Power-egg installation in British airplanes

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.

spicmart said:

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

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Bf 109 was never with the power egg installation (not even the Jumo-powered versions) nor were the other MTT fighters, like the 110/210/410 or the 309. Heinkel got to the power-egg installation only in the He 219 and 177?
Merlin 20 series installation was used on the Lancaster and Beaufighter, IIRC. I'm not sure about the Hercules power-egg installations, perhaps someone might want to give some feedback.

By the time many British, German, Soviet etc. ww2 aircraft were being designed, power-egg installation was not an universal thing. Even the aircraft powered with radials were often with remote oil coolers, so there is no power-egg there, either.

spicmart said:

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.

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I am not sure the Germans ever used the power-egg concept on a single engine engine fighter?

One the other hand, the British did use a power-egg (of sorts) on the Beaufighter II, as Tomo says, it was from the Lancaster. Miles did use the "egg" on M. 20

Which shows some of the problem with the "egg" on a single seat fighter. There is a lot of 'stuff' crammed in a small space on a single seat fighter which means problems for weight and balance. V-12 powered Fw 190s used a extra section in the tail to help balance things out so you can't 'simply' change the radial engine airframe to the V-12 version.

BTW - perhaps someone might check out whether the power-egg combo was shared by the Merlinized Whitley and the 1st Halifax version.

Power-egg installations were realized for mounting DB 603 or Jumo 213 engines on
next generation prop fighter developments Fw 190D, Ta 152, (Me 209 ll, Mẹ 309?)

Bmw-801 were delivered as power-eggs, let it be the C , D or S versions.
Swap time on a 190 by standard crew with standard equipment was approx 15minutes.
There is a note about this in the manual.

The Ministry of Aircraft Production has the category engines and the category power plants. The power plant data starts from January 1942, drawn from weekly reports, as a result the "months" are either exactly 4 or exactly 5 weeks long, total production over the period is summed then divided by the number of weeks and rounded, to create a weekly average. So calendar month December 1942 actual production of 219 Merlin XX, 309 Merlin 28, 11 Griffon II, 393 Hercules VI and 38 Hercules XVI power plants become weekly averages of 51, 68, 3, 87 and 11, measured over 4 weeks of the month.

In January 1942 power plant output was over 100 per week, rising to over 200 per week in November.

Power plant types in 1942, Merlin X, XX, 28, 60/62, Griffon II, Hercules VI, X, XI, XVI, with XX for Lancaster, 28 for Lancaster and York, Merlin 62 for Wellington VI, Griffon II for Firefly, Hercules VI and XVI for Lancaster II and Stirling III. The Hercules X were fitted to Albemarle, Beaufighter I, Stirling I and Wellington III, the XI to these and also the Wellington X, most probably the power plants are for Stirling. The Merlin X were fitted to Whitley V and VII, Halifax I and Wellington II, power plant production weekly average for 1942 was 10, 6, 4, 3, 2,1, 0, 0, 1, 4, 7, 0, Halifax I production ended in September 1941, Wellington II in June 1942, Whitley V in June 1943, Whitley VII in December 1942.

A later adjustment adds a set of Merlin 22 for a York.

In 1943 Hercules VI, Merlin XX and 60/62 end, additions are Merlin 22 for York and Lancaster, Merlin 24 and 38 for Lancaster, Hercules XVI for Halifax III.

Additions in 1944, Merlin 24 for York, Merlin 224 for Lancaster, Merlin 68 and 85 for Lincoln, Hercules XVI for Halifax VII, Hercules 100 for Halifax VI.

Geoffrey Sinclair said:

The Ministry of Aircraft Production has the category engines and the category power plants. The power plant data starts from January 1942, drawn from weekly reports, as a result the "months" are either exactly 4 or exactly 5 weeks long, total production over the period is summed then divided by the number of weeks and rounded, to create a weekly average. So calendar month December 1942 actual production of 219 Merlin XX, 309 Merlin 28, 11 Griffon II, 393 Hercules VI and 38 Hercules XVI power plants become weekly averages of 51, 68, 3, 87 and 11, measured over 4 weeks of the month.

In January 1942 power plant output was over 100 per week, rising to over 200 per week in November.

Power plant types in 1942, Merlin X, XX, 28, 60/62, Griffon II, Hercules VI, X, XI, XVI, with XX for Lancaster, 28 for Lancaster and York, Merlin 62 for Wellington VI, Griffon II for Firefly, Hercules VI and XVI for Lancaster II and Stirling III. The Hercules X were fitted to Albemarle, Beaufighter I, Stirling I and Wellington III, the XI to these and also the Wellington X, most probably the power plants are for Stirling. The Merlin X were fitted to Whitley V and VII, Halifax I and Wellington II, power plant production weekly average for 1942 was 10, 6, 4, 3, 2,1, 0, 0, 1, 4, 7, 0, Halifax I production ended in September 1941, Wellington II in June 1942, Whitley V in June 1943, Whitley VII in December 1942.

A later adjustment adds a set of Merlin 22 for a York.

In 1943 Hercules VI, Merlin XX and 60/62 end, additions are Merlin 22 for York and Lancaster, Merlin 24 and 38 for Lancaster, Hercules XVI for Halifax III.

Additions in 1944, Merlin 24 for York, Merlin 224 for Lancaster, Merlin 68 and 85 for Lincoln, Hercules XVI for Halifax VII, Hercules 100 for Halifax VI.

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Why were there no power plants for most fighter aircraft (single exception Beaufighter afaik)?

spicmart said:

Why were there no power plants for most fighter aircraft (single exception Beaufighter afaik)?

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Assuming Power Plant is what others call Power egg. Age of designs, radiator arrangements and lack of radial engine types for a start. The many different engines in Spitfires. In theory the Typhoon and Tempest could have been done but they were not. Nor were the Merlin engine Halifax. The other exception was the Firefly, it was considered a fighter, but note no mention of Beaufighter Power Plants.

Some installations that might be considered as power egg:



Merlin for Lancaster, for all 4 engine positions; caption claims that similar installation exists for the Halifax:



Schnellwechsel - fast change.

Hercules for different aircraft; up to 10 different types with exhaust and some auxiliary items changed:

The reports on the delivery program of Power Plants do not seem to have covered all engines, looking elsewhere gives end September 1942 as the first time the stocks report differentiates between Engines and Power Plants, no Merlin X Power Plants, while both Sabre III were in Power Plants. Skimming the reports it seems the few Sabre III were mostly Power Plants while uncovering the odd entry, like a few R-2800 Power Plants.

Engine stocks report as of end December 1944, number of Engines in Power Plants
414 Merlin XX
12 Merlin 21
596 Merlin 22
51 Merlin 23
1,299 Merlin 24
487 Merlin 224
72 Merlin 25
30 Merlin 28
41 Merlin 32
48 Merlin 38
none Merlin 68
5 Merlin 72
2 Merlin 73
127 Merlin 85
132 Griffon II
13 Griffon VI
146 Hercules VI
156 Hercules XI
1,391 Hercules XVI
762 Hercules 100

End January 1945, cumulative Power Plant deliveries,
Merlin X for Wellington II (880 for 400 mark II built)
Merlin XX for Lancaster I and Beaufighter II (the latter 1,031 for the 450 mark II built)
Merlin 22 and 24 for Lancaster I and York
Merlin 28, 38, 224 Lancaster III
Merlin 68 for Lincoln II
Merlin 85 for Lincoln I
Griffon II for Firefly I and II (547 versus 307 mark I and II built to end 1944)
Hercules VI for Stirling III and Lancaster II
Hercules XI for Albemarle I and Stirling I
Hercules XVI for Stirling III, IV, V, Halifax III and Lancaster II
Hercules 100 for Halifax VI (1,261 compared with 105 mark VI built to end 1944 and ultimate production run of 482, showing the British system of building engine stocks before starting aircraft manufacture.)

To end January 1945 Lancaster I production was 2,724, requiring 10,896 engines plus spares, Power Plant deliveries to end January 1945 were 3,777 Merlin 20, 2,444 Merlin 22 and 6,879 Merlin 24, total 13,100, while the Halifax used few to none Merlin 24.