WW2 Luftwaffe - what if strategic vision had prevailed?

[Grey Havoc]

It is somewhat ironic that the Luftwaffe initially had the advantage in the area of Radio Navigation and conversely in the area of night bombing.

 

[jsport]

View: https://www.youtube.com/live/4QfIfVpHXNk
Lengthy, but a detailed & fairly comprehensive explanation, but most importantly a systematic refutation of previous myths as well as Clausewitz

 

[Nicknick]

The real problem facing adoption of the Me262 earlier was not just a lack of vision. It was a lack of metallurgy. The Jumo 004 was held up because of an inability forge turbine blades of sufficient quality and duration that a single flight could be easily conducted without an engine failure occurring. Once that was overcome, in early 1944 engines with more than tens of hours of MTBF were possible and so it was the Luftwaffe was then able to order the Me262 into full production. There was the excuse that the aircraft had to be adopted to be a fighter-bomber which was bollocks.

The Luftwaffe would have been much better off with the He100 back in 1940 and the Fw187. Both were superior to the Bf109 and the Bf110. This would have enabled them to contest the Battle of Britain on an even footing with the RAF.

The Luftwaffe always lacked a true strategic vision. What it needed was both strategic and tactical bombers. The Ju88 was an excellent aircraft but overcomcentration on the He111 and Do17 had meant that the Ju88 was lacking in 1940. Without an adequate strategic bomber they didn't have the range to strike the fUSSR's industries, particularly after they had moved to beyond the Urals, while without a strategic fighter, they could not escort their bombers to the north of England.

Quite the opposite is true. The Germans had a well functioning prototype more than a year before the start of the serial production of the Me262. It had a higher thrust, lower fuel burn, higher turbine entry temperature and presumably a longer lifespan. The lack of Nickel and other strategic metalls forced them to develop an inferior version which required less critical metalls. The Germans were masters in forging at that time and so they forged hollow turbine blades with internal cooling. This was far ahead of the time and without internal cooling the lack of high temperature suited metalls would have made the turbine development to production impossible.

 

[Rule of cool]

German strategic bombers are a bit of a conundrum to me. I don't think Germany can undertake a comprehensive air strategy like the US and UK, who devoted something like a quarter of their total war efforts into air power; if Germany tried that their Army would weaken. On the other had they built ~1100 dud He177s and ~3700 obsolete He111s from 1942, so I think they could have built up a small/medium-size strategic bomber force without really negatively impacting the rest of their war effort. Such a force might have been put to good use in the East, Med and Atlantic but will never be able to 'duke it out' with the RAF over the UK.

 

[Nicknick]

German strategic bombers are a bit of a conundrum to me. I don't think Germany can undertake a comprehensive air strategy like the US and UK, who devoted something like a quarter of their total war efforts into air power; if Germany tried that their Army would weaken. On the other had they built ~1100 dud He177s and ~3700 obsolete He111s from 1942, so I think they could have built up a small/medium-size strategic bomber force without really negatively impacting the rest of their war effort. Such a force might have been put to good use in the East, Med and Atlantic but will never be able to 'duke it out' with the RAF over the UK.

German bombers were mainly designed to help at the frontline, not so much for area bombing over large distances. Of course, later on, there was a desire to be able to do that as well, but as you said, Germany never had the recourses to invest in a large fleet of four engine bombers. I believe, you really need a large fleet of bombers for such an attack, because the required protection of the bombers is not worth the effort for a small scale attack.

 

[Rule of cool]

German bombers were mainly designed to help at the frontline, not so much for area bombing over large distances. Of course, later on, there was a desire to be able to do that as well, but as you said, Germany never had the recourses to invest in a large fleet of four engine bombers. I believe, you really need a large fleet of bombers for such an attack, because the required protection of the bombers is not worth the effort for a small scale attack.

Bear with me I'm recalling the number off the top of my head from long ago. The USA armed forces slices were ~50% Ground Forces (~100 divisions), 25% Sea Forces and 25% Air Forces, the UK was similar at ~55% ground (~60 divisions), 22% Sea and 22% Air. In contrast the German slices were ~80% Ground (~260 divisions), 12% Air and 8% Sea. It's from these much larger slices devoted to Air Power that the USA and UK built their huge bomber forces and why Germany couldn't build up a similar huge bomber force without shrinking the land forces, which they needed to garrison their huge gains and fight the Soviets.

That said, Germany could have used the resources it did expend somewhat better and develop a useful heavy striking arm, perhaps for 'Operational' rather than 'Strategic' targets. Perhaps such an arm could strike Alexandria and the Suez Canal rather than trying to destroy Lliberty ship building yards or whatever.

 

[Nicknick]

After Germany was fighting against America and Russia, it was more than obvious that there weren't enough recourses to win the war. In fact, the overoptimistic assumption for war material production in the last years of the war weren't irrational, but based on that what was regarded of the necessary minimum to win the war. The consequence was degrading quality of war material which couldn't be compensated by the increased production numbers. In the end, much more tanks were running out of fuel or had mechanical defects than being destroyed by enemy action. Fuel starvation led to planes which couldn't be used anymore and new pilots couldn't be trained properly.

Building four engine bombers would worsened the situation, flying to the Suez canal or over the US would have needed a degree of sophistication which was only achieved after the war. I know, there have been plans of gigantic transcontinental super long-range bombers in Germany (as well as in the US and Japan) but none of these were available before the war ended. Building such a bomber fleet before the battle of Stalingrad would have never worked out.

I experienced this way of overoptimistic planning in a company in the last phase before everything collapsed...

 

[Rule of cool]

Germany's peak He177 deployment was about 350 in early-mid 1944 aircraft but only about 2/3 of those (~200-220) were operational. In contrast at about the same time the RAF kept 1,300-1,600 heavy bombers fuelled and crewed and the USAAF regularly dispatched over 2500 heavy bombers in a single morning from a force of 3,000-3,500.

In my mind Germany's best-case scenario is that the He177 isn't limited by the dive-bombing requirement, has 4 separate engine nacelles from the start and is apart from regular teething troubles a successful aircraft. In addition, given the success of this Alt-He177, He111 production is switched to Alt-He177 in 1942 with 1 Alt-He177 being produced for every 3 historical He111s more or less doubling production. As a result, by mid 1944 the Luftwaffe might have a bomber force of ~650-700 Alt-He177s and fly ~450 at a time.

Such a force is nothing to sneeze at, I could imagine it being deployed against the Normandy beaches or deep in the rear of Op Bagration. However, it's not going to cripple any economies like the Joint Bombing Campaign did.

 

[Scott Kenny]

Pardon me, this thread just popped back up.

The real problem facing adoption of the Me262 earlier was not just a lack of vision. It was a lack of metallurgy. The Jumo 004 was held up because of an inability forge turbine blades of sufficient quality and duration that a single flight could be easily conducted without an engine failure occurring. Once that was overcome, in early 1944 engines with more than tens of hours of MTBF were possible and so it was the Luftwaffe was then able to order the Me262 into full production. There was the excuse that the aircraft had to be adopted to be a fighter-bomber which was bollocks.

Or the recognition that an engine that last 50 hours is good enough.

I've often wondered about that reasoning. Surely just introducing longer engine bearers and revised oil piping couldn't have been that bigger a problem? Give the workers a day off while you change the parts and jigs 'round and bring in the next shift happy and rested and you really don't have to explain all that much to them.

Combined response:

No, it's not that easy. It's one thing to scratch-build a working example, another to introduce the redesigned components into mass production.

Combined response:

Why? All your doing is introducing redesigned parts that are already used...

You need to make new production jigs and prove the changed design.

Longer engine cradles means a change in your center of gravity, moving it forward. This may require a longer tail or just some lead ballast to keep the CG within limits.

Moving 3000lbs 2" forward of CG means you need 6000in-lbs aft. If you have 300" aft of CG, "all" you need is 20lbs ballast.

 

[Nicknick]

@Rule of cool : The He177 not only suffered from the request of being able to dive bomb, but, from what I read somewhere (?), also from to much standardisation. The Germans had standardised engine mounting geometry which worked fine for single engine arrangements. A switch between different engines like Jumo or Mercedes Benz was relatively easy because of this. The downside was, that the use of this standard mounting geometry for two engines very close to each other resulted in sharp 90 degree bends of hoses and oil pipes close to exhaust systems. After a couple of fires, this arrangement was changed and the aircraft became much more reliable.

The concept of four engines with two props was chosen for good reasons, it reduced the surface area and surly enabled a smaller rudder area compared to a four prop design. Despite that efficient propulsion design, the 6000 km range was not enough to attack the US or the Suez canal. At the same time, the speed wasn't high enough to attack without escort fighters, so that it would have required an enormous effort to built a large bomber fleet as well as the escort fighters to defend them. Help me out, I don't think Germany even had any long range escort fighter during the whole war, so a complete new development would have been needed for this too.


@Scott Kenny

Quite the opposite is true. The Germans had a well functioning prototype more than a year before the start of the serial production of the Me262. It had a higher thrust, lower fuel burn, higher turbine entry temperature and presumably a longer lifespan. The lack of Nickel and other strategic metalls forced them to develop an inferior version which required less critical metalls. The Germans were masters in forging at that time and so they forged hollow turbine blades with internal cooling. This was far ahead of the time and without internal cooling the lack of high temperature suited metalls would have made the turbine development to production impossible.

 

[T. A. Gardner]

Quite the opposite is true. The Germans had a well functioning prototype more than a year before the start of the serial production of the Me262. It had a higher thrust, lower fuel burn, higher turbine entry temperature and presumably a longer lifespan. The lack of Nickel and other strategic metalls forced them to develop an inferior version which required less critical metalls. The Germans were masters in forging at that time and so they forged hollow turbine blades with internal cooling. This was far ahead of the time and without internal cooling the lack of high temperature suited metalls would have made the turbine development to production impossible.

Actually, no. The 262 V1 ran on BMW 003's. These catastrophically failed on the first test flight. Both flamed out when the plane was put into a gentle turn because the compressor section was poorly designed and hadn't been tested for asymmetric air flow. BMW was forced to spend about 18 months redesigning their compressor section with lots of help from Brown Boveri in Switzerland.

Messerschmitt then redesigned the wing and aircraft to accommodate Jumo 004's taking about a year to do so. That delayed the project.

The hollow turbine blades were folded and welded sheet metal that was then flame sprayed with alumina to give some degree of heat resistance to them.

 

[T. A. Gardner]

As for 4-engine bombers. Given that Germany's aircraft industry could produce, using say 3 or 4 manufacturers, a total of about 8 to 16 4-engine bombers a day, at most, they wouldn't be able to keep up with even light losses and maintain any sort of really viable bomber fleet.

At a loss rate of 3% per day and a production rate of 16 planes per day, the Luftwaffe breaks even at 530 planes in service. That's losses from all causes: accidents, maintenance issues, enemy action, or whatever. If losses climb higher, the sustainable fleet gets smaller.

This means, realistically, that the Luftwaffe might have 250 to 300 usable bombers on any given day for operations everywhere. All that has to happen is one or two missions with serious losses and the whole fleet is reduced to impotence for weeks while it rebuilds.

Then there's the fuel issue...

 

[Nicknick]

The Jumo has been running long before, with better performance data but an unacceptable (for Germany at the time) high content of strategic alloys. The hollow turbine blades out of sheet metal were used in the Jumo 004, not the BMW. This was a remarkable trick to manufacture lightweight internally cooled turbine blades without requiring much of the critical metalls.

It's easy to say nowadays that the compressor design was poorly designed because it stalled when not being orientated perfectly to the incoming air, but this was the very first axial compressor ever taken a flight! Of course, you face new proplems when you are pioneering a technology!

300 Long range bombers without escort fighters wouldn't have helped a lot. At the same time, engine supply was very critically and each bomber would have reduced the number of much needed interceptors by four.

 

[T. A. Gardner]

The Jumo has been running long before, with better performance data but an unacceptable (for Germany at the time) high content of strategic alloys. The hollow turbine blades out of sheet metal were used in the Jumo 004, not the BMW. This was a remarkable trick to manufacture lightweight internally cooled turbine blades without requiring much of the critical metalls.

The Jumo 004 was not ready for use when the 262 V1 flew. It was ready before the 003 was redesigned and ready, so it was chosen.

It's easy to say nowadays that the compressor design was poorly designed because it stalled when not being orientated perfectly to the incoming air, but this was the very first axial compressor ever taken a flight! Of course, you face new proplems when you are pioneering a technology!

The problem was BMW had zero previous experience with gas turbines, or turbines of any sort. They were working blind, so-to-speak. When the Allies started developing axial turbojets, all the primary manufacturers were those in the steam turbine industry: Vickers, Westinghouse, and GE. They had long histories of developing steam and gas turbines and had massive research data to work from. German jet engine manufacturers didn't have that advantage. That's why BMW turned to Brown Boveri who was about their only available source of turbine blade profiles and knowledge on gas turbines.

300 Long range bombers without escort fighters wouldn't have helped a lot. At the same time, engine supply was very critically and each bomber would have reduced the number of much needed interceptors by four.

The Luftwaffe was well aware of the availability of engines. That's why the generally limited which engines a manufacturer could use in their designs. For example, Messerschmitt got priority on Daimler Benz engines in the 600 series. Bombers were to use Junkers 211 engines. Focke Wulf chose the BMW 801 for those same reasons. Engines weren't the problem. The supply of finished planes, crews, and fuel were.

 

[Nicknick]

The Lockheed Shooting Star arrived after the war couldn't even match the performance of the best piston fighters, let alone the Me 262. We had the discussion before, so try to learn something. Germany had a long tradition of building steam turbines. AEG, Siemens Vulcan, all started building steam turbines very successfully years before WW1 and were exporting steam turbines them all over the world!

As said, steam turbines are usually built as equal pressure types which work very different form gas turbines. They have almost no issues with sealing and parasitic flow, totally different blade geometries and a much lower working temperature. Of course, steam turbine development helps little in understanding compressor stalls.

So if BMW started with no idea at all (this was surly not the case...) it was even more remarkable that they managed serial production of axial gas turbines, something which the US could only achieve after they already analysed the German turbines!

The Jumo004 already made 10 hour runs 2 years before the first flight, but as said, it development was much delayed by material substitution. Neither the US nor the British were facing the same problem, but despite that, their development was slower.

http://www.aviation-history.com/engines/jumo004.html

 

[Scott Kenny]

It's easy to say nowadays that the compressor design was poorly designed because it stalled when not being orientated perfectly to the incoming air, but this was the very first axial compressor ever taken a flight! Of course, you face new proplems when you are pioneering a technology!

I mean, they were used to big centrifugal compressors, and those don't care that the airflow went through at least a pair of 90 bends.

 

[red admiral]

The Jumo has been running long before, with better performance data but an unacceptable (for Germany at the time) high content of strategic alloys

I have yet to see any sources showing that Germany developed even tiny quantities of nickel based superalloys like Nimonic and Inconel in the UK and USA respectively. They did manage some amounts of high temperature stainless steels (similar to UK mid 30s on early Power Jets units), but there is still a significant performance gap between these and the early superalloys.

 

[Nicknick]

I have yet to see any sources showing that Germany developed even tiny quantities of nickel based superalloys like Nimonic and Inconel in the UK and USA respectively. They did manage some amounts of high temperature stainless steels (similar to UK mid 30s on early Power Jets units), but there is still a significant performance gap between these and the early superalloys.

read my link above, it's even mentioned there.

Or take a look here (in German):

https://de-academic.com/dic.nsf/dewiki/723097

(Tinidur alloy)

The prototype Jumo004A even run for 100 hours flawlessly. It was capable of higher speed above the critical resonance of the shaft, which later on had to be reduced when the material had to be changed due to shortages.

So without the material shortages, Germany would have had a much better jet to an earlier time.

 

[Nicknick]

I mean, they were used to big centrifugal compressors, and those don't care that the airflow went through at least a pair of 90 bends.

In fact, they radial compressors are less sensible to stall than axial compressors, but they can also stall (see turbo surging). Steam turbine knowledge doesn't help with compressor stalls, high temperature alloys are blade sealing or the combustion chamber. If someone claims otherwise, he hasn't really understood gas turbine development.

 

[Scott Kenny]

In fact, they radial compressors are less sensible to stall than axial compressors, but they can also stall (see turbo surging).

Sure, that usually happens when you slam a throttle closed downstream of the compressor.

Steam turbine knowledge doesn't help with compressor stalls, high temperature alloys are blade sealing or the combustion chamber. If someone claims otherwise, he hasn't really understood gas turbine development.

Interestingly, GE was making the turbos for the US.

 

[red admiral]

read my link above, it's even mentioned there.

Or take a look here (in German):

https://de-academic.com/dic.nsf/dewiki/723097

(Tinidur alloy)

Yes this confirms my point that this was a high temperature steel rather than nickel superalloy like in the contemporary UK and USA engines. There is quite a difference in material performance at high temperatures.

 

[Nicknick]

Yes this confirms my point that this was a high temperature steel rather than nickel superalloy like in the contemporary UK and USA engines. There is quite a difference in material performance at high temperatures.

Tinidur could do the job very well, but even the 30 % Nickel content was regarded as to high. So using an alloy with an even higher nickel content (available or not) wasn't an option at all.

I wonder if the US really used nickel based alloy for the Shooting Star, or if they hesitated because of the manufacturing difficulties. The low performance indicates a more modest approach.

 

[Nicknick]

Sure, that usually happens when you slam a throttle closed downstream of the compressor.



Interestingly, GE was making the turbos for the US.

They made all kind of stuff, including Diesel engines, so it is not so suprizing.

 

[red admiral]

Tinidur could do the job very well, but even the 30 % Nickel content was regarded as to high. So using an alloy with an even higher nickel content (available or not) wasn't an option at all.

I wonder if the US really used nickel based alloy for the Shooting Star, or if they hesitated because of the manufacturing difficulties. The low performance indicates a more modest approach.

The eearly development and usage of better materials for jet engines is covered in detail beyond Wikipedia level e.g. in the Aeronautical Journal

 

[pathology_doc]

The Lockheed Shooting Star arrived after the war couldn't even match the performance of the best piston fighters,

The Shooting Star was present on a demonstration basis in Italy before the end of the war, and I seriously question your second assertion. Wikipedia only gives detailed figures for the C variant, but does mention the prototype topping out at over 500mph.

The Meteor Mk 1 was definitely slower than the best pistons.

 

[Nicknick]

The eearly development and usage of better materials for jet engines is covered in detail beyond Wikipedia level e.g. in the Aeronautical Journal

 

[Nicknick]

The eearly development and usage of better materials for jet engines is covered in detail beyond Wikipedia level e.g. in the Aeronautical Journal

Looks like you've been.searching for evidence but you couldn't find any evidence for it....

 

[Nicknick]

The Shooting Star was present on a demonstration basis in Italy before the end of the war, and I seriously question your second assertion. Wikipedia only gives detailed figures for the C variant, but does mention the prototype topping out at over 500mph.

The Meteor Mk 1 was definitely slower than the best pistons.

There was an article in the ""Spiegel magazine""magazine claiming the Me 262 reached supersonic speed, I put this in the same category....

 

[Arjen]

The Shooting Star was present on a demonstration basis in Italy before the end of the war, and I seriously question your second assertion. Wikipedia only gives detailed figures for the C variant, but does mention the prototype topping out at over 500mph.

The Meteor Mk 1 was definitely slower than the best pistons.

From United States Military Aircraft since 1909 by Gordon Swanborough and Peter M Bowers, Putnam 1989:

The first YP-80A was delivered in October 1944, and two aircraft reached Italy shortly before VE day.
[...]
Deliveries to the USAAF [of the production P-80A] began in Dec. 1945.

Maximum speed data for early P-80s from Lockheed Aircraft since 1913 by René J Francillon, Putnam 1982:
- XP-80: 502 mph / 808 km/h at 20,840 ft / 6,240 m - first prototype, de Havilland H.1B Goblin turbojet
- XP-80A: 553 mph / 890 km/h at 5,700 ft / 1,735 m - second and third prototypes, General Electric I-40 turbojet
- YP-80A: no data - service trials aircraft, reduced weight, General Electric J33-GE-11/ Allison J33-A-9 developed from I-40,
- P-80A: 558 mph / 898 km/h at sea level - J33 powered production aircraft

From The American Fighter by Enzo Angelucci and Peter M Bowers, Haynes 1987:
- P-80A: 492 mph / 792 km/h at 40,000 ft / 12,192 m

From https://www.defensemedianetwork.com...aversion-p-80-shooting-stars-in-world-war-ii/:

Possibly by coincidence, two YP-80As (44-83028/44-83029) arrived in Lesina, Italy in late January 1945, around the time Arado Ar 234B reconnaissance jets based at Udine, Northern Italy, began flying reconnaissance missions over Allied lines on the Italian front. It’s clear the YP-80As weren’t sent in response to Ar 234B operations, but it isn’t clear whether, if events had unfolded differently, the Lockheed jets might have intercepted the Arado jets. Lesina, with its single, pierced-steel planking runway, was part of the Foggia Airfield Complex, a series of World War II military airfields located within a 25-mile radius of the city of Foggia.

Exact dates for the start of both YP-80A and Ar 234B operations in Italy are in dispute; dates for the latter appear variously as January, February or March 1945 in various histories. “Pete 57,” a blogger who has studied both YP-80A and Ar 234B operations in Italy, wrote that, “One cannot help but wonder if the delivery of the YP-80As to an operational unit, just weeks after the beginning of the Arados’ operations, was merely coincidental…”

Almost everything we know about Project Extraversion in Italy comes from a draftee just past his 20th birthday. Albert James “Jim” Bertoglio was the official photographer for the Italy-based 94th Fighter Squadron “Hat In The Ring,” a part of the 1st Fighter Group, equipped with P-38J Lightnings – and destined, later, to re-equip with P-80 Shooting Stars in 1946. Bertoglio (1925-2012), who hailed from Medicine Lodge, Kan., was widely interviewed after the war. He remembered that while both test and operational pilots flew the YP-80As, civilians maintained them. Bertoglio is widely quoted as seeing a YP-80A flying north of its base near Foggia, Italy on some mysterious mission that was never explained.

According to Bob Esposito, a historian who studies the history of the P-80, the jet deployments to Europe were already classified and became even more so after the Borsodi crash in England. “The YP-80A operations were strictly off-limits to regular AAF personnel,” Esposito said in a March 24 telephone interview. “The whole thing was very hush-hush.”

An official history of the 1st Fighter Group states that a 94th FS pilot, Maj. Ed LaClare, flew “two operational sorties” in a YP-80A but “without encountering combat.” Other historians speculate that the YP-80As would have been used in battle if they had encountered a German adversary under the right circumstances.

 

[red admiral]

Looks like you've been.searching for evidence but you couldn't find any evidence for it....

No, I'm simply pointing out that if people wish to learn something about a subject there are resources available rather than just peddling the same old myths

 

[pathology_doc]

There was an article in the ""Spiegel magazine""magazine claiming the Me 262 reached supersonic speed, I put this in the same category....

Your combativeness is not backed by evidence.

I can see your future, and my vision thereof shows a permaban looming in it.

 

[T. A. Gardner]

The Lockheed Shooting Star arrived after the war couldn't even match the performance of the best piston fighters, let alone the Me 262. We had the discussion before, so try to learn something. Germany had a long tradition of building steam turbines. AEG, Siemens Vulcan, all started building steam turbines very successfully years before WW1 and were exporting steam turbines them all over the world!

What I stated is documented as the cause of the German jet engine industry being so slow to develop operational engines. The German steam turbine industry was relatively small in the 1930's. Germany was not a major shipbuilder by world standards.

As for the P-80, or the DeHavilland Vampire, or whatever, the Allied jets were adequate and competitive with what Germany was producing only they were vastly more reliable.

As said, steam turbines are usually built as equal pressure types which work very different form gas turbines. They have almost no issues with sealing and parasitic flow, totally different blade geometries and a much lower working temperature. Of course, steam turbine development helps little in understanding compressor stalls.

Yes, there is a difference between how you design a gas turbine using compressed air and then jet fuel versus a steam turbine. The world's leading expert on that happens to be, at the time, Sanford Moss at GE who had been experimenting with turbochargers for over a decade and had amassed the largest blade profile library in existence. A turbocharger is, for all intents, a jet engine run backwards.

So if BMW started with no idea at all (this was surly not the case...) it was even more remarkable that they managed serial production of axial gas turbines, something which the US could only achieve after they already analysed the German turbines!

Little idea. v, Ohain at Henkel worked around the issue by using a compound engine with an axial and centrifugal compressor section. Daimler Benz tried to use fixed and rotating turbine blades in their compressor section, a common thing with steam turbines, unsuccessfully.

GE, Westinghouse, Lockheed, and Vickers all began developing axial jet engines before any of them saw a German one. The most complex was undoubtedly Lockheed's where Nathan Pierce, a protege of the steam engine genius of Abner Doble, built the utterly massive J37 / L 1000 engine with a two-section 32 stage compressor with variable speed and a 5 turbine section to drive it.

GE started development of their J35 axial turbojet in 1943. Vickers began work on their F1 axial turbojet based on previous design work on the Freda that dated back to 1926 in mid 1940. The Freda bench ran--it was an axial turbojet--in April 1939. A Gloster Meteor flew successfully on the F2, a progression of the F1, in June of 1943. But issues with reliability and heat kept it from going into production.

The Westinghouse J 30 axial turbojet was first flight tested in Jan 1944. It too was developed from about 1942 on.

By the end of WW 2, the Allies were easily equal or ahead of Germany in turbojet designs and found little need to use German technology in this area for anything they developed postwar.

The Jumo004 already made 10 hour runs 2 years before the first flight, but as said, it development was much delayed by material substitution. Neither the US nor the British were facing the same problem, but despite that, their development was slower.

http://www.aviation-history.com/engines/jumo004.html

The US and Britain expected their jet engines to be reliable. That took time, time they had because they were winning without this technology. Certainly, the Germans were not streets ahead of the Allies in terms of jet engine development, issues with high temperature alloys aside. It is just the Allies weren't desperate and Germany was.

 

[Scott Kenny]

The US and Britain expected their jet engines to be reliable. That took time, time they had because they were winning without this technology. Certainly, the Germans were not streets ahead of the Allies in terms of jet engine development, issues with high temperature alloys aside. It is just the Allies weren't desperate and Germany was.

Right, and desperation should have resulted in accepting reduced lifespan for getting the engines in service now.

The Russians did accept greatly reduced engine lifespan for improved performance. I mean, if your fighter isn't expected to survive but 25 hours, why bother designing an engine to last longer than that? If the plane crashes, you're overhauling the engine anyways.

And, if your engine only has to last 25 hours or so, you can make a whole lot more power. As an aviation example, the BMW 801 versus a Kinsei. Same displacement, but a Kinsei is down 200hp on the same fuel. And the Kinsei was noted to be more reliable than the 801.

That said, turbine engines on the ragged edge of the limits like a J58 only picked up a few percent power when NASA was dragging the huge linear aerospike on the back of their Blackbirds, but IIRC went from 400hours TBO down to 40 hours.

 

[Rule of cool]

The concept of four engines with two props was chosen for good reasons, it reduced the surface area and surly enabled a smaller rudder area compared to a four prop design.

Good in theory, horrendous in practice, the simpler 4 nacelle arrangement is a much more effective path to success.

6000 km range was not enough to attack the US or the Suez canal. At the same time, the speed wasn't high enough to attack without escort fighters, so that it would have required an enormous effort to built a large bomber fleet as well as the escort fighters to defend them. Help me out, I don't think Germany even had any long range escort fighter during the whole war, so a complete new development would have been needed for this too.

The Amerikabomber is a flight of fancy that I don't give any credence to. On the other hand, the Suez Canal was mined and other deep targets in Egypt bombed in 1941 with He111s and Ju88s. A 4 engined bomber force could deliver a heavier weight of bombs over a longer distance.

Like the RAF the Luftwaffe bombed at night to reduce losses, the Me110 was used as an escort fighter during the BoB but was ineffective against faster and more nimble Spitfires despite generally being faster than Hurricanes. Small numbers of night fighters can and did escort RAF night bombing raids, presumably the Luftwaffe could do the same.


However, like almost all German WW2 things, it was never going to allow Germany to win the war with the sort of victory the Nazis wanted.

 

[Rule of cool]

As for 4-engine bombers. Given that Germany's aircraft industry could produce, using say 3 or 4 manufacturers, a total of about 8 to 16 4-engine bombers a day, at most, they wouldn't be able to keep up with even light losses and maintain any sort of really viable bomber fleet.

At a loss rate of 3% per day and a production rate of 16 planes per day, the Luftwaffe breaks even at 530 planes in service. That's losses from all causes: accidents, maintenance issues, enemy action, or whatever. If losses climb higher, the sustainable fleet gets smaller.

This means, realistically, that the Luftwaffe might have 250 to 300 usable bombers on any given day for operations everywhere. All that has to happen is one or two missions with serious losses and the whole fleet is reduced to impotence for weeks while it rebuilds.

Then there's the fuel issue...

These maths would drive how such a bomber force would be used. The RAF aand USAAF generally only put about 60% of their available bombers into the air on any day, but this low utility rate combined with the huge numbers of operational bombers allowed them to sustain large raids day after day in spite of the losses. The Luftwaffe could not operate like this, even with an optimised heavy bomber production programme.

I suspect they'd focus the force for a particular operation, like opposing the D-day landings or the moronic 1944 Baby Blitz. They'd fly at higher rates than the RAF/USAAF for a period and then withdraw to recover, fix their damaged planes, do deep maintenance, allow crew rest and integrate new planes and crews. Perhaps in the process they'd redeploy to the East for a similar operation.

I think it's important to keep in mind the Germans ket a lot of obsolescent aircraft in production well past their use-by date. I bang on about the He111 from 1942 but I don't think the Do 217 was much chop and perhaps it's production resources would have been better directed into a heavy bomber. Those two aircraft might have instead resuted in ~1500-2000 heavy bombers.

 

[T. A. Gardner]

These maths would drive how such a bomber force would be used. The RAF aand USAAF generally only put about 60% of their available bombers into the air on any day, but this low utility rate combined with the huge numbers of operational bombers allowed them to sustain large raids day after day in spite of the losses. The Luftwaffe could not operate like this, even with an optimised heavy bomber production programme.

I suspect they'd focus the force for a particular operation, like opposing the D-day landings or the moronic 1944 Baby Blitz. They'd fly at higher rates than the RAF/USAAF for a period and then withdraw to recover, fix their damaged planes, do deep maintenance, allow crew rest and integrate new planes and crews. Perhaps in the process they'd redeploy to the East for a similar operation.

I think it's important to keep in mind the Germans ket a lot of obsolescent aircraft in production well past their use-by date. I bang on about the He111 from 1942 but I don't think the Do 217 was much chop and perhaps it's production resources would have been better directed into a heavy bomber. Those two aircraft might have instead resuted in ~1500-2000 heavy bombers.

The US / RAF loss rate for sustained campaigns was supposed to be equal to or less than 6%. By 1944, the US was turning out, roughly, about 35 to 40 B-24 a day. They could sustain a thousand bomber force with that production.

 

[Rule of cool]

The US / RAF loss rate for sustained campaigns was supposed to be equal to or less than 6%. By 1944, the US was turning out, roughly, about 35 to 40 B-24 a day. They could sustain a thousand bomber force with that production.

Correct me if I'm wrong, but that loss rate would be 6% of the 60% of the bombers flying daily, rather than of the entire 3,000-3,500 operational bombers in the 8th and 15th Air Forces in 1944 or so. Similarly, it would be 6% of the 700-900 RAF heavies actually flying tat day rather than the 1,300-1,600 built and crewed bombers in Bomber Command. That's how these efforts were sustained day in and day out for months on end without a significant break.

As an aside, those numbers are staggering, Britain must have been close to capsizing with those thousands of bombers packed on the eastern side of the country.

 

[T. A. Gardner]

Correct me if I'm wrong, but that loss rate would be 6% of the 60% of the bombers flying daily, rather than of the entire 3,000-3,500 operational bombers in the 8th and 15th Air Forces in 1944 or so. Similarly, it would be 6% of the 700-900 RAF heavies actually flying tat day rather than the 1,300-1,600 built and crewed bombers in Bomber Command. That's how these efforts were sustained day in and day out for months on end without a significant break.

As an aside, those numbers are staggering, Britain must have been close to capsizing with those thousands of bombers packed on the eastern side of the country.

Yes, the per mission rate. The British and US not only had the bombers available, but they had the fuel and crews to go with them. In fact, by 1944 the US found they had too many aircrew and started cutting back on the number in the pipeline.

 

[Nicknick]

What I stated is documented as the cause of the German jet engine industry being so slow to develop operational engines. The German steam turbine industry was relatively small in the 1930's. Germany was not a major shipbuilder by world standards.

As for the P-80, or the DeHavilland Vampire, or whatever, the Allied jets were adequate and competitive with what Germany was producing only they were vastly more reliable.


Yes, there is a difference between how you design a gas turbine using compressed air and then jet fuel versus a steam turbine. The world's leading expert on that happens to be, at the time, Sanford Moss at GE who had been experimenting with turbochargers for over a decade and had amassed the largest blade profile library in existence. A turbocharger is, for all intents, a jet engine run backwards.


Little idea. v, Ohain at Henkel worked around the issue by using a compound engine with an axial and centrifugal compressor section. Daimler Benz tried to use fixed and rotating turbine blades in their compressor section, a common thing with steam turbines, unsuccessfully.

G

GE started development of their J35 axial turbojet in 1943. Vickers began work on their F1 axial turbojet based on previous design work on the Freda that dated back to 1926 in mid 1940. The Freda bench ran--it was an axial turbojet--in April 1939. A Gloster Meteor flew successfully on the F2, a progression of the F1, in June of 1943. But issues with reliability and heat kept it from going into production.

The Westinghouse J 30 axial turbojet was first flight tested in Jan 1944. It too was developed from about 1942 on.

By the end of WW 2, the Allies were easily equal or ahead of Germany in turbojet designs and found little need to use German technology in this area for anything they developed postwar.

The US and Britain expected their jet engines to be reliable. That took time, time they had because they were winning without this technology. Certainly, the Germans were not streets ahead of the Allies in terms of jet engine development, issues with high temperature alloys aside. It is just the Allies weren't desperate and Germany was.

I was missing a zero, The Jumo004 A ran for 100 h on the test stand where as the later stages American jet engines disintegrated after 75 hours in 1943 which was as I understand it the longest test run (ironically, the super-alloy low pressure parts fall apart....). To make it reliable, you have to fly it, no wonder that the US had no compressor stalls when the BMW jet were destroyed by one, it doesn't happen on a dyno. Also, most problems with the early Jumo engines occurred during fast load changes from the pilots, this is also a phenomenon which don't happen on dyno runs. I'm sure, the American developers had to sort out all these problems as well during flight testing.

German Ocean liner like the Vaterland were among the top, if not the top ocean liner of their time (1914), but after WW1 German steam turbines were mainly used in Power stations. AEG and Siemens became industrial giants by building thermal power stations all over the world (just like GE).

So the German Jumo004 (which had little to do with con Ohain) made successfully 100 h test runs in 1940, were is the American counterpart?

How can you call the development slow, if all others in this world have been slower?? Even with the best materials available the US didn't manage to built anything which came close to the performance of the M232 years after it was introduced.


If this would have been made by Germans you would surly call it over complex:

''E, Westinghouse, Lockheed, and Vickers all began developing axial jet engines before any of them saw a German one. The most complex was undoubtedly Lockheed's where Nathan Pierce, a protege of the steam engine genius of Abner Doble, built the utterly massive J37 / L 1000 engine with a two-section 32 stage compressor with variable speed and a 5 turbine section to drive it.''

 

[Nicknick]

No, I'm simply pointing out that if people wish to learn something about a subject there are resources available rather than just peddling the same old myths

So, were is the source for the 500 mph top speed of the Shooting star?

The Me262 was faster anyway...