British engine serials - A.M. Forms?

[HGabor]

Hi Folks,

Most A.M. Forms (eg. 78, 1180) list engine numbers for certain AC types, like Wellington, Halifax, etc. But these numbers are not the official engine serial numbers, which can be found at crash sites, like: SS-28031 for Wellington X., LP732.

Is there any database, or record which maps these Air Ministry numbers to the actual engine serial numbers for proper wreck identification? See 2 examples.

What was eg. the 'real', or factory dataplate engine serial number of Wellington X., LP303 for A.M. engine # '426401'? SS-?????
Thanks,

Gabor

[edwest2]

I have found some information that I hope is useful. From another site:


"The A prefix is the Air Ministry contract number, the other is the Rolls-Royce engine num[b]er, which is always an odd number on right-hand rotation Merlins. Both numbers are unique to that particular engine."


"The A-number is unique to the engine and was used across the board, so Hercules engines as mentioned would also have a unique A-prefixed contract number.
On paper, the engines were built in batches to Air Ministry contracts which had another number, for example, Merlin III, No 19407 / A144641 was one of a batch of 600 built to contract No 974105/38 (1938), and also an order No 4950, which I think is a Rolls-Royce order number. The only way all these numbers relate is on paper. I don`t know if there is any logic to the AM number stamped on the engine, they appear to have been issued roughly serially, earlier engines have a lower number.
People do sometimes quote the AM number as the "engine number", which is often done on Air Ministry records, but with Merlin engines, the true engine number is agreed to be the Rolls-Royce one."


"...both numbers appear on the plate and the port front mounting foot, the Rolls-Royce engine number usually appears in many places. There are exceptions to this, but it's nearly always the case."

[HGabor]

Edwest2, so far this is the best explanation of the British AC engine numbering. Thank you so much, this is very informative!
Gabor

[HGabor]

Excellent, found pic of Wellington X. engine dataplate ,showing both Air Ministry and S/N numbers. Would be nice to find the matching pairs for all engines since A.M. Form 78 lists only the A.M. numbers... Anyways, this can help identifying recovered engines too.
Gabor