Westland P.9 Whirlwind (1 Viewer)

Ad: This forum contains affiliate links to products on Amazon and eBay. More information in Terms and rules

The wish to avoid a major change is why I usually limit my proposals for changing the Peregrine to using the central intake on the supercharger and the two speed supercharger drive, minimal weight and only a few inches, basically bring it up to MK XX standards. It does mean limited altitude performance but it also means that the weight and length of the two stage set up is avoided along with the inter-cooler radiators. It also avoids needing larger propellers to handle a big increase in power at high altitudes. Maybe the existing props would be maxed out any way but I think I read somewhere that a Merlin 60 series offered twice the power at 30,000ft that a MK III Merlin did even though the "max" power was only a few hundred apart (before the large increases in boost that came later). The Whirlwind was not a good climber at low altitude and an extra 100-200hp per engine would have had a big effect. Any further changes would really require too much development work and too many changes to be worthwhile on both the engine and airframe. Considering that ONLY P&W, Allison and R-R put 2 stage superchargers into large scale production out of all the engine makers in world rather hints that it wasn't all that easy to do or at least do right. The Principal and theory was well known but practice may have been much more difficult. No service two stage Wrights, Napairs or Bristols.

As far as the later Spitfires needing the raked forward landing gear for the cannon? I think it might have had something to do with heavier 2 stage engines and the larger, heavier propeller hanging off the nose.
 
As far as the later Spitfires needing the raked forward landing gear for the cannon? I think it might have had something to do with heavier 2 stage engines and the larger, heavier propeller hanging off the nose.
That wouldn't have applied to the Vc early Seafires, though.
There was discussion on a new prop, if a modified Whirlwind went ahead, but de Havilland Hydromatic would have been preferred to a Rotol type.
Edgar
 
The ultimate Whirlwind/Peregrine practical 'what if' requires decisions years before the war. If it was the standard day fighter RR development would have been Peregrine/Vulture. The Vulture was tamed but too late. The equivalent power to Merlins in our time line and the capacity to change to twin jets whenever they could be produced. Meandering further; twin Vulture Mosquito, Peregrine Blenheim? Underwing bomb capacity of 2x500lb suggests the range extension by drop tanks and it was certainly capable of carrying x8 60lb rockets or 2x 40mm cannon (my preferred choice with thin case HE rounds for non heavy armour accuracy.)
 
de Havillands did do a proposal for a "super" Mosquito using 2 x Sabres. By that time the Vulture had gone, though, so the choice was Sabres or nothing. But the Sabres were experiencing their own problems and the project was dropped.

Handley Page's chief engineer wrote a paper about bomber design philosophy, arguing that an unarmed bomber would give better results than the slowe and heavier armed bombers. He schemed an unarmed bomber using 2 x Vultures along the same lines as P.13/36 - which led to the Manchester and Halifax.

No doubt that the Vulture and Peregrine suffered for not being used in more than one in-service type.
 
Granted, our own readie will agree with me that this should've been built 'stead Whirlwinds w/ Merlins (ie. double Spit; here Spit V with clipped wings):
 

Attachments

  • SpitDouble800.JPG
    SpitDouble800.JPG
    14.7 KB · Views: 127
To repeat myself, an Americanized Whirlwind would've been nice: two Twin Wasps (even single stage, for 1940-42), 5-6 x 0.50cals, produced abroad (Canada, Australia) + at Westland (plus at Boulton Paul, plus at Blackburn etc), fuel tanks inboard of engines (now that radiators are deleted) for twice as much fuel as before.
Cutaway, provided by skiswimcycle, member of this forum:

http://www.ww2aircraft.net/forum/attachments/schematics/58266d1205176736-westland-whirlwind-cutaway-whirlwind-2.gif
 
Something to consider for the 'twin hulled" machines. while the frontal area is less than a conventional twin they a lot more surface area creating friction and drag and you have to build two fuselages instead of one fuselage and two engine nacelles. They may actually be heavier than a conventional twin or at best not any lighter. While you may have the tooling in place, if you can't build the single fuselage fighters fast enough building twin fuselage machines is only going to cut your total fighter production. It is debatable as to wither their rolling performance is better or worse than a conventional twin. If you are going to have twin cockpits (nice for night fighters and very long range escorts) the extra weight and volume will count against it compared to a true single seat twin engine fighter.

The US had the Grumman F5F/XP-50. P&W engines would have been a bit better streamlined but a bit a heavier. With weights within a few hundred pounds of the Whirlwinds in questionable just how much fuel they carried.
 
...while the frontal area is less than a conventional twin they a lot more surface area creating friction and drag and you have to build two fuselages instead of one fuselage and two engine nacelles.

In this particular case, total wing area is at 320-350 sq ft range - a few procents more than for P-38/47. We have almost 3000 HP to propel that, in 1941 :)
A high performance, conventional twin with decent range firepower was available for some airforces in 1st part of WW2, for some it was not. It was not available for RAF/RAAF/RCAF surely. Hence this proposal - a twin hulled Spitfire.

They may actually be heavier than a conventional twin or at best not any lighter.

Spit was a pretty light aircraft to boot with, so the twin hulled plane would still be a pretty light one.
Wiki says (I know...) 6500 lbs 'loaded' for Mk.Vb =13 000 lbs 'loaded' twin; lets make it 14K - at least equal to P-38s, while beating P-47s in power to weight category. Available a year or two earlier; of course, by late 1942/early 1943 we can make Mk.VIII/IX twins :D

While you may have the tooling in place, if you can't build the single fuselage fighters fast enough building twin fuselage machines is only going to cut your total fighter production.

It would make much more sense to tool up Westland to build Spits, both single twin, than to tool up for production of Whirlwind.

It is debatable as to wither their rolling performance is better or worse than a conventional twin.

Agreed, not the very brightest spot :)

If you are going to have twin cockpits (nice for night fighters and very long range escorts) the extra weight and volume will count against it compared to a true single seat twin engine fighter.

Twin hull has only 4 wing attachment points 2 'hulls', while conventional twin has 3 'hulls' 6 wing attachment points. No advantage for the conventional?
The extra pair of eyes can watch it's own 6 o'clock when pilot is focused onto target, plus the new pilot can learn hands-on about combat, while not jeopardizing itself plane.
 
Rather optimistic Supermarine's expectations (460mph with 2 Merlins that are yet to be produced?), while the wing is as tick as Beufighter's for the most part, plus 6 cannons (none in 1937 for RAF in relaity?)?
 
Typhoon was also expected top top 460mph...

Engines were based on development engines of the time - RM.2SM IIRC. 1250hp each. By the time it would have entered service the Merlins would have been 1500hp engines.

This project came after the Whirlwind - so no problem with Cannon. 6 probably was overkill, and they may have had trouble fitting them.
 
Yesterday, I had a look in the government files, in our National Archives, and found the following. There was never a plan to fit Merlins to a Mk.II, because they simply would not fit; the Whirlwind was designed around the Peregrine to be as small as possible. There was even talk of trying to find an American engine that would fit.
The biggest problem was the Peregrine; the original specification called for a maximum ceiling of (at least) 30,000', but the Whirlwind could barely reach 25,000', where its fighting qualities tailed off dramatically. The engine needed to be able to use 100 octane, but had only been designed for 87, so would need a lot of further development, and Rolls-Royce simply didn't have the capacity.
Edgar

Hi
Sorry to disagree but there were at least two plans to fit merlins to the whirlwind.
In fact one letter at least existed ( at least until the late 90's ) in the national archives at Kew.
I have corresponded with an ex westland employee in the USA who was on the design team in 1939/40 who designed the fitting of early merlins to the whirlwind.
Again in 1941 menesforth offered the whirlwind with merlin XX engines 'after sorting out undercarriage retraction issues'
So the manuafcturer at least believed the whirlwind airframe could take merlins..
Of interest there was also the suggestions of fitting Napier Dagger VIII , or bristol taurus engines,which both being air cooled would have released the radiator space in the whirlwind wings for extra fuel tanks.
I have still personally not convinced myself which american engine was used in the 1940 proposal, ( when the peregrine production was cancelled ).

100 octane was in use.
I have research from R-R mentioning use of 100 octane and the official pilots/ air publication notes for the whirlwind mentions ' take off with 100 octane, 3000 rpm at +9 lb/sq in.
I have not found a pilot notes copy earlier than april '41,
but the R_R notes are from June 1940,( cut out mods being carried out and new spark plus sourced )

Unfortunately there are still a lot of misquotes about what the whirlwind airframe was actually capable of doing.

Cheers
Jerry
 
Last edited:
they were running out of airframes and engines by 43, the surviving aircraft from 263 squadron who were being re-equiped were passed on to keep the 137 squadron going, (think thats the right way round)

Hi
Actually it is the other way around, 137 squadron re equipped and gave the whirlwind to 263 squadron who operated them until dec 43, not bad for a un-developed 1940 aircraft. it would be interesting to to see what loss rates a spitfire I or hurricane I would have had in the same use.
cheers
Jerry
 
Hi
SNIP

I have corresponded with an ex westland employee in the USA who was on the design team in 1939/40 who designed the fitting of early merlins to the whirlwind.
Again in 1941 menesforth offered the whirlwind with merlin XX engines 'after sorting out undercarriage retraction issues'
So the manuafcturer at least believed the whirlwind airframe could take merlins..
SNIP
I have still personally not convinced myself which American engine was used in the 1940 proposal, ( when the peregrine production was cancelled ).


Cheers
Jerry

Allison V-1710 comes to mind, if the Merlin could be fitted then surely so could the Allison.
 
I am fairly sure that Westland would have been pitching "improved" Whirlwinds to the air ministry. The question is how much of the original Whirlwind would have been left. The Whirlwind was a small airplane. It's wing was in between the Spitfire and the Hurricane in size and about 10% bigger than a Mustangs. The Original only had 67 imp gallons of fuel for each engine and even with the proposed fuselage tanks it would have had about the same amount of fuel per engine as a Spitfire. Throw in the bigger props, radiators and other bits and pieces and it is hard to see hoe it was going to work without "stretching" the airframe a bit.
It would be interesting to see when the "Merlin Whirlwind" turned into the Welkin? Like if there was an intermediate stage (on paper) for a Westland twin Merlin fighter that was a bit bigger bigger than a Whirlwind and yet smaller than the Welkin wound up?
Design work on the Welkin started in 1941 didn't it?
 

Users who are viewing this thread

Back