Franco-British vs. USSR in 1942 (1 Viewer)

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Lichtenstein was historically ordered after the collapse of the Nazi regime in this scenario and was contingent on the RAF night bombing to a large degree. In this scenario the RAF doesn't really develop that same strategy due to the collapse of the Nazi regime before BC starts to develop into a heavy hitting force in 1942. Maybe they will get some work they can use, but ultimately there won't be a lot available after Hitler is killed and the Civil War/power struggle prevents the Germans from really focusing on new developments when their country is falling apart.

Yes but Becker had got the first FuG 202 kill already in August 1941, so even if not yet in widespread production there were some sets and info on its successes around and Soviets were effective to extract info.
 
Yes but Becker had got the first FuG 202 kill already in August 1941, so even if not yet in widespread production there were some sets and info on its successes around and Soviets were effective to extract info.

I did not know that. It would seem it started earlier than I thought, but nevertheless we don't know if the Soviet electronic industry was capable of making those prototypes into serial production. I'd say it would take years probably.
 
depends on what you call serial production. A couple of dozen sets or 3-400 hundred. If the Russians can't fit radios into some of the their aircraft and a large number of their tanks I find it hard to believe they could build radars by the hundreds.

They did have an amazing ability to build things by the dozen though.
 
Soviet were developing several twin-engine fighters in 1939-41 but the crisis of 41 stopped most projects and only Pe-3 (the fighter version of Pe-2) went to production
Weren't most of them stopped because they were failures? Such as the Mig-5
Were they failures or did they fall out of favor due to shifting requirements? The MiG 5 seems to be the best of the lot and mainly held back by the cancellation of the AM-37 engines and possibly overall shift in emphasis towards low altitudes along with limited value of the later M-82 powered version. (an AM-38 powered low-alt heavy fighter/attack variant may have been more attractive, but there doesn't seem to have been interest in that and it would be directly competing with Il-2 production -and regardless of potential greater effectiveness and survivability of a higher performance fighter/bomber attack plane with more accurate centerline armament, the Soviets didn't seem to be favoring that direction of development)

However, with this scenario avoiding the Soviet evacuation and industrial relocation as well as having greater need for long-range, high altitude fighters as escorts, the MiG twin and its AM-37 engines might have been given much higher priority. A developed AM-37 would also benefit the Pe-8. Same for the AM-39 as a potential followon high altitude engine. (though the AM-35 may have been reasonable to apply to the MiG early on in the interim before production problems with the AM-37 were worked out, and while performance would obviously be lower, you'd at least save some weight with the lighter AM-35As)

I know the AM-37 was abandoned historically, and its existing problems may not have been totally solved without curtailing power output somewhat (at least in the short term), but given the success of the AM-38 (and later AM-42) and overheating apparently being the main problem on the AM-37 there seems to be plenty of room for solving those issues. The AM-37 seems to be to the AM-38 what the AM-39 was to the AM-42, and in both cases the low altitude versions seem to have gotten priority.


Beyond that, a smaller twin using Klimov engines might have been more attractive as an escort fighter. The Ta-3 seems more in that size class, though used rather bulky radial engines and the range cited on wiki isn't very promising. Still, it seems like an aircraft that would be better suited to the Klimov V12s than the large, fairly heavy 14 cylinder M-88 radials it used. (a bit like situation in the Fw 187 discussions regarding using captured Gnome Rhone 14N radials, or a bit worse even)


Fine points.
The AM 38 was indeed to the AM 35A what basically the Merlin VIII was to the Merlin III - an engine with lower S/C grearing, with most of everything else remaining the same. The difference was a bit lower compression ratio (7:1 down to 6.8:1), and the AM 38 was rated for extra 100 rpm more for take off. The S/C gear ratio for the AM 35A was 14.6:1, for the AM 38 it was 11.05:1.
BTW, the AM 38F was turning 2350 rpm for take off (and emergency; the impeller was of smaller diameter; CR was down to 6:1), 2150 was for the AM 38 and 2050 was for AM 35A.
The AM-38 really seems more related to AM 37 development given the timing, power output, weight, and structural reinforcements.

I'm sure an AM-35 derivative with supercharger configuration similar to the AM-38 would have been possible and allow for a substantial power increase at low altitudes, but not the 1,680 hp the AM38 was producing. (something in the 1,400-1,500 hp range seems more realistic, and should be a good deal lighter than the AM-38 as well, and somewhat lighter than the AM-35)




Can we at least agree that in terms of radar the Soviets aren't going to capture the later developments and will be stuck trying to make sense of whatever the Germans were working on, as most of the scientists would probably flee west? They were remain at a major disadvantage and maybe would be lucky to get some Wurzburg radars. By this point airborne radar has been developed, probably not even Hohentwiel due to the lack of need without an Atlantic front.
The most useful german technology captured would be examples and plans that actually fit better with the Soviet's more limited manufacturing capabilities. Some of the German turbine developments might be useful for both jet and turbocharger development, but a lot of that would probably be limited as well. If they captured Heinkel/Ohain's early development work and/or some of their materials that had been moved to museums in Berlin (I believe both the He 178 and some of their prototype engines were moved there) it may have been fairly significant. Using radial turbines in jets or especially turbochargers may have overcome some of the issues the soviets were dealing with. (at least those relating to turbine burnout due to thermal and aerodynamic stresses -radial turbines allow practical use of considerably lower quality metals and scale in size somewhat more easily than axial turbines -all modern automotive turbochargers use radial turbines)
 
AFAIK despite serious effort the AM37 just couldn't pan out. Perhaps with captured German engineers they could, but I imagine most them would flee to the west or were already there. The headquarters of BMW and DB were in the West, where the engineering work was done, but Jumo was in Dessau, in the Soviet zone; I imagine they would flee west without the historical destruction of infrastructure and Hitler not around to shoot them for fleeing. The Soviets would get some goodies in the East, but I doubt enough to get to altitude in enough time considering how many issues the Germans had doing so themselves with their country intact. Inheriting the remnants of East Germany probably isn't going to be good enough.
 
Were they failures or did they fall out of favor due to shifting requirements? The MiG 5 seems to be the best of the lot and mainly held back by the cancellation of the AM-37 engines and possibly overall shift in emphasis towards low altitudes along with limited value of the later M-82 powered version.........I know the AM-37 was abandoned historically, and its existing problems may not have been totally solved without curtailing power output somewhat (at least in the short term), but given the success of the AM-38 (and later AM-42) and overheating apparently being the main problem on the AM-37 there seems to be plenty of room for solving those issues. The AM-37 seems to be to the AM-38 what the AM-39 was to the AM-42, and in both cases the low altitude versions seem to have gotten priority.

we do not have good information on the AM-37. It seems to be an AM-35 fitted with "boosted supercharging" were is not a very precise term. Higher gear ratio or new supercharger? Sounds like higher pressure not how it was obtained. It was also fitted with a water/radiator (intercooler) in the intake duct. Since only HP ratings appear in most sources without altitudes, or rpm or manifold pressure we are left guessing. Trying to make 1500-1600hp at altitude is a lot harder than making 1500-1600hp at low altitude, The air is compressed more which means it is hotter (less dense) and the added heat throws more heat stress on the engine, add 100 degrees to the intake temperature and the peak combustion temperature goes up 100 degrees and the exhaust temperature goes up 100 degrees. Add in the fact that you may be making 100-150 more Hp in the cylinders in order to drive the supercharger and still get the 1500-1600hp to the crankshaft and cooling problems can be much worse than in a low altitude engine making the same power.


Beyond that, a smaller twin using Klimov engines might have been more attractive as an escort fighter. The Ta-3 seems more in that size class, though used rather bulky radial engines and the range cited on wiki isn't very promising. Still, it seems like an aircraft that would be better suited to the Klimov V12s than the large, fairly heavy 14 cylinder M-88 radials it used. (a bit like situation in the Fw 187 discussions regarding using captured Gnome Rhone 14N radials, or a bit worse even)

The M-88s may have been large but they were not all that heavy. They weighed within 20-30lbs of most P W R-1830 engines. They weighed about 50-90KG more than a M-105 engine depending on model but that doesn't include radiator and coolant. The M-88 would also make more power higher up than the M-105 engine/s.



The AM-38 really seems more related to AM 37 development given the timing, power output, weight, and structural reinforcements.
I'm sure an AM-35 derivative with supercharger configuration similar to the AM-38 would have been possible and allow for a substantial power increase at low altitudes, but not the 1,680 hp the AM38 was producing. (something in the 1,400-1,500 hp range seems more realistic, and should be a good deal lighter than the AM-38 as well, and somewhat lighter than the AM-35)

The AM-35A went about 830kg, the AM-37 was 885kg, the AM-37A was 850kg, the AM-38 was 850kg and the AM-38F was 880kg. The heaviest was 6% more than the lightest. It's enough to win a bar bet but not enough to much practical difference. Granted the different engines may have required different radiators and/or intercoolers which can change the weight a bit. The AM-42 picked up about 100kg.
 
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Were they failures or did they fall out of favor due to shifting requirements? The MiG 5 seems to be the best of the lot and mainly held back by the cancellation of the AM-37 engines and possibly overall shift in emphasis towards low altitudes along with limited value of the later M-82 powered version. (an AM-38 powered low-alt heavy fighter/attack variant may have been more attractive, but there doesn't seem to have been interest in that and it would be directly competing with Il-2 production -and regardless of potential greater effectiveness and survivability of a higher performance fighter/bomber attack plane with more accurate centerline armament, the Soviets didn't seem to be favoring that direction of development)

Historicaly, the German invasion of SU threw many wrenches in Soviet plans. After shortly, the only aircraft to receive Mikulin engines in series was the Il-2, deemed as necessary as bread and air for Red Army. Without invasion, the derivative of the MiG 5 might come in handy, but that one would've probably involved M-82 as engines if we want it to mix it at low level. With either Mikulin or Shvetsov, it wouldn't be so limited in capability as Il-2.

However, with this scenario avoiding the Soviet evacuation and industrial relocation as well as having greater need for long-range, high altitude fighters as escorts, the MiG twin and its AM-37 engines might have been given much higher priority. A developed AM-37 would also benefit the Pe-8. Same for the AM-39 as a potential followon high altitude engine. (though the AM-35 may have been reasonable to apply to the MiG early on in the interim before production problems with the AM-37 were worked out, and while performance would obviously be lower, you'd at least save some weight with the lighter AM-35As)

I'd try the Mikulin engines on the future Tu-2, since the 1st two prototypes have the AM 37 installed, and performance capability was promising. Pe-8 without escort won't do much for SU, though.

Beyond that, a smaller twin using Klimov engines might have been more attractive as an escort fighter. The Ta-3 seems more in that size class, though used rather bulky radial engines and the range cited on wiki isn't very promising. Still, it seems like an aircraft that would be better suited to the Klimov V12s than the large, fairly heavy 14 cylinder M-88 radials it used. (a bit like situation in the Fw 187 discussions regarding using captured Gnome Rhone 14N radials, or a bit worse even)

Soviet 'DB Fw 187'? For altitudes between SL and 5000m, the M-105 will do (1000 CV at 4 km), above that the M-88B would be a better idea (1100 CV at 4 km in 1st S/C gear, but also 1000 CV at 6 km in 2nd S/C gear; all values for no ram).

The AM-38 really seems more related to AM 37 development given the timing, power output, weight, and structural reinforcements.
I'm sure an AM-35 derivative with supercharger configuration similar to the AM-38 would have been possible and allow for a substantial power increase at low altitudes, but not the 1,680 hp the AM38 was producing. (something in the 1,400-1,500 hp range seems more realistic, and should be a good deal lighter than the AM-38 as well, and somewhat lighter than the AM-35)

The AM 38 was a development of AM 35A, same S/C with lower gearing and with 100 rpm more allowed for take off. Weight difference was negligible. AM 38 produced 1600 CV, the AM 38F was at 1700.
If we want a small fast power boost for the Mikulins, then installing the inter-cooler on the -35A or/and -38 might be good; maybe also rate the AM 35A for higher boost and/or extra 100 rpm. Other options include the medium-altitude gearing, and later the 2-speed gearing; a little decrease of CR for the AM 35A would also come in handy for extra boost.
 
AFAIK despite serious effort the AM37 just couldn't pan out. Perhaps with captured German engineers they could, but I imagine most them would flee to the west or were already there. The headquarters of BMW and DB were in the West, where the engineering work was done, but Jumo was in Dessau, in the Soviet zone; I imagine they would flee west without the historical destruction of infrastructure and Hitler not around to shoot them for fleeing. The Soviets would get some goodies in the East, but I doubt enough to get to altitude in enough time considering how many issues the Germans had doing so themselves with their country intact. Inheriting the remnants of East Germany probably isn't going to be good enough.

The Eastern part of Germany, the ones the Soviets occupied and communised, was then the technological heart of Germany. It had much of the high tech electrical electronics industry, machine tools, aviation, optics, radar, engine and automotive industry. Firms such as Junkers and Argus/Horche(now Audi) came from there. Firms like Daimler Benz and BMW were more the exception.
 
we do not have good information on the AM-37. It seems to be an AM-35 fitted with "boosted supercharging" were is not a very precise term. Higher gear ratio or new supercharger? Sounds like higher pressure not how it was obtained. It was also fitted with a water/radiator (intercooler) in the intake duct. Since only HP ratings appear in most sources without altitudes, or rpm or manifold pressure we are left guessing. Trying to make 1500-1600hp at altitude is a lot harder than making 1500-1600hp at low altitude, The air is compressed more which means it is hotter (less dense) and the added heat throws more heat stress on the engine, add 100 degrees to the intake temperature and the peak combustion temperature goes up 100 degrees and the exhaust temperature goes up 100 degrees. Add in the fact that you may be making 100-150 more Hp in the cylinders in order to drive the supercharger and still get the 1500-1600hp to the crankshaft and cooling problems can be much worse than in a low altitude engine making the same power.
I wasn't expecting the AM-37 to be making power on the level of the AM-38, less in the 1,600 range, more in the 1,400 range. Somewhat like comparing the Merlin 50M to the Merlin 47 (except with an intercooler), while the Merlin 45 would be more like the AM-38 (or 38F) with the AM-35's supercharger gearing with increases to boost and RPM and possibly an inter/aftercooler and power more in the 1,500 hp range.

2-speed supercharger gearing would obviously be useful and make inclusion of an inter/aftercooler less critical.



Soviet 'DB Fw 187'? For altitudes between SL and 5000m, the M-105 will do (1000 CV at 4 km), above that the M-88B would be a better idea (1100 CV at 4 km in 1st S/C gear, but also 1000 CV at 6 km in 2nd S/C gear; all values for no ram).
Might higher altitude supercharged Klimov engines be developed if there was a greater need? (with corresponding decrease in take-off power, of course)

Plus, on an escort fighter, range and fuel efficiency are more important, so the reduced drag of the V-12s may have been worth some performance loss there. (unless the M-88 also had an edge in specific fuel consumption)

If we want a small fast power boost for the Mikulins, then installing the inter-cooler on the -35A or/and -38 might be good; maybe also rate the AM 35A for higher boost and/or extra 100 rpm. Other options include the medium-altitude gearing, and later the 2-speed gearing; a little decrease of CR for the AM 35A would also come in handy for extra boost.
Wiki has references to the AM-35A using an aftercooler, but I'm not sure of this or how it compares to the AM-37's intercooler if the AM-35 didn't implement one at all.



The Eastern part of Germany, the ones the Soviets occupied and communised, was then the technological heart of Germany. It had much of the high tech electrical electronics industry, machine tools, aviation, optics, radar, engine and automotive industry. Firms such as Junkers and Argus/Horche(now Audi) came from there. Firms like Daimler Benz and BMW were more the exception.
What about the Bramo portion of BMW or Heinkel and Hirth?
 
The Eastern part of Germany, the ones the Soviets occupied and communised, was then the technological heart of Germany. It had much of the high tech electrical electronics industry, machine tools, aviation, optics, radar, engine and automotive industry. Firms such as Junkers and Argus/Horche(now Audi) came from there. Firms like Daimler Benz and BMW were more the exception.

Do you have any sourcing on German industry during this period? I'd be curious to learn more
 
...
Might higher altitude supercharged Klimov engines be developed if there was a greater need? (with corresponding decrease in take-off power, of course)

Maybe worth a try, that approach gave a bit of extra power above 14000 ft to the V-1710 in 1942. Other options might include installation of bigger S/C (with or without intercooler), and/or debugging the 2-stage supercharged M-105PD.

Plus, on an escort fighter, range and fuel efficiency are more important, so the reduced drag of the V-12s may have been worth some performance loss there. (unless the M-88 also had an edge in specific fuel consumption)

I was thinking about a heavy fighter that would be operating 300-500 km away from front line , at least until the WAllies introduce a proper LR fighter - a heavy fighter with 2 M-105 engines would be hard pressed to do anything vs. Spitfire V, let alone Spitfire IX or other A/C the WAllies might throw in in 1942.

Wiki has references to the AM-35A using an aftercooler, but I'm not sure of this or how it compares to the AM-37's intercooler if the AM-35 didn't implement one at all.

Enlish language Wikipedia states the AM 35A as having an aftercooler, but it is not listed for AM 37 ;)
From here in Russian, my translation:

"— АМ-37 имел воздухо-водяной радиатор для охлаждения воздуха, подаваемого в карбюраторы после нагнетателя, а на моторе АМ-35А вместо него устанавливалась так называемая проставка, т.е. отрезок воздухопровода; "

AM-37 have had the air-water radiator for cooling the air, located next to the carburetors and after supercharger, on the place where the AM-35A have had a piece of ducting for air;

"— АМ-37 имел дополнительный насос для нагнетания воды в воздухо-водяной радиатор; "

AM-37 have had the additional water pump for air-water radiator;

"— диаметр крыльчатки нагнетателя мотора АМ-37 равнялся 285 мм вместо 275 мм у мотора АМ-35А"

Supercharger's impeller's diameter of engine AM-37 was increased to 285 mm instead of 275 mm on the engine AM-35A

BTW, the Russian language WIkipedia does not state that AM 35A was outfitted with intercooler.
 
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Yes but Becker had got the first FuG 202 kill already in August 1941, so even if not yet in widespread production there were some sets and info on its successes around and Soviets were effective to extract info.

Airborne radar wasn't quite so important for the Luftwaffe. By June 1941 the Luftwaffe has several Wurzburg Riessen in service which with a beam accuracy of 0,2 degrees and range accuracy of 25 meters can guide a night fighter to within 100m or so at 70km away. It was a FLAK radar that was misused. Wurzburg D could also do the job albeit at half the range and half the angular accuracy. Wurzburg C had been in service since early 1941 and already had conical scan and could do the job though its range accuracy was poorer. Wurzburg A had been in service since 1940, still fairly accurate, 2-4 degrees by wobbling the disc.

The Wurzburg partially down because its could be saturated, mainly because only 500 were built presumably due to expense, but at a certain level one may as well put ones radars on the ground rather than in aircraft.
 
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BRAMO BRandenberg MOtorworks. Brandenberg, east Germany Belin. Previously Siemens and Halske also associated with Siemens Schukert. Siemens itself was Berlin based.
At least one of Heinkel's major factory complexes was in Marienehe (now part of Rostock), and that would be in the east as well.

Depending at what point in 1941 Germany fell, Heinkel also may not have yet acquired Hirth either, so the jet engine (along with airframe) developments would have been presumably limited to Heinkel sites.

Engine development work and production at Bramo sites could have fallen into Russian hands (turbine and piston engine) as well.
 
Airborne radar wasn't quite so important for the Luftwaffe. By June 1941 the Luftwaffe has several Wurzburg Riessen in service which with a beam accuracy of 0,2 degrees and range accuracy of 25 meters can guide a night fighter to within 100m or so at 70km away. It was a FLAK radar that was misused. ...

Airborne radar was important. Once the night fighters were outfitted with it, and in decent numbers, they were able to kill same amount of RAF heavies with 300 night fighters as the Flak force (also outfitted with radars by then) was doing with ~3000 of heavy guns (and another thousands of light guns). By 1942, let alone 1943, most of the Flak batteries west of Oder were outfitted with fire control radars.
 
Airborne radar was important. Once the night fighters were outfitted with it, and in decent numbers, they were able to kill same amount of RAF heavies with 300 night fighters as the Flak force (also outfitted with radars by then) was doing with ~3000 of heavy guns (and another thousands of light guns). By 1942, let alone 1943, most of the Flak batteries west of Oder were outfitted with fire control radars.
I think one of the arguments being made was that with sufficient application and coordination of ground radar (and reliable radios on night fighters) onboard airborne radar wasn't entirely necessary to be effective.
 
Airborne radar was important. Once the night fighters were outfitted with it, and in decent numbers, they were able to kill same amount of RAF heavies with 300 night fighters as the Flak force (also outfitted with radars by then) was doing with ~3000 of heavy guns (and another thousands of light guns). By 1942, let alone 1943, most of the Flak batteries west of Oder were outfitted with fire control radars.

The Belt of Wurzburg Riessen, Himmelbelt or "Sky/Heaven Belt" became insufficient only when Bomber Command began dense bomber streams which would pass through the belt. The belt could only handle so many interceptions.
 
I think one of the arguments being made was that with sufficient application and coordination of ground radar (and reliable radios on night fighters) onboard airborne radar wasn't entirely necessary to be effective.

Te onboard radar was indeed just one of ingredients of the NF arm, it's importance increasing with greater distance from own GCI. LW made a number of night interceptions both in early days and later in the war with fighters without radars

The Belt of Wurzburg Riessen, Himmelbelt or "Sky/Heaven Belt" became insufficient only when Bomber Command began dense bomber streams which would pass through the belt. The belt could only handle so many interceptions.

IIRC Napoleon once said that armies deployed in long, thin lines are good to fight smugglers, but not against a powerful enemy.
 

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