Have I got too many holes?

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Hi guys, I'm trying to find the origin of a propeller hub that I have. I've been googling and pouring over Janes aero engines for a few days now but I'm just even more confused now, because mine has 9 holes!!

I'm assuming it's a British prop because it has it's single gun timing mark, and it came with an RNAS pilot's flying log book. There are a few 'stamped' markings and numbers on it. I'll get some photos of it on here in a bit, but I was wondering if it's extra hole made it easier to identify?

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[Dave]

It's too bad that the hub has also been split in half lengthwise, removing the remaining digits in the drawing number, but there are several props whose drawing numbers begin with AB70__. A few of them were used on a Siddely Puma engine (which had 8 holes) and the others used either a Galloway Adriatic or a Sunbeam Maori engine. I have no information about the hub pattern on either of those. The Adriatic powered a DH4 or a DH9, and the Sunbeam powered a Short 184. Under the drawing number on yours appears a "D" and what looks like an "F" but could be an "E", in which case it may have finished as DEH for "DeHavilland".

Maybe Bob is familiar with the hub patterns on those other two.

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A Short 184 would fit, as in his log book the pilot logs flights in a Short sea plane.

[Dave]

Maybe you can find out if one of those engines had a nine hole hub.

[pmdec]

Hi,

I have seen a nine holes prop marked for a 200 HP BHP SIDDELEY. It was a serial AB 7901 (with the "9" not sure) for a DH9.

I can find the hub measurements if necessary.

Regards,
PM

[Bob Gardner]

'Afternoon Barry,

Your hub remnant is from a prop intended for use with the Siddeley Puma of 200 or 230hp. It was made for the DH4 or DH9 aircraft. The drawing number is AB703X, where AB indicates a design of the Air Board (and hence from October 1917 or later), and where X could be any numeral from 0 to 7 as variations on the theme proliferated. The most widely used was AB7031 which was the standard prop for the DH4 and DH9 from November 1917 onwards.

The prop was also used on the Bristol F2B with the Siddeley Puma from July 1919 and on the Short 184 with the Siddeley Maori engine of 260hp, also from July 1919. But your prop was made for the DH4 or DH9 as indicated by the stamping on the prop.

With kind regards,

Bob

[Dave]

My apologies, guys. I made the assumption that the Siddeley engine had 8 bolt holes without ever looking at one that I own (Bristol Fighter) and actually counting the holes.

[Bob Gardner]

Sorry Dave. I hadn't realised that I had contradicted you.

Bob

[Dave]

Sorry Dave. I hadn't realised that I had contradicted you.

Bob

No apology needed, as I was clearly wrong to eliminate the Siddeley engine from contention thinking it was an 8 hole hub, which it obviously insn't. Under those circumstances, it's good that I was contradicted.