enginehistory.org

[dbirch]

I have noted that some foreign (as in non-British) -built engines supplied to the UK during WW1 have serial numbers that appear to be different in some way from the same types supplied to the air forces of the manufacturing nations. To give examples:

Gnome Monosoupape: 5155B232. French-used Monos did not have the B-number suffix.
Liberty: 37775/B274. Most Liberties suplied to the UK did not have a B number, but instead had a dual number, e.g. 19202/2010.
Anzani: There are examples of some of these engines having a B number, though examples known do not seem to have a prefix number.

Could it be that these engines were deliberately marked thus to diffrentiate them from indiginous engines, so that at a glance - both British and French engines of same type being in operation in France - it could be seen as to who they belonged to (during overhaul?)

Regarding the Liberties, why were there two serials (not the B ones) per engine - was one an Air Service serial?

Similarly, Le Rhone had the habit of giving some engines a double serial, e.g. 5892C2343, and these appear to only concern those engines supplied to Britain, in this case the 80hp Type 9C. There is an odd example of a letter E as the divider, and also BB. With these engines I suspect that ownership had nothing to do with the reason for the letter.

Nearly all of the above engines were given Air Ministry WD numbers on acquisition, but that has nothing to do with the above query.

Dave Birch

[rfinnerty]

Dave,

I know that this is an old question, but I was trolling through the members forum, and serial numbers are a special interest of mine. You have provided some serials for me in the past. If you have not already found your answer for the Liberty, here is the explanation. 37775 is the U.S. Army Air Service serial number. B274 is the Buick constructors number. This particular engine is from a batch of 1000 A.S.37503 to 38502 license-built by the Buick division of General Motors. 19202 was from a Packard-built batch of 6000 from A.S. 17435 to 23434. 2010 would appear to be the Packard constructor number, although the numbers do not seem to line up. Some of this batch were 12N engines with reduced compression, i.e. "Navy" models, and this may be a Bureau of Aeronautics number. There is an excellent book on the Liberty by Robert Neal, A Technical and Operational History of the Liberty Engine. Also, the is another excellent book by Robert Casari, U.S. Army Aviation Serial Numbers and Orders 1908-1923 Reconstructed, which includes engine serial from 1908 to 1919.

Roger