Please help me identify this

[MrJ]

Hi there,
I’ve been helping my other half sort out her uncle’s things and we found this wooden propeller amongst some old aircraft gauges, plans and parts.
We know he liked his antiques and was rebuilding a Gypsy Moth however this is clearly a decorative item and was probably hung on a wall at some time.
It’s 2.4m long and a transfer on each blade which reads The General Aeronautical Co Ltd, License “Regy”
On one side of the hub it is embossed with D2400 P1350, on the other is Type A4 No 7.
Other than that nothing else is known.

Any help would be great!
Thanks

[pmdec]

Hi,

The prop was made under French R?gy maker license and it has the shape of R?gy props have until the mid 20's.There is no R?gy prop of these size and pitch for the period around WW1 and I don't know when GAC was making props. R?gy does exist from 1909 to the WW2, so it is not a limiting factor. Measures of the hub could help, with a non deformed pic of it.

Regards,
PM

EDIT: I don't know why direct typing of e acute is converted in ?

EDIT 2: From Bob Gardner book "British Propeller Makers of WW1: Part 3" pages 16 and 17, this prop if from the beginning of WW1, say between 1914 and 1917.

[MrJ]

Hi PM,

Thank you for your help so far. I have found on aviation ancestry a similar advert from 1915 that matches the transfers on the prop which matches your thoughts.

I’ve attached a picture of the hub. It has an overall diameter of 17cm and the centre hole is approx 5cm.

Hope that helps.

[Dbahnson]

Thanks for the input Pi?rre-Mich?l, even though my keyboard can do "Pierre-Michel". I have no idea why that happens on yours.

[pmdec]

Thanks for the input Pi?rre-Mich?l, even though my keyboard can do "Pierre-Michel". I have no idea why that happens on yours.

Hi Dave,
What is very curious is that the ? appears normally when I type, appears also in the preview windows but disappears and is replaced by a ? when I post. The same for others specific French letters ?, ?, ?, and ? (which are on the caps of the French keyboard) and for ? ? ?, ? I have to "make" using ALT + code (or directly by changing keyboard codes). I made screen copies to show what happens .
Regards,
PM
TypingWindow.jpg
PreviewWindow.jpg
TypingWindow.jpg

[pmdec]

Hi PM,

Thank you for your help so far. I have found on aviation ancestry a similar advert from 1915 that matches the transfers on the prop which matches your thoughts.

I’ve attached a picture of the hub. It has an overall diameter of 17cm and the centre hole is approx 5cm.

Hope that helps.

I MrJ,
Thank you for the ad (could I have a larger one at pmdecombeix ---at--- yahoo dot com?) and for the hub pic: I have to make some research in my files to find if I have some more info from the size of the central hole and the diameter of the bolt holes. I think I can find the engine (there are mounting marks, so it is sure the prop was fitted to an engine in the past).
Regards,
PM

[MrJ]

Hi PM,

I found the advert here : https://www.aviationancestry.co.uk/?...=ASC&pageNum=3

There’s three pages of adverts for GAC there and the decals from the propeller were on a couple of pages indicating 1915.
I spotted the marks on the hub which was a relief - I’d have been disappointed and surprised if this was a later copy.
Thank you for your help so far, really looking forward to finding out where it came from especially as my others half’s uncle, who would have known, is no longer with us.

cheers

[pmdec]

Hi PM,

I found the advert here : https://www.aviationancestry.co.uk/?...=ASC&pageNum=3
.../...

Hi MrJ, thank you for the link, it is perfect.

I need some other info about the hub of your prop: can you measure precisely:
- the central hole (I have 4 "standards" for this kind of hub: 46.5, 47, 49 and 50mm, for four different engines)
- the bolt circle (from your pic, if (IF) central hole is 50mm I found 110 or 112 because the pic has not been made exactly perpendicularly)
- the hub thickness.
And I have also to know if the central hole is "tapered" on the other side.

Regards,
PM

[MrJ]

Hi PM,

I’m limited at the moment to a tape measure, borrowing a vernier gauge tomorrow hopefully for precise measurements.

I’d say the central hole is 50mm however it’s impossible to be sure due to wear. The vernier gauge will sort that!
Bolt circle is difficult, more like 112, not 110.
Thickness looks to be 100mm.
The hole is slightly tapered on the other side, see picture below. Although the taper is limited to the first 5mm.

I’ll do some more precise measurements when I get the vernier gauge.

Cheers,
Brian

[pmdec]

Hi Brian,

Normally, a tape measure is enough. Look at those pics:
papTrou.jpgmesure2b.jpg
(from the French page http://www.ratier.org/identification/identnew_.html ).


The fact that the central hole is tapered on the rear side of the prop tells that the prop is a tractor. It comes from the way the metallic hubs are made:
moyeu10.jpg

Regards,
PM

[MrJ]

Hi PM,
I’ve measured the central hole with manual and digital vernier gauges. Both agreed. The paper method wasn’t working for me unfortunately.
Strangely the hole is actual slightly oval. From left to right (parallel to the blades) it measures 50mm however, from top to bottom (90 degrees from the blades) it’s 49mm.
I measured both sides and got the same readings.

Not sure that helps!

Many thanks,
Brian

[Dbahnson]

Strangely the hole is actual slightly oval. From left to right (parallel to the blades) it measures 50mm however, from top to bottom (90 degrees from the blades) it’s 49mm.
I measured both sides and got the same readings.

It's not strange. Wood expands and contracts with changes in moisture, but the change occurs primarily perpendicular to the wood grain. So typically the size along its long axis would be more constant that the size across its perpendicular axis.

[MrJ]

Ok so I guess it’s 50mm in that case. Does that help PM?
thanks

[pmdec]

Hi,

Sorry for the long silence... I have not found any useful in my props data to make a definitive answer. I thought I could give you some direction at least for the engine, but even this I can't.
On French props, 46.5 and 49 mm central bore would have "spoken" for an Anzani engine, but 50mm, no.

I suspect that your "50 mm" could possibly be a "shrunk 50.8", that is 2 inches and thus probably an English made metallic hub.
The other explanation could be that the central hole was ovalized by an imbalance. Look at the mounting marks: They are more visible on the blade sides of the hub, as if the prop has been "pushed" rear and back by the blades, which would have also enlarge the central hole the same way. In this case, the metallic hub could have been for an Anzani or for an engine for which I don't know the dimensions of the metallic hub.

Sorry for not be able to give you some better advice!
Regards,
PM

[MrJ]

Ok so I get that it could be enlarged. That would make sense. Especially as the hole is wider on a plane, you can imagine the force from the blades wearing the hole.

Given that, what were the aircraft fitted with an Anzani engine?

Regards,
Brian