Information regarding US propeller

[Gelica]

Hi... Just wondering if anyone can help with identifying this propeller blade?
As you can see from the pictures, there's a fair amount of information stamped onto it.
I am told that it is a blade from an airship but would like this confirming, if at all possible.
It has CAMFIELD , US & anchor stamped into the base
There are a couple of stickers on the blade, placed by the previous owner, which read: 1st war airship blade American & Camfield US - other than this I have struggled to identify... so any help/ information would be very much appreciated.

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[Dave]

Can't answer, but I will say that what was written on it seems implausible. All of the airship propellers I've seen have been two blade fixed pitch wooden propellers, some as large as 20 feet or more in diameter. I don't see the need to employ a variable pitch propeller on an airship in the first place, and I think variable pitch props were not usefully employed until well after the "1st war". Also, I think but don't know for sure that the microlamination of wood seen there was also a later development.


I've seen all kinds of stickers and notations on propellers that do nothing more than perpetuate totally false information that inflates the value for the owner.

The U.S. and anchor stamped on the blade does suggest that it may have originated in the teens or twenties, however. I'm sure a good bit more research is needed to answer your question.

[Gelica]

Thanks, Dave
I really appreciate your quick response.
I actually found an article on Compregwood this evening (http://www.notplanejane.com/camfield.htm) and exactly as you have advised it seems to be a material that was used in the 40's- due to a lack of aluminium during the war- so that would date it much later than originally thought.
We inherited this from my Uncle, and the stickers were in place when my Uncle acquired it.... so I think it may be as you suggest- a previous owner's attempt at inflation of it's age/ value. Any hints as to how I can find out a little more about it's history?
Thanks again

[Dave]

All I could suggest is to contact Monte Chase at that notplanejane website. Variable pitch props are his field of expertise. I know very little about them.

[Gelica]

Thanks... I'll send him an email.

[Dave]

I don't think this is Compregwood, although I could be wrong. It looks more like microlaminated plywood.

[Bob Gardner]

It looks very similar to British WW2 adjustable props. The Hordern-Richmond Co was one company that made them, using the Hydulignum process of compressing wood laminations, often birch, in a bath of thermo-setting resin.

Airships and dirigibles had no need for conventional adjustable pitch, from fine to coarse pitch etc but they needed a reverse when approaching a mooring tower, to stop forward movement of the craft. This was invented by Chauviere around 1913 and first used around 1915, I think. These were called adjustable pitch props for at least a decade, although reversible pitch propellers would have been an easier name for researchers a century later!

With kind regards,

Bob

[pmdec]

Hi Bob,

Happy to see you back from Manila

We have a 1938 Ratier variable pitch prop with blades made in Permali. See: http://www.permalideho.co.uk/permali.asp which seems to be a German process.
There is also Röchling which makes similar compressed wood using chimical process.
All seems to be from the late 30's.

Micarta is another process: it is used from the 10's, but does not use wood: http://en.wikipedia.org/wiki/Micarta . Some German blades seem made with this process during WW2: paper based and covered with metal mesh and painted. In this case I do think it could be named wood Ersatz!

Regards,
PM

The Ratier prop is 3,10 meters long and was designed for D-520. The pitch variation system was "hollow" to fit a gun firing in the axis of the prop.

[Bob Gardner]

Thanks PM!

I knew of ersatz coffee that was made of roasted acorns, but not ersatz wood. Mind you the Germans also had ersatz dope (the stuff that goes on fabric) in 1918 made out of potatoes (cellulose).

With kind regards,

Bob

[Dave]

And Bob, I second the welcome back from Manila.

Did you ever get the money I sent you via Western Union?