Ju-288 vs Do-317

[davebender]

I get the impression the Luftwaffe wanted the Jumo211 to power most German military aircraft. If not for Messerschmitt's preference for Daimler-Benz engines the DB601 program may also have been cancelled.

RLM didn't get serious about DB601 engine production until 1940. So I don't see any connection with cancellation of the DB603 program during 1937.

 

[Siegfried]

Udet allowed the FW 187 to procede on the provision that it use the Jumo 210 since the DB600/601 was in short supply. I suspect this hid the aircraft's potential and so the Luftwaffe missed out on a long range escort fighter.

 

[davebender]

I think I have this dispute between RLM and Daimler-Benz figured out.

Daimler-Benz in the Third Reich - Neil Gregor - Google Books

October 1935. RLM wants to build a relatively large aircraft engine factory at Genshagen to produce the new DB601 V12.
.....Seperate company to be formed. It would be under Daimler-Benz control.
.....RLM to provide start up capital of 5 to 10 million RM.
.....Daimler-Benz to finance the remainder with a loan of 40 to 45 million RM. RLM would guarantee the loan.

Daimler-Benz refused this contract offer. They wanted RLM to finance the entire engine plant, which Daimler-Benz would operate and profit from.

Daimler-Benz had RLM over a barrel. The German fighter competition was in full swing and both finalists (Me-109 and He-112) wanted the DB601 engine.

RLM relented but the new DB601 engine plant was scaled back by over 50%. 20 million RM total capital. All but 750,000 RM provided by RLM.

RLM did not fund expansion of the Genshagen DB601 engine plant until 1940 and only because that engine was desperately needed by the growing Me-109 fighter program. RLM also cancelled funding for the DB603 engine program during 1937 to 1940.

Other aircraft proposals powered by Daimler-Benz engines (Fw-187, He-100, Fw-190 and Do-217) were turned down by RLM. Fw-190 and Do-217 aircraft proposals were ressurected after they considered other engine choices.

If not for bone headed decisions by Daimler-Benz management and RLM during October 1935...
- There would be twice as many DB601 engines available by 1940.
- The DB603A engine would probably enter mass production during 1941. Continued development of more powerful versions would receive adequate funding.
- The Fw-187 and He-100 would enter service during 1940 powered by DB601 engines.
- The Fw-191C would enter service during 1941 powered by DB603 engine.
- There would be no BMW801 radial engine. And nobody would miss it as the DB603 engine was superior in most respects.

 

[Shortround6]

Other aircraft powered by the DB series of engines

He 111B series,
He 111D series runs into supply problems with DB engines leading to Jumo E series. No production of "D"s
He 111J series reverts to DB 600 engines.
He 111P series changes to DB 601 engines in 1938. last "P"s built use 601N engines.
Do 215 series.
Fi 167 dive bomber

and a few other prototype aircraft including the He 118 dive bomber. The DB series of engines were not fighter engines, they were a general purpose engine to be used in what ever air frame needed them. I believe over 600 He 111s were powered bu DB engines leading up to the war, almost 400 of the "P" series alone. Not big numbers by later standards but how many other counties had 400 twin engine bombers of a single type in 1939?

 

[davebender]

The He-111 bomber would probably be replaced by the Do-217 during 1941. Heinkel production would mostly switch to the He-100 fighter.

The Do-17 / Do-215 was a dead end. Production will end during early 1941 whether additional DB601 engines are available or not.

I wonder if there would be a Fw-190 at all? RLM would already have two excellent short range fighter aircraft (Me-109 and He-100) plus the excellent Fw-187 long range day fighter. Not producing the Fw-190C would free up a lot of DB603 engines for other airframes. Perhaps the Ju-88 series.

 

[Siegfried]

SNIP

I wonder if there would be a Fw-190 at all? RLM would already have two excellent short range fighter aircraft (Me-109 and He-100) plus the excellent Fw-187 long range day fighter. Not producing the Fw-190C would free up a lot of DB603 engines for other airframes. Perhaps the Ju-88 series.

Large scale production of the DB601, DB605 and DB603 eats into both BMW's and Junker's combat aircraft market however second line aircraft benefit. The Junkers 211 is simply heavier though the latter versions with the presurised cooling circuits (Jumo 211J, P and F) were good while the BMW 801 also has issues.

The scenario I immagine is that Daimler Benz concentrates on improving its DB600 series engines, not bothering with too much effort on the DB604 but Junkers is allowed to continue with the Jumo 222 a full speed but abandons the Jumo 213 since the DB603 has taken its role completely. The Jumo 222 is the companies future and then enters service in derated form (say 1800hp or 2000hp) rather than the full 2500 demanded for the Ju 288 and takes over powering Ju 88S, Ju 188, Ju 388. It's smaller and lighter than the BMW 801 and yet a little more powerfull in derated form; eventually it grows to its full 2500hp form and propells the Ju 388J3 at speeds of 444 mph.

The Jumo 211 is now not in short supply and is therefor installed on the Ju 252 or 352 transports (instead of the BMW 323), which now creates and extremely impressive transport. A Ju 252 can fly all the way from Berlin to Stalingrad with 2.5 tons of cargo, of load its supplies and fly back without refueling. The Arado 234 STOL transport is also built, using the BMW 801, which is also not in critical supply. (both Ju 252 and Ar 234 were effected by engine supply issues of the Jumo 211 and BMW 801)

 

[davebender]

Dr. Tank preferred the DB603 engine for the Fw-190 from 1937 right to the end of the war. Dornier preferred the DB603 engine for their new Do-217 bomber. Junkers preferred their own engines for the Ju-87 and Ju-88 dive bombers. Why would the BMW801 engine be developed at considerable cost when nobody wants to use it?

I consider it more likely BMW would return to their roots and design a new water cooled engine. Daimler-Benz would have plenty on their plate if the DB601 and DB603 engine programs are fully supported. As a trade off DB does not develop the DB604 engine. Instead BMW will compete for the V24 contract.

Commercial rivalry between Daimler-Benz and Junkers was fierce. If the DB603 engine program is fully funded Junkers will have no choice but to kick their Jumo213 program into high gear. Otherwise the unthinkable might happen - DB603 engines might power newer versions of the Ju-88 / Ju-188. Personally I have my doubts as to whether Junkers can catch up to Daimler-Benz V12 engine development. But they would almost certainly try.

 

[Siegfried]

The problem for the Luftwaffe is that the Jumo 213 doesn't do anything that the DB603 can't already do (and of course vica versa). At least one of the next generation engines whether the Jumo 222, DB604 or BMW 802 will add immeasurably to the performance of certain aircraft.

The Jumo 222 has about the same swept volume as the DB603 but is heavier at 1088kg dry as opposed to 920kg dry. In theory a Jumo 222 derated to 2070 hp matches the power to weight ratio of the DB603. The BMW 801 was 1012kg dry so the Jumo 222 derated to 1870hp matches the 801's power to weight ratio. (I realise the wet weight of the Jumo will be higher). I find it difficult to believe that the 2200-2500hp Jumo 222 couldn't be derated to the 1870hp to 2070 range: and not produce a reliable engine a drop in RPM from 3250 to 3000and a drop in boost by 10%. I had afterall achieved about 25 hours MTBO, better than the BMW 801C when it was suspended.

The hypothetical derated Jumo 222 is too weak to make the Ju 288 worthwhile but it can fit into anything the BMW 801 does: Ju 88G, Ju 188, Ju 388, Do 217, Fw 190, He 219 etc and likely provide better performance than even the DB603 and 801. Eventually it will reach its projected 2500 (n fact it was rated at 2800 and even 3000hp at the end of the war). These aircraft in the 400+ mph to 450 mph range with this engine as it develops.

Of course everyone wanted the best, I think it was Milch decision, but the Germans repeatedly gambled on a short war or took emergency compromises to keep production up.

 

[davebender]

I agree.

However Junkers was favored by RLM right from the beginning. During the 1930s large, modern engine plants for the Jumo211 were built at Magdeburg and Kothen. During 1938 the Ju-88 was selected for mass production on an incredible scale (by German standards). At the beginning of WWII the Ju-88 program comprised over half the total German airframe construction workforce. Junkers also became the main player in the German jet engine program and the V24 engine program.

It's safe to say Junkers was not short of RLM funding. Unless RLM imposes more control over Junkers then happened historically they will compete for the DB603 contract also.

 

[gjs238]

If we favor DB for piston engines, BMW Junkers can concentrate on the turbojets.

 

[davebender]

It's not a matter of RLM favoring Daimler-Benz. Aircraft designers at Focke-Wulf, Heinkel, Dornier and Messerschmitt all preferred Daimler-Benz engines. Common sense suggests aircraft engineers have a better grasp as to which engines are superior then government bureaucrats would have. So RLM should listen to people like Dr. Tank.

Junkers will not go bankrupt. The huge Jumo211 engine program would continue. So would the moderate size Ju-87 and massive Ju-88 aircraft programs.

BMW would still make the BMW132 radial engine in sizable quantities. If they want a bigger piece of the military procurement pie they need to design something the military wants to purchase. Perhaps a compact and lightweight air cooled twin radial engine producing about 750hp. Just what the Luftwaffe needs for the Hs-129 CAS aircraft and for newer versions of the Fw-189 Heer cooperation aircraft. It would compete against the Argus As411 V12 engine for that contract.

 

[Denniss]

The Jumo 213 was born out of the 211, just more rpm, higher boost pressures etc. Why should Junkers stop this development ? AFAIK durig development it was named Jumo 211 with a high version number.
I don't know why RLM asked for a high-power radial engine but why not? For a gound attack fighter it's often better to have air-cooled engines. Or they just wanted to have more options on the engine market.

 

[davebender]

Daimler-Benz has just been blacklisted by RLM. Junkers has yet to perfect the Jumo211 engine. What are the chances they can develop an even more powerful V12? V24 engines and jet engines are many years away if they work at all. That leaves 1938 Germany with no aircraft engine more powerful then the imperfect Jumo211 for the next 5 years or so.

BMW steps in and offers to build a high performance radial engine. BMW management suggest this lightweight, powerful and reliable engine will be in mass production within 3 years if only RLM will bankroll development. Bureaucrats at RLM accept these promises. What other choice do they have after cancelling the DB603 engine program and cutting the DB601 program back to half size?

Ostracizing Daimler-Benz during 1936 was perhaps the worst decision made by RLM during its entire history. That decision negatively impacted German aircraft production right up to 1945.

 

[Shortround6]

In 1936 neither the DB 600 or the Jumo 211 was "Perfected". Getting DB to finish up on the DB 601 may have been more important than trying build two different V-12s at the same time. Much like R-R shelving the Griffon for several years. When did the first pre-production 109s get DB601 engines? The E-O series of ten in late 1938?

 

[davebender]

RLM cut DB601 engine program funding by more then 50% during 1936. They wouldn't do that if the DB601 program was considered a high priority.

 

[Shortround6]

Then what was the "high priority" engine program in 1936?

 

[davebender]

Junkers was the fair haired boy of the Luftwaffe.

A large Junkers engine plant was built at Magdeburg during 1937 and a second large engine plant at Kothen during 1938. That's in addition to the massive Ju-88 program which absorbed about half of the total German airframe workforce all by itself.