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[SteveJ]

Hi, I've just been asked to 'look after', what I believe to be, the centre laminate section of an old hard wood propeller (or should I say airscrew). It was found on a local beach 50 years ago in the condition that you see it in.
Though it appears to be broken in half, the end section near the boss has a neat edge and is painted red in colour, ie. the design looks as if the completed blade is made up of two halves ??
There are six bolt holes visible in this section which show signs of bolts being inserted into them at one time. The other small holes have possibly been the result of marine worms ?? after its time in the sea.

I have three theories as to it's origin:

1. It was from a radio-controlled target a/c from WW2; Queen Bee/Tiger Moth, which crashed into the sea. Aerial target range approx 40 miles away on the coast.
2. It was part of the cargo from a ship which sank 1/2 mile away - though there are signs that bolts have been inserted in the boss holes at one time.
3. It is from an early a/c type which was flown on the beach in 1911. This a/c is known to have had a few accidents as the pilot was teaching himself to fly. Possibly the first a/c to fly in the area ?

I'd be grateful for any input anyone can give me as I know nothing at all about old airscrews.
Many thanks for your anticipated help.
Steve Jones,
South Wales,
UK.

[Dave]

It looks like a 10 bolt hole pattern, which narrows down the engine possibilities but still doesn't identify it.

The original diameter is probably 8 to 10 feet, which is considerably longer than propellers commonly used on target drones. That size is more typical of early (WW1 era) low RPM engines.

Usually when there are neat cut edges through the hub it's been intentionally cut in half, usually for transport. No airworthy propeller will have the hub assembled in separate pieces like that because the centrifugal forces are highest in that region.

I think no matter what theories can be conjured up, it's unlikely that you will ever know exactly what its usage was. While the 1911 event sounds interesting, it's hard to imagine the item laying on the beach for the next 50 years.

[pmdec]

Hi,

The first French props with 10 holes ("D" type hub) are from the twenties, with the arrival of ~400 HP engines (for example, it seems all Breguet 19 (first flight in 1922) props were 10 holes). Had to be quite the same in UK.

I think it is impossible the prop broke like this. As Dave, I think it was sawn for deco use. My guess is the prop was thrown away ... ... or wash by a flood!

PM

[SteveJ]

Thanks both for your input. Here's a close-up of the boss-end, with red paint which extends up the leading & trailing edge by about 12".