Blohm &VoSS BV 155
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DanSharp
SecretProjectS oftheLuftwaffe
BOOKS
ForRonnieOlsthoornwho alwaysbelievedinme.
FirstpublishedinGreatBritainin2019
by
TempestBooks animprintofMortonsBooksLtd. MediaCentre Morton Way HorncastleLN96JR www.mortonsbooks.co.uk
Copyright ©TempestBooks,2019
Allrightsreserved.Nopartofthispublication maybereproducedortransmittedinanyformorbyany means,electronicormechanicalincludingphotocopying,recording,or anyinformationstorageretrieval systemwithoutpriorpermissioninwritingfromthepublisher.
ISBN978 1911658320
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5 Contents Chapter 1–Introduction 6 Chapter 2–Origins 12 May1942to April1943 (Me409,Me155andMe209Höhenjäger) Chapter 3–Blohm &Vosstotherescue 26 May1943toSeptember1943 (P1091andMe155B) Chapter 4–SplitwithMesserschmitt 38 September1943to Februar y1944 (Me155 BandBV155B-1) Chapter 5–Backfromthebrink 58 Februar y1944toJanuar y1945 (BV155B-1toBV155C) Chapter 6–Thebeginningandtheend 80 Februar ytoMay1945 (Flighttestsandcapture) Summar y93 Colourprofiles 48 Acknowledgements 95 Notes 96 Index100 Appendix I– BV155technicaldescription 102 AppendixII –BV155specifications 114
FollowingthesurrenderofGermanforcesinHamburg, northern Germany,at1pm onMay 3,1945,thecitywasoccupied by Britishtroops. Nearly amonthlater, on Wednesday,May 30,ateamofthreeintelligence officersfrom theCombined IntelligenceObjectivesSub-committeeset offfromLondonona mission to assess39‘target’ locationsinthe BremenandHamburgarea thoughttobeofmilitaryandindustrialinterest.
Colonel WA Shuping,Lee Worley andRichard HDepewJr, allemployeesoftheFairchild Engine &AircraftCorporationin theUS,were first flowntoVenlointhe Netherlandswhere they obtainedtwo FordcarsfromtheBritish Army withtwoBelgianArmyprivates as drivers.TheyeventuallyarrivedinBremen,Germany,ontheeveningof May31,readyto begintheirtask.
Aftera weekoftouringtargetsconnectedtoFocke-Wulf, Weser FlugzeugbauandBlohm &Vossin theBremenarea,and nowwith theassistanceofBritishFlightLieutenantE ALittlefield,attachedto the2nd Tactical AirForce,RAF,theymovedontoHamburg. Amongthethreetargetsvisitedduringthe firstday inthis area, June 9,wastheBlohm& Vossexperimentalaircraft factoryat Finkenwärder–actuallyanislandontheriver Elbe tothewestofthe city centre.Thisconsistedofwell-equipped engineeringworkshops, administrativebuildings,laboratoriesand alargehangar.
Damagefrom bombingwas minimal –although mostwindowshadbeenshattered during thebombingof nearby submarine pens.TheAmericanswereimpressedto findexamplesof thehugeBV222andBV238 flyingboatsunderconstruction,alongside BV246glide bombs andanotheraircraftaboutwhichAlliedintelligencehad, uptothis point,knownverylittle–theBV155.
Shuping, WorleyandDepewwereabletotrack down several ofthekeypeoplewho workedontheBV155,includingBlohm& VosschiefdesignerRichardVogtandhisassistant Hermann Pohlmann,and interrogatethemabout it. Accordingtotheirreport:1 “In1943 MesserschmittofferedtheGermanAirMinistry ahighaltitude fighterwithadesignationMe 155,butreceivednoorder. Later,B&Vwasfurnishedwith asketch of this Messerschmitt aircraft,butafterstudy changedit completelyinevolvingtheB&V155.
“Thisaircraftis asingleengine highaltitude fighter with adesignceilingof16,000m (52,480ft).Thecalculatedspeedatceiling was750km/h(470mph).Theengine wasa Daimler-Benz603 Uandexhaustpipes passeddowneach sideofthefuselageanddrovea 2-stage turbosuperchargermade byHirthofStuttgart.
“The airfromthe2-stageturbo supercharger passedthroughintercoolerstotheengine drivensuperchargerand thencetotheengine.Inthe155 Bseenbythisteam, these intercoolers werelocatedoneateach endofthecentresection.Inthelatermodel,155C,of whichwesawthemock-up,theintercoolerwaslocatedunderthe fuselagebeneathandtothe rear oftheengine.Thecabinwaspressurised to7,000m. Aningeniousinflatedtubesealed the sliding hatchcovertomaintainthecabinpressure.
“Thelengthofthe airplane wasapproximately 11mandthespanapproximately19.5m, the spanofthecentresection beingabout10m.DrVogtstated that hebelievedthewingofthis aircraft was possiblythe firstGermanwing withlaminar flow.Flapsofsplittypeswere used
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Introduction Chapter1
onthecentresection.Thecentre sectionused asinglebox spar ofweldedsteelconstruction (125,000psi normalised). The outer wing panels were ofmonospar construction.
“Therangewas about3hours.Thearmamentconsistsofone30mmcannoninfuselage, firing through propeller hub, plus two20mm cannon located one in each side ofthe centre section.Inthe 155C it wasproposed to useone30mm and four20mmcannon.
“It has been statedbyDr Vogt that one B&V 155 airplane had been completed and flown awaytoanotherlocation,butwas crashed inlandingnearNeuminster[Neumünster –about 60km directly northofHamburg], whereupon itwas removed to a Lufthansa field. The crash wasattributedtofailureofthe retractable landinggear toextend.
“The second B&V 155B fighter wasnearly completed ready for final assembly and this aircraftandonespareengine,hasbeen securedandtaggedfor evacuationtothe UKby thisteam. Also,we havesecured, packedand marked for shipment to the UK,all original drawings,stressdata,wind tunnel data, statictestdata,what flight testdatawas available, partslist,etc. forthisairplane.”
On June 14theAmericanstagged up29separatecomponentparts of thedisassembledBV 155 V2, includingthe spare Daimler-Benz DB 603 Uengine, plus50 boxes of documents, andLittlefieldarranged fortheirtransportationbacktoBritain.Theydecidedtoleave behind asecond BV 155 Bfuselage stillinits jigand 75% complete– presumablythe third prototype –a tail wheelshockstrut andforkforthe155B, theweldedstructureandjigofa BV 155 Cfuselage, outerwing panel jigs, aBV 155 Cmock-upanda further five spareDB 603 Uengines.And onJune 18,1945,theteamreturnedtoLondon.
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ABOVE: BritishRAFRegimentsoldiersholdup acapturedmodeloftheBV155 BforthecameraatBlohm &Voss’s officesinFinkenwärder,HamburginJune1945.Thephoto wasamongseveralincludedintheCIOSXXV-53German AircraftIndustryBremen-HamburgAreaintelligence report by FairchildemployeesShuping,WorleyandDepew.
Itwas theend of astorywhichbeganthreeyearsearlier duringthespringof1942. At that time,following theGerman declarationofwar on the USA, onDecember 11, 1941, theLuftwaffeandtheReichsluftfahrtministerium(RLM– theGerman AirMinistry)were considering what sort of weapons the Americans might employ in the European theatre and how they mightcombatthem.
In particular,the Germans were aware thatthe USAAF hadeitherorderedorintended toordera fleet of high-altitudebombers.Detailswereevidently scanton theprecise performance of these aircraftbut it was expected that they would be capable ofoperating wellabove10km(32,800ft)andwould makeanappearancetowards theend of 1942at the earliest.
The firsttopicupfordiscussionattheGL-Besprechung or ‘Generalluftzeugmeister meeting’
effectivelya gathering of key decision-makersfrom withinthe RLM and the Luftwaffe –onMay12,1942,wastheHöhenjägeror‘high-altitude fighter’2.Attheoutset RLMengineerFlugbaumeisterWalterFriebel statedthatthereweretwooptions forthis role:aircraft with pistonenginesandaircraftwithjet enginesbutthe second wouldnotyet be discussed.Hethen readout alistofstandardproduction fightertypes“availableinthe period1942/43”– theMesserschmittBf109F-4,Bf 109G-1 andMe309,Focke-Wulf Fw 190 A-3, Fw 190 BandFw190 C–“which,withtheexceptionofminorspecialequipment such as pressurisedcabinsorequipmentfortheuseof GM 1[nitrousoxideinjection],were notspeciallydesignedforuseinverygreataltitudes”.
Hesaid:“Beforetaking intoaccount themeasuresavailable whichcan leadtoan improvementinhigh-altitudeperformance,itmustbestatedinprinciplethatthewidelyheld view that increasingwingareaoffersa significantimprovementinclimbtimeandmaximum ceilingiswrong”.
Thebestwaysofincreasingclimbtimewere, hesaid,increasingenginepower or reducingweight.Work was alreadybeingundertakenbasedon aproposalbytheRLM’s C-E 2departmenttoimprovetheBf109’sperformancebyeliminatingallarmour,saving180kg. “Aircraftofthisdesignarealreadyrunninginserieswith thedesignationBf109 G-1/R2,” he added.
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1.INTRODUCTION
ABOVE: AnotherimagefromCIOSXXV-53takeninside ahangaratFinkenwärdershowing amanposingwith acaptured BV246glidebomb.MostofthebuildingsatFinkenwärderhadsuffereddamageas aresultofheavyAlliedbombing.
UsingGM 1toimproveperformancehadsignificantdrawbacksthough:“Theadditionof GM 1isassociated with a considerable weight expenditure due to the high consumption and the largecontainer weights. GM 1hasgreatadvantagesforshort-termincreaseinspeed at highaltitude, butdue to thelarge additional weight only smallbenefits to improve climbing performance.”
Engines were being designed specifically for use athigh-altitude –theDB614, DB628 andBMW8028– but“only on aproject basis”.Theengineswouldnotbeavailableinany numbers until 1944 at theearliest and when they were available the additional performance theyofferedhad tobe measuredagainsttheirincreasedweightand drag. However,“of the mentioned high-altitudeengines the installationofthe DB 628 in the Bf 109 G shouldhave the greatestprospects forthe preparationof agoodhigh-altitude fighter.Work toaccelerate the provision of such engines, albeit in small numbers, should bemade withutmost urgency.Incooperation between Messerschmitt and Daimler-Benz is currentlyanaircraft with DB 605 with intercooler (forerunner DB 628)being prepared. The experiencegained hereshouldserveforfurtherwork in this direction”.
The DB 628 was essentially aDB605 inverted V12, thepowerplant intended to replace the 109’sDB601 fortheG-series,but withtwosuperchargers.Friebelsaidfurther improvements to the109’saltitude performance would be possible by reducingboth the 109’s fuelandammunitionload.
GeneraloberstHans Jeschonnek replied: “Reducing fuel, yes, reducing armamentis a joke. If Ihave ahigh-altitude fighter andcomeclosetotheenemyand have no weaponto fight him, then that’suseless.”
TheInspekteurder Jagdflieger, Generalmajor AdolfGalland,added:“Hewillnotgetthat far withthe reductionoffuel.”
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ABOVE: ThesameBV246butthistimethelargehullofanunfinishedBV222flyingboatcanalsobeseeninthe background.
Furtherdiscussiononthispointfollowed before theGeneralluftzeugmeister himself, GeneralfeldmarschallErhardMilch,said: “Then a question that is veryimportant: whether oneshould developwithournormal gasolineenginea special high-altitude fighter, whichisactuallyusefulonlyathigh altitudeandwith which onecannot fight in the intermediate altitudes.”
Friebel responded: “The second question iswhetherit is timeto dividethe[current ongoing] development into aspecial highaltitude fighter, whichcanbedesigned properlyformaximumaltitude, but which, ofcourse,is handicapped inintermediate altitudes by its larger wing surfacearea and all sortsofotherthings.”
After some debate about the need for bothday andnighthigh-altitude fightersand whetherevaporativecooling could be used toreplace radiatorstoreducedrag,Luftwaffe staff officer Major WalterStorpsaid: “I think the Americansareworkingonthefurther developmentofthehigh-altitude aircraft. I donotknowiftheywillmakeanappreciable appearance in 1942,butcertainly in1947 withbombers.
“For this reason, it seems necessaryand expedient,apartfrom theinterceptorthing and the special high-altitude, to try a special Bf109 at leastnow.Becauseonethingseems tome agiven:thedemand forthehighest altitudeandthehighestspeed contradict each other –theyareopposed.If Iwanttohave greaterspeed,I inevitablycometo asmaller wingarea.Forthe high-altitudes Ineeda larger wing area.
“Iwouldsuggestthatweprepare theBf 109 developmentallyinserieswith alarger area,togetsafelyto13,000 to 14,000m.”
Discussionthen turnedtothebestengine for aspecialhigh-altitude fighter.RLM General-Ingenieur WolframEisenlohrsaid: “The[DB]605waspresented with asecond turbine,whichincreases performanceby 50%,sowewouldhave1200bhpinsteadof 750.Nowthe questioniswhethertheaircraft
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ABOVE: Blohm &Voss chiefdesignerRichardVogt, centre, picturedwithaerodynamicistLudwigPrandtl,left, andthedirectoroftheDeutschen Versuchsanstaltfür Luftfahrt(DVL)GünterBock,right.
1.INTRODUCTION
ABOVE: GeneralfeldmarschallErhardMilch,headofthe RLM, wasapivotalfigurethroughoutthedevelopment oftheMe155andBV155.