Siddeley

[Mike Hill]

I have a propeller hub with 9 bolt holes with the following stamped into the wood which I think is mahogany -
G399 N70
D E H 4
R H
AB7031E
200HP
BHP SIDDELEY
P2530 D2750
then stamped vertically GUN TIMING
Any ideas which plane this came from and/or its approx age?
Thanks

[Dave]

That drawing number (AB7031) was used on Bristol F2 A and B, DH 4, and DH9 aircraft. Since yours is stamped DEH 4 it was specifically assigned to the DH4 (DH = DEHavilland). with the Siddeley Puma engine.

Bob may be able to date it more accurately with the production (G/N) numbers, and perhaps clarify the "E" suffix, which may indicate experimental.

[Bob Gardner]

Hello Mike,

Welcome to the forum. Thanks for telling us about this data which I have added to my database. The batch number 399 shows that it was made under contract by the British & Colonial Co. The Government paid £46 for it.

The records of the British and Colonial Co show that this batch was made around March 1918. The data shows the prop was made for the 200hp Siddeley engine designed by Beardmore Halford and Pullinger. Shortly afterwards Siddeley produced its own reworked version of this engine, the Siddeley Puma of 230hp.

I don't know what E indicates. This drg no, AB7031 was the standard prop for the DH4 from November 1917 until the end of the war and was very widely used, so I don't think E indicates experimental. Props designed by the Air Board occasionally carried the additional letter A, B or C to indicate variants. Experimental props were marked (exp).

Props made by the Lang Co were also marked variants with the letters A, B and C and one of their drawing nos was marked AE. This was a standard prop so I don't think there would be anything experimental about it, either.

If you have a British or German prop and have not given me the data on the hub, please do so. Many kind people have and it is helping me build up an extensive database, something which would hardly have been possible before the advent of this forum.

With kind regards,

Bob

[Charles Lambrou]

image_10085.jpg
Hi everyone, I am an aviation professional living in Athens, Greece .I have recently acquired from a junk dealer a Siddeley wooden prop .The prop was sloppily painted and also has a leading edge and tip brass protection that doesn’t look factory made but a later professionally made modification.
The prop's stamped markings are horizontally placed on the hub and are:
G688 N13
AB7031 RH
D2750 P2530
200 HP
BHP SIDDELEY

Greece's Airforce and Navy airforce of the time, used a wide range of aircraft in this period including Aircos and Bristols (https://www.haf.gr/en/history/historical-aircraft/)
Any suggestion regarding the plane the prop came off ?
Thanks for helping ,
Charlie

[Dbahnson]

See my post above regarding the drawing number, AB7031, and Bob Gardner's subsequent addition. The prop was manufactured to use on any one of those aircraft, not unlike a specific tire model might fit on several different car models. The "BHP" refers to the earlier model of the Siddeley engine, and your batch number of 688 would indicate that it was a later production for that model engine, but would still be suitable for any of the aircraft listed above. Sometimes a specific make and model would be stamped on the hub, but absent that the only way to know which one of those models it may have been mounted on would be to somehow stumble across a logbook or other record, an extremely unlikely occurrence.

On your photos I don't see convincing evidence that it was mounted on an engine (i.e. "witness marks" where the metal hub compressed the wood.) I'm also not sure that the metal sheathing was done later either. Many of the early propellers that have survived the past 100 years did so because they were never used and ended up being sold off as surplus.

[Charles Lambrou]

See my post above regarding the drawing number, AB7031, and Bob Gardner's subsequent addition. The prop was manufactured to use on any one of those aircraft, not unlike a specific tire model might fit on several different car models. .........

So ,the 200HP stamp does not restrict the use of the prop on a bigger horsepower plane ? ie DH9 or Bristol F2B or 81A

[Dbahnson]

So ,the 200HP stamp does not restrict the use of the prop on a bigger horsepower plane ? ie DH9 or Bristol F2B or 81A

My guess (and it's only a guess) is that it doesn't, since the Puma engine was a later development and the same design may have just rolled over to the higher HP. In the listing I have they don't specify the BHP engine, just the Puma. Although my listing is quite large there are apparently occasional errors or omissions.

[Charles Lambrou]

Does G688 N13 specify a certain batch , order or aircraft type ?

According to era types , in my opinion,the most possible candidates for the prop seem to be

https://www.haf.gr/en/history/histor...greek-version/
https://www.haf.gr/en/history/histor...avilland-dh-4/
https://www.haf.gr/en/history/histor...avilland-dh-9/

[Dbahnson]

The "G" and "N" numbers only specify the production sequence but follow a timeline rather than an aircraft type.