A strange propeller

[Philiprop]

Hello,

I am a french merchant (Paris) and I would be pleased to have your opinion about a quite special propeller.

It is a Chauvière Integrale (260 cm / 102.36”) with a 8 bolt holes hub (diameter 20.5 cm / 8.,07” and center bore 7cm / 2.76”) with a large metal plate fixed on the back of each blade. It is a very strange assemblage because the metal doesn’t stick at all to each blade (a spacing of 4 cm / 1,57” near the trailing edge)

I never seen anything like it before. It could be an armour plating (with bullet impact ?)... but how can a blade work with such a shape ?

I placed some pictures on a temporary website : http://pagesperso-orange.fr/aviaspot/prop.htm

Have you ever seen this kind of propeller ?

Thank you for your help !

Philippe

[pmdec]

Bonjour Philippe !

Chauvière serial 2276 is referenced in the WW1 military books I have:
Diameter: 2m55
Pitch: 2m30
Blades: 225 mm wide
Hub thickness: 150 mm
Central hole: 70 mm
Fixations: 8 bolts (11 mm holes on a 150 mm circle)

Chauvière serial 2276 was approved for school use on a SPAD fitted with a 110 HP Le Rhône. It seems 2276 is an early Chauvière serial.

So, all markings I can read on your prop fit (I can read only one letter of the aircraft code on your picture "091003_helice_detail_1.jpg", but it is a "S", so it could be a Spad (please, try to read it all: it have to be "Spa"). The only difference is diameter (2m60 vs 2m55): are you sure about your measurement?

Your prop has the airworthiness stamps, so this very one was approved for military use as a "normal" unit. Normally, there are three others on one of the flat sides of the hub, with two numbers. Could you give a look? Perhaps they have been removed when the metal plates were fitted ... And, please, could you tell what is near the stamps (I read "M" on one picture, but I don't read the other for sure).

As the Chauvière decal is under the metal plate, I think those metal plates were not fixed in Chauvière workshop. But the prop number (30001) seems very special and could be a special work the militaries were using at the time they tried to fire guns through airscrew circle (1916 ?). Alternatively, as the prop was for school use, a protection for clumsy shooters?

If you want to sell this prop, let me know: we are trying to make a "prop museum" in Figeac, and the right place for your prop is a museum if my guessing is correct. You can also try to show it at "Les Ailes Anciennes" at Duny near MAE. If you are able to see them, I am sure they will be interested.

And, please, resist the desire to restore it ! See http://woodenpropeller.com/forumvB/showthread.php?t=674

Best regards,
PM

[Philiprop]

Bonsoir "pmdec",

I am very impressed !!!!

Thank you very much for all those informations !

I placed better pictures online but unfortunately there is no other marking than those shown.

I apologize for my quick measurement. You are right the diameter is exactly 2.55 m !

This propeller is for sale, but I am not sure that any museum can consider the price asked by the owner as reasonable ...

Best Regards,

Philippe