Power-egg installation on British airplanes

[spicmart]

What was the reason that the power-egg concept, like the German manufacturers adopted, never got introduced by the RAF for their fighter aircraft?

Such a modular installation enabled an easy engine change by simply unplugging an engine and plug another one to the same standardized pick-up points for attachments, fuel and control line connections.

 

[WatcherZero]

It was heavily used on bombers by the RAF, not so much on single engine fighters because the fighters engine arrangement predated the concept and its integrated into the fuselage rather than in an engine nacelle. The Germans didnt use it on single engine fighters either (outside the Komet) but on their twin engine bombers and twin engine night fighters, the Bf 109z prototype for example used it because the engine was lifted straight from a Jumo bomber.

A 1937 Air Ministry specification standardised fitting dimensions for Radial Engines.

Hercules Power Egg developed by Bristol was used on: Bristol Beaufighter, Armstrong Whitworth Albemarle, Vickers Wellington, Short Stirling, and Handley Page Halifax.

Rolls Royce used a Power Egg 'Power Unit' from the Merlin XX onwards appearing on the Whitley, Wellington, Halifax, Lancaster, York, Miles M20. and CASA 2.111.

An improved 'Universal Power Plant Power Egg with radiator connections for larger Merlin engines and the Griffon engine was used on the Lincoln, Windsor, Tudor, Argonaut and Shackleton.

 

[spicmart]

Why should fighter engine arrangement predating the concept be a hindrance?
The Germans realized it in their later fighter designs mounting the DB 603 or Jumo 213.

 

[WatcherZero]

You would have had to totally redesign the engine mounting points and structural frame on the Spitfire and Hurricane to accommodate an engine drop capability (making the engine incompatible with earlier variants) and there weren't any new single engine fighters developed that weren't derivatives of them.

The ME 209-II didnt enter serial production because too many changes had to be made to accommodate the engine including a total redesign of the cooling system.
The FW-190D was a switch in powerplant from a radial to a V block and required a complete redesign of the front end and significant lengthening, the engine cooling system was also customised and not compatible with the power egg engine mounts in other aircraft. It didn't enter production until August 1944! You could also question whether it was worth it, it never was used for its design purpose of high altitude bomber interceptor and without the Methanol for the injection system (which was always in short supply) it was slower than the FW-190A and less manoeuvrable.
You also had the FW Ta 152 which used it but didnt enter production until January 1945 with only 44 being built.

One other thing that may have affected it was a Merlin generally operated for 100 hours before requiring an engine out service with a factory overhaul after 250-500 hours whereas the Jumo only managed 50-60 hours so the Germans would need to replace them twice as often.

 

[spicmart]

The power-egg I meant was designed for making conversion of DB 603 to Jumo 213 ( and vice versa), not for other engines.
Together with the aerodynamically effective annular/drum radiator in front as part of it this lessened production and maintenance efforts.

I was not talking about the required modification of Fw 190A to a D-airframe.
Even without MW50 the Dora was just as fast or faster than the Anton. It turned better because of better aerodynamics and roll rate shouldn't have been much worse as mass distribution stayed just as near centerline.