Westland Whirlwind revisited

[yulzari]

The Gloster G9/37 carried both Peregrine and Taurus installations so gives some idea of a contemporary installation in an Whirlwind.

The Taurus version was 50kph faster than the Peregrine.

 

[Shortround6]

The Gloster G9/37 carried both Peregrine and Taurus installations so gives some idea of a contemporary installation in an Whirlwind.
View attachment 591695View attachment 591696
The Taurus version was 50kph faster than the Peregrine.

And the 2nd prototype with Taurus engines (or the first airframe with a new set of Taurus engines?) was about 50kph slower than the first tests.
few, if any, Taurus engines built afterwards matched that level of power at that altitude and indeed, for several years Taurus engines were rather known for overheating.
Not really sorted out until the spring of 1941.
Not sure if the chin radiator on the F.9/37 was higher drag than the in wing radiators of the Whirlwind.

 

[buffnut453]

Always thought the Gloster G9/37 was a very pretty aeroplane.

 

[pinsog]

The R-1830 weighed about 350lbs more than a Peregrine. This is for the two speed version. Granted there is no radiator or coolant. What kind of games have to played to keep the CG in the proper place I don't know, The radiators being either on on nearly on the CG.

The P & W R-1830 two speed offers about 13% more power at nearly the same altitude (I am not going to argue over 500ft out of 15,000) as the Peregrine. so either the installation causes less than a 13% increase in drag or performance at altitude falls. Please note that the 14,500ft rating is at 2700rpm and many charts limit most R-1830s to 2550rpm in high gear.

this shows the 2 speed Japanese engine being inferior to the 1830 P&W at altitude. That model Ki46 would do 375 mph at 19,000 feet

(FWIW I don't think the Whirlwind had enough wing to handle the 1830 P&W. Just pointing out that a twin radial can have great performance)

 

[Admiral Beez]

I'd like to see what the Whirlwind could have done with high octane fuel and high compression. I bet well over 400 mph was possible.

This would be only a theoretical exercise, since by the time high octane fuels were available the Spitfire and Tempest were regularly doing over 400 mph.

 

[Shortround6]

this shows the 2 speed Japanese engine being inferior to the 1830 P&W at altitude. That model Ki46 would do 375 mph at 19,000 feet

This is NOT quite true but the information on the Ha-102 engine may not be quite correct (or it is correct as far as it goes but does not go far enough). An R-1830 making 1000hp at 14,000ft would be good for a bit over 880hp at 19,000ft. Adjust as you see fit.

The two speed Ha-102 was supposed to give 950hp at 5800 meters (19,030 ft ) which is pretty consistent with the top speed altitude. Engine giving peak power at 9.200 ft and plane hitting top speed at 19,000ft is pretty absurd. The 1055hp at 9,200ft may be FTH in the low supercharger speed.

BTW the same engine/s were fitted to the Ki-45 Toryu two seat fighter which managed 335mph at 19,685ft.

The engines in the KI-46 III Diana were HA-112s with 1500hp for take-off, 1350hp at 6,560ft and 1250hp at 19,030ft.
At least according to some sources.

 

[pinsog]

This is NOT quite true but the information on the Ha-102 engine may not be quite correct (or it is correct as far as it goes but does not go far enough). An R-1830 making 1000hp at 14,000ft would be good for a bit over 880hp at 19,000ft. Adjust as you see fit.

The two speed Ha-102 was supposed to give 950hp at 5800 meters (19,030 ft ) which is pretty consistent with the top speed altitude. Engine giving peak power at 9.200 ft and plane hitting top speed at 19,000ft is pretty absurd. The 1055hp at 9,200ft may be FTH in the low supercharger speed.

BTW the same engine/s were fitted to the Ki-45 Toryu two seat fighter which managed 335mph at 19,685ft.

The engines in the KI-46 III Diana were HA-112s with 1500hp for take-off, 1350hp at 6,560ft and 1250hp at 19,030ft.
At least according to some sources.

Sounds much more reasonable than the info I had. Thank you.
How were the Japanese able to get more power, higher up with a slightly smaller engine and worse fuel than the USA?

 

[Shortround6]

Possible answers are accepting shorter service life and/or differences in cooling. AIr cooled engines as a general rule of thumb would not tolerate as high a boost as liquid cooled engines but that was rather dependent on the how well the cylinders were cooled.
It may also be somewhat dependent on the superchargers and some of the American superchargers on the early engines may not have been very good? Speculation on my part but during the mid to late 30s US superchargers (all supplied by General Electric) were so bad that both Wright and P & W decided to design their own. They might still have been a bit on the low performing side.

for some undisclosed reason the R-1830 was rarely given a a "Military rating" at least by P & W. Despite being rated at 2700rpm in many models for take-off it seems to have been rated at 2550rpm at higher altitudes (high gear or with two stage supercharger?) in many versions?

 

[Admiral Beez]

I'd say a pre-Hercules radial-powered Whirlwind will be about the same speed as the sub-320 mph IMAM Ro.57.

If we want to give the Whirlwind swifter legs, especially at altitude it has to be higher performance inline V-12s or Wellands/Derwents. Radials and X-crank inline engines and the like are but a distraction.

 

[nuuumannn]

Let's think a bit about what modifications would need to be made to the Whirlwind by putting radials onto it and the impact it would have on its timeline. If it were to be fitted with radials, it would have to be designed from scratch with them and then there is no guarantee that it would have gotten into service any sooner. The problem was not just the powerplant, but the firm itself.

Now, I can be one of those contrarians Admiral mentioned, but, like Dave and Steve (Graugeist and Stona) state, examining the facts as they stand is not being deliberately contrarian, but advising of the realism behind a particular situation.

(With that out of the way...) Let's look at Westland as a company. In the late 20s to early 30s, Westland was busy, but compared to the likes of Bristol and Shorts and Vickers, for example, it was a small company with a small workforce, although its book orders were large for the time. It's primary bread and butter was the Wapiti, of which it produced a total of 558; the most was of the Wapiti IIa, of which 430 were built between 1929 and 1932.

Until the Whirlwind, the Lysander was the most modern aircraft Westland had built. The Wapiti was essentially Great War technology - it was an open cockpit, fixed gear externally braced biplane with a metal tube fuselage covered in fabric, although the Wapiti I was all-wooden structure. The Lysander didn't offer too many more challenges to the Westland production staff when the first order for 169 aircraft was placed in December 1936 - its first flight had taken place on 15 June from Boscombe Down rather than from Yeovil following taxiing trials. The first production Lysander was received by the RAF in May 1938 (16 Squadron at Old Sarum).

Technologically, the Lysander was very much 'steady as she goes' rather than pushing the boundaries. That's where the Whirlwind comes in. Westland had never built an all-metal high performance cantilever monoplane with retractable gear and enclosed cockpit in a semi-monocoque fuselage before. The workforce had to be trained how to do this, the workshops had to be equipped to undertake metal bashing and the production line had to be modernised.

The Whirlwind prototype completion was delayed by supply of engines and undercarriage, it had the fourth and seventh production Peregrines, it first flew on 11 October 1938, after instruction to proceed in February 1937. The first production order came in January 1939 for 200 aircraft, with a promise from Petter that the first deliveries would be in nine months time, but the first production aircraft first flew on 22 May 1940. By this time the 200 order had been cancelled and in December 1939 an order for 114 was given, by the Air Ministry. Delivery of the first Whirlwinds to the RAF took place in June 1940, to 25 Sqn.

In his book Westland Aircraft since 1915 (Putnam, 1991) Derek James states that five years had elapsed between issuing of F.37/35 and introduction into service and that many were surprised when the order was given to Westland, as Bristol, Boulton Paul, Hawker and Supermarine were among those who offered submissions to the specification.

Delays to production aircraft came from Rolls-Royce, who was experiencing issues in producing Peregrines; part of the delay came from the supply of Hobson downdraught carbs.

So, this gives an idea behind timelines and changing the powerplant isn't going to offer much less time on that taken in real life to get the Whirlwind into service sooner, despite not having the delays from getting Peregrines from RR if a different engine is used.

 

[yulzari]

Reverting to the Whirlwind as a. ersatz Typhoon instead of Spitfire. The radials would fit the OTL role of the OTL Typhoon better for the low level job and the Taurus worked quite adequately for the FAA in the Albacore and the RAF in the Beaufort at these altitudes and are not impinging upon Rolls Royce design and development Merlin work. Not to mention being in production. One can rivet counter quibble about the margins of differential performance but you still get a 24 cylinder 2,000+bhp 4 cannon fighter without a new design nor a complex new engine.

Ideally, of course, one would prefer a Peregrine mirroring Merlin developments but that best is not too far away from the low level good of a pair of Taurus.

Just for fun: triple the Whirlwind power with a pair of Rolls Royce Crecy. Wooo...5,400 bhp.............

 

[pbehn]

Just for fun: triple the Whirlwind power with a pair of Rolls Royce Crecy. Wooo...5,400 bhp.............

It would have made RADAR obsolete.

 

[pbehn]

Technologically, the Lysander was very much 'steady as she goes' rather than pushing the boundaries. That's where the Whirlwind comes in. Westland had never built an all-metal high performance cantilever monoplane with retractable gear and enclosed cockpit in a semi-monocoque fuselage before. The workforce had to be trained how to do this, the workshops had to be equipped to undertake metal bashing and the production line had to be modernised.

.

Westland were no mugs in technology, they worked on the Spitfire and introduced improvements known as the "Westland tail" which were to do with balance of controls I believe. I read about it recently and cant find it again (does anyone have details).

 

[wuzak]

Reverting to the Whirlwind as a. ersatz Typhoon instead of Spitfire. The radials would fit the OTL role of the OTL Typhoon better for the low level job and the Taurus worked quite adequately for the FAA in the Albacore and the RAF in the Beaufort at these altitudes and are not impinging upon Rolls Royce design and development Merlin work. Not to mention being in production. One can rivet counter quibble about the margins of differential performance but you still get a 24 cylinder 2,000+bhp 4 cannon fighter without a new design nor a complex new engine.

The problem is that the Typhoon's intended role was to replace the Spitfire and Hurricane. That it ended up as a low level fighter was a function of the state of development of the Sabre and the draggy airframe (due to the thick wings).

 

[pbehn]

The problem is that the Typhoon's intended role was to replace the Spitfire and Hurricane. That it ended up as a low level fighter was a function of the state of development of the Sabre and the draggy airframe (due to the thick wings).

And the chin radiator.

 

[nuuumannn]

Westland were no mugs in technology, they worked on the Spitfire and introduced improvements known as the "Westland tail" which were to do with balance of controls I believe.

That doesn't necessarily translate to an entire production line established for constructing all metal aircraft after not having built them though. That's the point. Obviously the designers had the ideas and the skills to do it otherwise the Whirlwind simply would not have been designed or built. That it took so long is partially because the workforce, the guys at floor level had to learn new skills, new tooling had to be bought and taught to the workers how to use, etc.

 

[pbehn]

Just for fun: triple the Whirlwind power with a pair of Rolls Royce Crecy. Wooo...5,400 bhp.............

Just reading about the Crecy and thinking about it, it was a type of jet/pulse jet/turboprop engine (depending on the revs and whether the power recovery was hooked up) no wonder RR kept it in development until 1945. It is the only engine I have read about where a comment was made on how loud it was, having run a two stroke twin for a few seconds with no exhausts I imagine the Crecy was deafening, all the engines at the time were LOUD.

 

[Admiral Beez]

The Peregrine was a compact unit, specs per Wikipedia:

• Length: 73.6 in (1,869 mm)
• Width: 27.1 in (688 mm)
• Height: 41.0 in (1,041 mm)
• Dry weight: 1,140 lb (517 kg)

Were there other compact V-12s of this size or weight that offered similar power to the Peregrine? Or were all the other V-12 aero engines of larger Merlin-sized proportions?

For example, the Hispano-Suiza 12Y is shorter and lighter than the Peregrine. It doesn't offer any power advantage, but perhaps the 12Y addresses the Peregrine's shortcomings in both availability (it was used or license-built by much of non-Germany Europe, including in the Fairey Fox and Fantôme) and high altitude performance?

• Length: 1,722 mm (67.8 in)
• Width: 764 mm (30.08 in)
• Height: 935 mm (36.81 in)
• Dry weight: 475 kg (1,047 lb)

 

[Shortround6]

That doesn't necessarily translate to an entire production line established for constructing all metal aircraft after not having built them though. That's the point. Obviously the designers had the ideas and the skills to do it otherwise the Whirlwind simply would not have been designed or built. That it took so long is partially because the workforce, the guys at floor level had to learn new skills, new tooling had to be bought and taught to the workers how to use, etc.

Go back to page 1 or 2, I am on a tablet and can't get the photo. Picture of Westland factory with Whirlwinds on one side of a low wall and Lysanders on the other side. Lysanders were being built at a rate roughly 3 times higher than Whirlwind during some of this period.
Lysander was all metal except for the covering, it was not a slightly updated Sopwith Camal in terms of construction. No wood formers like the Hurricane. Full span slats inter-connected with flaps. Machine guns in the wheel fairings with the ammo supply in the leg fairings. Sprung wheels and brakes on the wheels. Every plane had bomb racks from the factory.
Aside from the "fixed" landing gear it had every "system" a fighter had and more.
Westland workers couldn't be taught to put on metal skins?

Air ministry had screwed the pooch on which plane had priority and either there was a problem with subcontractors supplying parts or the there was a bit of cover up going on. Perhaps both.

Petter may have done himself no favors and been difficult to work with but there were a lot of stories going around about how difficult the Whirlwind was to maintain and fly that were not true.

 

[nuuumannn]

Lysander was all metal except for the covering, it was not a slightly updated Sopwith Camal in terms of construction. No wood formers like the Hurricane. Full span slats inter-connected with flaps. Machine guns in the wheel fairings with the ammo supply in the leg fairings. Sprung wheels and brakes on the wheels. Every plane had bomb racks from the factory.
Aside from the "fixed" landing gear it had every "system" a fighter had and more.
Westland workers couldn't be taught to put on metal skins?

There is a vast difference in construction techniques between metal tubing covered in fabric and all-metal monocoque, Shorty. Between the metal Wapitis and Wallaces and the Lysander there isn't such a great leap in technique, but transitioning onto metal fabrication doesn't just happen. The workforce needed training. Sure, it isn't impossible, as the Whirly wouldn't have been built, but you can't just go from working on the Lysander line onto the Whirlwind line without training. Just because they are in the same building, doesn't mean the Whirlwind guys didn't receive any training on sheet metalwork techniques.

A number of years ago I used to work in museums and a few of the guys I worked with were planewrights. They had spent the entirety of their career working on wooden aircraft. When they had to transition onto working on metal aircraft it was a big change for them. They could do it, but it required training, and the term 'Planewright' disappeared as a skillset.