One of the few things Germany did not have a shortage of at the end of World War II was rubble. There were over 400 million cubic meters of rubble on the streets of Germany at the end of World War II – and remnants of several BMW facilities contributed to it.

At war’s end BMW facilities in the Munich area were heavily damaged and under American occupation. The factory in Spandau, a Berlin suburb, was in the British sector of the partitioned city and the facility at Eisenach was just inside the Soviet zone of occupation. BMW was not operating as a company at the end of the war.

The National Socialist’s 12 year run had resulted in death and destruction on an unimaginable scale and debased a culture that had, up to that time, given the world so much good. They had barreled down that road with a vengeance after a series of ‘diplomatic’ victories in 1938 which led to further impetuous bellicosity and eventual ruin.

It was in 1938 that the German Air Ministry, the RLM, forced a working partnership between BMW and Bramo. Bramo was soon absorbed by BMW and that effectively placed the development and manufacture of radial aircraft engines in the hands of one company, BMW.

And radial engines would be the company’s main focus from 1938 on – car production, and racing activities dried up as Germany geared up for war. BMW’s wins in races held in 1940 were last gasps for the duration – and the truncated list of competitors were but a faint echo of the great races held in the middle ’30s. The one exception to the focus on aero engines was motorcycles, which could be used by the Wehrmacht, and for whom BMW built the R75 military motorcycle.

BMW moved motorcycle production from Munich to Eisenach on orders from the RLM. Munich was to be devoted to aero engine manufacture and BMW’s list of local facilities included Milbertshofen, Allach (a ‘shadow’ factory), and its original location. In Brandenburg BMW was managing what was Bramo in Spandau and another nearby ‘shadow’ factory.

Air-cooled radial engines had a horsepower/weight advantage over water cooled inline/v engines originally, but their significant frontal area initially vexed aerodynamicists. Aerodynamic cowlings and efficient fans were developed that mitigated the issues. And radials were used in variants of a number of German aircraft of the era. Variants of the Focke Wulf 200 used BMW 132s, derived from experience with the Pratt & Whitney Hornet license, as did the revered ‘Tanta Ju’, Junkers 52, and the Dornier 17. The Henschel 123 bi-plane used a Bramo radial, the 323 Fafnir, whose origins could be traced back to the Bristol Jupiter radial engine.

Radial engines have their cylinders arranged in a star pattern in a single plane, with four stroke engines using an odd-number of cylinders to maintain an every-other-piston firing order (given that an ignition impulse occurs once in a cylinder per two revolutions of the crankshaft). The German word for the radial engine is ‘sternmotor’ – star motor.

Radial engines use a master connecting rod and articulating connecting rods for the remaining cylinders. Radials can be built in multi-row configurations, which the BMW 801 is an example of. There is an excellent gif of a radial engine in action showing the connecting rod assembly and the planetary gearset used for valve actuation in Wikipedia.

The RLM at first was reluctant to allow BMW to pursue the twin row radial, but eventually relented and many versions of the 801 made their way into aircraft. The Junkers 88 and follow on 188 used BMW 801 radial engines as did the fearsome Focke Wulf 190.

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But BMW did not supply engines for all of the variations of the planes that BMW engines were used in – Jumo, Junkers Motorenwerke, and Daimler-Benz also supplied engines that could be used. The BMW 801, however, was one of the first motors to be built ready-to-install. It also incorporated direct fuel injection, and in some turbo-supercharged variants, water-methanol injection. In addition the 801 was equipped with a significant productivity enhancement for pilots, the ‘Kommandogerät”, an analog hydra-mechanical computer that managed propeller pitch, ignition timing, fuel flow, and supercharger settings with a single lever.

BMW also developed the 003 jet engine, which was to have powered the Messerschmidt 262, but that engine was not as fully developed as the Jumo jet which did power the Me 262. In addition to the jet motor, BMW also developed rocket motors, some used in novel new air-to-air guided missiles. There is some thought that it was the work on jets and rockets that placed BMW on a post-war allied ‘do not revive’ list.

With the increased demand for aero engines BMW was forced by the RLM to shelve any planning/production of automobiles onto the back burner. In addition they had forced BMW to move production of motorcycles to Eisenach where the BMW R75 was built. The R75 was equipped with an OHV boxer two cylinder motor, propshaft and driven-wheel side car. During the war years continuous development occurred to meet the extraordinary conditions on the eastern front. The Soviets were impressed with the R75 and copied it. (See

Needing manpower to operate the factories, as Germany mobilized more of its young men for armed service, required that Germans’ places on farms and factory floors be taken by ‘volunteer’ labor from the western conquests, and Italians – among others – migrating north. As time went on and more of eastern Europe and Russia were subsumed in German military advances, the prisoner populations of those conquests were forcibly put to work – as slave labor – in German farms and factories. BMW’s ‘shadow’ factory in Allach was supplied by labor from satellites of the Dachau concentration camp. It was another dark facet of an incredibly cruel regime.

(Author’s note: My father, Hugo H. Becker, was a Technician 4th Grade – technical sergeant – in the US Army Medical Corps in World War II. He was part of a team that provided emergency medical services to one of Dachau’s satellite slave labor camps at the end of April, 1945. He does not speak of the conditions they encountered.)

BMW, during 100 year anniversary ceremonies, expressed profound regret for their use of slave labor during the war and Horst Mönnich’s book, The BMW Story – A Company in its Time, explores in depth BMW’s use of slave labor. The BMW Museum also unhesitatingly acknowledges their use of slave labor to fulfill their production requirements during the war.

Most of BMW’s facilities were damaged at some point during the war and as the allied armies approached, from west and east, production fell dramatically. The ‘null stunde’, zero hour – or end of the war, overtook the lives of Germans fully on the 7th of May when the surrender document was signed in Reims, France (later to be signed in Berlin on 8th May – the day now recognized as VE day in the US and Russia).

The subtitle of Hitler’s propaganda tome, Mein Kampf, was ‘a Reckoning’ – that was what faced Germans in May 1945, a reckoning after 12 years of evil propagated in their names. Factories were stripped of machine tools and test equipment as reparations. The conscripted and slave labor workers were treated as ‘displaced persons’, DPs, and were repatriated over time to their home countries while millions of ethnic Germans in eastern lands were forcibly moved west. The turmoil at the end of the war left factories idle with many so heavily damaged that restarting production would be impossible regardless of the availability of labor.

BMW was not functioning as a corporation; the Allach facility was commandeered by the Americans to refurbish military vehicles. The Eisenach facility, though initially occupied by American troops, was inside the Soviet zone of occupation and was scheduled for complete dismantlement. But employees at Eisenach were able to quickly assemble a number of BMW 326 autos and convince the Soviets that they were better off having a functioning factory. BMW Eisenach, however, was now permanently divorced from Munich – Eisenach being behind what was soon to be called the Iron Curtain.

In time the Morgenthau plan, which would have seen the ruins of industrial Germany replaced by an agrarian society, was supplanted by the notion that an economically strong Germany was needed. In April 1948 the Marshall Plan, the European Recovery Program, was put into operation. The Marshall Plan coupled with the German currency reform in 1948 led to the ‘wirtschaftswunder’, the German economic miracle, and to two distinct German entities, the Federal Republic of Germany, Bundesrepublik Deutschland – West Germnay, and the German Democratic Republic, Deutsche Demokratische Republik – East Germany.

And BMW was allowed to reconstitute itself, at first building consumer goods – household necessities – and in due time to resume production of motorcycles and cars.