Chauviere Metal Prop

[Mooseflyer]

I know this might be "blasphemy" to many, but my French brother-in-law gave me his father's metal two-blade Chauviere prop. I really would like to learn more about it but have exhausted my search on the internet and library. Could anyone be so kind as to point me in a new direction?

If there happens to be someone smart on these:

It has a 1920 stamp on the hub so I assume that's when it was made.
Serial #: S 258 N 150 9
It's approx 76" in diameter.

Thanks for any help and sorry to "pollute" the wooden prop forum!

Mike

[Mooseflyer]

No love for the metal prop?

[Dave]

Nice looking piece, but I don't think it's for a certified aircraft.

[Mooseflyer]

Why do you think that?

[Dave]

The hub is not typical of any certificated aircraft installation that I've seen, certainly not in the era usually associated with Chauviere wooden propellers (i.e. WW1 era). I've seen that kind of hub on some windmill propellers, but never on an aircraft. I don't know much about the history of Chauviere after WW1, but maybe pmdec will chime in at some point if he has any information.

It's also hard to tell from the picture, but it looks as if it is a very coarse pitch, which would also be a little unusual for a typical aircraft application.

[Mooseflyer]

Maybe the hub looks goofy because the mounting hardware is still in it. It was purchased after WWII from a French military surplus auction.

[Dave]

Well, even the hardware looks "goofy" compared to typical aircraft hubs, which are generally secured by 8 (sometimes 6, sometimes 10 . . .) radially arranged bolts around the hub itself.

The high pitch and two bolts suggest a low speed application of some kind to me.

[Mooseflyer]

You make good points. Maybe it was a low horsepower prop? Thank you for taking the time to help. Have a great weekend!

[pmdec]

Hi,
Very interesting thing, indeed!
Could you post large pics of all the markings? Also of the decals (some small details may give a datation). Or sent send the pics by mail to pmdecombeix at yahoo dot com (written like this to evade robots...)?
Regards,
PM

[Dave]

Notice also that it's a left hand thread. Not sure if that means anything in this particular situation. Hopefully with a few pictures Pierre-Michel will know something about it.

I must say, it's an elegant and graceful looking "thing".

[pmdec]

Hi,

If Dave did have seen the black intrados (3rd pic), he would have guessed it was a "true" prop ...

Mike sent me some more pics and there are what I think to be airworthy stamps on it. The pics are to small to read them and find a precise date, but Chauvière made this kind of prop between (at least) 1928 and 1936.
Mike promised to sent larger pics and close-ups of the stamps by the end of November. So, be patient!
I also will try to find a patent, but for now Espacenet (the european site for patents) is down...

The fact the prop is black painted on intrados tell us it was for a single engine a/c, but it was pretty sure just with the prop diameter: probably for an engine between 100 and 150HP.


The text of the 1st pic is from a 1928 L'Aérophile (an aviation magazine) and is about forged (or wrought?) Duralumin propeller made by Chauvière, with a very special hub in relation with differential dilatation of iron (engine shaft and internal part of the hub) and Duralumin.
The ad on the 2nd pic is from 1936.

PM

[Dave]

Interesting, PM. I'm not too familiar with these newer model props, and I didn't realize that Chauviere was still in business in the 20s and 30s.

But what about the coarse pitch? It seems to me that it would require an engine that obtained high power at a low rpm.

[pmdec]

Hi,

Coarse pitch is effectively a question. I will try to find picture of a/c fitted with this kind of propeller.

About Chauvière, their history is quite complicated. And difficult to find from props, because, at least until the mid twenties, serial number is not time dependent and there are two prop number systems, one for props made in Paris, the other for props made in Lyon.

In the twenties, the prop numbers are incremented Paris factory ones, but there are also Chauvière-Farman props (with a specific decal), with prop number in the same numerotation system that "pure" Chauvière.

After that (or at the same time?), they begin a new serial (or type) number (5xxx), which seems to be incremental. But they begin a new numbering in the thirties for metal props which seems to have "their own life"...
They made variable pitch props, with, for example, one type which was successfuly used on MS-406 (the 3-bladed type 351), in competition with Ratier.

Between 1941 and 1943 (at least), they merged with Olaer (landing gears), then with Berger (electric starters) in CGE (Compagnie Générale pour l'Équipement aéronautique). There are Chauvière wooden props with this specific decal.

But in 1945, one can find again "pure" wooden Chauvière propellers (with the "old" decal, excepted lettering has some very minor differences) and there are still in the wooden props making in 1947 (I have a serial 6003 n°1222 dated july 1947).

After that, or even between 193x and 194x, one can find Chauvière decals and serial number on props made by Merville perhaps under licence: I don't know because it appears that no archives have survived, but some props do exist.

PM

[Mooseflyer]

Finally got home and sent pmdec some better pics of the prop. It weighed in at 40.4lbs so I'm thinking the engine might have to crank out a bit more hp...

[pmdec]

Hi,

Finally, got a pic of such a prop on a Potez 53:


Same shape, same hub, same orientation of the decals but they are not in the same place (farther from the hub).

The fact that Potez-53 were racer made for Coupe Deutsch could explain the coarse pitch remarked by Dave. The take-off had to ask for some long field!

Regards,
PM

EDIT: OUPS! If the pic I found is not flipped, it is of a right handed prop vs left handed for the prop of this thread... So, same kind of prop, but not for the same engine. Some racers of this era had left rotating Renault engine, for example the Caudron: