940,whenthesixsurvivingoperational2CswereknockedoutwhilestillontheirrailcarswhenGermanyinvaded.

THECHARB1Inthecaseofbattletanks,fiveproposalseventuallycameoutofthe1921programme,

but it was 1927 before the prototypes were ordered from FAMH, FCM andRenault/Schneiderofwhatwas tobecome theCharB1.Thespecificationcalled fora15-tonnetankwithacrewoffour,tobearmedwithahull-mounted47mmor75mmgun.Whentheprototypesappeared,between1929and1931,theyweighedaround25tonnes.Thiswasfoundtobeacceptable,though,andafterexhaustivetrials,thetankwasorderedintoproductionwithitsarmamentsupplementedbya37mmguninaturretwithall-roundtraverse.Just36B1swerecompletedbeforea revisedspecificationwas issuedforwhatwastobecalledtheB1-bis,witharmourupto40mm(1.57in),a47mmguninitsturret,anda250hpenginetoreplacetheoriginal180hpunit.Atotalof365hadbeenproducedwhenFrancewasoverruninJune1940,bywhichtimeayetmorepotentversion, theBB1-ter,hadbeguntoappear.Thismodelhadarmouruptoamaximumthicknessof70mm(2.75in)anda310hpenginetocompensatefortheextraweight.

By1926, a replacement for the long-obsoleteRenaultFTwasurgentlyneeded in thelighttankcategory.Moneywastight,andtheresultwasnotanewvehicle,butanupdatingof the FT into the CharNC1/NC27 and CharNC2/NC31. Neither was adopted by theFrenchArmy, although somewere sold abroad.Then, in1931,orders for a categoryoflighttanksknownascharslgerswereplacedwithFCM,HotchkissandRenault,forwhatwere to be the FCM-36, the H-38 and the R-35, respectively. The first to appear, theRenault,wasa10-tonne tankwitha two-mancrew,armedwitha short-barrelled37mmgunandamachineguninitsturret,poweredbyan82hppetrolengineandarmouredupto45mm(1.75in).ThemaingunwasneversatisfactoryandwasreplacedbyalongerL/33version.Inall,some300of thesetankswereproducedfor theFrenchArmy,andexportorders were secured from Poland, Romania, Turkey and Yugoslavia. The R-35s maindrawback was its relative slowness. Amaximum speed of just 20km/h (12.5mph) washardlywhatwas expectedof a tankdesigned to exploit a breakthroughand support thecavalry.TheFCM-36,when it appeared the followingyear,was essentially similar, buthadaRicardo-designed,Berliet-builtdieselengine.This tankhadaconsiderablygreaterrangethanthepetrol-drivenRenault320km(200miles)against140km(85miles)anda25percenthighertopspeed.Nonetheless,theFCM-36alwaystookabackseattotheR-35/R-40, largelybecauseonlyabout100wereeverproduced.And itnever received themorepowerfulSA38guntoreplaceitsoriginalSA18.

THEHOTCHKISSH-38The Hotchkiss H-35 also shared the same main armament as the R-35, but had

considerablylighterarmour.Beforelong,arevisedspecification,callingforarmourofthesamethicknessasthatfoundontheothertwocomparablevehicles,wasissued,andwasrealisedastheH-38.TheH-38s120hppetrolenginegaveitabettertopspeedthaneitherof the other two 36km/h (23mph). Over the next two years, the H-38 was furtheruparmoured,anditalsoreceivedthelonger-barrelledSA38gun.Itiswidelyacceptedthatthese three tankswere the equal of their German counterparts in 1940. Their downfallcamemainlyasa resultof thesmallnumber thatwereavailableand theway theyweredeployedinsmallpackets,ratherthaninstrength.

To theBritish, theclassificationof theabove tanksas lightwasa littleodd,but theFrench also had armoured vehicles which came closer to the British notion of whatconstitutedalighttank.Theseweretheauto-mitrailleuses(AMs),whichtranslatesasself-propelled machine guns. Tracked AMs came in two classes auto-mitrailleuses dereconnaissance(AMR)andauto-mitrailleusesdecombat(AMC).ThefourmodelsofAMthat entered service between 1933 and 1935 were all designed and produced (at leastinitially)byRenault.ThecompanysTypesVMandZTwereacceptedastheAMR33RandtheAMR35Rrespectively,andtheheavierTypesYRandACG1becametheAMC34RandAMC35R.

HEAVIERANDHEAVIERTheTypeVMwasa5-tonnevehiclewitharmourtoamaximumof13mm(.5in)andan

82hppetrolenginethatgaveitaroadspeedof60km/h(38mph).Ithadacrewoftwo,andone7.5mmmachinegun ina turret.The rathermore sophisticatedTypeZTwasa littleheavier at6.5 tonnes, andalthough it hada slightlymorepowerful85hpengine, itwas

somewhatslowerasaresult.TherealimprovementtheZTbroughtovertheearliervehiclewasinitssuspensionsystem,whichwassturdyenoughtosupportevenheaviervehiclesandwasused in later light andmedium tanks.TheZThadheavier armament, too, andcouldmounttheHotchkiss25mmantitankgun,a13.2mmheavymachinegunora7.5mmmachinegun.Some200ZTswereproducedinalltocomplementthe125AMR33Rstheninservice.

FRENCHCAVALRYTANKSThe automitrailleuses de combatwere intended for hit-and-run cavalryoperations, so

theyweredesignedprimarilyasfightingvehiclesandnotasreconnaissancevehicleswithdefensive armament. TheAMC34Rwas a simple adaptation of theAMR33R,with atwo-man turretmounting a 25mm gun and a co-axial 7.5mmmachine gun.Despite itscombatweightofalmost11 tonnes, theAMC34Rs120hpenginegave ita respectabletopspeedof40km/h(25mph).ThesuccessorAMC35RwasavariantoftheAMR35R,uparmouredtoamaximumof25mm(1in)andarmedwitha47mmmaingunandaco-axialmachinegun.The180hpenginewasenoughtogivea40km/h(25mph) topspeed,eventhoughtheall-upweighthadincreasedto14.5tonnes.

AtthesametimethattheAMprogrammewascomingtofruition,theFrenchArmyalsobegan to take delivery of yet another class of armoured vehicles. Thesewere the charsmoyens,whichcamebetweenthecharslourdsandthecharslgers.Twovehiclesfellintothecharmoyencategory theCharRenaultDlandtheCharSOMUAS-35.Theyweredistinctlydifferentfromoneanotherincharacter.Theformerwasclassifiedasaninfantrytank, whereas the latter, although it was 50 per cent heavier and better protected, wasdesignated a cavalry tank. The Renault D1 first made an appearance in 1931.Mechanically itwasa simplederivativeof theNC1/NC27 light tank, fittedwitha two-mancast-steelturretmountinga37mmmaingunandaco-axialmachinegun.Armouredskirtplatesprotecteditssuspension.A65hpenginecombinedwithacombatweightof12tonnes,thankstoits12-30mm(.5-1.18in)ofarmour,madetheD1asomewhatponderousvehicle,withatopspeedofjust18km/h(11mph).Satisfactorythoughthedesignwas,ithad never been intended as more than a first step, and was soon superseded by theupgunnedandupenginedD1B.Inall,160Dlswereproducedbetween1932and1935,bywhichtimetheywerelookingratherinadequate.In1934anew,improvedversion,theD2,wentintoproduction,withamorepowerful150hpengineand20mm(.8in)ofsecondaryarmour,togetherwitha47mmgun.Ithadbeenenvisagedthatatotalof100D2swouldbeproduced,butitsoonbecameobviousthatthetankwasdecidedlyinferiortotheSOMUAS-35,andtheorderwashalved.

THESUPERIORSOMUAS-35Fromtheoutset,theSOMUAS-35wasclearlyaverysuperiortankindeed.Principally,

itwasthefirstevertanktohaveacast-steelhull,ratherthanonefabricatedfromplates.The three individualcastings,whichvaried in thickness from20 to56mm(.8 to2.2in),were the lower hull, a rear upper easing and a front upper easing. These three hugecomponentswereboltedtogether.

The S-35s suspension was distinctly different from the coil-sprung bellcranksemployedbyRenault andHotchkiss and employednine roadwheelsper side, fourpairs

andasingle,coveredbyanarmouredskirtplate.Thecastturretwaselectricallypoweredandmounted the47mmSA35gun and a co-axialmachinegunwith a small degreeofindependenceofmovement.Ifthetankhadamajorfault,beyondtheweakpointswhereitwas bolted together, itwas that it could carry just 18 rounds ofmain gun ammunition.Despite an all-up weight of over 20 tonnes, the S-35 could achieve 40km/h (25mph),thankstoits190hppetrolengine;andits410litres(110USgallons)offuelgaveitaveryuseful 260km (160-mile) range.Thevehicles success canbe gauged from the fact thatmorethan500wereproducedinfouryears.In1940,animprovedversion,withmodifiedsuspensionanda220hpengine,startedtocomeofftheproductionlines,butveryfewS-40s,astheyweredesignated,evermadeittofrontlineunits.

THEUNITEDSTATESOFAMERICABytheclosingmonthsof1918,theUSArmywaspoisedtothrowitselfwholeheartedly

intoaEuropeanwarthat ithadbeenslowtoenter.OneresultofUSinvolvementinthewarwashugeordersfortanks.Andthencamethearmistice,andwithitthecancellationofalltankprojectsandthedemobilisationofmillionsofmen.TheUSArmyfounditselfbackatpeacetimeestablishmentinveryshortorder,andin1920,itstankcorpsceasedtoexistaltogether.Responsibilityforsucharmouredoperationsastherewerepassedtotheinfantry.Therewasagreatdangerofarmouredvehicledevelopmentcomingtoacompletehalt,butthiswasavertedbytheformation,in1922,oftheTankBoard,chargedwithbothdevelopingstrategicandtacticalpolicyandspecifyingvehiclescapableofcarryingitout.The board opted for a combination of light andmedium tanks. The formerwere to bearmed with machine guns only, weigh in at 5 tonnes, and be transportable over longdistancesbyroadontrucks.Thelatterweretomounta37mmgunandamachinegun,belimited inweight to the15 tonnescapacityofcontemporarybridgingequipmentandbecapableof20km/h(12mph).

TheUSArmyhadsuccessfullyoperatedRenaultFTsduring thewarandhadorderedalmost4500fromAmericanmanufacturersjustbeforethearmistice.Itthereforecomesasnorealsurprisetofindthatthedesignspecificationforthelighttankboreaconsiderableresemblance to the French vehicle, although the design was modified considerably tomakethetankeasiertoproduce.Asitsnamesuggests,theSix-TonTank,orM1917,wasalittleovertheweightlimit,butotherwiseitmetitsspecificationfairlywell.Its42hpBudaengine was never quite powerful enough, however, and was being replaced in newvehicleswitha100hpair-cooledFranklinpowerunitwhenin1929aradicalrethinkhaltedthedevelopmentprogrammeinfavourofawhollynewvehicle.

ROCKISLANDSTANKSThefirstprototypeoftheM1917sreplacement,designatedT1E1,wasatwo-mantank,

almost7tonnesinweightandarmedwitha37mm.gunanda.30-calibremachinegun.Its105hpenginegaveitatopspeedof32km/h(20mph),butwitharmouronly9.5mm(.37in)thickatmost,thetankwouldhavebeenveryvulnerableindeed,eventolightATfire.Thefinalversion,theT1E6,wasabetterproposition,havingbeenuparmouredandupengined.In1933, theRock IslandArsenal tookover theproject, rollingout theT2E1andT2E2prototypesthefollowingyear.TheyhadVickers-Armstrong-patternsuspensionandwerearmedwitha .5inanda .3inmachinegun inacylindrical, slope-top turret.Powercame

fromamodifiedContinentalradialaircraftenginethatdeveloped250hp.Smallproductionorders were placed for what came to be the M2A1 and M2A2 light tanks, 8.5-tonnevehicles capable of 72km/h (45mph). The M2A2 went through a considerabledevelopmentprogrammeandwastriedoutwithavarietyofengines,heavierarmouranddifferentturretdesigns.In1938amodifiedversiononalongerwheelbase,designatedtheM2A3, was put into production, and the following year its twin turrets gave way to asingleunitmountinga37mmgunandapairofmachinegunsinsidesponsons.Thefrontalarmourofwhatwasnow theM2A4was thickened to25mm(1in),which increased thetanks all-upweight to about 10.5 tonnes. Nonetheless, the original 250hp, engine stillbowleditalongatarespectable55km/h(35mph).Inall,some375M2A4swereproduced,andtheyweretobemostvaluableas trainingtools in1940and1941,eventhoughtheyweretechnicallyobsoletebythen.SomeevensawactionagainsttheJapaneseattheveryoutbreakofwarinthePacifictheatre.ThesamebasicdesignoftankwasadoptedfortheUSCavalryaspartofthewholesalemechanisationprogrammeputintrainbythenChiefofStaffGeneralDouglasMacArthurin1932.ItwasoriginallydesignatedtheCombatCarM1butin1940becametheLightTankM1A2.

AMERICANMEDIUMSMediumtankdesignintheUnitedStatesimmediatelyafterWorldWarIwentdowntwo

distinctlydifferentpaths.Ontheonehand,thereweretanksdevelopedbytheUSArmy;on the other, a series of private initiatives, largely the work of Walter Christie. TheofficialdesignsbeganwithasetofproposalsfromtheCaliberBoard,whichputforwardaplanforan18-tonne,four/fivemantank,mountingeithera57mmora76mmmaingunandwithprotectionenough tostopa12.7mm/.5inanti-tank round,suchas that firedbytheGermanT-Gew,atcloserange.Theresultsawthelightofdayin1922astheMediumTankA,orM1921,whichwasobsoletebeforeiteventurnedatrack,butwhichprovidedvaluableexperience todesignersandengineersquitenew to the taskathand.A revisedversionwasconstructedat theRockIslandArsenalas theMediumTankM1922,whichwasbasicallysimilartotheM1921butwithaflexibletrackandcablesuspensionsystemalong the lines of that fitted to the British Medium Mk D. The M1922 also had aconsiderablerise to therear,whichwas intendedto increase tractionwhenthe tankwasclimbingobstaclesoroutoftrenches.Despitebeing4tonnesheavierthantheM1921,theM1922was50percentfaster,withamaximumroadspeedof24km/h(15mph).Itcarriedthesamearmamentarrangementasitspredecessora57mmgunandaco-axialmachineguninthemainturretandasecondmachineguninanindependentsuperimposedturret.Eventhoughthislayoutmadethetanktallanddifficulttoconceal,itwascontinuedintotheMediumTankT1,builtin1925.

WALTERCHRISTIESTANKSTheT1designrevertedtothemoreconventionaltrackandsuspensionsystemusedin

theM1921,andthesingleexamplebuiltwasusedasthebasisfora testingprogramme.TheT1wasjoined,overthedecadethatfollowed,byotherexperimentalvehicles,untilaT5 designwas adopted as theMediumTankM2 in June 1939. Itwas providedwith a37mmmaingunandnofewerthaneight.30-calibremachineguns,inlinewithitsmainroleofclosesupportof infantryoperations.However, less inkeepingwith theaccepted

specificationforaninfantrytankwasitsperformance.A350hpWrightradialenginegavetheMediumTankM2atopspeedof40km/h(25mph),despiteanall-upweight,withthesix-mancrew,ofover17tonnes.Alsounusualforaninfantrytankwasthevehiclesmere25mm (1in) of armour. Therewas considerable concern at themeagreness of theM2sprotection,andthiswasimprovedby25percentinthetankssuccessor,theM2A1,whichappearedin1940.EventhislefttheM2A1lightlyprotectedcomparedwithsimilarclassesoftank.

WalterChristie,meanwhile,hadcometotanksviathemanufactureofcivilianvehiclesandthedesignofself-propelled(SP)guncarriages.Hewasconvinced,inaccordancewiththeideasofBritishtankofficerandarmouredwarfaretheoristJ.F.C.Fullerandothers,thatthefutureofthetankonthebattlefieldlaynotinclosesupportofinfantryoperations,butin the sort of offensive manoeuvres usually reserved for the cavalry. He saw the tankcarrying out long-range penetration missions, with speed, tactical agility and surprisetakingtheplaceofheavyarmour-platingasameansofprotection.In1919,Christiebeganworkondesignsforatankcapableofmovingathighspeedoveropencountry,ratherthanoneoptimisedforoperationsinanenvironmentofbarbedwire,trenchesandpillboxes.

M1919TOM1921Thereweretwomainconsiderationsindesigningsuchatankthevehiclespower-to-

weightratioanditssuspensionsystem.Eveninhisfirsttank,theM1919,Christieoptedforhavingbothwheelsandtracks.Wheelsweretobeusedforhigh-speedstrategictransitontheroad;tracksfortacticaloperationsacrossopencountry.Thevehiclewasfittedwithfourrubber-tyredroadwheelsoverwhichthetracksranwheninplace.Thetrackstensionand the vehicles rough-terrain traction was maintained by paired, coil-sprung rollerstogetherwithatrack-returnrollermountedabovethemthatcouldberaisedoutofthewaywhenthetrackswereremovedforroadrunning.Christiehadinmindaversatileall-terrainvehicle when he designed the M1919. The box-like area in the centre of the vehicle,betweentheforwarddrivingpositionandtherear-mountedengineandtransmission,couldbeusedascargospaceortomountaturretandsecondaryarmament.Whenfittedoutasafighting vehicle, the M1919 had a single, large (for its day) circular turret carrying a57mmgun,superimposedonwhichwasasmaller,independent,domedturretmountingamachinegun.Bothturretshad360-degreetraverse.Thetankhad25mm(1in)ofprimaryarmour,7mm(.25in)ofsecondaryprotectionandanallupweight,withitscrewoffour,of12.25 tonnes. It was underpowered, though, its 120hp powerplant giving it a fairlypedestriantopspeedof11km/h(7mph).

TheM1919 design was extensively revised the following year, the resulting vehiclebeingsimilaronlyinitspowerplantandtrack/suspensionlayout.

The fighting compartment had been moved to the front, while the driver andcommanderwere positioned in the centre. The turretswere deleted in favour of a ball-mounted57mmgunsetintothefrontplatealongwithtwoco-axial.30-calibremachineguns.Themainarmourwasreducedto19mm(.75in).Thelighterall-upweightdoubledtheM1921stopspeed,whiledetailimprovementstothesuspension,includingthefittingof larger-diameter roadwheels, also helped performance as well as improving the ridequality.Tosomeoneactuallyconcernedwithfightinginanarmouredvehicle,theM1921

appearedasaretrogradestep.Notonlywasitsprotectionthinneddown,butthelocationofitsarmamentwouldhaveputitataseriousdisadvantageinarunningfight.ToChristie,however,thiswasofsecondaryimportance.TheM1921wasnevermeanttobethebasisforanoperationaltank,butwas,rather,adesignexercise.Itexcitedlittleinterest.

CHRISTIESM1928Christiesubsequentlyslippedfromviewforsixyears,resurfacingin1928withanew

company - theUSWheel andTrackLayerCorporation - and a new tank design.Gonewerethepairedsmall-diameterrollersandtheiraccompanyingtrack-returnroller,andintheirplaceappearedfull-diameterrubber-tyredroadwheels,fourtoaside.Thetrack,whenfitted,ranoverthemandoversmalleridlerwheelsatfrontandrear.Theroadwheelsweresuspendedonshort,crankedarms,whichwereinturnhungoncoilspringslocatedwithinthe vehicles double-skinned side panels. The 385hp Liberty-engined M1928 wasevaluated by theUSArmy inOctober 1930 and put up a very impressive performanceindeed,runningat115km/h(70mph)onitswheelsontheroadandat48km/h(30mph)onitstracksacrossroughterrain.Italsoshoweditselfcapableofcrossingobstaclesthatothertrackedvehiclesofthedayfoundimpossibletonegotiate.Theassessors,whoincludedacertain Major George Patton and a Lieutenant-Colonel Adna Chaffee, unanimouslyrecommended acceptance, and Christie received an order for five vehicles, the first ofwhichwasdeliveredinSeptember1931.

TheM1928wasevaluatedoperationallybyboththeinfantrystill,then,inchargeoftankoperationsastheMediumTankT3andbythecavalryastheCombatCarT1ButwhenChristierefusedtomakecertainchangestothetanksdesigntobringitmoreinlinewith the specification, he fell out of favour.Responsibility for theUSArmysmediumtankprojectwashandedover to theRock IslandArsenal,whichpromptly reverted toamore conventional suspension arrangement for its designs. The Medium Tank T5 andCombatCarT2hadVickers- typesmallwheelsmountedonleaf-sprungbogies tobeginwith.Later,verticalvolutespringingwasused,whichretainedthetwosmallwheelsperbogiebutreplacedtheleafspringswithcoilspringsinthebogiemountings,asoriginallydeveloped for theLightTankM2A1.Christiewentondesigningandbuilding tanksbutneverwith anydegreeof personal success, althoughhedid sell one, theM1937, to theBritish.Theydrewheavilyonelementsofitsdesign,particularlythesuspension,fortheircruisertankprogrammethatculminatedintheall-roundbestofthebreed,theA27CruiserTankMkVIIICromwell.

THESOVIETUNIONTankproductionintheSovietUnionbeganin1919withthelocalmanufactureofa7-

tonneversionoftheRenaultFTTheKrasno-Sormova(KS),asthelittletankwascalled,lookedvirtuallyidenticaltotheFrenchoriginalbutdifferedfromitintworespects-ithada 45hpFIAT engine and anAmerican-designed gearbox.That same year, theTreaty ofVersaillescodifiedtheAlliesrevengeonGermanyforthedestructioncausedbythewarjust ended.Oneof its provisions banned theGermans frommanufacturing or operatingtanks, and to circumvent that restriction theGermans looked to two areas outside theirownborders. In Sweden, theGerman-designedLKII light tankwent into production in1921. In the Soviet Union, meanwhile, a secret tank development establishment and

provinggroundwascreatednearthecityofKazan,60Okm(400miles)eastofMoscow.This centre provided theGermanswith themeans of sustaining a continuing armouredvehicledevelopmentprogramme,inreturnforgivingtheSovietgovernmentmuch-neededinsight intomodern tankdesign,even though itwas tobesome timebefore theSovietswereabletocapitaliseonit.

SOVIETCOPIESUsing the KS as a basis, the SovietWar Department Tank Bureau evolved the first

Russian-designedtrackedarmouredvehicles,theMailySoprovozhdieniya(MS),orsmallsupport tanks,series,which,notsurprisingly, leanedheavilyon theFrenchNC1/NC27.TheMS-1went intoproduction in1928 and entered service as theT-18.Over thenextthreeyears,around1000of thesewerebuilt in threevariants.TheT-18was lighterandmorepowerfulthantheKS,anditssuccessinfluencedtheSovietarmourpolicythenbeingformulated.

In1929, thefirstSovietFiveYearPlanwasput intoeffect,withoneof itssubsidiaryaimsbeingthemechanisationoftheRedArmy.Accordingly,plansweredrawnupforaselectionoftanks,butwithoutanyreallynotableearlysuccess.

A prototype heavy tank, the T-12, was abandoned as unreliable in 1930 and wasfollowedbyaseriesofotherdesignstheT-17andT-23,whichwereone-andtwo-mantankettes;theT-19,T-20andT-21two-manlighttanks;theT-24three-manmediumtank;and the TG heavy tank. None of these fared much better than the T-12. As well asdevelopingtheirownideas,SovietdesignerspurchasedseveralBritishtanks,includingtheVickersSix-TonandtheMediumMkII,aswellasavarietyofCarden-Loydtankettesandcarriers,and it isnotsurprising thatelementsof thesevehiclesdesigncrept intoSoviettanktechnology.Indeed,somevehicleswereputintolocalproductionvirtuallyunchangedinprinciple.TheSix-TonTankwasmanufacturedas theT-26, forexample, theCarden-LoydMkVI as theT-27 tankette, and theA4E11 as theT-37/T-38 light tank.Manyofthese vehicles were then developed to a considerable extent. The T-26, for example,appeared with twin turrets, each mounting a single 7.62mm machine gun, and with asingleturretmountingeithera27mmora45mmmaingunaswellasaco-axialmachinegun.Bythetimeitappearedinthelatterform,theT-26sall-upweighthadgonefromjustover 7 tonnes to just over 10. And since it had not been upengined in the process, itsperformance had fallen off a good deal. It is not surprising, either, that British tanksbought by the Russians also found their way into German hands, and that Germandesigners plagiarised them, too. The Russian designers also looked further afield thanBritain for inspiration, though. Late in 1931, they acquired, along with two prototypeChristieM1928s,alicencetotheAmericanssuspensionsystem,andputamediumtankthusequippedintolimitedproductionasthefirstBistrokhodnyTankoi(BT),orfasttank.Fastitmostcertainlywas,bythestandardsoftheday.Itcouldmanage65km/h(40mph)on its tracks and 110km/h (68mph) on its rubber-tyred roadwheels with the tracksremoved.Christiesdesignhadproveditspointyetagain.

The BT-1s and BT-2s were very much state-of-the-art tanks in terms of theirperformance,althoughtheyweredesignexercises,ratherthanseriousattemptstofieldanewtypeofvehicle.Thelatervariantmounteda37mmM1930gun,whichputitscombat

weightuptojustover11tonnes,butimprovementstotheSoviet-modifiedLibertyenginethatpowereditkeptthetanksperformanceuptothatofitslighterolderbrother.ThefirstBTmodeltogointoseriousproductionwastheBT-5of1935.Thishadanenlargedturret,whichmountedanM193545mmL/46gun,andanewengine,developedfromaHispano-Suizadesign.TheBT-5wasfollowedbytheBT-7,withthickerarmouroflargelywelded,rather than riveted, construction,whichvariedbetween7mm (.25in) and22mm (.86in).TheBT-7senginewasupratedtodeliver450hp,andaversionwitha500hpdieselenginewasalsoproducedinlimitednumbers.ChristiessuspensionprinciplesbutwithouttheoptionofrunningonroadwheelsalonewerealsoappliedtotheT-34of1940,thebestandmostimportanttankofitsday.

THET-28EvenwhiletheearlyBTswereprovingtheirworthin1931,adesignteamattheMirov

factoryinLeningradwassettingouttoproduceaspecificationforwhateventuallyturnedout to be a six-manmedium tank, although at 29 tonnes itwas a heavyweight bymoststandards.Thetankssuspension,alongwithotherfeaturessuchasmultipleturrets,boreasuspiciously close resemblance to the still-secret British A6 specification. Indeed, theSovietshadaccesstothisspecification,havingstolentheplans.TheT-28,astheresultantvehiclewas knownwhen it entered service in 1934, proved reliable.Although itwas alittle slow,withamaximumspeedof37km/h (23mph), the tankseemedwellprotected,with frontal armour 30mm. (.4in) thick and secondary armour 10mm (1.2in) thick. Inaddition,theT-28hadgoodobstacle-crossingcapabilityandadvancedfeaturessuchasastabilisation system for its 76mm main gun something as yet unheard-of in otherEuropean designs. In fact, by the time it went into action, against the Finns and theJapanesein1939,theT-28sarmourwasfoundtobeinsufficient,andtheimprovedT-28Cwas developed, uparmoured to 80mm. (3.15in) and 40mm (1.6in) by the application ofadd-onplates.

TheT-28sweresoonsupplementedbytheevenheavier,45-tonneT-32and50-tonneT-35-tankswithastrongconceptuallinkwiththeBritishIndependent.LiketheA1El,eachhadfoursecondaryturretstobackupthemain,whichwasarmedwitha76mmgun.Twoofthesecondariescarriedhighvelocityanti-tankguns(37mmintheT-32;45mmintheT-35),and theother twomounted7.62mmmachineguns.Additionalmachineguns inco-axialmountswerecarried in the threeheavy turretsanda further flexiblymountedgunwas fitted in the frontal glacis plate. Enhanced-performance Liberty-derived engines(350hp in the earlier version; 500hp in the later) gave these monsters adequateperformanceforinfantrytanks.Theywereeventuallyjoinedinservicebythe57-tonneT-100andthe46-tonneSMK.Bothhadtheirsecondaryturretsuperimposedontheprimary.Theprimary,with its76mmgun,had360-degree traverse,while the secondary,with a45mmgun,wascapableofrotatingthrough300degrees.Bothtanksalsohadthreetertiaryturrets, mounting machine guns. Unsurprisingly, this arrangement led to the vehiclesstandingover3m(10ft)high,andthatmadethemextremelyvulnerable.TheysawactionintheWinterWaragainstFinlandin1939-40,butweresoonwithdrawn,asweretheT-32sandT-35s.Themulti-turretdesign,ofwhichtheseSoviettankswerebyfarthemostexaggeratedexamples,wasfinallydiscredited.Itwasvulnerablebecauseoftheshot-trapsitcreated,andinefficientbecauseof thenumberofmenitrequiredtocrewthemultiple

turrets. That is not to say that tankswithmore than one heavy gun emplacement thendisappearedfarfromit.

POLANDThePolishArmyof1920hadsmallnumbersofcapturedGermanA7Vtanksandalso

someFTsacquiredfromPolandsallyFrance.BoththesetypesplayedanimportantpartintheeventualPolishvictoryovertheSovietsintheEasternEuropeanconflictthatfollowedWorldWarI.ThetanksrolewasnotlostonthePolishHighCommand,andassoonasitwaseconomically feasible,Polandembarkedonamodest tankdevelopmentprogrammeofitsown.Thefirstphase,whichinitiallycalledforthedevelopmentinparallelofanewlight tank and a breakthrough medium tank, was eventually concentrated on the 12-tonneW13-10,whichwastohavehada47mmgun,atopspeedof25km/h(15mph)andarangeofmorethan200km(125miles).Intheevent,theWB-10cametonothingandwasabandoned.Then,in1928,thePolishArmyacquiredaCarden-LoydMkVItankettefromVickers, and this led to thedevelopmentof a seriesof indigenous tankettes, the firstofwhichtogointoproductionwastheTK.3.This2.5-tonne,two-manweaponscarrierwasarmedwithasingle7.92mmmachinegun(somewerelaterrearmedwith20mmcannon),hada40hpFordModelAengineandwasprotectedbyprimaryarmour8mm(.3in)thick.Some300TK.3sweredeliveredinallandequippedthePolishArmysfledglingarmouredcorpsfrom1930.TheTK.3sdesignershitonanovelmeansofsavingontrackwearifthetanketteshadtotravelanydistancebyroad.Theyproducedafour-wheeltrailerthatcouldbetowedalongbehindthetankette,andontowhichtheTK.3couldbedriven.Onceonthetrailer, the tankettes tracks were removed, and drive chains fixed between the drivesprocketsandsimilarfixturesonthetrailersrearhubs.Theensemblewasthensteeredbythetankettesdriverviathevehiclesclutchesintheordinaryway.

POLISHTKSTheTKSwas an improved version of theTK.3. Its armamentwas still one 7.92mm

machinegunbutitsarmourwasslightlyheavierupto10mm(.4in)thick.TheTKShadwider tracks, heavier-duty suspension and a locally producedFIAT engine. Itwent intoproductionin1933,andinallsome390wentintoservice.Thefollowingyear,theTKWreachedtheprototypestage.TheTKWwasamodifiedversionof theTKSwithasmallturrettoaccommodatethecommanderandaheavymachinegun.Itwasabandoned,andin1936 another unsuccessful attempt to improveupon theTKS sawa 27mmBofors anti-tankgunreplacethemachineguninastrengthenedfrontplate.Thethirdandlaststillborndevelopment of the TKSwas the TKF, which had an uprated engine and a secondary,probably9mm,machinegunmountedasananti-aircraftweapon.

POLANDSTANKPLANSThePoleswerealsotakenwithanotherVickersproduct-theSix-TonTankMkE.They

manufactureda twin-turretvehiclevery similar to theoriginalTypeAas the7TP lighttank,withprimaryarmour17mm(.67in)thickanda110hpSaurerdieselpowerplant.Thiswas the first time a compression-ignition engine had been fitted to a production tank.Whenitenteredservicein1934,withacrewofthree,two7.92mmmachinegunsandanall-upweightjustshortof10tonnes,the7TPwasaratherbettervehiclethantheoriginal

thathadinspiredit.Itwassucceededin1937byarevisedversion,the7TPjw,withbutasingleturretmountinga37mmBoforsanti-tankgunandaco-axialmachinegun.The7TPjwhadbeenuparmouredto40mm(1.6in)andh