A Shocking Absurdity - Jumo 004 Engine Development

[Mosshorn]

This passage below comes from: Messerschmitt Me-262 Arrow to the Future by Walter Boyne

Pg 36 - speaking of the head of Jumo's jet engine program...

"Franz had started with just a few key people, and as he was unable, under the Reich's labor priority system, to hire engineers from the already hard pressed piston engine community, he was forced to take new engineers, just graduated from school, and press them into service. It was not until 1944 that the entire jet division grew to more than 500 people."

Man-o-man...

Meanwhile, P&W had 39,000 people working on engine development...

Moss

 

[BombTaxi]

This has been covered in another thread recently. But to add my own .02...

It makes perfect sense to keep skilled engineers working on piston engines; at this stage they are cheaper and more reliable than jets and 95% of LW aircraft need them. Also, your comparison to P&W is somewhat disingenuous, as you compare 500 in Junkers jet R&D dept with (I presume), 39000 people in P&W's entire R&D function.

 

[Hop]

P&W had about 40,000 workers in total, production and development.

 

[Glider]

Anyone know how many Frank Whittle had?

 

[davebender]

unable, under the Reich's labor priority system, to hire engineers from the already hard pressed piston engine community

As I understand it some of the early German jet engineers had previous experience with turbochargers. Which makes sense as turbochargers and turbojets have some similiarity. It also suggests not all engineers were hired straight from college.

 

[red admiral]

Anyone know how many Frank Whittle had?

From memory, there were only three technical staff at Power Jets.

500 engineers working on the 004 is quite a lot. Pratt and Whitney's ~40,000 would also include technicians and fitters.

 

[Colin1]

From memory, there were only three technical staff at Power Jets

I believe that's true
Whittle relied on hired hands from time to time but this was in a non-technical capacity

 

[davebender]

According to the original post there were 500 Jumo engineers working on jet engine development during 1944. That includes more then just the 004B engine.

Junkers Jet Engine Developements
Jumo 004-A. Original engine. Design completed by 1943 but not mass produced.
Jumo 004-B. Essentially a Jumo 004-A which uses less nickel and chromium.
Jumo 004-C Had increased thrust, auxiliary fuel injection and afterburner. This series was only projected, none was built.
Jumo 004-D With regulator for throttle movement and two stage fuel injection. Prototypes were built and tested, serial production began shortly before end of WWII.
Jumo 004-E The D-series engine with a shorter tail pipe and a double tube, as well as an afterburner. This engine was developed for getting a better altitude performance. At the end of the war several test engines were ready and serial production was planned for summer 1945.

Junkers Jumo 012 (Eleven stage compressor with a double stage turbine)
The Jumo 012 was a special designed for the Junkers Ju 287. The engine was designed with a thrust of 6000 to 6400 lbs . Some parts were ready at the end of the war, however the prototype was not completed. When the Russians occupied Dessau, they decided to continue the Jumo 012 development A total of 15 engines were ordered for the end of 1946. The Jumo 012 prototype was ready for static tests at the end of June, but this was destroyed during tests in August . A second prototype was built in autumn 1946 and several changes were introduced. The new engine was designated Jumo 012B. In Summer 1948 the first five Jumo 012Bs were built, but as other jet engines offer more power at a more compact design, the Jumo 012 development was stopped in 1948.

Junkers Jumo 022
Developed at Junkers Motorenbau in 1944,this was the final Junkers engine project before the end of the war. Based on the Jumo 012 it was designed with a gearing for a contra rotating airscrews, one engine was made before the wars end but it was never tested. In 1947 how ever the Soviets asked the Junkers design team in the USSR to develop this engine. In 1950 the first 022 was ready for static tests and given the designation TV-2 or TV-12, by 1951 the engine was making 5,050 hp and by 1955 7,650 hp as the TV-2M. At around this time there was a twined TV-2, given the designation 2TV-2F this engine made 12,000 hp

 

[Mosshorn]

FAOW - Famous Aircraft of the World - No.24 - Army Japanese Fighters has several pictures of the Ki-94II prototype production crew rushing to finish the aircraft...all eight of them. Eight guys, total, that's it, as in 8, assigned to build a new - desperately needed - high-performance prototype aircraft from scratch during a war you are losing...badly. (6 of the 8 pictured below.)

Why start a war, if you have no intention of actually trying to win it... Yeesh.

Moss

 

[Colin1]

FAOW - Famous Aircraft of the World - No.24 - Army Japanese Fighters has several pictures of the Ki-94II prototype production crew rushing to finish the aircraft...all eight of them. Eight guys, total, that's it, as in 8, assigned to build a new - desperately needed - high-performance prototype aircraft from scratch during a war you are losing...badly. (6 of the 8 pictured below.)

Why start a war, if you have no intention of actually trying to win it... Yeesh.

Moss

That's a big plane for a single

 

[BombTaxi]

FAOW - Famous Aircraft of the World - No.24 - Army Japanese Fighters has several pictures of the Ki-94II prototype production crew rushing to finish the aircraft...all eight of them. Eight guys, total, that's it, as in 8, assigned to build a new - desperately needed - high-performance prototype aircraft from scratch during a war you are losing...badly. (6 of the 8 pictured below.)

Why start a war, if you have no intention of actually trying to win it... Yeesh.

Moss

I think you forget, or take for granted, that the US had a huge population, many more skilled technicians than other countries, was not being bomber around the clock, and was not being subjected to a crippling naval blockade, as Japan was at that point in the war

And the Japanese were deadly serious about winning, but went well beyond the six months timescale that Yamamoto prophetically gave them for success...

 

[DerAdlerIstGelandet]

I think you forget, or take for granted, that the US had a huge population, many more skilled technicians than other countries, was not being bomber around the clock, and was not being subjected to a crippling naval blockade, as Japan was at that point in the war

And the Japanese were deadly serious about winning, but went well beyond the six months timescale that Yamamoto prophetically gave them for success...

I also don't think he is looking at the overall picture of things. There are many more aircraft being built than just that one aircraft he posted a picture of. Workers are going to be allocated more to the larger production runs and aircraft that have already been in mass production for quite some time. This way the most aircraft can be produced which is what Japan really needed.

Also that picture and the post he made does not describe at what stage the production is in. This could be the end and these are the 8 workers that are assigned to do finish it. It does not say how many workers were allocated to the whole assembly process.

 

[Mosshorn]

The book has a couple pages of pictures at various stages of build and it's always the same eight {8} guys standing around. Plus, nobody is ever in the background, no machine tools, no equipment, it really is a bizarre series of pictures.

Apparently, the first Ki-94II prototype finally did get finished, but it was still being prepared for it's first flight at wars end and never did fly.

There does not appear to be a "sense of urgency" in the program at all. But compared to this picture of an Ki-43 Oscar factory, maybe that's how the Japanese went about building airplanes...

Moss

 

[BombTaxi]

You're still missing the point Mosshorn. Towards the end of WWII, the Japanese would not have had the resources to have thousands of guys with machine tools building aircraft in huge factories. I suspect that the Japanese also had a much less 'production-line' orientated approach to aircraft manufacture than the US - as did France, Italy, the UK and many other powers. It's not a sign of military inferiority, just a sign that the US was ahead of the rest of the world in mass production techniques - which wouldn't be surprising if you realised such techniques were invented in the USA

 

[Mosshorn]

Bomb Taxi wrote: "You're still missing the point Mosshorn. Towards the end of WWII, the Japanese would not have had the resources to have thousands of guys with machine tools building aircraft in huge factories. I suspect that the Japanese also had a much less 'production-line' orientated approach to aircraft manufacture than the US - as did France, Italy, the UK and many other powers. It's not a sign of military inferiority, just a sign that the US was ahead of the rest of the world in mass production techniques - which wouldn't be surprising if you realised such techniques were invented in the USA."

Never thought about that, but I guess you're right. Milch talks about how much "craft" was involved in German aircraft production until he stepped in and put an end to it all with much faster and more productive semi-skilled assembly line techniques and workers.

If the Japanese never converted over, they were at a huge fundemental disadvantage.

It really is strange trying to "think back" 65 years in time {much less 2,000 years!}

I wonder what we are doing today that in 50-100 years people will be asking, "What were those guys thinking?"

Moss

 

[davebender]

What makes you say that?

http://www.econ.yale.edu/growth_pdf/cdp905.pdf

The Ju 88-program constituted one of the largest German armament projects. The firms
which took part in the original plan of 1938 employed more than half of the workforce
engaged in German airframe production.

Ju 88-program, which was established by Göring in mid-1938 and was
aimed at exploiting economies of scale and raising the technological standards of aircraft
production,

I suspect the Me-109 program was organized on a similiarly massive scale. However I don't have production information for the Me-109. Perhaps Kurfurst can dig something up.

These two programs (Ju-88 and Me-109) constituted about 75% of the total German aircraft production effort during 1939. I don't think any other nation had their aircraft production focused on only two models. How much more mass production could you ask for?

 

[Mosshorn]

Eagle in Flames by E.R. Hooten has this passage:

Pg 146 - speaking of Milch...

"While the workforce increased it was considerably diluted, reducing the emphasis upon craft-work, and between 1941 and 1944 the percentage of skilled male workers ay Messerschmitt dropped from 59 to 21, with skilled workers used in a supervisory role as new processes enabled semi-skilled workers, including women, to operate specialized equipment. [...] The reorganization saved both time and material. By 1944 there was a 53% saving in Bf 109 production time, man-hours had been halved and there was a 25% saving in raw materials; and between 1940 and 1944 the amount of metal for each BMW 801 radial dropped from 5.14 tons to 2.79 tons and man-hours had been reduced from 3,260 to 1,250 per engine."

Moss

 

[davebender]

The source I provided shows that mass production was employed in the Ju-88 program from the beginning and provides plenty of detail. However I'm not as familiar with Me-109 production. Please provide a historical example where "craft-work" was used in the Me-109 program rather then mass production.

 

[BombTaxi]

I think it's a reference by inference Dave - the author states 'craft-work' was reduced, so there must have been 'craft-work' to start with. My own 0.02 is that the Germans simply streamlined production processes as compared to prewar 109 manufacture, and spent less time on pretty finishing and other non-essentials. Virtually every major combatant country underwent the same journey between 1939-45.

 

[cherry blossom]

There is an account by Jiro Horikoshi of Reppu design posted at the J_aircraft board The Design and Development of Carrier Fighter Reppu by Jiro HORIKOSHI! Part I~II which discusses how pressure for maximum production slowed prototype construction. There was once a photograph of a factory producing the N1K2 also at J_aircraft, which suggests an assembly line but I have not yet rediscovered it. All the Hayabusas seem to be in a similar state in the picture with engines already fitted, so perhaps the aircraft were finished by skilled workers after the structure was built with special purpose tools.

ps. The pictures were of the N1K1-J prototypes and are at http://www.colesaircraft.com/N1K1-J.html. Sorry for the confusion.