Westland Whirlwind revisited
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Shortround6
Major General
I am afraid that Stona is right, RR did not play well with others (licence RR engines to other people), I am not sure when it was said but one RR director said he would rather go to jail than see other companies make RR designed engines. This director had been around in WW I when sub contractors or licenced builders of Hispano V-8s and other engines made hundreds if not thousands of appallingly bad engines (some wouldn't even last 5 hours) and killed hundreds of RAF pilots and aircrew.
Only extraordinary circumstances forced the British and RR to allow Ford of England and Packard to make Merlins in 1940 (or earlier for Ford of England).
Most of the alternatives listed in this thread are not real alternatives. Either the manufacturing plant doesn't exist in England (and/or won't exist in the time line needed) or the engine has more problems than the Peregrine or is such power and drag that the resulting airplane would be near useless.
Now long time members know I like the Whirlwind, but the timeline was against it. it was canceled (or at least put on hold) before the first one ever reached a service squadron so most of the explanations as to why it was canceled don't hold water.
However the notion that small is better is a false one, it only works in certain applications or when the small airplane (or engine) can use technology that the larger aircraft or engines are not using.
P&W wanted nothing to do with the R-1535 radial for most of it's life, it was actually designed after the R-1830 for the navy, pretty much to improve the view over the nose.
It had few if any real commercial success (everybody wanted airliners powered by R-1830s and R-1820s, not smaller airliners with less seats powered by R-1535s)
There was list of French fighters posted earlier, over half were small light weight fighters as the French bought the light fighter concept hook line and sinker.
The trouble is that small fighters really aren't enough cheaper to make up for the lack of capability. You can't shrink the pilots/cockpits, or the instrument panels or the radios or the guns to suit the engines, you can't use fixed pitch props instead of constant speed and so on.
A 14 cylinder 19 liter G-R 14M engine is not going to be that much cheaper to build than a 38 liter G-R 14N engine, same number of parts (pistons, cylinders, valves connecting rods, etc) just bigger.
The Hispano 12 X engine was not that much cheaper to build than the 12Y.
The Taurus was not a good engine, one source claims about 3400 were made, it had chronic overheating problems in the Beaufort operating around England. Fortunately Australia dodged that one and got R-1830s instead for the Beauforts.
The Mercury was great engine for a 24.9 liter 9 cylinder single row radial but you don't get 1941-42 FW 190 engine cowls in 1940 even if they would work on a Mercury (single row instead of two row, no fan, exhaust ports on the front of the cylinder not the rear. and so on).
Only extraordinary circumstances forced the British and RR to allow Ford of England and Packard to make Merlins in 1940 (or earlier for Ford of England).
Most of the alternatives listed in this thread are not real alternatives. Either the manufacturing plant doesn't exist in England (and/or won't exist in the time line needed) or the engine has more problems than the Peregrine or is such power and drag that the resulting airplane would be near useless.
Now long time members know I like the Whirlwind, but the timeline was against it. it was canceled (or at least put on hold) before the first one ever reached a service squadron so most of the explanations as to why it was canceled don't hold water.
However the notion that small is better is a false one, it only works in certain applications or when the small airplane (or engine) can use technology that the larger aircraft or engines are not using.
P&W wanted nothing to do with the R-1535 radial for most of it's life, it was actually designed after the R-1830 for the navy, pretty much to improve the view over the nose.
It had few if any real commercial success (everybody wanted airliners powered by R-1830s and R-1820s, not smaller airliners with less seats powered by R-1535s)
There was list of French fighters posted earlier, over half were small light weight fighters as the French bought the light fighter concept hook line and sinker.
The trouble is that small fighters really aren't enough cheaper to make up for the lack of capability. You can't shrink the pilots/cockpits, or the instrument panels or the radios or the guns to suit the engines, you can't use fixed pitch props instead of constant speed and so on.
A 14 cylinder 19 liter G-R 14M engine is not going to be that much cheaper to build than a 38 liter G-R 14N engine, same number of parts (pistons, cylinders, valves connecting rods, etc) just bigger.
The Hispano 12 X engine was not that much cheaper to build than the 12Y.
The Taurus was not a good engine, one source claims about 3400 were made, it had chronic overheating problems in the Beaufort operating around England. Fortunately Australia dodged that one and got R-1830s instead for the Beauforts.
The Mercury was great engine for a 24.9 liter 9 cylinder single row radial but you don't get 1941-42 FW 190 engine cowls in 1940 even if they would work on a Mercury (single row instead of two row, no fan, exhaust ports on the front of the cylinder not the rear. and so on).
You just contradicted yourself very badly amigo.
As for the notion of small fighters, it depends what you mean by small. I'm not talking about point defense fighters like a CW-21 or Caudron C.714.
I'm talking small as in Bf 109, MC.202, D.520, or Yak-1. As in 32'-34' wingspan and 27-29' length, and a small body cross section.
Airplane - wingspan - length - empty weight - engine HP - top speed
Dewoitine D.520 - 33' 6" - 28' 3"- 4,680 lb - 950 hp - 350 mph
Bf 109E3 - 32' 4.5"- 28' 8" - 4,685 lbs- 1,175 hp - 354 mph
MC.202 - 34 9" - 29' - 5,180 lbs - 1,075 hp - 372 mph
Yak-1 - 32' 10" - 27' 10" - 5,106 lbs - 1,180 - 367 mph
Spitfire kind of threads the needle despite having a 36' wingspan, it's a small plane with a low drag design. Ki-43 and A6M were similarly small, slim airframes though with big wings.
Compare this group to the larger single engined fighters of the early war:
Brewster F2A - 35' wingspan but very fat body 1,200 hp for ~320 mph
F4F Wildcat - 38' wingspan, fat body, 1,200 hp for ~330 mph
Hawker Hurricane - 40' wingspan with 1,300 hp engine for ~340 mph
P-40E- 37' wingspan with 1,240 hp for ~ 350 mph
Typhoon - 41' 7" wingspan with 2,000 + hp, 400+ mph but not ready for fighter combat until 1943
Of the two lists above, the top is the more successful, arguably.
And then you have the larger twin engine fighters like the Beaufighter (57" span - 320 mph) Me -110C (53" span - ~330 mph) and P-38F (52' span, ~390 mph) - of the three only the P-38 became a fully viable daytime fighter capable of engaging the best Luftwaffe planes, but it took two years of debugging and improvements before it was truly ready for that role.
Until reliable 1,500 + hp engines were out, the smaller fighter designs generally worked out best as fighters.
What makes Whirlwind so interesting is that it was a twin, but a small twin, with roughly half the weight of a Beaufighter and 12' smaller wingspan (80% the span, 50% of the wing area), that managed to be in that higher category of speed, of over 350 mph, which was needed for a front line fighter.
Later when reliable P&W R-2600 and 2800, RR Merlin 60 series, RR Griffon, Bristol Centaurus and so on were available, then the bigger planes became truly viable and started to pull ahead, so to speak, of the smaller planes - P-47, Hellcat, Corsair, Tempest and so on. Until then it was a tradeoff. If you wanted the longer range and payload it came with increased vulnerability. This is where the small well streamlined fighters had their day, in the early war.
I'm talking small as in Bf 109, MC.202, D.520, or Yak-1. As in 32'-34' wingspan and 27-29' length, and a small body cross section.
Airplane - wingspan - length - empty weight - engine HP - top speed
Dewoitine D.520 - 33' 6" - 28' 3"- 4,680 lb - 950 hp - 350 mph
Bf 109E3 - 32' 4.5"- 28' 8" - 4,685 lbs- 1,175 hp - 354 mph
MC.202 - 34 9" - 29' - 5,180 lbs - 1,075 hp - 372 mph
Yak-1 - 32' 10" - 27' 10" - 5,106 lbs - 1,180 - 367 mph
Spitfire kind of threads the needle despite having a 36' wingspan, it's a small plane with a low drag design. Ki-43 and A6M were similarly small, slim airframes though with big wings.
Compare this group to the larger single engined fighters of the early war:
Brewster F2A - 35' wingspan but very fat body 1,200 hp for ~320 mph
F4F Wildcat - 38' wingspan, fat body, 1,200 hp for ~330 mph
Hawker Hurricane - 40' wingspan with 1,300 hp engine for ~340 mph
P-40E- 37' wingspan with 1,240 hp for ~ 350 mph
Typhoon - 41' 7" wingspan with 2,000 + hp, 400+ mph but not ready for fighter combat until 1943
Of the two lists above, the top is the more successful, arguably.
And then you have the larger twin engine fighters like the Beaufighter (57" span - 320 mph) Me -110C (53" span - ~330 mph) and P-38F (52' span, ~390 mph) - of the three only the P-38 became a fully viable daytime fighter capable of engaging the best Luftwaffe planes, but it took two years of debugging and improvements before it was truly ready for that role.
Until reliable 1,500 + hp engines were out, the smaller fighter designs generally worked out best as fighters.
What makes Whirlwind so interesting is that it was a twin, but a small twin, with roughly half the weight of a Beaufighter and 12' smaller wingspan (80% the span, 50% of the wing area), that managed to be in that higher category of speed, of over 350 mph, which was needed for a front line fighter.
Later when reliable P&W R-2600 and 2800, RR Merlin 60 series, RR Griffon, Bristol Centaurus and so on were available, then the bigger planes became truly viable and started to pull ahead, so to speak, of the smaller planes - P-47, Hellcat, Corsair, Tempest and so on. Until then it was a tradeoff. If you wanted the longer range and payload it came with increased vulnerability. This is where the small well streamlined fighters had their day, in the early war.
Shortround6
Major General
Not really, RR was certainly not in favor of licensing their designs (al least pre war, post war is something else) and any plan to keep the Whirlwind and Peregrine going is going to need to made in late 1939 or very early 1940 at the latest.
Ford of England was brought into the shadow scheme before the war broke out because when your major customer says they want more factories telling them no is difficult.
Talks with Ford of America and Packard don't start until France has already fallen so circumstances took a radical change.
England's manufacturing was getting maxed out, there was no empty factory space (it would have to be built) and there were no machine tools to put in it and there were few skilled workers who were not already doing something else. conjuring up a factory to make any type of aircraft engine in 1940 was not going to happen. Work on Crew and Glascow had started long before.
RRs was not the only one to resist sharing, it took considerable pressure to get Bristol to "share" the secret/s of the Taurus sleeve valve with Napier, much later in the war. It then took the appropriation of 6 Sundstrand centerless grinders from P & W (delaying start of production at the Kansas city plant by 6 weeks) and a fast voyage (not in convoy) by the Queen Mary (?) to deliver the grinders. This was in 1943. Cooperation between companies in 1939 was ??????????
BTW this deal with the Grinders delayed the introduction of the C series engines used in the P-47M/N and other aircraft.
Shortround6
Major General
And you are mixing up apples and watermelons.
The first four are land based fighters of not particularly great range, and only the D.520 and Yak 1 flew pretty close to the original design, the other 2 are much evolved.modified.
Of the 2nd group the first two are carrier aircraft, the F4F in particular might be pudgy but it also had a 260 sq ft wing which slowed it down, however it was this wing that allowed to to take-off and land on carrier decks.
The Hurricane (and Spitfire) were required to get in and out of small airfields with a fixed pitch prop, you might as well have tried to design a fighter to take-off out of a small airfield with several hundred pound anchor dragging in the grass behind it. The Merlin II and III was rated at 880hp at 3000rpm at 6lbs of boost for take-off but the fixed pitch prop required the engine to be limited to just over 2000rpm in order to get any bite on the air at all.
I am don't even know where you got the power figure for the P-40E. The P-36 held about 160 gallons (605 liters) of internal fuel to meet US requirements, the 109 was originally designed to hold 235-255 liters of fuel, amazing how small you can make a plane if it doesn't have to have much range or carry much armament.
BTW the Caudron 714 wasn't a point defence fighter, it was basically a piece of crap or at best a place holder while Caudron worked on a different version with something approaching a real engine. (something with over 700 hp). the Caudron 714 couldn't climb for used spit making it rather useless as an interceptor. A Hurricane I with fixed pitch prop could make it to 20,000ft in the time it took the 714 to get to 13,000ft.
MiTasol
1st Lieutenant
Or a Pratt and Whitney R-1690-S1C3G 1,050 hp (780 kW) which was in production at that time would have possibly been viable. The Brits had no spare engine capacity and fitted R-1830s to Beaufort's and Sunderland's. Possibly a major redesign to eliminate the liquid cooling system but a lighter well proven engine (built under licence in Germany by BMW and in Italy as the Fiat A.59) with significantly more power and the cooling system space could have been used for fuel storage.
Shortround6
Major General
I am not sure such an engine existed. There is a P & W R-1830-S1C3G
See. http://www.enginehistory.org/Piston/P&W/R-1690/Hornet.pdf
and try to find a 1050hp engine.
MiTasol
1st Lieutenant
You are right - I got my info from Wikipedia and we all know that is suspect so I should have checked other sources.
Bugga or words to that effect.That makes the Hornet 10 hp less so the performance would possibly be reduced as nothing to compensate for the larger frontal area other than the lighter, cleaner wing from having no cooling system and that may not have been enough. The fuel and range benefits would have helped but the redesign time would be against it.
I doubt the R-1830 would be practical - too much weight and too much power to be a "simple" replacement and the Americans had no other small radials in production that I can think of.
Admiral Beez
Major
As a competitor to the Whirlwind, was an enlarged, military spec version of the 1934 de Havilland DH.88 Comet ever considered for the twin engined, single seat fighter role?
MiTasol
1st Lieutenant
Bristol could not build the Taurus fast enough for Beauforts, let alone another airframe, and a twin at that.
Bristol's inability to provide the Taurus to Australia lead to the Australians fitting Hudson powerplants to the first 52 and an Australian derivative to the rest.
Bristol themselves then took the concept but did a different installation.
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I never said the Caudron 714 was a good plane, we can debate the design philosophy of it in another thread (whether it's supposed to be for point defense or not) or another side argument to this one, but keep in mind I only brought it up as an example of what I was not talking about. Now if you want to talk about another light fighter like the Arsenal VG.33 then we have yet another discussion on our hands.
Yes the first four aircraft - the small ones - had shortcomings (pun intended) especially in that they had short range and endurance. Quite a setback. Most also carried fairly light armament. And yet all four (even the D.520) remained in combat, albeit with some changes for a couple of them, well into 1944.
More generally speaking, this small interceptor type fighter - I would argue the first category of truly successful WW2 monoplane fighters, (flying initially with about ~1,000 hp engines), remained a major type basically for the whole war - granted with more and more powerful engines. That speed and performance advantage of the small size and short wingspan remained in demand. War planners and air force commanders (and pilots, in most cases) always wanted that edge in speed.
The big beefy fighters that started arriving on the battlefield in 1943 dispensed with the benefits and drawbacks of small size and used big powerful engines in the 1,800 - 2,000+ hp range (later up to almost 3,000 hp for short sprints) to give the needed performance to shove those big airframes around the sky. That is what I consider the second category of successful fighter designs in WW2 - the P-47, F4U, F6F, N1K1, Tempest and so on. I would also include the one really successful twin engined day fighter in that group - the P-38 (which in the definitive L variant was producing 3,200 hp). It was more streamlined but considerably larger in terms of wingspan than most of the others.
The very best all around fighter designs though, like the mid-to-later model Spitfire, the P-51, the Fw 190, and the 5 series Italian fighters, were in between these two. I call them the 1.5 category. They combined fairly slim and well streamlined bodies with large but relatively low drag wings. These kind of threaded the needle between the first and second type. They had the bigger wingspan - to a point, most were around 36 - 38 ft but not much more than that - but they had a low enough drag that they could still get excellent speed with smaller engines, basically improved versions of the original 1st generation engines, starting around 1,000 hp but now reliably up in the 1,500 hp range. With the greater lift of the bigger wings these aircraft could carry the much harder hitting armament of the big sized 2nd category of fighters. And they usually had better range (even the Spit got better than interceptor range with the Mk. VIII).
Effectively the Whirlwind is a design shortcut to this kind of plane. You want a 4 cannon fighter in 1940, but no suitable engines are available (not that really work yet anyway). So you take two ~800 hp engines and build a relatively small and very nicely streamlined body and a relatively short span, thin chord, low drag wing and make a 1,600 hp fighter than can carry 4 x 20mm cannon, two years before any reliable 1,600 hp engines are actually in the field.
By the way the horsepower rating on the P-40E was cribbed from what it says in the current incarnation of the Wikipedia page, as we both know the actual horsepower output of a V-1710-39 could vary quite widely depending on if it was using military, takeoff or WEP power. Apparently they got that number from Americas 100,000 along with a 334 mph top speed, which I think is rather a lowball figure but that aint worth wading into Wikipedia...
ThomasP
Senior Master Sergeant
Hey guys,
FWIW, I did a basic engineering study and some calculations for a Merlin 46 Whirlwind (I used the Merlin 46 since the low performance at altitude seemed to be the most serious drawback in the eyes of Fighter Command). It is somewhat general but this is what I came up with.
The minimum TOGW would be 11,350 lbs clean. This weight is with the same or similar armament and internal fuel load. The weight increase is composed of the Merlin 46 engines, 4-blade props, increased cooling systems, increased oil load, and detail strengthening for the fuselage, wings, engine mounts, landing gear, etc.
The performance difference would be around:
400 mph TAS at 22,000 ft vs 355 mph TAS at 15,000 ft, both at max sustained boost for 5 min (with Merlin 46 at +9 lb boost, Peregrine I at +6.75 lbs boost)
360 mph TAS at 20,000 ft vs 330 mph TAS combat cruise at 15,000 ft, both at max rich cruise
200 mph TAS vs 180 mph TAS best range cruise, both at 15,000 ft
540 mile vs 760 mile range on internal fuel (160 USgal) at best range cruise speeds and 15,000 ft
940 mile vs 1350 mile range with 2x 54 USgal DT at best range cruise speeds and 15,000 ft
3000 ft/min to 18,000 ft vs 2600 ft/min to 15,000 ft
38,000 ft vs 30,000 ft service ceiling
Although the performance increase is impressive, by the time it could have been implemented (my best estimate is mid-1942 at the earliest?) the Spit Mk IX and Typhoon are already available. So even if Merlins were available, much as I like the Whirlwind, I would have to say the modifications would be pointless in a strategic sense.
FWIW, I did a basic engineering study and some calculations for a Merlin 46 Whirlwind (I used the Merlin 46 since the low performance at altitude seemed to be the most serious drawback in the eyes of Fighter Command). It is somewhat general but this is what I came up with.
The minimum TOGW would be 11,350 lbs clean. This weight is with the same or similar armament and internal fuel load. The weight increase is composed of the Merlin 46 engines, 4-blade props, increased cooling systems, increased oil load, and detail strengthening for the fuselage, wings, engine mounts, landing gear, etc.
The performance difference would be around:
400 mph TAS at 22,000 ft vs 355 mph TAS at 15,000 ft, both at max sustained boost for 5 min (with Merlin 46 at +9 lb boost, Peregrine I at +6.75 lbs boost)
360 mph TAS at 20,000 ft vs 330 mph TAS combat cruise at 15,000 ft, both at max rich cruise
200 mph TAS vs 180 mph TAS best range cruise, both at 15,000 ft
540 mile vs 760 mile range on internal fuel (160 USgal) at best range cruise speeds and 15,000 ft
940 mile vs 1350 mile range with 2x 54 USgal DT at best range cruise speeds and 15,000 ft
3000 ft/min to 18,000 ft vs 2600 ft/min to 15,000 ft
38,000 ft vs 30,000 ft service ceiling
Although the performance increase is impressive, by the time it could have been implemented (my best estimate is mid-1942 at the earliest?) the Spit Mk IX and Typhoon are already available. So even if Merlins were available, much as I like the Whirlwind, I would have to say the modifications would be pointless in a strategic sense.
wuzak
Captain
Why 4 blade propeller for the Merlin 45? They only used 3 blade propellers on the Spitfire.
By using the Merlin 45 you are sacrificing some of the performance at lower altitudes. A better bet would be the Merlin XX.
Better than that would be putting the Merlin XX into the Spitfire.
Fitting Merlin 45s to Whirlwinds would cost at least 2 Spitfire Vs to each Whirlwind made and, of course, any Merlin XX used in the Spitfire or Whirlwind takes away from the Hurricane and other types that really need that engine.
By using the Merlin 45 you are sacrificing some of the performance at lower altitudes. A better bet would be the Merlin XX.
Better than that would be putting the Merlin XX into the Spitfire.
Fitting Merlin 45s to Whirlwinds would cost at least 2 Spitfire Vs to each Whirlwind made and, of course, any Merlin XX used in the Spitfire or Whirlwind takes away from the Hurricane and other types that really need that engine.
Not according to Rolls-Royce.
It had to be a four blade propeller on any Merlin version of the Whirlwind because the proximity of the nacelles to the fuselage limit the maximum diameter of the propeller. To absorb the increase in power a four blade propeller was required. This is about the only issue that Petter did address with his 'Whirlwind II'.
- Thread starter
- #377
(way off topic)
Stick the G&R 14M on the Caudron 714 instead of the Reanult's engine?
Kevin J
Banned
Problem with French engines is they're metric no Imperial.
- Thread starter
- #379
People at Caudron won't mind.
Admiral Beez
Major
As a previous decade-long owner of a 1960s Triumph motorcycle with Whitworth and other CEI fasteners, plus an early 1980s Suzuki shafty, I must give kudos to those WW2 mechanics which may have to maintain a mixed force of European metric, American imperial and British aircraft. The Russians with all the Lend Lease types must have been kings at this.
Such as the DEI air force, with Martin bombers and Brewster fighters from USA, Dornier flying boats from Germany and in the end Hawker Hurricanes from Britain. Those Dutch mechanics must have had comprehensive tool boxes and knowledge.
