Fast bombers for the RAF, 1943-45

[wuzak]

Impressed by the performance of the Mosquito prototype and early production models, the RAF looks for the next generation high speed bomber aircraft.

The aim is to have a prototype flying by mid to late 1943, production beginning in the latter half of 1943 and service use in the first half of 1944.

The bomb load would be larger and more flexible than the Mosquito's:

The desired load would be 6,000lb internal - 6 x 1,000lb MCs, 12 x 500lb MCs, or a combination with small bomb carriers (for incediaries). Alternate internal bomb load would be 1 x 4,000lb HC/MC plus additional smaller bombs/incendiaries.

External - up to 1,000lb on two wing hard points.

(Incidentally this is largely the bomb load spec required for the English Electric Canberra later.)

Range would be ~2,000 miles with full internal bomb load.

Engines could be drawn from the US or UK - and this is where the problem may lie.

Possible UK Engines:
Rolls-Royce Griffon
Napier Sabre
Bristol Centaurus
Rolls-Royce Merlin

Possible US Engines:
Pratt & Whitney R-2800
Wright R-3350
Allison V-3420
Allison V-1710

Of those only the Merlin, V-1710 and R-2800 are the engines most available.

A twin engine aircraft is preferred, but more can be used if to take advantage of the availability of the Merlin or V-1710.

Installation of guns is optional.

Desired top speed of 450 miles per hour - a speed which the Mosquito prototype was able to do when fitted with two stage Merlins in 1942.

Structures and materials are what was available at the time.

 

[wuzak]

The Bristol Buckingham was a light/medium bomber using twin Centauruses (Centauri?) . It first flew in early 1943 and was in production late in the year. Service entry was set for 1944, but problems with handling and performance saw orders curtailed.

Instead of committing these Centaurus to the Buckingham, would it have been more prudent to try to get the Hawker P.1005 into production with them?

Or a new design from another manufacturer?

 

[Shortround6]

I believe the speed is too ambitious.

Or the bomb load.

Tony Butler's books have some information the DH 102 but it carried about 4000lbs (at best, four 1,000lb short or two 2,000lb bombs inside) and was estimated to do 404-417 at 25,000ft using Sabre IVs.
There was also a proposal for Jet Mosquito using two Halford H. 1 engines and estimates were 445mph with a 2,000lb load.

Perhaps something could have been done with the Centaurus using Tempest or Fury type cowls?

 

[wuzak]

I believe the speed is too ambitious.

Maybe. Just a desired top speed, but as fast as possible.

Tony Butler's books have some information the DH 102 but it carried about 4000lbs (at best, four 1,000lb short or two 2,000lb bombs inside) and was estimated to do 404-417 at 25,000ft using Sabre IVs.

Those numbers are for the DH101.

btw, I'm not sure what the two 2,000lb bombs were - unless it was the 1,900lb GP (26% charge to weight ratio).

It could also carry a single 4,000lb HC or MC bomb.

 

[wuzak]

Perhaps something could have been done with the Centaurus using Tempest or Fury type cowls?

The Bristol Buckingham had reasonable looking cowls, not sure how aerodynamic they truly are.

Bristol Buckingham - Wikipedia

But the Tempest style cowl would be preferable

Hawker Tempest - Wikipedia

Would it be possible to a turbo or turbos with the Centaurus, arranged to direct the exhaust out the rear of the nacelle?

What about using four 2 stage Merlins or Griffons, possibly in a push/pull configuration?

 

[tomo pauk]

Something like a big Mosquito. Start with Sabres until the desired engine - the 2-stage Griffon - is available. Wing profile stolen from Tempest. Fowler flaps.
Have De Havilland make it.

 

[wuzak]

Something like a big Mosquito. Start with Sabres until the desired engine - the 2-stage Griffon - is available. Wing profile stolen from Tempest. Fowler flaps.
Have De Havilland make it.

Out of wood or aluminium?

 

[tomo pauk]

Out of wood or aluminium?

They can probably do it either from one or another material.

 

[fastmongrel]

Griffon could be pushed along a bit I am sure a 2,200hp engine like that fitted to the Spiteful could be expedited.

Build a better Mossie using DH Hornet technology with 2 stage Griffons and you could get close to the spec.

 

[Admiral Beez]

Impressed by the performance of the Mosquito prototype and early production models, the RAF looks for the next generation high speed bomber aircraft.

Can we get an early Canberra?

 

[wuzak]

Can we get an early Canberra?

Not likely.

UK jet engines of the period were 2-2,500lbf thrust, compared to 6,000-8,000lbf thrust for Canberras.

Derwent V is available near or after the end of the war, had 3,500lbf thrust.

The de Havilland H-1 Goblin I had up to 2,700lbf in production models, but these were thin on the ground before WW1. The failure of the H-1 in the XP-80 prototype delayed de Havilland's Vampire because the engine that was to be used in the prototype was shipped to Lockheed instead.

The Lockheed P-80 ended up with the J-33 of around 4,000lbf thrust. Four service test YP-80s made it to Italy by 1945.

Don't think the J-33 would have been available in quantity soon enough for an early Canberra to make it into the war.

In an extra what if scenario, if Whittle had been supported by the Air Ministry earlier and/or Griffiths had been sent to an aero engine manufacturer, rather than Metropolitan Vickers, more suitable jet engines may have been available for an early Canberra.

 

[HarryMann]

Not likely.

UK jet engines of the period were 2-2,500lbf thrust, compared to 6,000-8,000lbf thrust for Canberras.

Derwent V is available near or after the end of the war, had 3,500lbf thrust.

The de Havilland H-1 Goblin I had up to 2,700lbf in production models, but these were thin on the ground before WW1. The failure of the H-1 in the XP-80 prototype delayed de Havilland's Vampire because the engine that was to be used in the prototype was shipped to Lockheed instead.

The Lockheed P-80 ended up with the J-33 of around 4,000lbf thrust. Four service test YP-80s made it to Italy by 1945.

Don't think the J-33 would have been available in quantity soon enough for an early Canberra to make it into the war.

In an extra what if scenario, if Whittle had been supported by the Air Ministry earlier and/or Griffiths had been sent to an aero engine manufacturer, rather than Metropolitan Vickers, more suitable jet engines may have been available for an early Canberra.

The Halford H-1 Goblin did not fail in the XP-80 as such... the XP-80's inlet ducting failed under the suction.
The engine was capable of 3000 lb st. thrust as delivered I believe.
Seems like if the Ministry said jump to dH Halford then they had to... after all the munitions that came our way I suppose there was never any question.

 

[HarryMann]

Last Goblin Mk was nearer 3500 lbf

 

[wuzak]

The Halford H-1 Goblin did not fail in the XP-80 as such... the XP-80's inlet ducting failed under the suction.

Very true.

 

[wuzak]

Last Goblin Mk was nearer 3500 lbf

And when was that?

 

[HarryMann]

And when was that?

Probably '47 - 50. Was a very well engineered reliable engine. First ran within a year of Halford seeing a Whittle compressor wheel and being let into the secret.