Anybody recognize these propellers?

[mcourdin]

The first prop is a pusher, no markings or stampings with the original finish. It is said to be from the Monett Biplane from around 1908.

The second prop is a tractor with markings of 9' 8" D. and 6' Pitch. SC 105055R4-- Maybe Curtiss R4? 1916?

[Dave]

Boy, on the first one without markings or drillings on the hub to substantiate a particular engine as likely, it will be very difficult to identify with any certainty at all. Left hand props were frequently, but not always, a pusher configuration, occurring when a standard right hand rotating engine was simply turned around and mounted "backwards". But some engines were left hand rotating and some right hand rotating engines were geared (e.g. SPAD with Hisso engine), so there's really no way of verifying that it was even a pusher without knowing the engine.

The second one may very well be for a Curtiss R4, since that number is stamped on the hub. I'll see if I can measure the bolt diameter and the bolt hole circle diameter on my R4 propeller and see if they match yours. They do look larger than the more common Liberty hub, but I'll have to measure to confirm. If you can find "11612" stamped on it that should pretty much confirm the R4 usage. I've actually never seen a Signal Corps number that high numerically, which doesn't seem to fit with anything as early as 1916, and I'm not sure when "S.C." stampings began appearing on propellers, but my sense is that it was not until 1917 or 1918, even though the Signal Corps aeronautical origin goes back as far as 1907.

[pmdec]

Hi,

It seems there is a (thin?) lamination gone on the first prop. It seems also there are markings upper on the side of the hub on the second picture: could you post a close up picture? Anyway, I don't think such shape and shielding could by from before WW1. In France, such shape show up around 1916 (Éclair props).

Regards,
PM