German Bomber-B Engines

[case.vw]

I am in search for more information why the development of the DB 604, the Jumo 222 and BMW 802 failed. The British built the Napier Sabre, an equivalent to the DB 604. The Americans built the Pratt Whitney R-2800, also a R-18 engine, just like a BMW 802. The configuration of the Jumo 222 was one of a kind.

I can't find much information about the development of these engines and why the projects were finally abandoned.

Can someone help me?

 

[HoHun]

Hi Case,

>I am in search for more information why the development of the DB 604, the Jumo 222 and BMW 802 failed.

I believe in the case of the Jumo 222, one of the reason it didn't reach fruition is that the power requirement for this engine was stepped up twice - from 2000 HP to 2500 HP, then to 3000 HP - during the design process. Additionally, there seem to have been some materials-related difficulties resulting from the lack of strategic raw materials in war-time Germany - a problem underestimated at the beginning of the war.

Regards,

Henning (HoHun)

 

[kool kitty89]

The BMW 802 was a relatively straightforeward development of the 801, with 2 rows of 9 rather than 7.

Much like the P&W R-2180 and R-2800, or Wright R-2600 and R-3350.

I think the 802 just had too low development priorety and BMW was puting a lot of work into the problematic 803 design as well.

 

[case.vw]

Hohun, I found this information from you on LEMB:

Jumo 222 - complete failure? - Luftwaffe Experten Message Board.

Summarized from von Gersdorff et al.:

Based on 1936 Jumo studies for a 1800 PS engine, in 1937 the RLM ordered a 1900 PS engine (24 cylinders, liquid-cooled) for left- and right-handed operation. Ferdinand Brandner, who was new at Junkers, was to develop this engine, which he projected as a 2000 PS, 6 rows of 4 cylinders design. It ran first in 1939 and in 1940 developed 2000 PS on the dynamometer and was flown as middle engine in a Ju 52. In 1941, it completed a 100 hour test on the dynamometer. In the meanwhile, combat experience had caused the RLM to demand more from the Ju 288 (which was to be the main user of the Jumo 222) than originally planned, and it turned out it would need 2 x 2500 PS instead of the 2 x 2000 PS of the Jumo 222 provided. Preparations for series production (which had progressed very far) were stopped.

There were two main causes for the teething problems of the Jumo 222: Inferior main and connection rod bearings (for lack of tin, a strategic material) and inferior lubrication properties of the synthetic lubricants.

The next generation of Jumo 222 engines had an increased bore for increased power. In December 1942 a 100 hour test at 2500 PS was completed successfully. However, in the summer of 1943 the Bomber B was cancelled due to the change of the strategic situation, and Jumo's priorities shifted to the Jumo 213 which was better suited for the use in fighters.

In April 1944, Dessau was bombed heavily, necessitating the move of Jumo 222 production and development to Oberursel. The power requirement increased again to 3000 PS, leading to another increase of bore and stroke. This generation was split into an advanced high-altitude engine with two-stage, hydraulically driven supercharger with charge mass control and intercooling and MW50 and GM-1 boost for 2500 PS (dry), and a less sophisticated mid-altitude engine of 3000 PS.

Changing requirements is always a major problem during the development. Was this a common problem of the RLM, or was it also a problem from English and American administrations?

 

[case.vw]

I found an interessting quote in this thread:

Air Warfare Forum :: View topic - Totally unknown German airplane

Schnauferheinz wrote:

In 1992 I met one of the constructors of the DB 604.
Apart from the fact that he was convinced of "his engine" he told me, that the RLM in Berlin at this time (1942) favored the JUMO 222-engine and the DB 604 was too expensive for the RLM in its price to buy the engine and for reasons of fuel-consumption

Can someone confirm this story?

 

[Romantic Technofreak]

The dissertation of Dr. Lutz Budrass: "Flugzeugindustrie und Luftrüstung in Deutschland 1918 - 1945" ended up in a thick book (publishing house Droste, Düsseldorf 1998 ).

From page 725 to some following ones, he explains the generation of the failure of both Ju 288 and Jumo 222 by nothing but an administrative act by Field Marshal Milch. Goal was to destroy the position of power the Junkers trust as well as its general manager Heinrich Koppenberg had gained. In September 1941, Milch ordered the until then parallel development of the Ju 288 and Jumo 222 to be split. Neither aircraft nor engine had shown considerable flaws. The Jumo 222 was even cheaper in terms of labourforce cost and in use of strategic materials than the standard engine Jumo 211. The Ju 288 had laborously to be reconstruted to the use of a different engine (the Daimler-Benz coupled), while the Jumo 222 stood without aircraft to be used for. Koppenberg, who also had to face being sued for smuggling (Göring later turned that down) retired.

Regards,RT

 

[Soren]

Great info RT.

 

[HoHun]

Hi Technofreak,

>The dissertation of Dr. Lutz Budrass: "Flugzeugindustrie und Luftrüstung in Deutschland 1918 - 1945" ended up in a thick book (publishing house Droste, Düsseldorf 1998 ).

What do you think of this book? Sounds promising, but seems to be fairly expensive, so I wonder if it's worth it ...

Regards,

Henning (HoHun)

 

[kool kitty89]

Romantic Technofreak,
Was the Jumo 222 easier to build and maintain compared to the 211 on an one to one basis, or relative to the 222's greater size and power?

 

[Romantic Technofreak]

Thank you Soren.

Henning,
if it's only the money, spend it. The book is worth every € it costs. But what Budrass concentrates on is the development of the administrative level of the RLM and its predecessors and the relations of the Junkers trust to them. What we all would like to read is a comprehensive story about what the German aircraft industry would have been able to or not and what was only cancelled by administrative misdeterminations. Exactly that you cannot extract from this book - except the one find I quoted.

Kool Kitty89,
I read the given statement as "one to one basis". But if you read the statement as economist, you see that some values are missing. Use of non-strategic materials, employment of machine tools, transportation of components are not mentioned. Also, the statement is only meant about production, not about maintenance - although one might conclude an engine easier to produce is also easier to maintain.

Regards, RT

 

[case.vw]

In a recommended list of literature on the History Facts website I found a reference to this book.

Vajda, Ferenc A.; Dancey, Peter : German Aircraft Industry and Production 1933 - 1945 : Shrewsbury 1998 : Airlife : ISBN 1853108642

Does anyone know and reccommend this book? The review on Amazon.com isn't very promissing.