Placing the Bell P39 Aircobra.

[Graham Boak]

I never claimed that any engine design was easy: however Fedden's relations with his management might have been better had he taken a more conventional route requiring less investment in research and development. But then he was a genius: my single advantage is hindsight.

[Jukka Juutinen]

Originally Posted by Graham Boak

I never claimed that any engine design was easy: however Fedden's relations with his management might have been better had he taken a more conventional route requiring less investment in research and development. But then he was a genius: my single advantage is hindsight.

Well, the R-3350 is a perfect example of "a more conventional route requiring less investment in research and development." At least so did Wright´s purse string holders believe...

[Graham Boak]

Cherrypicking Jukka: the equivalents of the Hercules and the Centaurus are the R2340 and R2800. Neither had particularly difficult or extended development histories, both had exemplary war records. The R3350 was a 4-row radial "corncob" of double the power and later in concept - although earlier than the Centaurus into service. Which I think supports my point not yours. Did Fedden ever propose a massive 4-row radial?

Tom: Shores does not support emotive and slanderous comments such as you produce. Not getting the armour to the Mediterranean operations does not imply any deliberate obstructionism. I find it difficult to conceive of RAF officers on their tour of staff duty at the Ministry deliberately cancelling deliveries of armour to Hurricane units - on the grounds presumably that they enjoyed the idea of extra casualties, or perhaps just because they never did like old Bloggs since that rugger match at Cranfield..........

I suggest that the additional weight of armour was additional to that concurrently in production on the Mk.II. This would exclude the rear pilot's armour and for that matter the armoured windscreen. Taking the differences back to prewar Mk.1s is just fatuous.

As is comparing the finest of German 1945 types with an aircraft that had already been in service for three years, with a replacement in service alongside it and production running down. In any war, airforces will have a mix of the latest and earlier types. Compare like with like.

Few have doubted the accuracy of the Hurricane IId. Some have suggested that the claims were overinflated, but that is true of all areas of combat. What was clearly in doubt was its survivability and hence overall efficacy. You are repeating arguments that have been countered, and continue to misrepresent officers who dedicated their careers to close partnership between the Army and the RAF.

Do you really think that Tedder, in his position as head of the Desert Air Force in 1942, was in a position to call for the specification, design, development, placing into production and then service, of some wonderful aircraft combining the precision of the Ju 87, the armour of the Il 2, and the performance of the Ta 152? All in less than two years? Such a chimera would be impossible in any timescale: any decent compromise impossible in that one. Tedder, much more so than Coningham in his lower position, could have been one of the influences on the production schedules that led to the 1944 order of battle, but he could not start with a clean sheet and had to deal with the options available.

[Jukka Juutinen]

Originally Posted by Graham Boak

Cherrypicking Jukka: the equivalents of the Hercules and the Centaurus are the R2340 and R2800. Neither had particularly difficult or extended development histories, both had exemplary war records. The R3350 was a 4-row radial "corncob" of double the power and later in concept - although earlier than the Centaurus into service. Which I think supports my point not yours. Did Fedden ever propose a massive 4-row radial?

What the hell is "R-2340"? This is a completely new design to me. When did the 18-cylinder R-3350 transform into a 4-row radial? BTW, Centaurus´s capacity is 3270 cu.in. BTW, an R2800 is a 2800 cc small radial, an R-2800 is something else.

[Graham Boak]

I blame increasing arthritis in my fingers - which this series of postings sin't helping? I meant of course the Twin Wasp R-1340 and the R-2800. I don't see that the other errors affect my point.

[Juha]

Tony
living in Finland and knowing what forests are alike and having been in a army I really wonder how P-39s of Il-2s could have significantly reduce casualties of an army attacking through thick forest against dug-in fanatical enemy. So can you enlight me?
Have you ever advances through thick forest in attack formation or have you ever laid in ambush position waiting for attacking force appearing to your hidden killing zone, or in middle of firefight trying to figure out what was the right moment to disengage and withdraw your men to next ambush position?

Juha

[Jukka Juutinen]

And when did the Twin Wasp become an R-1340??? And comparing even the R-1830 (=Twin Wasp) and the Hercules is absurd at best since the fomer topped at around 1350 hp, the latter at over 2000 hp. The closests realistic comparison are the the R-2600/the Hercules and the R-3350/the Centaurus. Even the larger R-4360 (=Wasp Major, poppet valves) topped at about 3000 hp with 100/130 fuel (3500 hp and over ratings required higher PN fuel) while the Centaurus achieved the same on the same fuel from over 1000 cu.in smaller displacement with at least double the TBO.

[Graham Boak]

You are stepping outside the point of the original comment. Both the Hercules and the Twin Wasp were in the 1300-1500hp class in 1941: that the Hercules was later developed beyond that is a measure of its quality rather than relevant to a discussion on entry-into-service dates. In 1943, both the Double Wasp and the Centaurus were in the 2000hp class (as indeed was the Sabre). Postwar power outputs are irrelevant here.

That the US chose to make bigger engines rather than developing their earlier designs to the utmost is an interesting engineering option: it does not make the long-delayed Centaurus an equivalent to the 3350.

I stand by my initial premise: that British engine production policy in WW2 was biased towards the in-line engine because of a failure of British radial manufacturers to produce competitive engines in the requisite timescale, and that this was because the sleeve-valve approach ran into problems that extended development times.

[Jukka Juutinen]

Originally Posted by Graham Boak

You are stepping outside the point of the original comment. Both the Hercules and the Twin Wasp were in the 1300-1500hp class in 1941: that the Hercules was later developed beyond that is a measure of its quality rather than relevant to a discussion on entry-into-service dates. In 1943, both the Double Wasp and the Centaurus were in the 2000hp class (as indeed was the Sabre). Postwar power outputs are irrelevant here.

That the US chose to make bigger engines rather than developing their earlier designs to the utmost is an interesting engineering option: it does not make the long-delayed Centaurus an equivalent to the 3350.

I stand by my initial premise: that British engine production policy in WW2 was biased towards the in-line engine because of a failure of British radial manufacturers to produce competitive engines in the requisite timescale, and that this was because the sleeve-valve approach ran into problems that extended development times.

The Twin Wasp was mostly a 1200 hp engine during the war (and a 1065 hp engine with 87-octane fuel). You simply cannot consider it to be in any way equivalent to the Hercules which was producing 1600 hp+ by that time. And the same applies to the R-2800 vs. Centaurus situation. With 100/130 fuel and no ADI, the wartime ratings of the latter are considerably higher (by several hundred hp in single stage versions)). That is a fact.

Besides, the other major British radial maker, Armstrong-Siddeley, was not involved in sleeve valves in any way and could have designed a Boak-valved engine, had they wished.

[RodM]

Hi Tony,

I am referring to contrary evidence that has been presented on three different threads.

"For the rest, you believe 2TAF supplied effective CAS, RPs were good enough, and 2TAF was better than nothing."

While I suspect that many would concede that CAS could have been better, it was just a component of the whole combined force. I will repeat that in the West, the German ground forces had comparatively very little air support, while facing constant air attack from the front lines to the industrial heartland. I will challenge anyone to find proof that overall, this aspect of Allied air power did not have a major effect on the ability of the Germans to wage war (quoting of a minor isolated incident or incidents, outside of the wider context, does not constitute proof).

Also, as has been pointed out, the decisions against the dive bomber and for the fighter bomber over Europe were not made with hindsight, they were made at a time when it was expected that such aircraft would have to survive in the face of enemy fighters and Flak.

Am I to understand that your view is that 2TAF was NOT better than nothing? That would be a mighty statement, and I, for one, have seen nothing of substance in these threads that would convince me that this is true.

The reasons for the lack of progress by the British and Commonwealth armies does not rest solely on 2TAF, the Typhoon, or the existence of Bomber Command.

The argument about the suitability of actual alternate types to the Typhoon is, at best, extremely hypothetical. It has been shown (at least no contrary evidence has been presented) that the IL-2 suffered very high combat losses (and hence it remains to be seen how you could justify such a type being employed in the west if it were to have sustained the same level of attrition), and there is no proof that the likes of the Vengence would not also have suffered high losses or been substantially more effective in the face of intense ground fire. Comparing the success of the Vengence in another completely different theatre of war is, in effect, about as relevant under the circumstances as comparing to successes achieved on a testing ground or fighter performance in a clean configuration.

The reason to use RPs, probably goes beyond what has so far been presented in these threads - overall projected requirements versus projected supply of bombs (the RAF did suffer shortages post-D-Day - saying that this could have been solved by not having Bomber Command in 1944/45 is not a rational position, if causality is taken into account); logistical considerations of supplying munitions to front line units. Also what not has been considered because the RP has so conveniencely been totally written off, is what actions could have been taken to improve the accuracy of delivery of the weapon on the platform upon which it was mounted.

As to the reference to that other historian, I only mean that in the way I perceive certain views/arguments/statements have been presented. If you collate facts 1, 2, 3, x, y, z and form a hypothesis, but then find that facts 1. 3. and z are either false or doubtful, and that you haven't considered 4, 5, 6, then the hyphothesis needs to be revised. This is what I meant by silence after the refutation of several of the conclusions expressed/supporting facts given. Then again, there is the hyphothesis that is formed with an agenda, where selective evidence that only supports the hyphothesis is gathered after the fact (something that has become more and more common in sponser-driven research). The other point with that other historian is an inability to review or conceed certain views in the face of refuting evidence.

I back what you have said only as far as there were various deficiencies with CAS that could, even should, have been better (but then army performance wasn't entirely up to stratch either, was it?), and that a dive bomber may have been a good option beside the various other CAS aircraft. Beyond that, I haven't seen anything convincing as to most of the broader accusations/rationalisations/generalisations (2TAF useless / Typhoon useless / RP totally useless / Bomber Command unless / Bomber Command only attacked cities / various RAF commanders mostly to blame for lack of army progress / certain alternate aircraft would have been more successful in CAS role in western Europe), and, IMHO, some of these unsupported accusations have lowered the quality of a series of really interesting threads.

Cheers

Rod