Why was the Seafire Mk.III so slow? (1 Viewer)

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So who else can build them? Well Fairey was the obvious choice, but firstly it was already committed to developing the Fulmar. At the end of 1938 the Admiralty tried to persuade Richard Fairey to build Spitfires for them. But he wasn't interested in building someone else's aircraft designs (still peacetime - more profit in building his own designs). So you need to find a manufacturer with spare production capacity even if Supermarine have the design capacity in late 1938, which is perhaps open to question given the other projects they had in progress at the time.
It's only more profitable if you have surplus manufacturing capacity. If it was more profitable for companies to build their own designs the contract manufacturing industry would exist.

The cost of manufacturing equipment - furnaces, presses, machine tools, building space, etc is a huge expense. Having staff good at both design and manufacturing is something only handful of companies successfully achieved.

And if you start manufacturing for the competition, you won't retain your own design team. Then, if requirement for the product you are building dries up, you have nothing.

Richard Fairey (and Sidney Camm) were protecting both their design and manufacturing teams.

IMHO, FAA planes would have benefit from 2 (or 3) speed supercharger like the 2 stage P&W powered USN planes did (Neutral to 1k', low to 7.5k, and then high - effectively giving 3 speeds)
 
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IMHO, FAA planes would have benefit from 2 (or 3) speed supercharger like the 2 stage P&W powered USN planes did (Neutral to 1k', low to 7.5k, and then high - effectively giving 3 stages)
Hi,

That is probably true but, If I am recalling correctly the F4F-3 was the first operational aircraft to be fitted with a two-stage two-speed supercharger and there were some issues with them that took a bit of time to resolve, such as over speeding in certain conditions, if I am recalling correctly. And early supply of the two-stage two-speed superchargers were limited leading to the F4F-3A aircraft which substituted a single-stage two-speed supercharger for the twin-stage supercharger in the baseline F4F-3 (if I am recalling my speeds and stages right).

If my information is correct, the two-stage two-speed P&W engined F4F-3 only started to be supplied in 1940, with the F4F-3A's being delivered from 1940 into 1941, with some of the F4F-3A's still being in active service early in the US involvement of the war, through at least to the Battle of Midway in June 1942.

As such, its not fully clear how quickly a two-stage two-speed supercharger could have been supplied for RN use, even assuming that they were working along a similar schedule to what was being done in the US.
 
That is probably true but, If I am recalling correctly the F4F-3 was the first operational aircraft to be fitted with a two-stage two-speed supercharger and there were some issues with them that took a bit of time to resolve, such as over speeding in certain conditions, if I am recalling correctly. And early supply of the two-stage two-speed superchargers were limited leading to the F4F-3A aircraft which substituted a single-stage two-speed supercharger for the twin-stage supercharger in the baseline F4F-3 (if I am recalling my speeds and stages right).

As such, its not fully clear how quickly a two-stage two-speed supercharger could have been supplied for RN use, even assuming that they were working along a similar schedule to what was being done in the US.
I'm not talking two-stage, just multi speed. (I corrected my mistake where I put stages not speed) And RR was building two speed Merlins (Merlin X) very early - in production by 5/Dec/'38.

So, there is no reason Fulmar/Seafire/Barracuda couldn't have had Merlin X (or improved Merlin 2x) right from the start. That would go a long ways to eliminate the Seafire seeming to be slow due to engine optimized for low altitude.
 
Ooops, sorry about that. I should have read more carefully. When I saw the mention of P&W engines it triggered a memory in my mind about some stuff I hade read on the F4F-3 and -3A.

Sorry again for my mistake, I should be more careful when I read :p
 
The Armstrong SIddeley Tiger was the first production engine with a two speed supercharger. Unfortunately the rest of the engine was pretty much crap.
Wright and RR were close to being tied for the next two speed supercharger. Wright was even claiming that they could refit exiting engines with the two speed supercharger drive although I have no idea if this was ever done in practice.

Now please note that the Merlin X only improved the altitude performance over the Merlin III by a very small amount. Instead of 1030hp at 16,250 ft the Merlin X gave 1010-1025hp at 17750ft. What it did do was offer 1125hp at 5,250ft on 87 octane fuel and around 1050hp for take off (sources differ) instead of the 880hp of the Merlin III.

The Merlin XX used the same supercharger (inlet cover/elbow) that the Merlin 45 did. Both used whatever stronger parts that the Merlin XII did and both used the same pressure water cooling (introduced on the Merlin IV used in the Whitley) There was no early shortcut to the Merlin XX engine.

Now unlike the Japanese, the German and Italian aircraft fighting the RN were often flying/operating at under 6300 ft (2000 meters) and extra altitude capability wouldn't have done much. Who cares if the Hurricane I could do 320mph at 18,000ft if all the fighting was done at 6,000ft or under for example.

The Spitfire especially made do with the single speed supercharger because, in combat, they made use of the higher combat boost for performance. This was a bit of crutch and it hurt cruise at low attitude. The crutch doesn't work as well for heavier aircraft that need the extra power at low altitude in non combat conditions for decent climb.

Please look again at Seafire Mk. III Trials

Note that the climb was at 9lbs boost at 2850rpm which was the 30 minute rating while the speed numbers are for 16lbs of boost at 3000rpm. which is the emergency max for 5 minutes.
A Seafire III in combat at low altitude can climb much, much better than the figures shown.
The reason of putting cropped impeller engines to get even more performance down low may be another story.
 
If you wade through this.

to pages 5-6 we will find that the F4F-3 Hellcat will good for 371mph at 18,700ft it was only good for 332mph at 10,000ft and so was about 15-20mph slower than the Seafire III with Merlin 50 engine.

The F6F-3 was good for 315mph at 2000ft and for 314 mph at 6000ft which also helps put things into perspective for some the British fighters. For the F6F-3 this test was in Aug 1943 and was done without water injection. The F6F-3 shifted into low gear on the 2nd stage at about 6000ft so this makes it a worst case for the F6F-3. In Neutral the manifold pressure had dropped from 52in at 2000ft to 45.5in at 6,000ft but shifting to low gear brought the pressure back up to 52.0in. Unfortunately the engine only makes 1800hp in low gear compared to 2000hp in makes under 2000ft in neutral.
 
Interesting. Fairey sounds like a British equal to Brewster. I wonder what the FAA thought of their USA-rejected F3F Corsairs.
Not sure what you are talking about re the F3A (not F3F) Brewster built Corsair. It has been discussed on this site as recently as Dec last year

Firstly, the USN did not reject the F3A. Just over 40% went to the USN.

Secondly there was nothing wrong with Brewster's engineering skills or with the quality of their product. They had been tasked with a the design and engineering of several modifications and carried them out successfully. And the USN never questionned the quality of Brewster's work. From a production perspective the problem lay in their inability to keep up to date with implementing the latest modifications. Every time that there was a significant change they lagged behind Vought and Goodyear in getting it into production.

Where the USN did have a problem with Brewster was with the management of the company. It was a change of directors on the Board in April 1944, some of whom were not looked on favourably by the USN, that led to termination of the Corsair contract on 22 May 1944 with the last F3A-1D coming off the line in July. The last for Britain was delivered in May 1944.

Dana Bell has researched and written about the Corsair extensively. This was the last post he made on the subject in Dec 2022.


Virtually all the FAA F3A Corsair III went to squadrons that were working up or to training units. One thing that may have influenced this is that none of the Corsair III delivered to Britain was fitted with the water injected R-2800-8W engine (only the last 86 F3As received that engine and they went to the USN). Vought and Goodyear had introduced it in late 1943. Britain was receiving Vought built Corsair II until mid-1944 with Goodyear built Corsair IV beginning to be received around the same time.

Looking at some other stuff earlier, Fairey were still driving the Admiralty nuts at the end of Nov 1943 about the poor level of production of the Firefly at the Hayes factory. By then the discussion is about appointing a second new manager to run the place and try to sort out the problems.
 
Please note, I am not proposing waving a magic wand to have the Merlin XX early, but rather:

a. Replacing the Merlin VIII with Merlin X in the Fulmar I. Historic timeline allows this. And while I won't turn down the extra 5hp at sea level from the X, the additional performance at altitude from 2nd speed is the benefit. Having both speed and altitude when entering combat is not to be knocked.

b. Replace the Merlin XXX with Merlin XX in the Fulmar II. Again historic timeline permits. TBH, I'd modify Merlin XX with either lower speed gear in supercharger or crop the impeller or both. The result would be 1,500+ hp (10% more) down low, and better altitude performance to boot.

c. Replace the Merlin 46/55/55m in Seafire I/II/III. This is even later than Fulmar II, so no issues with timeline. No loss in performance down low, better altitude performance.

In all cases, Bomber Command is going to have to give up couple hundred 2 speed Merlins.
 
Their creations were certainly as ugly!
The AEW Gannet is a pig, but Fairey made some lookers. I especially like the F.III when with its inline engine.

Fairey_III_F.jpg
 
Guys, stop blaming Fairey for the ugly layout of the Barracuda. Blame those who drew up the Spec S.24/37 it was meant to fulfil. That is what drove many of the design characteristics. No one did any better. And at least Fairey made the undercart fold!

The Barracuda pic posted by AB was the much modified Mk.V. This was the main production model the Mk.II

1684915913800.jpeg


And the competitors

Supermarine Type 322 Dumbo with variable incidence wings and leading edge slats. Only went to the prototype stage because of that wing and didn't fly until 1943. Supermarine was too busy from 1938 building Spitfires and designing heavy bombers.

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And some of the ones rejected at an early stage.

The Blackburn B-29 mock-up.

1684916208766.jpeg



And a model of the Taurus engined Bristol proposal.

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Remember, he who pays the piper calls the tune!
 
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