Numbers on RFC propellers

[wulffo]

I own a number of propellers of RFC machines among them a Sopwith Baby Schneider, DH2, SE5A, Avro 504 and Bristol Scout. Obviously all of these are numbered. Is there any relation between the number on the prop and the number of the plane and if so could one potentially trace the

[dbahn]

That's a good question. I have one D VII prop that has the plane number painted on it, but I haven't seen RFC or other props with similar information.

Since most of what is stamped on there has a meaning other than the specific aircraft, I would have to say most props can't be traced back to the plane they were used on. On the other hand, some props have a "G" followed by a number and an "N" also followed by a number, and I haven't been able to figure out what that means. It's possible that might link to a specifc usage, but maybe someone else has an idea if that could be the case.

By the way, if you collect props we should talk some more.

Dave

[wulffo]

thanks dave, and yes we should get into contact.
concerning the props there is a series of numbers and identification letters plus generally the engine type, sometimes with an indication of horsepower on the prop, but as stated earlier, ihave no clue what they mean. i have attached some pics this time as i am emerging from the internet stoneage.

[dbahn]

Even though there is no "standard" propeller format, here are some of the likely numbers to find stamped around the hub:

Pitch and Diameter - Often preceded by "P" and "D", but sometimes just a number that refers to length in millimeters or inches and the pitch in the same units. The pitch is the mathematical forward travel in one revolution, similar to the thread length on a scew.

Drawing number - Refers to the blueprint from which the prop was manufactured. There are some listings of British props (Windsock Datafile has one) and a few of some other Allied props, but these can be hard to find. The number is often preceded by a letter, so that "IPC 2360" would have been built by the Imperial Propeller Company, and that particular number was for the Sopwith Pup. "Y58" was manufactured by Avroe and was used on an AVRO 504 with the 100 hp Monosoupape, for example.

Rotation - RH or LH. I'm not sure where the polarity came from, but I think of it like a screw; turning the prop to the right (like a screw) would screw it into the air, and vice versa. People erroneously infer pusher application from the rotation, but you cannot tell pusher from tractor without know the engine type and configuration.

Engine, Horsepower, or Aircraft - self explanatory

Serial number - might even be the shorter of two numbers stamped. The drawing numbers are often 5 digits.

Blade number (1, 2 for a two blade) - could be used to maintain balance or gun timing for reinstallation.