B-29 vs Me 264 Dimensions

[SpicyJuan11]

I've been comparing the two recently and despite having almost the same wingspan (~43m, off by two inches), the B-29 has almost twice the height of the Me 264 (8.5m vs 4.2m) and an additional 10m in length (20.9m vs 30.2m). My question is, what exactly accounts for the design differences? Besides looking quite similar, both have the same mission, but the Me 264 is significantly smaller while having a relatively similar performance. Why was the Me 264 designed so short?

 

[pbehn]

What is "height" the 264 had a double tail fin design. The B-29 was longer but narrower it had two bomb bays because of that. They are just different airplanes, similar but not the same.

 

[SpicyJuan11]

What is "height" the 264 had a double tail fin design. The B-29 was longer but narrower it had two bomb bays because of that. They are just different airplanes, similar but not the same.

Thank you. I'm just trying to understand the reasoning behind the "odd" proportions of the Me 264.

 

[pbehn]

Thank you. I'm just trying to understand the reasoning behind the "odd" proportions of the Me 264.

It doesn't have odd proportions, it just has proportions, some aircraft had both single and double tails during their life, The Manchester had a triple tail to start with.

 

[SpicyJuan11]

It doesn't have odd proportions, it just has proportions, some aircraft had both single and double tails during their life, The Manchester had a triple tail to start with.

No I don't mean the shape of the tail, I'm thinking of the fuselage length/wing span ratio.

 

[pbehn]

I believe that to reduce drag the B29 fuselage was made long and narrower. You can make the same comparison between a Lancaster and a Stirling which had the same wing span but the Stirling was bigger in every other respect.

 

[Koopernic]

I've been comparing the two recently and despite having almost the same wingspan (~43m, off by two inches), the B-29 has almost twice the height of the Me 264 (8.5m vs 4.2m) and an additional 10m in length (20.9m vs 30.2m). My question is, what exactly accounts for the design differences? Besides looking quite similar, both have the same mission, but the Me 264 is significantly smaller while having a relatively similar performance. Why was the Me 264 designed so short?

I wouldn't say that the Me 264 and B29 had the same mission. The Me 264 was expected to conduct 10,000 mile round trip missions with around a 5000kg lb bombload from Europe to the East Coast to bomb Sperry Works and Alcoa etc. The B29 could perhaps do 6200 miles ferry range. The Me 264 was also only 75% of the size of the B29. It had to lot of challenges.

The Me 264 ran into several problems, mostly political it seems some strategic.
1 There was a very bad relationship between Professor Messerschmitt and Erhard Milch who was in charge of procurement at the time for the Luftwaffe. Milch did support the Me 262 mJet but in the minutes of meetings published by Manfred Griehls book "The Luftwaffe over Amerika" he is constantly making quips and sarcastic comments about the practicality of the concept of such a mission and aircraft.

2 The Me 264 could do the mission, the only problem was that with Jumo 211 engines it would take 2500m take-off roll and needed a nearly a 3000m runway. That run way was seen as a vulnerable target for allied bombing. Using RATO to shorten the takeoff roll was seen as too risky for standard missions.

3 The aircraft itself was large and would have been spotted and become a target for allied bombers.

4 When 2000hp variants of the BMW 801 became available the aircraft was capable of about 9200 miles range and (from, with about memory about 2000kg to 3000kg of bombs). There was flight test data at this point and the run way length requirements had become more acceptable but by that time too much time had been lost.

5 Messerschmitt was sensible about the about the expectation for his design. He envisaged the initial version with the the Jumo 211 as being a lightly armed maritime reconnaissance aircraft and a courier aircraft that could reach japan. It was quite a fast aircraft anyway at nearly 340mph and had sufficient cryogenic nitrous oxide for a 40 minute burst of speed at high altitude. It would have been lightly armed with waist guns and maybe a manned dorsal manualy aimed gun.

The aircraft in the fullness of time was to receive the 2400hp DB603H engine (which used 100/130 octane C3 fuel). The 2250hp DB603LA (on 87 octane with MW50) engine actually entered production for the Ta 152C so they actually achieved the required horsepower.

This aircraft had retractable remotely controlled turrets with duel 20mm guns. These turrets were actually developed and fitted to the second prototype (which was lost in bombing but there are many excellent photos). The aircraft could defend itself from any angle including the tail by super firing the ventral and dorsal turrets between the twin tails. With twin 20mm guns I would argue it had enough punch to stop a fighter before the fighter got through. There is no such thing as bullet proof glass that can withstand 20mm rounds.

6 The Germans had very successful in flight refuelling tests in 1942/1943 and I imagine they could have used Schwann-Luft radio buoys to organise rendezvous but it seen to have been too radical idea for Milch.

7 This very much gets down to resources such as hanger space, engineers and draftsmen. These were in short supply and never assigned. The me 264 did not have sufficient priority.

8 This also gets down to a strategic decision. Do you put resources into this. You would need to put hundreds of Me 264 over the USA to sufficiently saturate American defences to minimise attrition. It just seems to expensive. The other alternative was night bombing but that only becomes feasible when the Germans recover a British H2S.

9 Nevertheless just as a maritime reconnaissance bomber it would have been justified with the occasional nuisance raid occupying US and Canadian resources into continental defence.

 

[rinkol]

I wouldn't say that the Me 264 and B29 had the same mission. The Me 264 was expected to conduct 10,000 mile round trip missions with around a 5000kg lb bombload from Europe to the East Coast to bomb Sperry Works and Alcoa etc. The B29 could perhaps do 6200 miles ferry range. The Me 264 was also only 75% of the size of the B29. It had to lot of challenges.

The Me 264 ran into several problems, mostly political it seems some strategic.
1 There was a very bad relationship between Professor Messerschmitt and Erhard Milch who was in charge of procurement at the time for the Luftwaffe. Milch did support the Me 262 mJet but in the minutes of meetings published by Manfred Griehls book "The Luftwaffe over Amerika" he is constantly making quips and sarcastic comments about the practicality of the concept of such a mission and aircraft.

2 The Me 264 could do the mission, the only problem was that with Jumo 211 engines it would take 2500m take-off roll and needed a nearly a 3000m runway. That run way was seen as a vulnerable target for allied bombing. Using RATO to shorten the takeoff roll was seen as too risky for standard missions.

3 The aircraft itself was large and would have been spotted and become a target for allied bombers.

4 When 2000hp variants of the BMW 801 became available the aircraft was capable of about 9200 miles range and (from, with about memory about 2000kg to 3000kg of bombs). There was flight test data at this point and the run way length requirements had become more acceptable but by that time too much time had been lost.

5 Messerschmitt was sensible about the about the expectation for his design. He envisaged the initial version with the the Jumo 211 as being a lightly armed maritime reconnaissance aircraft and a courier aircraft that could reach japan. It was quite a fast aircraft anyway at nearly 340mph and had sufficient cryogenic nitrous oxide for a 40 minute burst of speed at high altitude. It would have been lightly armed with waist guns and maybe a manned dorsal manualy aimed gun.

The aircraft in the fullness of time was to receive the 2400hp DB603H engine (which used 100/130 octane C3 fuel). The 2250hp DB603LA (on 87 octane with MW50) engine actually entered production for the Ta 152C so they actually achieved the required horsepower.

This aircraft had retractable remotely controlled turrets with duel 20mm guns. These turrets were actually developed and fitted to the second prototype (which was lost in bombing but there are many excellent photos). The aircraft could defend itself from any angle including the tail by super firing the ventral and dorsal turrets between the twin tails. With twin 20mm guns I would argue it had enough punch to stop a fighter before the fighter got through. There is no such thing as bullet proof glass that can withstand 20mm rounds.

6 The Germans had very successful in flight refuelling tests in 1942/1943 and I imagine they could have used Schwann-Luft radio buoys to organise rendezvous but it seen to have been too radical idea for Milch.

7 This very much gets down to resources such as hanger space, engineers and draftsmen. These were in short supply and never assigned. The me 264 did not have sufficient priority.

8 This also gets down to a strategic decision. Do you put resources into this. You would need to put hundreds of Me 264 over the USA to sufficiently saturate American defences to minimise attrition. It just seems to expensive. The other alternative was night bombing but that only becomes feasible when the Germans recover a British H2S.

9 Nevertheless just as a maritime reconnaissance bomber it would have been justified with the occasional nuisance raid occupying US and Canadian resources into continental defence.

 

[rinkol]

Both planes were representative of the aerodynamic state of the art. However, the Me 264 more in the way of being a powered glider. This was unavoidable given the range objectives and the lack of suitable high powered engines. It is interesting to note that, even given 2,200 hp Wright engines, the B29 was considered under-powered.

 

[SpicyJuan11]

Thank you for your post, Koopernic! I have some further questions:

I wouldn't say that the Me 264 and B29 had the same mission. The Me 264 was expected to conduct 10,000 mile round trip missions with around a 5000kg lb bombload from Europe to the East Coast to bomb Sperry Works and Alcoa etc. The B29 could perhaps do 6200 miles ferry range. The Me 264 was also only 75% of the size of the B29. It had to lot of challenges.

I understand that the mission of the Amerika Bombers and B-29s in the Pacific differed in many important ways, however I believe that this can be rectified by simply comparing the H3 Schwerer Bomber (Heavy Bomber) variant to the B-29. According to Creek and Forsyth, the H3 powered by four DB603H's was to have carried 14,000 kg (30865 lbs) over a length of 7,900km (range was projected to have been increased to 8,400km with Jumo 213's). This compares to the B-29's 9072kg (~20,000 lbs) bomb load over 5,556km (~3000 nautical miles, both stats are from the 1950 SAC manual). If the Me 264 was 25% smaller, how was it able to carry a higher payload over much greater distances (in theory)? This doesn't make much sense to me.

4 When 2000hp variants of the BMW 801 became available the aircraft was capable of about 9200 miles range and (from, with about memory about 2000kg to 3000kg of bombs). There was flight test data at this point and the run way length requirements had become more acceptable but by that time too much time had been lost.

How much of an impact would Jumo 222 engines have had on this? Would it have made the 264/6m redundant?

This aircraft had retractable remotely controlled turrets with duel 20mm guns. These turrets were actually developed and fitted to the second prototype (which was lost in bombing but there are many excellent photos). The aircraft could defend itself from any angle including the tail by super firing the ventral and dorsal turrets between the twin tails. With twin 20mm guns I would argue it had enough punch to stop a fighter before the fighter got through. There is no such thing as bullet proof glass that can withstand 20mm rounds.

This is fascinating to me, could you please point me towards more sources on this? It doesn't seem to have been included on any other bomber designs (such as the Ju 288, Ta 400, Fw 238, Ju 390, etc)

6 The Germans had very successful in flight refuelling tests in 1942/1943 and I imagine they could have used Schwann-Luft radio buoys to organise rendezvous but it seen to have been too radical idea for Milch.

Where can I find more info on this? I do have Luftwaffe over Amerika by Manfred Griehl as well.

Finally, a bit off-topic, but do you happen to know the performance of the Ju 290B? Dieter Herwig and Heinz Rode give the number of 4,500kg bomb load over 5,600km at 5,500m altitude, at a speed of 450km/h. Karl Heinz Regnat gives the same numbers, but divides them into two bullet points: bomb load and take-off weight in one, performance stats in another. Does Regnat imply that those performance numbers are with the 4,500kg bomb load, or are these two things separate? It seems hard to believe that the Ju 290B could cruise at the max speed of its predecessor, the Ju 290A-5/6/7.

 

[swampyankee]

Thank you for your post, Koopernic! I have some further questions:

I understand that the mission of the Amerika Bombers and B-29s in the Pacific differed in many important ways, however I believe that this can be rectified by simply comparing the H3 Schwerer Bomber (Heavy Bomber) variant to the B-29. According to Creek and Forsyth, the H3 powered by four DB603H's was to have carried 14,000 kg (30865 lbs) over a length of 7,900km (range was projected to have been increased to 8,400km with Jumo 213's). This compares to the B-29's 9072kg (~20,000 lbs) bomb load over 5,556km (~3000 nautical miles, both stats are from the 1950 SAC manual). If the Me 264 was 25% smaller, how was it able to carry a higher payload over much greater distances (in theory)? This doesn't make much sense to me.

You are comparing claimed or desired performance, for the Me264, vs actual performance, for the B-29. Leaving that aside, one should make sure that the Me264's maximum range is given with the 14,000 kg bomb load. It's not unlikely that the maximum range is with a reduced bomb load.

How much of an impact would Jumo 222 engines have had on this? Would it have made the 264/6m redundant?

Versus the Me264? It's difficult to tell. The engines are individually much more powerful, but they're also heavier (this is not as bad as it looks; engines reduce the bending loads on the wing in flight), and their increased power comes with increased fuel consumption, so more fuel would be required for the same range. In any case, bombing North America from Germany (or continental Europe) would probably end up hastening Germany's defeat: the hundreds of bombers needed for an effective air campaign with conventional weapons would mean that something else doesn't get built. What kind of attrition do those unescorted heavy bombers suffer? How many Fw190s, Bf109s, and Ju87s are the Germans willing to sacrifice while the Luftwaffe is heavily engaged against Western Allies' bombers and Soviet fighters trying to chew up Luftwaffe tactical aviation? The heavy bomber might be useful in the East, but, again, the Germans don't have anything to escort them.

 

[SpicyJuan11]

You are comparing claimed or desired performance, for the Me264, vs actual performance, for the B-29.

Of course we have to measure based on claimed/desired/projected performance, because the Me 264 prototypes that were built were not equipped with DB 603's nor Jumo 222's, nor AFAIK, did they ever fly with any sort of bomb load. I am not trying to make a value statement based on these projected performances (ie one plane is better than the other), I am trying to understand why the Me 264 had such a large projected performance advantage over the B-29 when it was smaller and used similar engines. How do you pack 10K lbs of bombs more than what the B-29 carried, at much greater ranges, despite being 3/4 of the size?

I know there is a big difference between projected and actual, but in the case of the B-29 how much of a gap was this? What was the projected payload over range of the B-29 during design/prototyping?

Leaving that aside, one should make sure that the Me264's maximum range is given with the 14,000 kg bomb load. It's not unlikely that the maximum range is with a reduced bomb load.

Nope, I made sure. 7,900km (actually more) is the projected range with 14,000 kg bomb load. See the photo below, from Forsyth and Creek's Messerschmitt Me 264

Versus the Me264? It's difficult to tell. The engines are individually much more powerful, but they're also heavier (this is not as bad as it looks; engines reduce the bending loads on the wing in flight), and their increased power comes with increased fuel consumption, so more fuel would be required for the same range.

Very interesting, thank you! Didn't the Jumo 222 also have pretty good power/weight ration (1.03 hp/lb)? Doesn't that help make up for the extra weight as well?

In any case, bombing North America from Germany (or continental Europe) would probably end up hastening Germany's defeat: the hundreds of bombers needed for an effective air campaign with conventional weapons would mean that something else doesn't get built. What kind of attrition do those unescorted heavy bombers suffer? How many Fw190s, Bf109s, and Ju87s are the Germans willing to sacrifice while the Luftwaffe is heavily engaged against Western Allies' bombers and Soviet fighters trying to chew up Luftwaffe tactical aviation? The heavy bomber might be useful in the East, but, again, the Germans don't have anything to escort them.

I don't mean to be rude, but I would prefer not to get into a discussion here regarding "operational what ifs", I'm trying to better understand the technical aspects of the aircraft instead.

 

[Koopernic]

Unfortunatly you've overlooked the full data spec Spicyjuan. The Me 264 H3 came in two variants a "Schwerer Bomber H3"(heavy bomber) and a "Langstrecken Bomber H3" (long range bomber. The Langstrecken bomber is the long range version. With 2000kg of bombs it could fly 15000km (9320 miles). This version in addition to the normal 14300kg of fuel in armoured tanks had an additional 5421kg in lightly self sealing fuel tanks for the outward bound journey when the aircraft was not expected to engage in combat. The distance Berlin to New York is 3,968.77 mi (6,387.12 km) which is 7937 mi 12774 km round trip More than enough to reach the East Coast from Germany proper and much more if bases in Norway or France are used.

The Germans had developed and tested in flight refuelling tested in a series of experiments between Ju 290 and Ju 352 around 1942/1943. That would extend range about 1/3rd ie to 20000km and put much of the Midwest within range.

Note Messerschmitt had flight data from the 1350hp Junkers Jumo 211F powered Me 264 V1 and the 1700hp BMW 801 powered Me 264 V2 so the estimates are likely accurate.

The original Me 264 had been designed for the 1500hp Junker Jumo 211P, an engine whose development was abandoned in favour of the 1750hp Junkers Jumo 213A.

The engine the Me 264 H4 needed to do its mission was the 2400hp DB603H.

Hence by early 1944 the Germans had engines that could make the Me 264 practical. Early 1944 BMW 801 (1900hp), Jumo 213A (1750hp) and DB601A (1750). By late 1944 all of these engines were producing over 2000hp. They BMW801TJ would have given 2000hp but allowed cruising at 11500m and the Jumo 213E1 was producing 2050hp at very high altitudes and the DB603LA was producing 2250hp. The 2400hp DB603H required was surely not far away. The Jumo 222 was also planed. It was benching 2800hp on B4 fuel in 1944 and production was planed if it could reach 3000.

The following is from Messerschmitt Me 264 Amerika Bomber by Rober Forsyth and Eddie J Creek. A good book from Men that I have given a lot of money too.
Note the extra fuel and range.

 

[SpicyJuan11]

Unfortunatly you've overlooked the full data spec Spicyjuan. The Me 264 H3 came in two variants a "Schwerer Bomber H3"(heavy bomber) and a "Langstrecken Bomber H3" (long range bomber.

Hi Koopernic, I am comparing the Me 264 "Schwerer Bomber H3"(heavy bomber) with the B-29. I understand that the engines required for this variant (DB 604H) was not tested with the aircraft, but I think it's a fair comparison since it's in the same HP class (2200 HP) and same time as the B-29 (1944). The two H3 variants appear to be the same, so why is it that the Me 264 heavy bomber could carry more bombs a longer ways away than the B-29 while being smaller and having similar engines?

The Germans had developed and tested in flight refuelling tested in a series of experiments between Ju 290 and Ju 352 around 1942/1943. That would extend range about 1/3rd ie to 20000km and put much of the Midwest within range.

Interesting, had this been accepted rather than rejected, I wonder if the German designs would have been more focused on packing as many bombs in the airframe as possible than going for range, and how those designs would have looked!

Hence by early 1944 the Germans had engines that could make the Me 264 practical. Early 1944 BMW 801 (1900hp), Jumo 213A (1750hp) and DB601A (1750). By late 1944 all of these engines were producing over 2000hp. They BMW801TJ would have given 2000hp but allowed cruising at 11500m and the Jumo 213E1 was producing 2050hp at very high altitudes and the DB603LA was producing 2250hp. The 2400hp DB603H required was surely not far away. The Jumo 222 was also planed. It was benching 2800hp on B4 fuel in 1944 and production was planed if it could reach 3000.

Without going too much into the Jumo 222, wasn't production planned for 2000-2500 HP in 1942? If it was benching 2800 HP on B4, what would it have been with C3? I was under the impression that the Me 264 had always the Jumo 222 in mind.

Weren't there designs of the Me 264 with BMW 803 (4,500HP) or BMW 109-028 (6,700 HP+2,645 lbs of thrust)?

The following is from Messerschmitt Me 264 Amerika Bomber by Rober Forsyth and Eddie J Creek. A good book from Men that I have given a lot of money too.

I have this book too, albeit in PDF. I'd like to get a print copy, but $100+ is too pricey for a book I already have.

 

[msxyz]

Does anybody have the exact specifications and performance data of the V2 prototype (the one with 801s, armor and some armament fitted, enlarged wingtips)? All I can find now is the data about the V1.

 

[Capt. Vick]

Are we sure the B-29 (fuselage?) Was narrower than the Me-264's? I don't see it that way.

 

[msxyz]

I think the Me 264 fuselage was quite small and cramped by what I've seen. In all pictures of the aircraft, the engine nacelles and propellers look huge compared to the body, while -in truth- they should be the same 'power eggs' units used on Ju-88 (Also, there is a galley but no toilet! How were the aviators supposed to relieve themselves during a >24hrs flight? Did they install 'special seats' in the bomb bay? )

 

[Koopernic]

Hi Koopernic, I am comparing the Me 264 "Schwerer Bomber H3"(heavy bomber) with the B-29. I understand that the engines required for this variant (DB 604H) was not tested with the aircraft, but I think it's a fair comparison since it's in the same HP class (2200 HP) and same time as the B-29 (1944). The two H3 variants appear to be the same, so why is it that the Me 264 heavy bomber could carry more bombs a longer ways away than the B-29 while being smaller and having similar engines?


Interesting, had this been accepted rather than rejected, I wonder if the German designs would have been more focused on packing as many bombs in the airframe as possible than going for range, and how those designs would have looked!


Without going too much into the Jumo 222, wasn't production planned for 2000-2500 HP in 1942? If it was benching 2800 HP on B4, what would it have been with C3? I was under the impression that the Me 264 had always the Jumo 222 in mind.

Weren't there designs of the Me 264 with BMW 803 (4,500HP) or BMW 109-028 (6,700 HP+2,645 lbs of thrust)?


I have this book too, albeit in PDF. I'd like to get a print copy, but $100+ is too pricey for a book I already have.

The Jumo 222A3/B3 and Jumo 222E/F (with two stages and inter cooler) was put back on the production list in 1944 at 2800hp on B4 + MW50 which it was passing Bench tests on. Circumstances were getting bad as Germany approached collapse so they reviewed it and reset the goal at 3000hp. The war ended. There was also a scaled up version of this engine known as the Jumo 222 C/D.

 

[Koopernic]

I think the Me 264 fuselage was quite small and cramped by what I've seen. In all pictures of the aircraft, the engine nacelles and propellers look huge compared to the body, while -in truth- they should be the same 'power eggs' units used on Ju-88 (Also, there is a galley but no toilet! How were the aviators supposed to relieve themselves during a >24hrs flight? Did they install 'special seats' in the bomb bay? )

View attachment 604245

To get more range than the B29 the Me 264 used a smaller more streamlined fuselage. The wing cross section and structure were designed to store a huge amount of fuel. The structure was extremely well engineered for light weight. The competing Ta 400 coukd not approach it. The aircraft ultimately used higher wing loadings to reduce aerodynamic parasitic drag. This combined with low power to weight ratio meant it needed a relatively long runway. More powerful engines of 2400hp instead of 1700hp were the solution but they would take time to develop (DB603H) . An alternative was a relatively simple 6 engine stretch known as the Me 364 or Me 264/6m that alleviated all of these issues using standard available engines. It would have had a B24 liberator style tail gun.

The failure to invest in such an aircraft was a strategic blunder. It would have provided communication to Japan, allowed Renaissance for u-boats, attacked any convoy and forced the US to invest extremely heavily in its own defense. The He 177/277 were half measures.

 

[msxyz]

The problem of any large aircraft cruising at 200-250kts is that it is bound to become an easy prey for high performance fighters. Not even the open ocean was a safe haven after '42 for such an aircraft. The sole solution was either altitude (B-29, Ju-86R) or speed (Ki-46) and it seems that the Me-264 lacked both making it only marginally safer than a Fw-200.

The Germans should have kept on doing what they were doing best: hitting vital targets with pin point precision using dive bombers instead of turning London and other British cities into rubble with aircrafts unsuited for the role. They wasted a lot of resources that would have been available to produce the next generation of fighter-bombers or to field 'smart' weapons earlier. The failure to cripple the British industry and ports in the latter part of 1940 and 1941 was the turning point of the war in Europe (and having the hands full with too many enemies didn't help either...)

PS: still looking for that V2 data Anybody?