During WWII, the Luftwaffe made use primarily of 2 series of in-line piston engines for their aircraft. These were the Jumo engines, and the DB 600 series engines. However, for whatever reason, as the RAF had a shortage of Merlin in-line piston engines, the Luftwaffe had a shortage of the Daimler-Benz engines, before and throughout the entire war. This shortage was arguably in large part responsible for the cancellation of several (potentially outstanding) aircraft (Focke-Wulf 187, Heinkel 100, the British Westland Whirlwind for lack of Merlins, etc...). Because of the shortage, the RLM was forced to prioritize which aircraft should receive the superior higher horsepower Daimler-Benz engines, and which should receive the inferior Jumo engines. The difference between the engines had a very large impact of the performance of the aircraft, and, had there been no shortage, some aircraft may (probably) would have been developped further and different aircraft would have been put into production from the aircraft that we all know did. My question is, what exactly is the reason for these shortages. I don't see how it could have been shortage of materials, and in 1944 they managed to stop production of virtually all aircraft with the exception of fighters, as at that point Germany was on the defensive. So, with that being said, if their industry was able to put fighters as priority number 1, why did they not focus production on the Daimler-Benz engines, and forget the Jumo ones. Please be specific, and thank you in advance.
There were a number of reasons for the shortage of DB 600 series engines in the late 1930s and early half of the war. Inline engines were complicated pieces of machinery and the 1930s were a period of intense technological development. Daimler-Benz was not the only firm that found itself struggling to meet production demands and remain competitive. Allison had numerous problems before and during the war at meeting demand, and at one point in 1938 the French Air Minister Guy La Chambre briefly considered purchasing DB 601s to make up for shortfalls in French industrial production and the inability of either the British or the Americans to meet French demands.
But there were some factors unique both to Germany and Daimler-Benz that made it much harder to rationalize production. The DB 600 series was an incredibly complicated piece of machinery. Its crankshaft in particular needed to be manufactured to fine tolerances. This was one of the main problems with the Japanese Ha-40/Atsuta version of the DB-601. Japanese engine manufacturers had very little experience with inline engines, and their licensed production of Daimler-Benz's product led to a great deal of headaches. In Germany, the shifts between the DB-600 and DB-601 meant having to shift to new machine tools and production methods.
Another problem relatively unique to Germany was the often dysfunctional relationship between state and private industry. In short, both sought to derive the maximum benefit out of the relationship with minimal effort on their part. Shortages in essential raw materials and hard currency cut into ambitious rearmament plans. The RLM's 1939 Production Plan No. 11, which planed for production from April 1939 to January 1942, had to scale back from the prior plan, No. 10, by 35% because of these delays. Within the RLM and the Luftwaffe's frontline squadrons there was an increasing pessimism about the ability of German industry to meet the state's plans. There were multiple reasons for RLM often made demands on German industry to meet the escalating demands of rearmament, but the chronic disorganization of the Luftwaffe, especially the internal competition between Milch and Udet, gave industry an initial edge in this conflict.
Daimler-Benz was able to capitalize on this state mismanagement to drag its heels with regards to rationalization and other innovations, but they were not alone. Only in middle of the war did the German aero-engine industry transition from workbench production to more streamlined conveyor-belt production. This foot-dragging was partly a function of traditional German manufacturing culture which stressed craftsmanship and high standards over Taylorist mass-production methods tainted by Americanism. For its part, the Third Reich helped to further entrench this mentality by valorizing the German worker as a skilled craftsman par excellence and pouring funds for worker facilities into strategic industries like aviation. But more than these traditional attitudes towards engineering and industrial work, German firms, Daimler-Benz in particular, tended to expect the war would be a short one and were reluctant to expand production facilities that would be superfluous in aftermath of German victory. Most of Daimler-Benz's leadership anticipated that automobiles and trucks would be the cornerstone of its postwar business, and thus was quite reluctant to build up its aero-engine divisions on its own initiative. The disorganization within RLM, especially in the early war period, meant there were few active forces for rationalization and streamlining.
Daimler-Benz's aero-engine division only managed to redress these problems in the second half of 1941. Rationalization, state investments in expanding older plant and constructing new ones, and a realization among industry that the war would be a long one helped to reverse the early war problems. In the last case, Daimler-Benz and its various compatriots abandoned some of the exaltation of craft labor and began to accept slave and forced labor on the shopfloor in unprecedented amounts. These efforts did accrue some benefits and the production of the DB series continued at a much faster rate than ever before.
In hindsight, the Germans could have saved themselves a good deal of headaches had they implemented various rationalization methods sooner. However, forcing industry to conform to these methods was not really the modus operandi of the Third Reich in the 1930s, which preferred co-option and subtle threats to direct control over private industry. Rationalization in peacetime would have cut into workers' wages and the Third Reich placed great political capital in the appearance that it had restored the German worker to his rightful place. By the same token, favoring one industrial concern over another (eg Daimler-Benz over BMW) meant alienating the loser in this decision. The polycratic Third Reich meant that industry could always find a patron within the third Reich's state structure (conversely, it also meant there were lasting enmities between industry and state such as Milch's hatred of Messerschmitt). Moreover, in this period of intense technological development, it was always unclear what the proper line of development to take. The Ju-86 debacle was emblematic of the dangers of pursuing dead-ends. This Junkers bomber was powered by the diesel Jumo 205, which promised fuel-efficiency and range, but the engine was too unresponsive and failed to deliver upon its promised power. The result was the Luftwaffe accepted a bomber in service that it knew was obsolescent before it reached operational status. As the Ju-86 incident indicates, this was a period of a number of technological dead-ends for aviation, such as rocket power or diesels, but they often looked good on paper. In this context, it made a certain degree of sense in aviation planing to hedge bets between higher-end machines like the DB-600 series, and lower-cost alternatives like Jumo's inlines and BMW's radials.
Sources
Gregor, Neil. Daimler-Benz in the Third Reich. New Haven, CT: Yale University Press, 1998.
Militärgeschichtliches Forschungsamt. Germany and the Second World War: Volume I, The Build-up of German Aggression. Oxford: Clarendon Press, 1990.
Uziel, Daniel. Arming the Luftwaffe: The German Aviation Industry in World War II. Jefferson, N.C.: McFarland & Co, 2012.
Vajda, Ferenc A., and Peter Dancey. German Aircraft Industry and Production, 1933-1945. Warrendale, Pa: SAE International, 1998.