Se5a Hub?

[Nickybiz]

Hi,
I have recently bought a wooden propeller hub. I didn’t pay a great deal for it and don’t expect it’s worth much, but wanted it as it’s a lovely thing and will be displayed at home. I believe it may have once been a clock, and the wood has been worked well, to remove 2 of the blades of what I believe was a four bladed prop. I have no intention of making it a clock and think it’s a great piece of history (or what’s left of it!)
From the research I’ve done, I believe it is from an RAF SE5a, with information on it as follows (missing/assumed info in brackets);
T280(96)
SE(5)
(H)ISPANO-SUIZA
(23)62. PITCH 3340
88 on hub surface, reference not know.
What I’d like to know is; what might the 88 refer to?
How many 4 blade props were made?
What is the wood?
Hope the photos attach ok. Thanks
Nick

[Dbahnson]

A number like your "88" is usually a production number that has no real significance, especially when seen at that location on the hub.

I don't know the number of 4-bladed props manufactured for that aircraft but would bet that it's higher than you'd think. As a reference, the American Propeller Manufacturing Company in the U.S. had manufactured 25,000 wooden propellers by the end of WW1, and they were just one of dozens of manufacturers active at that time. That volume had very little to do with the war, so I suspect that European manufacturers may have had even higher levels of production.

[Nickybiz]

Thanks for your reply, I wasn’t sure if the 88 had any significance.

I thought there were probably quite a few manufactured, but wasn’t sure if they were specific to aircraft or engine. There’s not much left of my propeller, but want to find out as much as I can, as it’s a great piece of history.

[Dbahnson]

They are VERY specific for engine (partly due to the standard hub for each engine) and moderately specific for aircraft make and model. The drawing number "T280" applied to several different engines but the suffix ("96") narrowed the engine down to just the 200HP Hispano Suiza engine.

[Nickybiz]

OK thanks, so the 4 blade hub I have is specific to the 200hp Hispano Suiza engine, and would have been fitted to an RAF SE5. That’s great.

[Garuda]

Welcome

Welcome to the Forum Nick!

I have just purchased a computer which is capable of running Photoshop. The reason for this is that I have a drawing for the T.28097-1 propeller. I don't remember where I obtained it, but someone at some time has photocopied it in A4 sections. Many parts of the drawing are duplicated (some parts more than twice) and other parts have not been copied at all. Most of the missing information is around the middle of the drawing, which shows the blade sections. In addition, many of the photocopies have greying and distortion, where the original drawing (quite a large size and awkward to handle) has not been held sufficiently close to the screen of the photocopier. I intend to use Photoshop to piece the individual drawings back together, and reconstruct it as a single drawing.

Does anyone have an original T.28097-1 drawing, and would not mind scanning the missing blade sections?

I can confirm that the drawing specifies the T.28097-1 as a 200 HP Hispano Suiza SE5 (not SE5a) propeller.

Regards,

David.

[Mtskull]

I can confirm that the drawing specifies the T.28097-1 as a 200 HP Hispano Suiza SE5 (not SE5a) propeller.

Specifying the “a” suffix would not have been necessary, as the fitment of the 200 HP Hispano Suiza engine (as opposed to the 150 HP version) is what defined the SE5a and distinguished it from the earlier SE5.

[Garuda]

SE5a / 200 HP

True, and thank you very much for making the point. In the scheme of things, adding an a to the specification SE5 would have been no trouble at all, but as you pointed out, the a specification must have been implied.