Luftwaffe copy the Merlin
 

Near the end of WW2 the Russian's captured four downed US B29's that had strayed off course into Russian owned lands. Within a short period the Russian's after spotting how good an aircraft it was had copied it rivet for rivet and put it into service as the TU-4.

Why then in the 1940's when the Luftwaffe captured many many Merlin engines and they must have realised it had far more scope for development than the Luftwaffe liquid cooled engines, as the latter stages of the war showed.

Why did they not just do an exact copy of the Merlin, and why stop with this, they captured and admired the Mosquito, Mustang, Tempest, Lancaster etc.....?

Was it down to National pride only, the shortages of materials did not really affect the production of aircraft production, even late in the war during the RAF and US bombing campaigns?

I will be interested in your thoughts on this.

Re: Luftwaffe copy the Merlin
 

It took the Soviets nearly 5 years to accomplish this. Most of this during peacetime.

Don

Re: Luftwaffe copy the Merlin
 

The Merlin was not a great advance over the German engines, which showed very much the same growth potential, and much the same power output at any given time. It was smaller than German engines, and relied upon 100 octane for its high power (thanks to an excellent supercharger using rare metals). It was easier to develop their own first-class designs than to change over production lines, at considerable cost in lost production, for something no better than their own, and relying upon exotic materials that they had no access to.

The B-29, however, was at least one complete generation ahead of Russian heavy bombers in airframe and systems technologies. It should be pointed out that the Tu 4 did have Russian engines and armament.

Re: Luftwaffe copy the Merlin
 

Hi Graham,

The Germans were experts at starting up and moving production lines so I can't see this as being the main reason. Interesting on the exotic materials in the supercharger though, the Germans had no access at all?
As for taking 5 years to develop the TU-4 from the B29 this was only started in earnest once the cold war began and the Russians found themselves needing a quick fix.
The Merlin was something that production could have been started. And I would guess, not that difficult in mating to the 109, just as the British did with the then average Mustang, to turn it into possibly the best offensive fighter of WW2.

I just dont understand the logic of not directly copying when you are fighting for survival. Im my eyes the hard work of initial development and design have been done

Re: Luftwaffe copy the Merlin
 

It isn't that easy. Where is the factory space that is not fully occupied? You want to build a new factory, where are the planners and builders to do this? Where are the machine tools that are not already being used full time? Where are the workers who are not already working overtime? You have to close down one line, clear the space, build up the new line, train the workers. This will take up to six months, in which time little is being produced, so the equivalent production is lost. When production does start, the workforce will be at the start of the learning curve, so initial production rates will be low. Your suppliers will not be set up to provide foreign technologies. Plus what you are then building is at least one more year out of date.....

No, Gemany did not have access to various exotic metals. This was partly what gave problems with the jet engine programme.

But the real question is why. You have this notion that the Merlin was something spectacularly better than what the Germans had. This isn't true. Yes, it was good, particularly the supercharger, but didn't offer them more power than they were already getting from their own industry - and their engines ran on poorer fuel.

Re: Luftwaffe copy the Merlin
 

Good evening Tapper !

Interesting question but I must agree Graham almost totally. There were three German factories, which developt and produced hight-performance piston-engines: Junkers with JUMO 211/213, Daimler-Benz with DB 601-605 and BMW (radia) 801. In development was jet-engine JUMO 004.

How and Why should a situation appear, that anyone in the German military equipment providement offices could come in war-times to the decision, to cut existing piston-engines lines, only to built up production-lines with all consequences in a time of war.

This would have been slightly thinkable in 1940 or 1941, but never under the circumstances of the years 1943 - 1945, when much of the key production went to the underground. This was much more important, than thinking about building the Merlin because the engine is some lighter and has a good supercharger, but no access to key-materials.

In this matter of questions, I could ask, why Great Britain, the USA and Russia never equipped their forces with own-built machineguns MG-42 of German origin, which are light, well designed, thrustworthy, cheap in production and with a high firepower of 1.200 rounds a minute. The German Army and many other forces are using this weapon for military purposes up to now.

Well, there are more examples like that, widespread all over the military world. It not so easy, to change a good-oiles own machienery-system in war-times with harsh changements.

All the best !

Horst Weber

Re: Luftwaffe copy the Merlin
 

"National pride"? I'm sure at the time they evaluated the Merlin they could see that there was more potential in continuing development of their axial flow jet engines such as the Junkers Jumo 004.

Re: Luftwaffe copy the Merlin
 

in August 1942 over station Касторная were shot down 9 Russian bombers.
what you know about this?

Re: Luftwaffe copy the Merlin
 

Also ...

Imperial measurements in Britain vs. metric ones in use throughout German industry? (We haven't quite cracked that one, 70 years on).

Deutsche Industrie Normen (DIN) vs. British Standards Institute (BSI) standards?

Re: Luftwaffe copy the Merlin
 

The US did seriously consider copying the 15mm Mauser aircraft gun. The British "Comet"-tank was suposedly heavily influenced by the German Panzer III.
Neither was successful copying.
On the other hand, the japanese bettered the original when they copied the .5 Browning machine gun. They turned it into a very successful 20mm cannon.

I have often wondered about a similar course of action, with better prognostication.
What would have happened if the French had licenced the Spitfire and the Merlin in 1937 to solve their fighter problems?
There was a longstanding tradition of such co-operation between Britain and France, so supposedly, the respective industries were quite capable of producing each others designs, despite the different measuring systems.

Birgir Thorisson

Re: Luftwaffe copy the Merlin
 

Re the B29/Tu4. The story goes that Stalin ordered the copy, saying "It must be exact, down to the last nut and bolt". Stalin's orders were not disobeyed, to do so meant a bullet in the back of the head.
So, the Russians produced nuts and bolts and everything else, to the American imperial measures, not even daring to use their own perfectly adequate metric equivalents. Thus prolonging development even further.

Re: Luftwaffe copy the Merlin
 

Hello,

As an interesting side note regarding copying of available equipment, the Swedes made a copy of the Pratt & Whitney Twin Wasp called the STWC-3. This was done due to the U.S. embargo on war material to Sweden. The copy was made without hardly any access to drawings etc. They also converted it from inches to mm. Totally 434 engines were made. A retroactive licence arrangement was later made after the war, something never expected by the US, the American firm claiming nothing but a symbolic payment (reputedly a licenses fee of 1 Swedish krona). The engine was used in types including the SAAB B 17, SAAB B 18 and FFV J 22.

Best wishes/Håkan

Re: Luftwaffe copy the Merlin
 

The French did have plans for using the Merlin in their fighters and bombers. However, given the designs they had coming along, setting up a line for the Spitfire would not be worthwhile. Although they fought the Battle of France largely with inferior types, the D520 was pretty good and other prototypes were flying.

Re: Luftwaffe copy the Merlin
 

I appreciate its where do you stop when you start copying enemy equipment, but with something as vital and war winning as an aero engine why not. By WW2 all sides appreciated that the war could not be won without winning the air war first. We all agree i am sure, that this is why D Day was a success and would not have even been contemplated without holding the air above the beaches.

By late 1941 the FW190 had made its appearance and had proven more than capable against Spitfire's however, I sure that the huge development potential for the Merlin had been recognised...that would have been the time to copy and improve for Germany.
Could the 109F have been fitted with the Merlin?
Would anyone care to guess on the 109F with a Merlin...better or worse?
And am I correct in saying that the potential for the Merlin was greater than any German liquid cooled engines of that time?

Re: Luftwaffe copy the Merlin
 

Graham Boak.

The question is; what where the prospects in 1936/37, when french re-armament plans were in deep trouble. The 1934 program had produced failed prototypes. (MS 405, Ni 161, Loire 250 and D.513). The 1936 program was some years into the future.
Hispano-Suiza and Lorraine-Dietrich were both having serious problems with the next generation of inline-engines. (Therefore the eventual use of Merlin in the D.521).

On the other hand, the Spitfire was flying, it´s performance was already in the range expected from the 1936 program-fighters, and Rolls Royce had spare capacity in mid 1938.
Vickers Armstrong had been connected to Wibault in France. RR did not licence it´s engines, but there was a long tradition of engine technology being passed back and forth over the channel.
So, why not order a stop gap quantity of 2-300 Spitfires, to be built in the new factories in France?
The main difference between the french and british aviation industries was not the nationalization in France, versus private enterprize in Britain. In both countries, the state built up the production capacity, which was run be favoured industrialists. Rather, the difference is that the french engineers failed to provide good-enough aircrafts, and aero-engines in time. No use having a large crop of super planes for use in 1941.
The importance of engines should not be underestimated. IF the MS 406 had been replaced by MS 411, it would have been far more competitive in may/june 1940. The 200 hp that the H-S 12Y was short in 1940 were sorely missed.

Birgir Thorisson

Re: Luftwaffe copy the Merlin
 

Birgir: This overlooks the problems and delays in getting the Spitfire produced in the first place.

I think you over-rate the Morane, although I entirely agree about the value of extra power.

Tapper. No, you are not right about extra potential. Yes, the 109F could have been fitted with the Merlin, as the Buchon proved, but at that stage (late 1940/1941) the DB601 had as much (or more) power as the Merlin so no advantage could have been gained - even ignoring the key point that only the previous year's Merlin could have been made available in any numbers.

Re: Luftwaffe copy the Merlin
 

The Griffon would have been a better engine to have been used. A much better engine all round.

Re: Luftwaffe copy the Merlin
 

But the Griffon was not something that the Germans could have copied, because of a lack of access to examples. Not were they without their equivalents: the DB603/Jumo 213 had the power and potential of the Griffon. The Jumo 222 and DB610 had even more potential - as indeed did the Eagle and Clyde, if rather further behind in development.

The Germans and the British had rather different development approaches (as indeed did the US) but it can't be justified that one was significantly superior to the other: certainly not to an extent to justify a direct copy.

The closest that actually occurred would be the way that the Centaurus was redesigned to an aft-exhaust system, in the light of Fw 190/BMW 801 experience, but this was a matter or airframe integration rather than internal engine design. It might be interestingly argued that this redesign, if producing a superior engine in the long run, meant that (arguably) Britain's finest aero engine missed the war. But that would be another thread altogether.

Re: Luftwaffe copy the Merlin
 

Graham:

If I overrate the MS 406, then you too overrate the D.520. Back in 1978, the belgian researcher Gaston Botquin sent to the Air International his figures for how many enemy planes were claimed, (confirmed and probable) for each french fighter pilot killed. I calculated the same statistic for the british Hurricane force from Brian Cull´s et.al. Twelwe Days in May. The figures are as follows.

MS 406 = 1:2.5
MB 151/2 = 1:2.9
H75A = 1:6.2
D.520 = 1:7.7
Hurricane = 1:11.1

The Hurricane is much superior to the D.520. Also, if you look at the Campaign in Syria in 1941, where the best French outfit faced fairly ordinary Hurricane outfits, the Hurricane still comes out on top. Ditto Operation Torch. Small samples to generalize, but...
One shortcoming of the MS 406 was that it rarely performed up to it´s advertized performance. (As is confirmed by Finnish performance tests). The HS 12Y-31 engine wore out quickly, and also lost power with altitude quickly. (Similar to the Allison V-1710.) It was only with the addition of the Szydlowski-Planion supercharger that this defect is alleviated. The MS 405 was of the same technical generation as the Hurricane. With comparable engine (MS 411) the aircraft should have performed similarly. The MS 406 had superior armament, (the motorcannon). The two/four wing-mounted machine guns were largely useless.

That brings up a different issue, which is more pertinent to the main theme of this thread. It is well known how the allies "lost" the opportunity to get their hands on the direct injection system before the war. But why didn´t they copy the strong points of the DB-601 series, as soon as war broke out. The Bosch injection system, and the supercharger gearing system. Both features kept the DB engines competitive for most of the war. Surely not Patent rights :)

Re: Luftwaffe copy the Merlin
 

It would have made more sense to keep the DB engine and copy the Spitfire!

http://www.unrealaircraft.com/hybrid/spitfire.php

Re: Luftwaffe copy the Merlin
 

Interesting Battle of France statistics, though I have to wonder about the consistency behind the claims. However, your comments on the Syrian campaign fly in the face of what I have read on the subject, where the Hurricane units came out very second-best against the D520, success coming more to the Tomahawk. But we have drifted from the subject of the thread....