PDA

View Full Version : old Propeller-half


horsa
02-25-2016, 05:46 PM
Dear All,

I am new to this forum and havenīt had much contact with early airscrews yet, but am an aviation enthusiast and currently receipt a piece of an old wooden airscrew. I hope you can help me with identifying that piece. It has some stamps (see images) and was painted in black in newer times.

Looking forward to your replies.

Thanks and best regards
Andreas

Dbahnson
02-25-2016, 06:25 PM
Not much to go on there. It looks like a 10 bolt hub, so there aren't as many possibilities as there are with 8 holes, but I think it's going to be hard to pin down.

horsa
02-25-2016, 06:37 PM
Thanks for your reply.
Is it possible to narrow its age down a bit?

Dbahnson
02-25-2016, 09:03 PM
Not very reliably. My guess (and I mean guess) is 20s or 30s. There's just not much to go on.

Sparrow
02-27-2016, 10:05 AM
The black coating on your propeller is probably Tonkilaque which was used after 1919 till the outbreak of second world war. The word LOR40... may be information of engine: LORRAINE DIETRICH 400 HP. This engine had 10 bolt hub. The bolt circle diameter was 200 mm. So your propeller could be French or Polish (because there were propellers made under French license).
Another 10 bolt hub propeller was for Bristol Jupiter but bolt circle diameter was larger 220 mm.

pmdec
02-27-2016, 03:42 PM
Hi,

I think like Sparrow: it is probably French, for an aircraft fitted with a Lorraine 400 HP engine (marking LOR 40...). Could you post another pic of the other side of the hub with better view of what could be stamped after 23?
It could be a Breguet prop serial 123 (with just the 23 remaining) for Breguet 19, but there many other possibilities!
Ten bolts are used in France from the early 20' for high powered engine.
The thickness of the hub and the diameter of the circle on which are the bolt holes could help.

Regards,
PM

horsa
02-28-2016, 12:17 PM
Thanks for the replies.
The black paint is definitely "new". I started to remove it and the original coat is still beneath. I am currently at holidays, will send the requested images and measures in a week.

Cheers
Andreas

pmdec
02-28-2016, 08:07 PM
Hi,

I am not sure it is good idea to remove any paint, even if it is "modern". The original finish have to be lacquer, and if the prop was refinish I think the lacquer was depolished (not sur it is the right word) because quite nothing can stick to lacquer.
But it is yours...

I have found the hub thickness for the 400 HP Lorraine: 220 mm, at least until 1926.

If there is a 1 after 23, it is a Ratier serial 231, serial made for the same aircraft+engine that the Breguetr serial 123. This serial had a ten bolts and 220 mm thick hub.

Regards,
PM

horsa
02-29-2016, 12:17 PM
Thanks for the further information. Will check if I can find more numbers once I am back home.
The lacquer is under the black paint which is easy to peel off. I think because what you mentioned - it doesnīt stick well.

Best regards
Andreas