RR Merlin / airframe tie up

A very kind soul has put online an exhaustive(?) visual list of all Lancaster AM Form 1180s. I’ve gone cross-eyed trawling through them all – resulting in the footballing analogy  of “hitting the post”.

17 April 43; Lancaster 1s W4279 and W4934 of 61 Sqn in collision and damaged at Syerston. 

W4279’s starboard outer was AM serial 395420. 

My engine plate is from AM serial 395421.

So close yet so far.

Nevertheless the forms themselves make fascinating and at times very moving reading.

T    

Thanks Lynx815. Any info RR Heritage do supply will be of interest, although as you say an airframe tie up won’t happen. As mentioned previously, the best chance of a tie up will be from 218 Sqn accident damaged Lancs who’s AM Form 1180s recorded engine numbers. Even then it will be only a very very large slice of luck that the engine in question happens to be on one of those Lancs and was recorded. But an enjoyable search all the same.

T.                    

I was passed on to the Head of Spitfire Engineering of the Rolls Royce Heritage Flight when I made an enquiry to the RR Heritage Trust. I had a Merlin engine number and the AM number. I received details of the build and dispatch dates, to where the engine was despatched along with the contract number and number of engines covered by the contract in which the engine featured. I assume RR still has the basic build data for all Merlin engines at least. RR does not have aircraft serial tie ups and never had.

Lynx815 – will you share details of the historical documents that The Rolls Royce Heritage Flight (not the Trust) hold? 

The Rolls Royce Heritage Flight (not the Trust) can only tell you the build and dispatch dates of engines and to where they were sent upon delivery, ie an aircraft manufacturer.  They have no record of what individual aircraft an engine was installed in when an aircraft was being built and nor would they.  Only the aircraft manufacturers would know this.

So many original AM / ARB documents have been lost – including duplicates held at regional offices. My reading of a Parliamentary debate that took place in the late 1950s is that all papers not being kept should have been microfiched before destroying the originals. I’ve have correspondence with the CAA to try and establish if this did happen or not. I did successfully extract copies of copied a few documents in my own area of research, but trying to get answers or more documents from the is like banging your head against a brick wall! So much more should have been saved for TNA vaults. 

“The Rolls-Royce Heritage Trust scanned and made available  “Air Ministry Aero-engine Serial Number Allocation  95400 – 667688 1918-1963” during 2010.”

That is excellent news; a valuable historic document preserved, digitised and (hopefully) fairly accessible. Congratulations must be given to Tim Mason (Well Done!) for recognising its value and being instrumental in saving it…

…plus the usual rolling of the eyes for utter indifference by officialdom!

Thanks Oracal; fascinating. The engine in question at least falls within the numbers  of the scanned document. Creaking Door – thanks for the info, I’m pretty certain AM Form 1180 was for accidents only,  so I’ll be giving the 218 Sqn ORB a very thorough investigation – any of its Lancs involved in accidents might just have a 1180 with an engine number.

Once again thanks for all the interest and info folks.  If nothing else this will be an enjoyable search.

Tim.   

The Rolls-Royce Heritage Trust scanned and made available  “Air Ministry Aero-engine Serial Number Allocation  95400 – 667688 1918-1963” during 2010. 

Within the excellent introduction to the document by David Birch is recorded the following;

“The master registers of engine numbers was held and maintained by the contemporary ministry. The engines given in the following listing are from the volume covering the period 1918 to 1963. This was rescued from scrapping by MoD employee Tim Mason; sadly the previous volume(s) were not saved, making it unlikely that a fully complete listing of all ministry numbers allocated to military engines will ever be known. 

The Rolls-Royce Heritage Trust considered the book to be of such historical value, and recognising its worn state undertook to have its pages digitally scanned to ensure that its contents were preserved in an accessible format.”

I have a copy of AM Form 1180 for a Lancaster lost in an accident in 1944.

The engine numbers are recorded as follows:

PORT/O: 250221

PORT/I:

STBD/I: 252142

STBD/O: 251567

The number for the port-inner engine is not recorded, leading me to speculate that the engine numbers were taken from the data plates on the engines as they were recovered at the crash-site; possibly the port-inner engine was not recovered (or the data plate was not recovered or illegible)?

[The ‘missing’ engine number has unfortunately led a family member of one of the lost crew to suggest that this aircraft was being flown with only three engines fitted to the airframe and to speculate that this was a factor in the loss of the aircraft and crew!]

Notice how wildly non-sequential the engine numbers are; even if you had the AM Form 1180 for a large number of 218 Squadron Lancasters that were lost (and many would have been) it would be impossible to match your engine to a single Lancaster by a process of elimination. And I am not sure there were AM Form 1180 issued for operational losses (the vast majority of losses) but I could be wrong?

Air Ministry Form 1180 (loss card) will usually record the (Air Ministry) engine number but not the manufacturer’s engine number; in that respect you are lucky you have both from the engine data plate.

Not sure why it was necessary for the Air Ministry to issue their own engine number; why not just use the manufacturer’s engine number?

’Somewhere’ there must have been a central list that cross-references the Air Ministry and manufacturer’s engine numbers; does it still exist?

Did Rolls Royce sell the engines to the private owners of  todays airworthy aircraft or was that done another way ?

Thanks P@P and Oracal. Valuable info. Thanks.

RAF Museum’s DORIS advise that some aircraft accident/crash cards hold engine details, so I shall go through the 218 Sqn ORB and establish which airframes are worth following up no matter how slim the chances are. The identity plate itself was found via metal detector near the airfield’s technical site. The area regularly gives up interesting items, the location being a source of wartime Bomber Command “litter”, not crash relics. (Don’t worry…it’s not one of the mythical burial pits containing entire aircraft etc.) Meanwhile, having spoken of the devil RR Heritage have coincidentally responded, and will get their Merlin expert to get back to me asap.

All long shots I know, and I’m fully aware the engine in question was probably married up to several different airframes, but if I can confirm one of those airframes to the engine’s life it’s a worthy (though probably fruitless) search.

Thanks once again for the replies. Greatly appreciated.

Any more thoughts please keep them coming.

Tim.

P&P, I too would have said “only” until a few months ago. Then I discovered that when a civilian aircraft was requisitioned my the RAF or RN the Air Ministry issued the engine(s) with AM numbers. In such situations the aircraft registration and engine manufacturer’s number would also be recorded.

Also, when a small batch of engines was ordered my the AM the engine manufacturer’s number was often quoted and tied to the AM number. 

But in the case of a batch of 7,000 Merlin XX engines… good luck… 

Same aircraft, many engine changes

Only an aircraft logbook, or status cards, will match an engine to an airframe, at a point in time.

Thanks for the replies folks. Greatly appreciated. The second number was always a mystery. Thanks Oracal. Great info. Gosh I wish that engine plate could talk.    

Yep l  knew engines (and indeed large bits of airframes) moved around – but presumably when an aircraft was first built, engine identities were recorded? Avro Heritage seemed pretty sure that Lancaster airframe / engine tie up records (at point of manufacture) did still exist and were now with RR Heritage Trust. Anyone know what’s happening with that organisation? It seems to be a dead duck.

Once again thanks for the replies. I used to be on here some years ago as TIMWING but had terrible trouble accessing the forum – but I’m back again now.

Tim

Tim. I can add a little more detail for you. The number ‘395421’ is likely to be the engine’s Air Ministry engine number. If that is the case it was one of a batch of 7,000 Merlin XX [AM #39,2000 to AM #398999] made to contract number SB4601. No dates I’m afraid. 

It is possible that you may find further details of the contract within the files at the National Archives, but they wouldn’t include specifics down to individual engine level. 

Tim  I was told a few years ago that there was a trick question – how many Rolls Royce Merlin engines did the RAF own in WW2 – answer none – they were all owned by RR and returned to RR for overhaul after X hours in use.  They were just leased by the RAF.

Hence as written above an engine may have been used on several different airframes after each return to service.

Over time engine was probably fitted to many different airframes. You will be very hard pressed to tie to plate/engine to any one airframe.