- Thread starter
- #21
wiking85
Staff Sergeant
Of course this ignores the Me262 and a matured Jumo 004's potential.
Ta-152C equivalent to Tempest?
- Thread starter wiking85
- Start date
Ad: This forum contains affiliate links to products on Amazon and eBay. More information in Terms and rules
Of course this ignores the Me262 and a matured Jumo 004's potential.
But when would this potential have been realised? The engine that entered production in 1944 was less reliable than the prototypes built more than two years earlier. This retrograde step was caused by many factors, not least a shortage of strategic materials, something that would only become more acute as the Reich shrank under allied offensives.
The Me 262 (the only non piston engine aircraft in which I've ever taken a real interest in) makes a foot note to WW2 because it was the first jet powered aircraft to see active service. Even an ardent fan like me has to concede that in terms of the air war of WW2 it was irrelevant. It caused more consternation to the allies than actual damage.
Cheers
Steve
The list pretty well lines up with the list in Thomas and Shores' The Typhoon and Tempest Story: Note that the Fw 190s claimed by 486(NZ) Squadron's Sheddan Shaw on 14 April 1945 were from the encounter with JG 301's Ta 152H.
- Thread starter
- #24
wiking85
Staff Sergeant
It may well be that Junkers was planning a series of more advanced Jumo 004s but the central problem, a lack of strategic materials such as suitable high-strength high temperature alloys, would have been even more acute: without such materials the greater complexity of these advanced 004 variants would most likely have led to even greater reliability problems during operations.
- Thread starter
- #26
wiking85
Staff Sergeant
The more developed versions of the Jumo 004 (not the 012) required no more materials than the 004B, which required less than even the Jumo 211. These versions were restricted in how quickly they could have fuel dumped into them, which prevented flame outs and increased lifespan to 50 hours. Other versions that were better designed, but again didn't require more strategic materials, boosted engine life to 100 hours. Fuel consumption issues though I'm not sure would require strategic materials (that is the 012 version). Can you provide some evidence that the jumo 012 needed extra materials over the 004?
davparlr
Senior Master Sergeant
As I have argued on other sites, I think the Germans made a major mistake on relying on primarily axial flow engines. By the end of the war, German engine development had already slipped behind both Britain and American engines. Both the American J-33 and later the British Nene engine was run at 4000 lbs thrust in 1944. As far as I know, no German jet engine ran producing much more than 2500 lbs of thrust. Indeed, the American axial flow J-35 ran at 3620 lbs thrust in 1944, although it had production problems not cured until later, another indication of the development difficulties of the much more complex axial flow engine. The Germans had a lot of plans and concepts but many of them did not pan out and maybe more concepts would not have worked.
- Thread starter
- #28
wiking85
Staff Sergeant
You're making the assumption that the Germans worked on the Jumo 004 as a future pathway for development; they realized it was a dead end, but designed it that way because it was easier to get working and in combat without strategic materials in quantities that would make them cost prohibitive.
Follow on engines like the HeS 011 was meant to be the future, I'm just suggesting that the Jumo 004 still had potential in the war years, but post-war or, depending on how long the war lasts, later in the war the Class II and III engines would replace the Jumo 004.
https://en.wikipedia.org/wiki/Junkers_Jumo_004
This engine was all about getting into production first, not being the best. It won handily in that regard and in 1945 and 1946 it would have improved, but still been behind more advanced engines of course, but these would not have been available until 1946-7 at the earliest, which would still leave space for the Jumo, which was buying time for the more advanced German engines to get their kinks worked out.
When did the Nene first power an aircraft? 1948, not much help in WW2 which is the goal here. The J35 ran in 1946 for the first time, which meant it was still years from service introduction. The J33 was just entering production when the war ended, which didn't mean it was necessarily ready for service introduction either, just that production had started. The Jumo 004 entered production in 1943, though not full production, but was rushed into service introduction in mid-1944 arguably before it was fully ready.
Also it ran first in 1940, which indicates the time frame jet engines were taking between first run and full service introduction.
Last edited:
And that illustrates the problem for the Germans. I don't believe that they could have had a matured Jumo or any other engine in 1945 or 1946 by which time they would once again have been playing catch up with allied developments.
There was never any chance of the war lasting long enough for this to be anything but a 'what' if and this had nothing to do with the air war, which the Germans had already lost.
Any suggestion that a developed Jumo 004 would have lasted 100 hours in service life is unproven.
The CAA in the UK sets inspection times for critical parts in the later Derwent engines still operated privately here. These intervals, as of 2003, are 450 hours for the turbine disc and 900 hours for the impellor and shaft section. That is an illustration of the problems that a shortage of strategic materials was causing the Germans.
Cheers
Steve
- Thread starter
- #31
wiking85
Staff Sergeant
And BMW 801s powered prototypes in 1940, but it wasn't ready for full service introduction until 1942; the Jumo 222 was flying on prototypes in 1941, but was not really ready until 1943. Considering that the Nene didn't fly on an operational aircraft in service until 1948 this means nothing about getting into service introduction.
Last edited:
Peace time regulations are very different to war time expediencies......as the Me 262 perfectly demonstrated.
Just to put the short lifespan of the Jumo jet into perspective, in 2003 the CAA, with input from Rolls Royce, set the inspection interval for the late model Derwent engines fitted to the Meteors flying in the UK today at 450 hours for the turbine disc (900 hours for the impellor and shaft sections). Rolls Royce suggested a 15 year calendar life for the engines after which the engine should be effectively re-built. This is for privately operated engines with the aircraft flown in what the CAA calls a 'benign regime' but the differences between this and even a 'matured' Jumo engine with a total engine life measured in tens of hours are manifest.
German jet reliability was being severely curtailed by a lack of strategic materials and the 'work arounds' (in English we'd call them bodges) that they undertook to overcome this. It was a situation which was only going to get worse for them and did not effect the development of British engines by the western allies at all.
The RAF was in no rush to get the Meteor into service because there was no need for it. It would be naïve to imagine that had the need for a jet aircraft developed the same attitude would have prevailed. More resources would have been poured into the project in an effort to accelerate development and introduction of an RAF jet. It would be a normal reaction to a development by the enemy.
Cheers
Steve
- Thread starter
- #33
wiking85
Staff Sergeant
I have to disagree about this. The Meteor was in service in 1944, just about the same time as the Me 262; both were defensively operational, but the 262 had much higher speed, though lower engine life. The Meteor was used against the V-1 bombs and would have been used against German bombers if need be. Still, they weren't any more ahead of German developments in terms of getting engines into service, because there is only so much that could be thrown at a problem. Potentially yes, they could have invested more in their various projects and potentially had them earlier than historically with less reliability, but even then we are looking at 1946 at the earliest. The US tried to get its P-80 into service in Italy in 1945, but it was totally non-operational due to engine issues.
The best the Allies were able to rush into service was the Meteor, which was still well below the performance of the 262 even in 1945 after the Derwent engines were introduced. This was a centrifugal compressed engine too and offered only 200 lbs of thrust more than the Jumo 004B, which entered production nearly a year earlier. The contemporary Jumo 004D (phasing into production in Spring 1945) would have offered more thrust than the Derwent Mk. I (in service in January 1945). Only the Derwent Mk. IV would have barely bested the Jumo 004D, which wasn't available until at least 1946 AFAIK. The Jumo 004H would have offered 3970 lbs thrust and been in service some time before the Nene, as it was just an enhancement of the 004 rather than a bigger Derwent, like the Nene was. Yes, the Nene would have been better than the Jumo 004H (though the Nene would have lost to the Jumo 012, which was a bigger 004 like the Nene was a bigger Derwent), but the Nene wouldn't fit on a Meteor, so would require a new jet fighter.
German jet engines were ahead of the British ones by about a year or so. Even with the Jumo 004 being a dead end there were still developments of it that would have kept its edge if the war had gone on for a few more years until it could be replaced by something better, of which there were several other designs still having their problems worked out. I find it interesting that so many here seem to think that the post-war designs of the Allies were indications of their superiority of the Germans, while ignoring the other engines which also had not reached service yet that were under development with German firms. Comparing the Jumo 004 to post-war designs is not comparing apples to apples.
The contemporary of the Jumo 004 was the Metropolitan-Vickers F.2, which was also Axial flow and never entered service. Otherwise it was the Welland turbojet engine, which was well below the Jumo in performance, despite being a centrifugal compressor design. The US didn't have a functional engine during WW2 to throw into the comparison. The Derwent was the next step and it was better than the Jumo 004B, but was about to be passed up by the Jumo 004D when the war ended. That would have given the Jumo engine greater performance until 1946, by which time the Mark IV Derwent would be around, but then so would the 004H and probably the Jumo 012.
Keep in mind too that the Allies were rushing to get engines into service in 1943-44 once they became aware of the German jet engines (1943), but were not able to get anything better into service, save the Derwent, which still left the Meteor behind the Me 262 in terms of performance. The P-80 was not able to get into service, despite being deployed to Italy in 1945; its engines were a mess and it couldn't even fly.
I don't know why people always compare things from different times. The Me262 from 1945 compared to the Meteor from the fifties. The Jumo 004 from 1945 to the RR Nene from the fifties aso.
1975 I owned a Mini Cooper which had a Morris A engine with twin SU carbs, in 1978 I changed to a Golf I GTI with K-jetronic fuel injection, should I compare….
BTW I had fun with both cars.
cimmex
1975 I owned a Mini Cooper which had a Morris A engine with twin SU carbs, in 1978 I changed to a Golf I GTI with K-jetronic fuel injection, should I compare….
BTW I had fun with both cars.
cimmex
The RAF didn't rush the Meteor into service at all. It was put on 'Diver' operations which it was not particularly suited for. Beamont, who knew a thing or two about shooting down V-1s, tested the Meteor in this role on 26th August 1944. His verdict is a perfect example of English understatement, "it's not very good" he said.
The RAF made absolutely sure that the Meteor didn't get too close to the Luftwaffe. On deployment to the continent in early 1945 there were strict limitations placed on where it could fly. It was largely relegated it to trying to catch V-1s which it failed to do consistently. Like all early jets, including the Me 262, it lacked acceleration.
I notice now that you are talking about the war continuing for 'a few more years' rather than months to give the time for the Germans to develop their engines. What makes you imagine that they would retain their early advantage for a few more years? It seems unlikely to me even in this improbable 'what if'.
Cheers
Steve
The RAF made absolutely sure that the Meteor didn't get too close to the Luftwaffe. On deployment to the continent in early 1945 there were strict limitations placed on where it could fly. It was largely relegated it to trying to catch V-1s which it failed to do consistently. Like all early jets, including the Me 262, it lacked acceleration.
I notice now that you are talking about the war continuing for 'a few more years' rather than months to give the time for the Germans to develop their engines. What makes you imagine that they would retain their early advantage for a few more years? It seems unlikely to me even in this improbable 'what if'.
Cheers
Steve
Last edited:
- Thread starter
- #36
wiking85
Staff Sergeant
Whether we are talking about 6 months or 2 years, the Germans would have been able to maintain their technical edge due to their advances in the field. As it was even in May 1945 there were no jets as good as the Me 262, which was on its way to get better with the Jumo 004D and later H. Strategic materials and the state of allied bombing of industry would have had a major effect on what the operational status of all of this was of course, but in terms of design and performance it would have been better than the Meteor or P-80.
davparlr
Senior Master Sergeant
And I think putting all their eggs into the axial flow design was a mistake. I believe that if they had pressed the much simpler centrifugal flow design that they could have had a single 4-5000 lb thrust engine, straight wing fighter fielded in late '43, in time to affect the air war over Germany. Possibly, such engine installed into a P1101 type fighter could have been in production by early '45, pre-dating the F-86/Mig 15 by 2 years.
According to Antony L Kays books, the Nene was first run at 4000 lbs thrust on 27 October, 1944. The J33 generated 4,000 lbs of thrust first in February, 1944. The Germans had never even run an engine much over 2500 lb thrust, much less getting one into production.
According to Kay, "On 21 April, 1944 the TG-180-A1 was given it first test. It gave a thrust of 1,643kg/sec (3,620lb/sec) for a weight of 1,044kg (2,300lb) and no serious problems were experienced". The TG-180-A1 was the J-35. It did, however, have development problems. Its first flight was in February, 1946.
- Thread starter
- #38
wiking85
Staff Sergeant
Which is why no centrifugal design was in service prior to 1945? Even then those designs were weaker than the developed Axial design of the Jumo 004. The entire point of the Axial flow design was it was easier to get into service quickly, even though the Centrifugal design was more efficient; it was more difficult to get into service quickly and needed many more years to get it into widespread service. The Derwent was the only centrifugal design that was in service, which was in 1945, with 2000 lbs thrust. The Jumo 004D offered more than that. Can you demonstrate that the Germans could have had a centrifugal design in service in 1943?
That was a first test, that means nothing about getting an engine ready for production and service. Otherwise the Jumo 222 would have been ready in 1941 along with the Jumo 004.
That's the subject of another thread.
I prefer to stick to reality.
How many Me 262s were produced before the end of the war? Difficult to say, but somewhere over 1500 and less than 1700 would fall in with current best estimates.
What was their effect on the air war in Europe? Insignificant.
I'm a big fan of the Me 262. It was a technically advanced aircraft for its time. It was built under the most difficult and sometimes primitive circumstances and yet not that many fell apart in the air. Many were really badly built. It was forced into roles for which it was never designed (as were many WW2 era aircraft) and the airframe did at least begin to evolve over it's short life span.
It was an aircraft forced into service well before it was ready, this is where I would dispute the idea that the Germans had any significant lead, and as a result suffered the inevitable failures and losses associated with such a premature introduction. It could have been worse.
The big problem was the engines and I don't believe that the Germans had the method or the means to overcome this as readily as many here seem to think.
Cheers
Steve
Shortround6
Major General
This is not quite right, in late 1944 and 1945 you almost have to go month by month as trying to state what was true for an entire year is subject to a lot of interpretation at best.
"Between January and March 1945 however, two American pre-production Lockheed YP-80A Shooting Star fighter jets did see limited service in Italy with the USAAF" OK "limited service" but with well over 2000lb thrust engines.
"The initial production order was for 344 P-80As after USAAF acceptance in February 1945. A total of 83 P-80s had been delivered by the end of July 1945" After the war in Europe but in month no 7 of 1945 and again, at well over 2000lb thrust.
First production DeHavilland Vampire flies in April 1945 with well over 2000lb thrust engine, granted squadron service takes a bit longer.
The Axial flow design was NOT easier to get into service quickly, the British had a least one if not more axial programs and the US and 2 or 3 programs, even allocating them to engineering firms with extensive steam turbine experience resulted in spotty results. In part because the US imposed some rather restrictive secrecy rules which prevented companies from talking to each other (although a few of them could talk to a "parent/partner" company in England) which meant a lot of the same problems had to solved a number of times independently.
The Axial compressor ( the rest of the "stuff" ie, combustion chambers and power turbines are pretty much interchangeable between the two types) was very hard to sort out. The early axial flow compressors (everybody's) were heavy, complex, and had lower compression ratios and efficiency than the centrifugal compressor. By the late 40s and very early 50s this had flipped and new axial compressors were showing much better performance than the centrifugals but that is several years too late.
