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Drew1251
12-09-2015, 05:11 PM
I have a prop that used to belong to Canadian fighter pilot Lt. Henry Botterell of RAF 208 Sqn. Here is a link to a story about Lt. Botterell (http://v1.theglobeandmail.com/series/remembrance/stories/botterell.html)from a local newspaper . He was the last surviving pilot from WW1 and passed away January 2003 at 106 YOA.

The markings on the hub read:
LP2850
130CL
D2590
P2270
Hub diameter is 7 cm and the thickness is 15cm. The bolt circle diameter is 154 mm. There are no other markings I can see.

My internet search suggests this is a Lang Prop for a Sopwith Camel which was a plane Lt. Botterell flew. The prop measures 259 cm (2590mm) so the diameter must be the third #and the last one is pitch. Am I correct so far?

5777

5778

5779

Bob Gardner
12-10-2015, 07:40 AM
Andrew,

Thank you for your email and details of your prop which I have added to my database.

Your prop is one of the standard props fitted to the Sopwith Camel from November 1917 to the end of the war in 1918. It was made to the design of Lang Propellers, hence the drawing number LP2850. This company made most of the propellers used by the firm of Sopwith and in late 1917 was purchased by Sopwith. After the war it re-emerged as the Airscrew Co and remained in existence until the late 1970s. Part Three of my series on British WW1 propellers has sixty pages which describe the history of the Lang Company.

Your data translates as:

LP2850; the propeller drawing number.
130 CL; the engine, the 130hp Clerget.
2590; diameter in mm.
2270; the pitch of the propeller.

You should not be concerned that the prop was cut into segments. It was the only way to get it home and therefore is a valid example of what happened to such props at the end of the war. But I agree that a complete prop would be the first choice of a collector.

The prop appears to have lost its original finish. The original lacquer appears to have been removed. There would have been fabric, Irish linen, applied to the tips of the blade to protect the wood from erosion, caused by the prop wash; dust, twigs etc blown up by the prop. The fabric may well have covered half a blade or perhaps all the surface down to the blade root. You should be able to find a witness mark where the man applying the fabric cut it, thus leaving a score mark on the wood.

I suspect that the flat surfaces of the hub have been sanded smooth. I think that the bolt holes are slightly elongated which, if so, indicates that the prop is a flown example. There would also be witness marks where the washers at either end of the bolt were pressed into the wood.

Before 1 April 1918, 208 Sqn was a naval sqn based at Dunkirk. (it was formed there in late 1916). On 1 April the Royal Naval Air Service merged with the Royal Flying Corps of the army to form the Royal Air Force. All naval sqns had the numbers 20 added to them, hence 8 Sqn RNAS became 208 Sqn RAF.

With kind regards,

Bob

Dave
12-10-2015, 09:56 AM
I can't add anything to Bob's response other than the fact that I'm not quite as convinced that the varnish has been removed (although I would expect to see decals on a Lang propeller). The hub finish looks a little less like it may have been refinished, and the photos don't show the finish on the blades very well, one way or the other.

Also, that metal banding around the neck of the blade is weird. I've seen painted stripes there but . . . metal???

Bob Gardner
12-10-2015, 10:13 AM
'Morning Dave,

I agree my thought on it having been stripped is a touch on the tenuous side, but the absence of any fabric supports my thoughts.

I think the two metal bands are covering the cuts which segmented the prop to get it home.

With kind regards,

Bob

Dbahnson
12-10-2015, 12:40 PM
Thanks, Bob. I missed that the prop had been cut into segments.

pmdec
12-10-2015, 10:03 PM
Hi,

Was it a Lang habit to have the stamping perpendicular to the laminations?

The shape of the prop is very like Régy props, which had a serial 2600mm long with a 2300mm pitch for the Sopwith fitted with a 130 HP Clerget (serial 343, also used on Caudron G6 with the same engines). Blade width for Régy 343 was 225mm.

What is the width of the blades of this one? Is it possible to have clear close up of the other sides of the hub?

Pics are from a Régy serial 343 n°700 repaired for the SFA (French Military Production Authority) and, shame on the one who made it, partially sanded.

Regards,
PM

Bob Gardner
12-11-2015, 06:08 AM
Bonjour Pierre-Michel,

Then this must be another French propeller made under licence by a British maker. Thank you for this insight. I shall add the details to my database.

With kind regards,

Bob