Was a competitive pre-Hercules Bristol-powered single-seat monoplane fighter feasible?

[Shortround6]

It got the Gloster F.9/37 to 360 mph in twin form.

Yes and no.
Yes a pair of experimental Taurus engines got the prototype F.9/37 up to that speed.

BUT, those engines seem to have disappeared after a landing accident and after the plane was repaired and given a different set of Taurus engines speed dropped to 332 mph.
No production Taurus engine was ever rated at higher than 3500ft (feet not meters) for it's FTH which makes for a pretty crappy fighter engine. No Taurus ever got a two speed supercharger. The Taurus engine had over heating problems, at least until late 1941/early 42 when it solved to the extent the British no longer felt the need to import R-1830s for the Beaufort.

 

[Shortround6]

The Gloster f.5/34, shown below seems the likely candidate for a Hercules retrofit, and I'm sure it's been discussed here before.

It's been discussed. But the short version?

4190lb airplane empty.
take out 1065lb engine and associated propeller
stick in 1850lb engine and associated propeller

early Hercules made 1210-1250 hp in high gear in the middle teens altitude.

The F.5/34 had a useful load of just over 1200lbs, I am sure there was some stretch but by the time you stick in the big engine and prop, add enough fuel to run the big engine, add armor and self sealing tanks you are going to have to go back and redo the structure and landing gear to hold the extra weight.

 

[tomo pauk]

A better airframe for Hercules will be Hurricane or Spitfire - those two are already stressed for greater powerplant weights.

 

[Admiral Beez]

The F.5/34 had a useful load of just over 1200lbs, I am sure there was some stretch but by the time you stick in the big engine and prop, add enough fuel to run the big engine, add armor and self sealing tanks you are going to have to go back and redo the structure and landing gear to hold the extra weight.

Rather than bolting on a much larger engine with the issues you present, the F.5/34 could have serve as a starting point to the Hercules fighter, same as the Wildcat led to the much larger Hellcat. It would help if the F.5/34 made it into service, but as long as it survives the prototype may be rolled out again to serve as Gloster's template for the Hercules fighter. Rather than Gloster starting fresh.

 

[Kevin J]

Rather than bolting on a much larger engine with the issues you present, the F.5/34 could have serve as a starting point to the Hercules fighter, same as the Wildcat led to the much larger Hellcat. It would help if the F.5/34 made it into service, but as long as it survives the prototype may be rolled out again to serve as Gloster's template for the Hercules fighter. Rather than Gloster starting fresh.

A Griffon Seafire would be much much better. Also Gloster wouldn't have the time for developing its jet fighters. Someone else would have too. Maybe Boulton Paul. They've got time on their hands.

 

[Admiral Beez]

A Griffon Seafire would be much much better. Also Gloster wouldn't have the time for developing its jet fighters. Someone else would have too. Maybe Boulton Paul. They've got time on their hands.

Gloster was busy making Gladiators. Had the F.5/34 been ordered, they could have swapped over from the Gladiator, years before the Spitfire or Hurricane entered production. As it was, Gloster didn't have the second F.5/34 ready for flight until 1938, after the Spitfire and Hurricane was already in service. Gloster was too slow, for example, the very first production Gloster Gladiator wasn't delivered to the RAF until February 1937, nearly three years after the prototype Gladiator first flew. By 1937, it should have been the F5/34 that was entering production, not the Gladiator.

As for Boulton Paul, I'd move those guys over to making dustbins or other non-aviation kit.

 

[swampyankee]

Gloster was busy making Gladiators. Had they been thus ordered, they could have swapped over to the F.5/34, years before the Spitfire or Hurricane entered production. As it was, Gloster didn't have the second F.5/34 ready for flight until 1938, after the Spitfire and Hurricane was already in service. Gloster was slow. As for Boulton Paul, I'd move those guys over to making dustbins or other non-aviation kit.

Boulton-Paul doesn't seem to havebeen able to design aircraft terribly well, but how was their construction quality?

 

[Shortround6]

Rather than bolting on a much larger engine with the issues you present, the F.5/34 could have serve as a starting point to the Hercules fighter, same as the Wildcat led to the much larger Hellcat. It would help if the F.5/34 made it into service, but as long as it survives the prototype may be rolled out again to serve as Gloster's template for the Hercules fighter. Rather than Gloster starting fresh.

Actually you are mistaken about the connection between the Wildcat and Hellcat. Grumman made at least 3 design studies to try to mount the Wright R-2600 in/on a Wildcat (forget the P & W R-2800 for the moment) and each time came to the conclusion that would be easier to start over with a clean sheet of paper. Aside from a family resemblance, in part due trying to keep a similar view from cockpit for deck landing there was very little carried over besides nuts, bolts, washers and rivets.

tying to use a template that is around 66-75% of the weight the resulting fighter will be seems to trying to force things a bit too much.

 

[gjs238]

Actually you are mistaken about the connection between the Wildcat and Hellcat. Grumman made at least 3 design studies to try to mount the Wright R-2600 in/on a Wildcat (forget the P & W R-2800 for the moment) and each time came to the conclusion that would be easier to start over with a clean sheet of paper. Aside from a family resemblance, in part due trying to keep a similar view from cockpit for deck landing there was very little carried over besides nuts, bolts, washers and rivets.

tying to use a template that is around 66-75% of the weight the resulting fighter will be seems to trying to force things a bit too much.

Would the Hercules have been a better fit for a Wildcat or P-36 than the R-2600?

 

[Admiral Beez]

Would the Hercules have been a better fit for a Wildcat or P-36 than the R-2600?

The Hercules is lighter and smaller than the Twin Cyclone, so it would fit. The Cyclone is more powerful, but is heavier.

Wright R-2600 Twin Cyclone - Wikipedia

• Length: 62.06 in (1,576 mm)
• Diameter: 55 in (1,397 mm)
• Dry weight: 2,045 lb (930 kg)
• 1,450 hp (1,080 kW) at 2,600 rpm at 15,000 ft (4,575 m) military power
• Specific power: 0.67 hp/in³ (30.6 kW/L)
• Enters general service, 1941-1943

Bristol Hercules - Wikipedia

• Length: 53.15 in (1,350 mm)
• Diameter: 55 in (1,397 mm)
• Dry weight: 1,929 lb (875 kg)
• 1,356 hp (1,012 kW) at 2,750 rpm at 4,000 ft (1,220 m)
• Specific power: 0.57 hp/in³ (26.15 kW/l)
• Enters general service, 1939-1941

But what applications would Britain or Empire/Commonwealth replace the Twin Cyclone with a Hercules? The only aircraft the Commonwealth produced with the Twin Cyclone was the Curtiss Helldiver at both CC&F and Fairchild in Canada (USN contract). Britain also ordered 165 Curtiss Helldivers from CC&F Canada but chose to keep the Twin Cyclone, and eventually reduced the order. This was probably the best opportunity for Britain to swap the Twin Cyclone for the Bristol Hercules.

The British also operated the Twin Cyclone powered Douglas A-20 Boston, Martin Baltimore, Brewster Bermuda and the Vultee A-31 Vengeance. I suppose any of these could be re-engined with the Hercules if there was a need, such as a shortage of Wright engines (along with a surplus of Hercules) for A-31 squadrons in India. It's noteworthy that Grumman rejected the Twin Cyclone for the Double Wasp in their Hellcat.

 

[gjs238]

The Hercules is lighter and smaller than the Twin Cyclone, so it would fit. The Cyclone is more powerful, but is heavier.

Wright R-2600 Twin Cyclone - Wikipedia

• Length: 62.06 in (1,576 mm)
• Diameter: 55 in (1,397 mm)
• Dry weight: 2,045 lb (930 kg)
• 1,450 hp (1,080 kW) at 2,600 rpm at 15,000 ft (4,575 m) military power
• Specific power: 0.67 hp/in³ (30.6 kW/L)
• Enters general service, 1941-1943

Bristol Hercules - Wikipedia

• Length: 53.15 in (1,350 mm)
• Diameter: 55 in (1,397 mm)
• Dry weight: 1,929 lb (875 kg)
• 1,356 hp (1,012 kW) at 2,750 rpm at 4,000 ft (1,220 m)
• Specific power: 0.57 hp/in³ (26.15 kW/l)
• Enters general service, 1939-1941

But what applications would Britain or Empire/Commonwealth replace the Twin Cyclone with a Hercules? The only aircraft the Commonwealth produced with the Twin Cyclone was the Curtiss Helldiver at both CC&F and Fairchild in Canada (USN contract). Britain also ordered 165 Curtiss Helldivers from CC&F Canada but chose to keep the Twin Cyclone, and eventually reduced the order. This was probably the best opportunity for Britain to swap the Twin Cyclone for the Bristol Hercules.

The British also operated the Twin Cyclone powered Douglas A-20 Boston, Martin Baltimore, Brewster Bermuda and the Vultee A-31 Vengeance. I suppose any of these could be re-engined with the Hercules if there was a need, such as a shortage of Wright engines (along with a surplus of Hercules) for A-31 squadrons in India. It's noteworthy that Grumman rejected the Twin Cyclone for the Double Wasp in their Hellcat.

Thanks for putting that together.
Generally raises my impression of the R-2600 and lowers my impression of the Hercules.

The Boeing Clippers were running the R-2600's earlier than the dates above would imply.
Boeing 314 Clipper - Wikipedia

 

[Admiral Beez]

Generally raises my impression of the R-2600 and lowers my impression of the Hercules.

I have a contrary view. Note how very few, if any of the best USA aircraft used the R-2600. Overall Wright trailed behind Pratt & Whitney in the choice of US aircraft manufacturers. Meanwhile, pretty much every top performing aircraft in the RAF that wasn't running a Merlin or Griffon (or Sabre) was powered by the Hercules, such as the Bristol Beaufighter, Handley Page Halifax, Short Stirling and Vickers Wellington. We would have seen the Hercules in more British aircraft, but for the superlative performance of the Merlin and Griffon.

Bristol Hercules. Why doesn't this engine get more respect?

 

[gjs238]

I have a contrary view. Note how very few, if any of the best USA aircraft used the R-2600. Overall Wright trailed behind Pratt & Whitney in the choice of US aircraft manufacturers. Meanwhile, pretty much every top performing aircraft in the RAF that wasn't running a Merlin or Griffon (or Sabre) was powered by the Hercules, such as the Bristol Beaufighter, Handley Page Halifax, Short Stirling and Vickers Wellington. We would have seen the Hercules in more British aircraft, but for the superlative performance of the Merlin and Griffon.

Bristol Hercules. Why doesn't this engine get more respect?

Using your data above, the Hercules and R-2600 appear to be competitors and the usage split along national lines.
What was the British competitor of the R-2800?

 

[Kevin J]

I've a better idea. Why don't we put a retractable undercarriage on the Gladiator and fit a two speed Pegasus on it. Maybe we could have got a similar performance out of it to the Buffalo I. Now that would have given the JAAF a nasty shock.

 

[Admiral Beez]

Using your data above, the Hercules and R-2600 appear to be competitors and the usage split along national lines.
What was the British competitor of the R-2800?

The Hercules was succeeded by Britain's best radial, the Bristol Centaurus. But the Centaurus is essentially a postwar engine. It's a challenge to compare specs because both the R-2800 and Centaurus had many variants.

 

[Shortround6]

The Hercules is lighter and smaller than the Twin Cyclone, so it would fit. The Cyclone is more powerful, but is heavier.

Timeline.....
Timeline.....
TIMELINE
TIMELINE

The R-2600 series comprised 3 different engines. Likewise there were several major changes in the Hercules as the war went on.

The engines weighed within 100lbs of each other, at least to start.

For the R-2600 you basically had the
A series, 1600hp for take-off/2400rpm, 1600hp military/2400rpm/1500ft, 1400hp Mil/2400rpm/11,500ft 100 oct weight 1935-1950lbs
B series, 1700hp for take-off/2500rpm, 1500hp military /2500rpm/4,100ft, 1450hp Mil/2500rpm/14,100ft 100 oct weight 1965-1980lbs
BB series, 1900hp for take-off/2800rpm, 1750hp military /2600rpm/3200ft, 1450hp Mil/2600rpm/15,000ft 100/130 oct weight 2080 lbs

The BB series doesn't show up until 1943, the 1700hp Bs didn't show up in numbers until the latter part of 1941.

The Hercules isn't that much smaller or lighter. Diameter in many sources often includes the cowl as the engine was often supplied as a power egg.
Wiki Figures are for a Hercules II which is obviously an early war (if not prewar) engine.
the Hercules VI didn't show up until some point in 1941.

Hercules III even on 100 octane fuel.
1400hp for take-off/2800rpm, 1410hp military/2800rpm/2750ft, 1250hp Mil/2800rpm/16,750ft 100 oct
You could run The Hercules III on 100 oct but they didn't seem to increase the boost much, (correction welcome)
The Hercules VI ran 8.25lbs of boost with 100 octane, when it first came out (or was limited to 87 octane?) the boost was limited to 5lbs.
The Hercules doesn't appear (using Lumsden ) to have hit 10lbs of boost until the 100 series engines.

So when figuring out the hypothetical engine swaps try to use the engine model that would have been available at the time in question.

 

[nuuumannn]

A Griffon Seafire would be much much better. Also Gloster wouldn't have the time for developing its jet fighters. Someone else would have too. Maybe Boulton Paul. They've got time on their hands.

This in essense is the crux of the matter; if we are diverting time and energy attempting to create Mercury, Taurus or Hercules engined single-seat fighters, or producing in quantity existing prototypes that didn't get past that point, what are we not allowing to happen? In 1940 the Spitfire and Hurricane were rightly Britain's primary fighters and even with the production capacity the UK had, there wasn't enough of them. By the time of the Battle of France and Britain in the summer of 1940, the Gladiator, the Blenheim and the Defiant squadrons were being counted as frontline fighter squadrons, with all their inadequacies out in the open.

Gloster did not continue with building the F.9/37 and the Reaper twin engined fighters because it was instructed to continue producing Hurricanes, which the RAF wanted and needed at the time, and its engineers were tasked with developing jet aircraft. A big ask for what was essentially a small company. Bristol was building the Blenheim, Beaufort and Beaufighter in 1940 and Vickers Supermarine were concentrating on Spitfires, which was a far more prescient choice than a small radial engined fighter that offered little potential going forward.

The purchase of US equipment didn't take place because Britain had a need for a particular aircraft for a particular role that it couldn't build itself. They were bought because Britain didn't have enough aircraft its own designs. The US aircraft were to supplement what it already had. I'm pretty certain that if the RAF could have sent Spitfires to aid in the defence of Singapore or Malaya it probably would have, but it barely had enough for its own home based needs.

 

[Admiral Beez]

This in essense is the crux of the matter; if we are diverting time and energy attempting to create Mercury, Taurus or Hercules engined single-seat fighters, or producing in quantity existing prototypes that didn't get past that point, what are we not allowing to happen?

There's a small window before the Hurricane and Spitfire are ordered for any potential for a Bristol-powered fighter. After that, everyone making fighters had better focus on Hurricanes and Spits.

 

[Kevin J]

There's a small window before the Hurricane and Spitfire are ordered for any potential for a Bristol-powered fighter. After that, everyone making fighters had better focus on Hurricanes and Spits.

In that case the only choice you have is to skip the Gladiator and have the Gloster F.5/34 flying in 1935 not 1937. Alternately, you up-engine the Gladiator to a Pegasus and retract the undercarriage like the I-153. You should get 276 mph at least out of it, so it would be competitive with both the A5M and Ki-27.

 

[Admiral Beez]

In that case the only choice you have is to skip the Gladiator and have the Gloster F.5/34 flying in 1935 not 1937. Alternately, you up-engine the Gladiator to a Pegasus and retract the undercarriage like the I-153. You should get 276 mph at least out of it, so it would be competitive with both the A5M and Ki-27.

My vote is to go from Gauntlet to F5/34, call the latter the Gladiator instead of another biplane. There's nothing cutting edge in 1934-5 on the F5/34 that couldn't be done by Gloster Instead of the Gladiator.

Of course they were busy making Spitfires for Vickers and other aircraft, but it's a funny thing that Glosters went from biplane fighter to jet fighter with nothing of their own namesake in between. Akin to the Royal Small Arms Factory producing the Mk. IV SMLE in 1937 and the SA80 in 1943.