Earlier Tempest/No Typhoon

GregP said:

So I still wonder why anyone in the world anyone would base anything new on the failed Peregrine that had reliability isuues as well as poor altitude performance. If you're going to start an expensive new development, start with an engine that is a winner or with a new design, but don't start with an engine having known performance problems.

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Agreed....The peregrine swept volume of 21.2L was just over half the DB605s 35.7L , even if it was a miracle in performance it wouldnt match the bigger opposition.

Gee, last one came off th line in Jan 1942, they only built 112-116 of them, (232 engines used with 60 something spares in crates) and yet........No 137 squadron flies it's last whirlwind combat mission 21st of June 1943 and No 263squadon flies it's last Whirlwind combat mission Nov 29th 1943. That is 23 months after the last plane left the factory. By this time the Whirlwind is a flying museum piece as aside from a few minor modifications, (new radios,etc) it is unchanged from the summer of 1940. Same engines, same props, same guns, same fuel system. The ONLY change is the addition of some primitive bomb racks.

Think about trying fly Spitfire Mk IIs with a bomb rack over France and the low countries in the summer/fall of 1943. Or try flying P-40Cs with a bomb rack across the channel in 1943.
Yep, the Whirlwind must have been one useless piece of junk to do what it did.

BTW the lines quoted by Greg are rather misleading in many respects. For example the Whirlwinds didn't get bomb racks until the summer of 1942 so the bit about being useful for a short time is suspect. As is the bit about restricted airfields. Whirlwinds were used in small numbers from one end of the channel to the other and while based out of a few fields they staged through most of the fields they weren't supposed to be able to use.

Shortround6 said:

Think about trying fly Spitfire Mk IIs with a bomb rack over France and the low countries in the summer/fall of 1943.

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Unlikely, since the Spitfire II was replaced by the V in 1941, relegating the II to training units. Think about flying the Hurricane II, loaded with bombs, and escorted by the Spitfire V in 1943 (which is what actually happened.)

Yep, the Whirlwind must have been one useless piece of junk to do what it did.

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Ah, the usual emotive nonsense about the airframe, while forgetting the manufacturer; Westland could only build one, maybe two airframes per week, which was nowhere near enough to equip any more Squadrons, never mind replace losses.
Continuing with the Whirlwind would have cost the Air Ministry and the Admiralty 685 Westland-built Spitfires and 1478 Seafires, but who needs them, anyway?

Nothing I said is suspect, Shortround but your logic certianly is. If the Whirlwind was good, why wasn't it developed further? Easy answer, see above. The only fighters with shorter service lives were complete failures, not the "seemed like a good idea at the time ... that turned out not to be" that the Whirlwind was.

Let's see ... 8 Whirlwinds received by the end of 1940 and the last Whirlwind was retired in Dec 1943. Servicve life about three years total and they were cancelled and placed out of production in January 1942. So, it basically came into service at the end of 1940 with a total of 8 flying and two years later was cancelled in the middle of a war for national survival that was not yet seeming to go all that well. That, in and of itself, says an awful lot.

At the start of the war in Sep 1939, only three Defiants were in service. It was already relegated to jamming duties by 1943 and is widely regarded as one of the worst fighters of the war. It had a service life about twice that of the Whirlwind.

As it transpired, aircraft designs rapidly increased in size and power requirements to the point where the Peregrine was simply too small to be useful. Although the Peregrine appeared to be a satisfactory design, it was never allowed to mature since Rolls-Royce's priority was refining and producing the Merlin. As a result the Peregrine saw use in only two aircraft: the Westland Whirlwind and the Gloster F.9/37, neither of which was noteworthy in any asepct except maybe looks.

Four Kestrel/Peregrine cylinder banks attached to a single crankcase and driving a single common crankshaft would produce the contemporary Rolls-Royce Vulture, a 1,700-horsepower (1,300 kW) X-24 which would be used for bombers. The Vulture was fitted to the Hawker Tornado and Avro Manchester, but proved unreliable in service, go figure. Let's see, unreliable as a single block and unreliable as a quadruple block ... do you see a trend here? I do.

With the Merlin soon pushing into the 1,500 horsepower (1,100 kW) range, the Peregrine was cancelled in 1943 with a total of 301 built. You might have picked the wrong airplane and engine to brag about there, Shortround. The Whirlwind just isn't worth much discussion as a potential fighter since it never was much good against single-seaters and the engines were a failure in the eyes of everyone associated with it during the war, to include even the Vulture 4 block engine.

But even I have to admit the picture above looks good. My ex-wife looked pretty as a picture, too. Looks can be deceiving.

The whirlwind had one thing going for it, 4 cannon in the nose. Ideal for ground attack. Two engines help although i think I read only one engine had all ancilliaries. A nice plane but cancelling the peregrine was correct.

The peregrine was considered problematic but it was developed from the kestrel of which 4750 were made in peacetime. No doubt they could have sorted it but why, when eyes were already looking beyond the merlin to the Griffon Sabre and Centaurus?

I think you missed the point. Name another aircraft flying in 1943 over France and Low Countries flying in essentially unmodified form from the fall of 1940.

The Hurricane II doesn't count because, unless you can say other wise, they were not using the IIa with eight .303 guns in 1943. I doubt they were using the same boost limits in 1943 as they were using in 1940 either on the Hurricane IIs, Wasn't it something like 14lbs in low gear and 16lbs in high gear by 1943 instead of 9lbs in the Summer of 1940, but hey, whats an extra 20-25mph at sea level between friends for the 1943 Hurricane.

I really love the Westland production figures too, Westland can only make 1-2 Whirlwinds per week but were churning out 5-6 almost useless Lysanders per week. Of course NONE of the workers who built Lysanders would have a clue about working on Whirlwinds even with several weeks of retraining, right? And somehow the Whirlwind was so complex that the work force that could build 1-2 Whirlwinds per week could build 5-6 Spitfires a week if not more. All the Lysander workers left Westland when Lysander production stopped and found other jobs rather than work on Spitfires?

I have said it before, stopping the Peregrine was the right thing to do from a production stand point. Buts lets cut out the phony justifications of " unreliable", "troublesome" and so on. Unless people can come up with instances of broken crankshafts, cracked blocks or heads, holed piston, broken rods or other examples of mechanical failures that were NOT the result of of failed engine controls (stuck/jammed throttle, runaway propeller, stuck/jammed radiator doors, etc).

I have always liked the Whirlwind's looks and the well-placed cannons. To me it looks "plucky," but I wasn't flying it. I would rank it up there with my favorite twin in looks, for sure. But the service life and lack of altitude performance means it was sort of the twin engine equivalent of the P-39 ... OK at low altitude but starts losing rapidly as the height increases past the low to mid teens ... and Europe wasn't exactly a low-altitude war ... most of the time.

It is quite possible the Whirly could have been used effectively in the PTO or MTO, but they didn't really get there in numbers because there weren't any numbers to speak of ... they only build 116 Whirlwinds. That's about the number prototypes for the Ju 88! They built more He 162's than Whirlwinds, for crying out loud, how good could it have been? They built ten times as many Defiants!

Now if they had possessed a suitable engine for it, perhaps it could have made a difference. As it turned out, they didn't and it didn't, sweet though it may look. I surely wish we had one flying today, and the engines wouldn't need any altitude performance for airshows. But I'd also hate to try to find spare parts for an engine they only made 301 of ... tough we DO fly a Northrop N9M-B and they only made 13 of those engines! ... we have 2 1/2 remaining. A Whirlwind might be easy maintenance by comparison, but it didn't make even a good footnote in WWII as far as impact on the war effort goes.

Here's a good cutaway:



Like I said, I like the looks of it.

And I didn't miss the point. The point was made when the Whirlwind was cancelled atfer about 2 years. You don't cnacel something all at once. It's not like it was OK until one day it wasn't. They accumulated a service hsitory that wasn't panning out to be good and finally had enough complaints about it to cancel it ... right at the time the Germans at sea were in the middle of "Our Happy Time" with U-boat wolfpacks and were doing OK on the land and in the air, too. If the Whirlwing had been useful and reliable, they would have kept building it.

We kept building P-39's and P-40's. Doesn't mean they were getting any better as the war went along ... quite the opposite.

Geez, I kicked a bigger hornet's nest than I thought...

Let us not forget that when the ramp head Merlin ran into serious development trouble, Rolls Royce dropped back, and scaled up the parallel valve Kestrel cylinder to become the Merlin II (and from there later developments like the Merlin 61). I think of the Peregrine as more or less a 9/10s scale Merlin.

As far as development problems with the historic Peregrine, remember this was now the fifth parallel valve V-12 Rolls Royce had developed. Before the Peregrine, the Kestrel, Buzzard, R, and Merlin had all come into their own IN DUE TIME. To say that the V-12 Peregrine could have been troubled with 'unsolvable' problems seems a stretch to me. Agreed, the Kestrel/Peregrine was too low of a power for a 1940 or later vintage single engine fighter. You are also right, spending time on a V-12 engine used in only the Whirlwind was not a good use of limited resources.

In my time line, the historic X-24 Vulture never gets designed or built. Rolls Royce builds 'a couple' developmental V-12 Peregrines, but they realize they aimed 'too low' and their primary effort becomes a 24 cylinder 'double Peregrine' with vertical cylinders and two crankshaft in an H arrangement. This doubled engine could have been 'the' engine for the 'new generation' Tornado / Typhoon / Tempest fighter line (and a couple of bomber projects).

Assuming there were technicians and time available (potentially a very big headache during the late summer and fall of 1940) my spin is that the problems with a H-24 double Peregrine would have been trampled to death in a reasonable time. That implies the H-24 double Pergrine would have been good for 1750 to 1800 HP in 1941. Assuming the people working on the H-24 double Peregrine were allowed to look over the shoulders of the Merlin development folks, the double Peregrine could have been at about 1 HP WEP per cubic Inch displacement (like the Merlin 45) i.e. 2500 HP for the double Pergrine, by late 1942 / early 1943. To chase buzz bombs in the fall of 1944, maybe 3200 HP on 150 grade fuel. Who needs the Sabre!!!

I heading to the bunker, closing the blast doors, and activating the deluge system.

Shortround6 said:

I believe the original presenter of this idea may have been suggesting a stacked pair of Peregrines? one inverted?

Lets not forget that the Sabre was essentially a 'stacked' engine. Two flat twelves geared together to use a common propeller and common supercharger/accessories. Granted they didn't make things easy on themselves by using paired cylinder blocks.

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Yes, I thought of that after I logged off last night. Also makes me wonder why none of the 'double V' engines opted for that. It seems like a more efficient arrangement than what the DB 606/610 or Allison V-3420 did. (though sharing the crank case and oil resources would make more sense than using 2 totally separate, coupled engines like the 606)

Many of the problems associated with the DB 606 would have been solved that way too.

The phrase "teething troubles" although often used, sometimes leaves a bit to be desired. Is the one of the teething troubles a poor control system from cockpit to engine or a tendency to put connecting rods through the side of the crankcase? Now either one could end a flight and cause the loss of the aircraft and crew but which one would be harder to "fix". A French Hispano Radial had a "teething trouble" in the 30s. The gear case tended to come apart in flight with the propeller parting company with the aircraft. Some American engines had "teething troubles" in high altitude flight with mis-firing engines. This was solved by pressurizing the magnetos. The thin air at altitude not acting as an insulator like the thicker low altitude air.
You have "teething troubles" and you have fundamental problems/flaws, like the Armstrong Siddeley Tiger and Gnome Rhone 14K&M engines having only two main bearings on the crankshaft which limited power (both rpm and cylinder pressure) without a major redesign.

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Indeed, the Peregrine's troubles (while still in development) seemed to be relatively trivial in that department, certainly not crippling and much less trouble to overcome than what many other engines faced.

The trouble was the engine was abandoned for logistical reasons and thus became a BAD engine BECAUSE of that, discontinued development and production left the Whirlwind stuck using basically 'dead' engines. All airframes had to be built with existing Peregrine resources and modifications to fix problems by altering the production line were impossible as the production line was closed. (all workarounds had to be done in the field or through modifications in repair/service depots and relatively little engineering resources would have been provided for actually providing those fixes)

The Peregrine was a dead end AFTER it was canceled, not before.

Edgar Brooks said:

Which it would have; according to Rolls-Royce, continuing with the Peregrine would have cost two Merlins for each Peregrine.
With the better-engined Hurricane II capable of delivering the same ordnance, with a single Merlin, the Whirlwind/Peregrine was a dead duck.
The (almost) year's delay in the Tempest was caused by the C-in-C Fighter Command's insistence on it having a universal wing, capable of having various combinations of guns. Hawker struggled for a year, and finally got the go-ahead for an all-cannon wing.

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Indeed, my suggestion was to license the Peregrine to Napier and avoid contetion for RR production and development resources. (or at least limit development to the same extent as cross-consulting work done on the Saber)

And I'm talking about the Whirlwind competing for the Typhoon's role, not the Hurricane's. A fast, high performance interceptor. (fighter-bomber considerations only came later) Even without structural redesign of the engine, supercharger improvements akin to the Merlin XX/45 series should have boosted peak power somewhat (even at +9 psi) and substantially increased critical altitude. Not to mention better range than the Typhoon, or Spitfire.

Fighter-bomber considerations would come later and likely well exceed what the modified Whirlybombers actually carried.

The Whirlwind may have been too tight a design to adopt merlins without a major redesign, but that doesn't mean it was too tight to have heavier external load carrying abilities adapted.

The Peregrine WAS also cheaper to produce than the Merlin in terms of materials. It was the opportunity cost that was high with Rolls Royce, not the material or labor costs. (economies of scale and streamlining production for the Merlin ... now if they'd switched to ONLY building paregrines, output should have been higher than ONLY merlins ... but building both means less of either) This is irrelevant when Napier is concerned, unless you want them to cancel the Saber and just build more Merlins. (which I admit is also an attractive option)

Shortround6 said:

BTW the lines quoted by Greg are rather misleading in many respects. For example the Whirlwinds didn't get bomb racks until the summer of 1942 so the bit about being useful for a short time is suspect. As is the bit about restricted airfields. Whirlwinds were used in small numbers from one end of the channel to the other and while based out of a few fields they staged through most of the fields they weren't supposed to be able to use.

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Indeed, you need much more context of those statements to not get misled by them (which Greg seems to be confused over). The Peregrine was certainly the reason the Whirlwind ended up a dead duck development wise and the main limiting factor that killed further production. HOWEVER, this was because the Peregrine's development and production had been halted in favor of Merlin R&D and production NOT because the Peregrine had any fundamental flaws.

Perpetuated mis-interpretation often takes a good bit of investigative analysis of the source material to actually work out what the truth is. A lot of encyclopedic style historical articles (and popular history type editorials) tend to fall into that trap of misinterpreting true/factual information and also failing to account for possible mistaken comments made in the original quoted statements. (due to mis-steps in speech or sometimes attempts of dumbing down explanations for interviewers -I see that all the time in popular mechanics and electronics type articles) 'What did they really mean by X?' is a very, very common question to deal with when trying to decipher explanations.

It's a bit like if Allison stopped V-1710 production entirely with the C series and left the existing lot of Tomahawks to make do with existing components and spares until they finally ran out. (or more like if the P-40 was a tighter design and the F series changes were -hypotehtically- too much for the airframe to cope with, thus dooming it to make do with the 'dead' engine -the C series was more mechanically troublesome than the F series too, even if it wasn't built in as small numbers as the Peregrine)


Actually, those early, lighter V-1710s came up a few times as alternate engines for the Whirlwind (along with the Hispano 12Y) as potentially having fewer problems than the Merlin partially due to the dimensions of the engine I believe (mounting geometry being closer to the Peregrine). Length and weight were a bit high to make that really plausible though, even if Allison engines were available in numbers in time (or licensed production was set up ... say with Napier ... ). The Hispano engine fit a bit better but seemed more a dead-end development wise. (and fuel efficiency was much worse than the Allison)

Hell, given the relatively conservative ratings by the USAAC/AAF, a moderately refined peregrine (particularly with improved supercharger) might match or exceed the military rating performace of the V-1710 in 1941. (more likely the 1040 hp of the -33, less likely to match/beat the 1150 hp of the -39) Granted, that would be due to more aggressive engine rating and not superior engineering/production ... aside from supercharger/manifold aerodynamics.

GregP said:

Nothing I said is suspect, Shortround but your logic certianly is. If the Whirlwind was good, why wasn't it developed further? Easy answer, see above. The only fighters with shorter service lives were complete failures, not the "seemed like a good idea at the time ... that turned out not to be" that the Whirlwind was.

Let's see ... 8 Whirlwinds received by the end of 1940 and the last Whirlwind was retired in Dec 1943. Servicve life about three years total and they were cancelled and placed out of production in January 1942. So, it basically came into service at the end of 1940 with a total of 8 flying and two years later was cancelled.

At the start of the war in Sep 1939, only three Defiants were in service. It was already relegated to jamming duties by 1943 and is widely regarded as one of the worst fighters of the war. It had a service life about twice that of the Whirlwind.

As it transpired, aircraft designs rapidly increased in size and power requirements to the point where the Peregrine was simply too small to be useful. Although the Peregrine appeared to be a satisfactory design, it was never allowed to mature since Rolls-Royce's priority was refining and producing the Merlin. As a result the Peregrine saw use in only two aircraft: the Westland Whirlwind and the Gloster F.9/37, neither of which was noteworthy in any asepct except maybe looks.

Four Kestrel/Peregrine cylinder banks attached to a single crankcase and driving a single common crankshaft would produce the contemporary Rolls-Royce Vulture, a 1,700-horsepower (1,300 kW) X-24 which would be used for bombers. The Vulture was fitted to the Hawker Tornado and Avro Manchester, but proved unreliable in service, go figure. Let's see, unreliable as a single block and unreliable as a quadruple block ... do you see a trend here? I do.

With the Merlin soon pushing into the 1,500 horsepower (1,100 kW) range, the Peregrine was cancelled in 1943 with a total of 301 built. You might have picked the wrong airplane and engine to brag about there, Shortround. The Whirlwind just isn't worth much discussion as a potential fighter since it never was much good against single-seaters and the engines were a failure in the eyes of everyone associated with it during the war, to include even the Vulture 4 block engine.

But even I have to admit the picture above looks good. My ex-wife looked pretty as a picture, too. Looks can be deceiving.

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My logic is just fine. Yours could use a bit of tune up. As could your facts.

They built over 1000 Defiants. Over 9 times as many as Whirlwinds. They had to see them for something. Flying 50 miles off the coast at night with jamming equipment is not quite the same as flying over occupied territory in daylight bombing and strafing (if your 20mm guns can hit them, their 20mm guns can hit you) and attacking ships in defended ports. I would hope that 1000 airplanes had a longer "service life" that 114-116 airplanes. I would also note the Defiant got a MK II version with more power.
Perhaps is was the fact that the Whirlwind was a single seat aircraft and could NOT be turned into a target tug easily that kept in the front lines so long.
BTW The British figured (estimated) it took 50 aircraft to keep one squadron in service for 6 months of front line use. The Whirlwind beat that estimate rather handsomely.

The Whirlwind was NOT canceled in 1942 or even 1941. It had been "canceled" (or more properly, it's option/s had not been picked up) in 1939. The odd number built was number they figured they already had long lead items built for that would be wasteful to scrap.

AS for "Four Kestrel/Peregrine cylinder banks attached to a single crankcase and driving a single common crankshaft would produce the contemporary Rolls-Royce Vulture, a 1,700-horsepower (1,300 kW) X-24 which would be used for bombers. The Vulture was fitted to the Hawker Tornado and Avro Manchester, but proved unreliable in service, go figure. Let's see, unreliable as a single block and unreliable as a quadruple block ... do you see a trend here? I do."

A. while the Bore of the Kestrel/Peregrine and Vulture was the same the bore spacing was not. Bore spacing was actually the same or very close to the bore spacing of the Merlin. The Vulture did not use Peregrine cylinder banks, or cylinder heads or even camshafts (lobes had to be spaced out further).
B. main failing of the Vulture was.....connecting rod failure. Four pistons operating on one master rod and 3 slave/articulated rods. Peregrine (and Kestrel) used normal forked rods, just like a Merlin. Sorry, I am not seeing the trend there.

Shortround,

Further production orders were terminated in 1942 and Westland finsihed the production still ongoing. The plane was withdrawn from service in 1943. That's according to several sources. Maybe they're all wrong? The last Whirlwind was delivered in January 1942.

If you are so loving of the Whirligig, take all 116 (or 114 in other sources) in your fictional air force and go attack fictional Germany. I'm sure with sufficient literary license the entire war could turn around.

In the real world they amount to nothing much, like this discussion. 116 airplanes of ANY sort really isn't much to argue about. Let's say you are right.

Tell me all about the wonderful things your Peregrine-based engines did in the war. I eagerly await your response. But wait, No. 263 Squadron, the first and last squadron to operate the Whirlwind, flew its last Whirlwind mission on 29 November 1943 and turned in their aeroplanes and converted to the Hawker Typhoon in December that year. On 1 January 1944, the type was officially declared obsolescent. The remaining serviceable aircraft were transferred to No. 18 Maintenance Unit, while those undergoing repairs or overhaul were only allowed to be repaired if they were in near-flyable condition. An official letter forbade aircraft needing repair to be worked on.

So don't tell me all about the possible developments, tell me about wonderful Peregrine use and Whirlwind successes. A bigger Whirlwind with Merlins, though maybe interesting, would be a new aircraft, not a Whirlwind.

Shortround, this was a singularly unremarkable fighter aircraft at a time when great ones were needed. It wasn't BAD, it was less than what was needed and the engines left no room for significant development. They realized that after a very few were made and stopped.

All your crying won't change that. And I know how many planes were built by almost everyone who made one for WWII, including obscure prototypes, which are one of my favorite subjects.

This dog won't hunt. The Whirlwind did little for the war effort and that won't change.

Shortround6 said:

They built over 1000 Defiants. Over 9 times as many as Whirlwinds. They had to see them for something.

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And that "something" was nightfighting; the Defiant shot down 152, mostly bombers and mostly in 1941 without the aid of radar, against losses of 37, mostly in 1940. Hardly qualifies it as being useless.

BTW The British figured (estimated) it took 50 aircraft to keep one squadron in service for 6 months of front line use. The Whirlwind beat that estimate rather handsomely.

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20:20 hindsight again; a bit late when production had already stopped.

The Whirlwind was NOT canceled in 1942 or even 1941. It had been "canceled" (or more properly, it's option/s had not been picked up) in 1939.

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Wrong; Sir Wilfrid Freeman decided on no new orders in May 1940, and it was 30-10-40, before Beaverbrook decided to stop production altogether.
Perhaps we can now turn to the Lysander, which you label as "useless." I suspect the hundreds of U.S.A.A.F. and R.A.F. aircrew who were saved from drowning, thanks to the aircraft of the four A.S.R. Squadrons, might possibly have a different view. The Lysander's low speed handling made it ideal for dropping dinghies exactly where they were needed, but there's no glamour in that role, of course.
P.S. The Defiant also saw service in ASR duties.

I like the Defiant and it was decent as a night fighter, but as a day fighter against single-einge opponents it was abysmal, after some initial successes. They saw some potential and that's fine, but they didn't ... thank heaven ... deploy it against actual single-seat, quality fighter opposition as a mainstay. Had they done so, the crew would have been sacrifices.

The Bf 110 was a very GOOD night fighter. It sucked as a primary day fighter. One failure can lead to success in another area, as with the very versatile Ju 88 ... but the Whirlwind apparently didn't have the development potential due to limited engine power development increases with the engine selected and the OK-but-nothing-to-write-home-about low level performance. If it HAD the potential, nobody in power saw it and neither did the firm that produced it.

One wonders why they didn't consider that at the start of the project. Perhaps the reality of war was beyond the forward vision at the time. The folks at Supermarine, Focke-Wulf, and Messerschmitt ... to name but a few ... didn't have that problem with their primary warhorses. These 1930's designs foresaw development and quantum jumps in performance ... or else they were all very similarly lucky. I'm not a big believer in luck.

The Peregrine had about .68 hp/cubic inch and so did the Vulture. The Merlin had .90 hp/cu in and the Griffon had .99 ... significantly better.

The German DB 601 had .57 but they compensated for lower-performace fuel with cubic inches and made competitive power. The DB 605 had .78 hp/cu in and the BMW 801 had .60, again using displacement to get the power required.

The lowest HP was the Peregrine. 885 versus 2,220 for the Griffon and even 1,700 for the DB 605. So both sides saw the lack of HP as well as Rolls Royce did. The powers above are not specific to any variant but are representative. Some were higher and some were lower, but the Peregrine stands out as a smaller, lower-power engine among this group, which other than the Peregrine, were the principal fighter engines of the major types in the ETO aside from the USA. We never DID have a problem with engine displacement. More is better ... to a point.

If it were to pick a bottom engine from the list above, the Peregrine stands out as the one to pick based on power, and everything else was only incidental. They COULD have made it reliable and COULD have improved it to to maybe 1,000 HP or a bit more, but they were looking for 2,000 HP and the Peregrine clearly wan't going to get close.

The answer was go with a bigger-dislacement engine and they did.

GregP said:

And I didn't miss the point. The point was made when the Whirlwind was cancelled atfer about 2 years. You don't cnacel something all at once.

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The point is there was shaky funding/interest for the Whirlwind in the first place and the Peregrine's cancellation more or less killed what remaining interest it did have for expanded production orders. AND that the Peregrine was canceled for practical, rational reasons, but not due to insurmountable, impossible, or even atypical engineering difficulties.

GregP said:

Shortround,

Further production orders were terminated in 1942 and Westland finsihed the production still ongoing. The plane was withdrawn from service in 1943. That's according to several sources. Maybe they're all wrong? The last Whirlwind was delivered in January 1942.

If you are so loving of the Whirligig, take all 116 (or 114 in other sources) in your fictional air force and go attack fictional Germany. I'm sure with sufficient literary license the entire war could turn around.

In the real world they amount to nothing much, like this discussion. 116 airplanes of ANY sort really isn't much to argue about. Let's say you are right.

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Who's arguing the Whirlwind made a big impact? Shortround is clearly just arguing that it made an impressive impact given the tiny number actually built and limited resources available ... and how much better their service record was (per aircraft and pilot) than several other planes at the time, thus demonstrating its potential had it been built in large numbers. (he didn't say it, but I've been implying it: it would have been a better Fw 190 killer than the Typhoon)

Tell me all about the wonderful things your Peregrine-based engines did in the war. I eagerly await your response.

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They canceled engine development and production before it had a chance. That's all there is to it. It HAD development potential, but it was always going to be proportionally less powerful than the Merlin at best, and outside the Whirlwind it had no major applications. (I still argue a developed Peregrine could have displaced the Taurus in some roles, namely the Beaufort -and do it better than the mercury or Perseus- but otherwise it was just a drag on Merlin production that was too small to be competitive for single-engine fighters)

There also might have been the perception that a twin (of any size and character) would never outperform a similar size/power single engine fighter, but there was so little really high-performance single seat day fighter development with twin engines (especially ones to actually see service and be tested against enemy fighters) that there wasn't really much of any chance to disprove that at all ... until the P-38 matured. (the Whirlwind's smaller size, lower weight and lighter engines should have made it more competitive as a dogfighter than the P-38, particularly once they got the slats working properly) If it had come down to a vulture or coupled peregrine powered Tornado vs the Whirlwind, I'd tend to think the latter would be the technically superior aircraft with the most development potential.

Edgar Brooks said:

Perhaps we can now turn to the Lysander, which you label as "useless." I suspect the hundreds of U.S.A.A.F. and R.A.F. aircrew who were saved from drowning, thanks to the aircraft of the four A.S.R. Squadrons, might possibly have a different view. The Lysander's low speed handling made it ideal for dropping dinghies exactly where they were needed, but there's no glamour in that role, of course.
P.S. The Defiant also saw service in ASR duties.

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The Lysander bit comes from several previous threads that brought up wasted resources at Westland (some of which Shortround quite reasonably countered as I recall), but the big point being that all the practical arguments (the non political ones) for why production resources were so heavily allotted to the Lysander didn't hold water. The Air Ministry wanted it, so they got it, simple as that. A variety of bureaucratic and political issues seemed to hold back transitioning resources to Whirlwind production, including lack of timely orders into production. Yes, Peregrine production ending put a hard cap on how many whirlwinds COULD be practically built, but that doesn't mean the airframes couldn't have been built sooner, and more resources put into correcting the lingering problems.

I forget some of the details from previous discussions, but one of the more conflicted areas seemed to be between historical points of the RAF (and Air Ministry?) trying to get the Whirlwind into service as soon a possible, including attempts to field it during the BoB, yet a general lack of willingness to divert greater resources to actually expediting production. (the rational argument was that the design was dead and would be strictly limited by the number of Peregrines being produced while Hawker's next generation fighters were of great interest as 'proper' Spitfire replacements and generally lost interest in the Whirlwind; the problem with that is it directly contradicts the 'trying to get the Whirlwind into service as quickly as possible' )

Piper106 said:

As far as development problems with the historic Peregrine, remember this was now the fifth parallel valve V-12 Rolls Royce had developed. Before the Peregrine, the Kestrel, Buzzard, R, and Merlin had all come into their own IN DUE TIME. To say that the V-12 Peregrine could have been troubled with 'unsolvable' problems seems a stretch to me. Agreed, the Kestrel/Peregrine was too low of a power for a 1940 or later vintage single engine fighter. You are also right, spending time on a V-12 engine used in only the Whirlwind was not a good use of limited resources.

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I agree with all of this, but on the latter point I don't think it was any worse a use of resources than what happened with the Sabre. In fact, it likely would have cost less in engineering resources than the Saber given how much engineering commonalty it shared with the Merlin (and Griffon). And unlike the Saber it MIGHT have still been useful in other multi-engine aircraft.

In my time line, the historic X-24 Vulture never gets designed or built. Rolls Royce builds 'a couple' developmental V-12 Peregrines, but they realize they aimed 'too low' and their primary effort becomes a 24 cylinder 'double Peregrine' with vertical cylinders and two crankshaft in an H arrangement. This doubled engine could have been 'the' engine for the 'new generation' Tornado / Typhoon / Tempest fighter line (and a couple of bomber projects).

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It would still be a waste unless Hawker got their act together sooner with high speed drag. The Whirlwind had an edge there, and Gloster seemed to have a better understanding as well (at least they didn't go AS thick on the F.5/34 and F.9/37 and those were both older designs, and the G40 jet testbed had rather thin wings, as did the Meteor -though the actual airfoils used were experimented with a bit, all started off thinner than the Spitfire's wing)

That said, would the H-24 configuration really be necessary? Could a vertically oriented mirrored double-V engine work while sharing near complete commonality with Peregrine parts? (mostly differing in crankcase, reduction gears, and lubrication system)

You also still have one more problem: unless you hand off production to another firm, you cut in on Merlin production capacity and (more critically) efficiency.


I think the broader argument in defense of the Peregrine is not so much looking at whether the Merlin deserved higher priority (that's an obvious yes), but whether the Peregrine was more worthy of remaining in production than some other engines that weren't canceled (or not discontinued as soon) be it existing newer engines like the Merlin, Perseus, Taurus, and Hercules, or designs still in the prototype phase (Exe, Saber, Centaurus), or some older designs still lingering in production or being wound down with further development arrested (Mercury, Pegasus, Kestrel ... Perseus might fit better here actually). You've also got some odd ones out like the Dagger which had lingering development resources going to them in spite of their dated nature (Peregrine would have better replaced any applications targeting the Dagger too).

Of those, you have both the Exe and Peregrine cancelled while both of those seemed to be more mature and reliable than the 2000 HP class prototype engines and quite possibly the troublesome Taurus. (granted, the Exe never reached mass production, so less tested ... but the prototype apparently gave a good, long, reliable service life)

With the exception of the Vulture, none of Rolls Royce's major pre-war projects seemed to merit outright cancellation and might well have proved more useful in service than engines actually pursued. The Exe might even have been a more direct alternative to the Taurus given the size, weight, power, and air-cooled nature.

OTOH, Rolls had multiple good designs competing for engineering resources and talent that spawned those designs in the first place. Still, it might have been wise to re-think canceling them outright and while transferring all R&D to an outside company might have been difficult and inefficient, continuing internal development and outsourcing only for mass production might have been more realistic.

Shortround6 said:

I think you missed the point. Name another aircraft flying in 1943 over France and Low Countries flying in essentially unmodified form from the fall of 1940.

The Hurricane II doesn't count because, unless you can say other wise, they were not using the IIa with eight .303 guns in 1943. I doubt they were using the same boost limits in 1943 as they were using in 1940 either on the Hurricane IIs, Wasn't it something like 14lbs in low gear and 16lbs in high gear by 1943 instead of 9lbs in the Summer of 1940, but hey, whats an extra 20-25mph at sea level between friends for the 1943 Hurricane.

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The Hurricane IIa was also using newer engines than the Peregrine, so wouldn't be fair to compare either. (Merlin XX came after the Peregrine was killed -I believe the Spitfire II's 2-speed Merlin XII may have been newer too)

Shortround6 said:

AS for "Four Kestrel/Peregrine cylinder banks attached to a single crankcase and driving a single common crankshaft would produce the contemporary Rolls-Royce Vulture, a 1,700-horsepower (1,300 kW) X-24 which would be used for bombers. The Vulture was fitted to the Hawker Tornado and Avro Manchester, but proved unreliable in service, go figure. Let's see, unreliable as a single block and unreliable as a quadruple block ... do you see a trend here? I do."

A. while the Bore of the Kestrel/Peregrine and Vulture was the same the bore spacing was not. Bore spacing was actually the same or very close to the bore spacing of the Merlin. The Vulture did not use Peregrine cylinder banks, or cylinder heads or even camshafts (lobes had to be spaced out further).
B. main failing of the Vulture was.....connecting rod failure. Four pistons operating on one master rod and 3 slave/articulated rods. Peregrine (and Kestrel) used normal forked rods, just like a Merlin. Sorry, I am not seeing the trend there.

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That and the Kestrel was not an unreliable engine either ... so 'unreliable as a single block' doesn't make any sense. (and unlike the Peregrine, the Kestrel was produced and used in enough numbers to be seriously tested in its reliability and overall potency, though I believe it used a pressurized water cooling system rather than pure glycol like the Peregrine and Early Merlins used, and thus avoided the problems associated with pure glycol)

The Kestrel, of course, had indeed reached the end of its development life and hit a wall in performance without a near-complete redesign. (which is what the Peregrine was)

Of course, the most extreme rational move would be to cancel all engine development and production outside the Merlin and Hercules and build as many of those as possible while having new designs target those engines exclusively. (maybe Bristol would have actually gotten their act together with better superchargers sooner if that was the case and get some more power and better altitude performance out of the Hercules.

A well developed twin merlin engined interceptor (and later fighter-bomber) could/should have managed to do better than the Typhoon did, and between Westland, Gloster, and Supermarine, there was plenty of potential there. The ministry put all their eggs in one basket with Hawker: sure, there were alternate engines but the basic Tornado/Typhoon design was flawed AND twin engines projects could have matured sooner than the Typhoon had there actually been interest. (there supposedly was SOME serious interest for a time for Gloster's twin, but it was shelved in order to focus on Meteor development -ironic given all the delays and lost time due to engine delays ... not to mention potential for the Vampire+Goblin to be put on higher priority and the Meteor + PowerJets engines kept more as the 'backup' designs)

When was the Whirlwind last used as a fighter? For most uses it was put the the beaufighter was much better all round. The Whirlwind would have come into its own in the case of an invasion late 1940 through 1941 after that what use was it? It seems to me the RAF found a use for them because they had them, if they didnt have them they wouldnt have been missed at all. As a fighter the Hurricane was obsolete in front line service in 1940 but there were still 14,500 produced. A much cheaper way of getting 4 cannons into action.

Edgar Brooks said:

And that "something" was nightfighting; the Defiant shot down 152, mostly bombers and mostly in 1941 without the aid of radar, against losses of 37, mostly in 1940. Hardly qualifies it as being useless.

20:20 hindsight again; a bit late when production had already stopped.

Wrong; Sir Wilfrid Freeman decided on no new orders in May 1940, and it was 30-10-40, before Beaverbrook decided to stop production altogether.
Perhaps we can now turn to the Lysander, which you label as "useless." I suspect the hundreds of U.S.A.A.F. and R.A.F. aircrew who were saved from drowning, thanks to the aircraft of the four A.S.R. Squadrons, might possibly have a different view. The Lysander's low speed handling made it ideal for dropping dinghies exactly where they were needed, but there's no glamour in that role, of course.
P.S. The Defiant also saw service in ASR duties.

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First let me thank you for the date correction/s. It still shows that the Whirlwind was effectively canceled before seeing combat service and not after 2 years of displaying problems in operation as Greg seems to think.

Some other British aircraft may have beaten the the 50 planes needed for 6 months service too,I don't know. Granted it is 20:20 hind sight but it rather points out that if the engines and airframe were so troublesome then something is way off. Perhaps the Whirlwinds didn't fly as many missions per month as some other types? Perhaps the plane and engines were not as troublesome as is commonly reported/portrayed?

As far as the Lysander goes, it was useless in it's intended role/s. No amount of use in other roles is going to change that. After being a total flop as a combat aircraft (or trying to exist in a combat zone) it saw a lot of use as a trainer, ASR, target tug and 'agent' dropper.

Now we can consider the Whirlwind was useless (or a failure) in it's intended role as a "fighter" because of it's lack of altitude ability. Fair enough but then it is in at least decent if not good company as the Typhoon was also a failure as a "fighter" at altitude, so was the P-40 and the P-39 and the.......

AS for the Defiant. Please show me where in my post #30 I said the Defiant was "useless"? Greg was trying to make a point regarding how long each plane "served". If you build 100 planes and use them in combat they aren't going to last for 3-5 years as a combat type. If you build 1000 planes some of them are going to last longer and be available for other roles and if you build 10,000 (especially with updates) they will last even longer. By 1943 (the date Greg was saying they were still flying 'service" missions, nobody was flying Defiants in any areas that put them in real jeopardy of enemy action. Flying single engine aircraft on long missions over water at night certainly put the crews in jeopardy of mechanical failure. Perhaps the Germans could have sent a night-fighter or two 50 miles of the coast. That is hardly the same level of jeopardy as train busting or bridge bombing or other low level strafing/bombing missions done by Whirlwinds (and Hurricanes and Spitfires and Typhoons) in 1943.
40% of the Defiant IIs were built as target tugs. That tells us several things. One is what they thought of the Defiant as a combat type near the end of production and two is another example of having too much material in the pipeline to simple cancel production of a type as it becomes obsolete. Yes you need target tugs.

Gee Greg, changing the argument in the middle? what a surprise.

GregP said:

Shortround,

Further production orders were terminated in 1942 and Westland finsihed the production still ongoing. The plane was withdrawn from service in 1943. That's according to several sources. Maybe they're all wrong? The last Whirlwind was delivered in January 1942.

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AS noted by Mr Brooks, production was canceled the 30th of Oct 1940. This is after several discussions and postponements. This was the final cancellation. It had little or nothing to do with the Whirlwinds operational record, or service use unless the Air ministry had a time machine.

If you are so loving of the Whirligig, take all 116 (or 114 in other sources) in your fictional air force and go attack fictional Germany. I'm sure with sufficient literary license the entire war could turn around.

In the real world they amount to nothing much, like this discussion. 116 airplanes of ANY sort really isn't much to argue about. Let's say you are right.

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Gee, starting to get personal here? Blow off the facts when they don't suit you and fall back on the condensed box score argument (don't look at how a plane was used or the conditions it operated under, just look at the final "scores" posted) . A lot of what was written about the Whirlwind is fiction. But hey, since only 114 were built and it didn't change the war lets keep the fiction going, right?

Tell me all about the wonderful things your Peregrine-based engines did in the war. I eagerly await your response. But wait, No. 263 Squadron, the first and last squadron to operate the Whirlwind, flew its last Whirlwind mission on 29 November 1943 and turned in their aeroplanes and converted to the Hawker Typhoon in December that year. On 1 January 1944, the type was officially declared obsolescent. The remaining serviceable aircraft were transferred to No. 18 Maintenance Unit, while those undergoing repairs or overhaul were only allowed to be repaired if they were in near-flyable condition. An official letter forbade aircraft needing repair to be worked on.

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Gee, why don't you tell me all the wonderful things the P-40Q did? I eagerly await your response.

Now, did you stop to think that just maybe, by the end of 1943 with both plane and engines out of production for over a year and half they were running out of spare parts?

So don't tell me all about the possible developments, tell me about wonderful Peregrine use and Whirlwind successes. A bigger Whirlwind with Merlins, though maybe interesting, would be a new aircraft, not a Whirlwind.

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Gee, Greg, 2 squadrons, slogging along for several years doing 'routine' strafing and train busting and coastal shipping strikes isn't good enough for you. In order to be any good they had to alter the course of the war in just a few missions? How many squadrons actually did "great" things? The Lancaster was great airplane and did some great things, but there were dozens of Lancaster squadrons and only a few did the "special" missions.
I believe in other threads I have said the Whirlwind was too small to take the Merlin without changing into a different airplane so I don't know why you are bringing that up.

Shortround, this was a singularly unremarkable fighter aircraft at a time when great ones were needed. It wasn't BAD, it was less than what was needed and the engines left no room for significant development. They realized that after a very few were made and stopped.

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I see, "singularly unremarkable fighter aircraft" when great ones were need.........Like the Defiant? Like the Typhoon in 1941/42? like the P-40?

All your crying won't change that.

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Gee, try to correct mistakes in some peoples accounts is crying?

Guess you better get your rain coat ready.

BTW, I am still waiting for accounts of those Peregrine engine failures that were due to fundamental flaws in in the engine. Either design or quality control.

More crying

GregP said:

The Peregrine had about .68 hp/cubic inch and so did the Vulture. The Merlin had .90 hp/cu in and the Griffon had .99 ... significantly better.

The German DB 601 had .57 but they compensated for lower-performace fuel with cubic inches and made competitive power. The DB 605 had .78 hp/cu in and the BMW 801 had .60, again using displacement to get the power required.

The lowest HP was the Peregrine. 885 versus 2,220 for the Griffon and even 1,700 for the DB 605. So both sides saw the lack of HP as well as Rolls Royce did. The powers above are not specific to any variant but are representative. Some were higher and some were lower, but the Peregrine stands out as a smaller, lower-power engine among this group, which other than the Peregrine, were the principal fighter engines of the major types in the ETO aside from the USA. We never DID have a problem with engine displacement. More is better ... to a point.

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More of the Greg "box score" method. just list what the max numbers were without regard for the year or the fuel used. Gee Greg, why don't you tell us the power per cu in of a 1950 race car engine and a 1955 race care engine? How about one running on pump gas and one running on alcohol? Makes about as much sense as this.

Peregrine and Vulture were running on 87 octane fuel. Merlin at .90 hp/cu in is making 1485hp. Now Greg has not seen fit to tell use which marks of Merlin of Griffon, using what kind of fuel and under what conditions (boost pressure and altitude) the numbers are from.

Apparently such details are unimportant. Or will tend to weaken his argument.

If it were to pick a bottom engine from the list above, the Peregrine stands out as the one to pick based on power, and everything else was only incidental. They COULD have made it reliable and COULD have improved it to to maybe 1,000 HP or a bit more, but they were looking for 2,000 HP and the Peregrine clearly wan't going to get close.

The answer was go with a bigger-dislacement engine and they did.

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Of course the Peregrine was the lowest power, it was the smallest engine. Another "detail" that isn't important apparently. The Peregrine weighed 1106lbs for a power to weight ratio or 1.25lbs per HP. A Merlin X two speed engine running on 87 octane had a power to weight ratio of 1.26lb per HP. granted is the power to weight ratio of the complete aircraft that counts so the smaller engine is at a disadvantage there.

BTW The Griffon that gets .99hp per cu in is a two stage engine using over 21lbs of boost and more than likely 100/150 grade fuel. It also weighs around 2075lbs. Yep, a direct plug in for a Peregrine replacement.

Canceling the Peregrine was the right thing to do. But let us let the record show the real reasons (production expediency and a diminishing need/market) rather than trumped up accusations of unreliability of the basic engine.

pbehn said:

When was the Whirlwind last used as a fighter? For most uses it was put the the beaufighter was much better all round. The Whirlwind would have come into its own in the case of an invasion late 1940 through 1941 after that what use was it? It seems to me the RAF found a use for them because they had them, if they didnt have them they wouldnt have been missed at all. As a fighter the Hurricane was obsolete in front line service in 1940 but there were still 14,500 produced. A much cheaper way of getting 4 cannons into action.

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If they were as much trouble as some writers have claimed (not just on this forum) the wonder is that they used them as long as they did. Beaufighter might have had a bit more trouble with the overland low level strikes. Whirlwind was as fast or faster than some early Spitfires at low level. It also had good roll response which is an advantage in tree top flying. Not trying to take anything away from the Beaufighter but you are comparing a 10,000lb airplane to an over 20,000lb airplane and while the Beaufighter was certainly versatile and did a number of jobs well, low level strikes in contested air space may not have been the best place for it.