Propeller ID

[Lilly6]

Hi
We have been given this propeller & would love to know more about it thanks.
Have supplied some photos so hopefully someone will know when & where it was built etc.
We would like to sell it so if anyone knows the current value that would be great.

It is roughly 8 feet long & does have some damage on the ends.
Thanks in advance for any help
Lil

[Bob Gardner]

Good Afternoon Lilly,

Your prop dates from circa 1912 to 1914 and was made by the British branch of the French Integrale Propeller Company for the French Maurice Farman aircraft. The stamp ADP indicates that it was intended for the British Royal Navy Air Service (It is an airworthiness stamp).

The data translates as:

MF Maurice Farman: the aircraft type.
IPC Integral Propeller Company.
RHT the prop was right-handed for use in a tractor configuration.
D2450 The diameter in mm.
P1750 The pitch in mm, the theoretical distance the prop would pull the aircraft through the air in one rotation.
HP80 The engine power.
Ren the manufacturer of the engine, Renault.
B23390 2 The serial number of the propeller.

With kind regards,

Bob Gardner

[Lilly6]

Wow
Thanks Bob.
Thats great information & appreciate you getting back to me so quickly.

Do you know roughly the value of the propeller?
Thanks again
Lilly

[Bob Gardner]

Lilly,

If you live in GB, polish the prop with bees-wax polish (bought in a tin from B & Q) which will enhance the appearance and protect the wood.

The insurance value of your prop is £2000.00 GBP which is what it would cost you to buy a replacement.

I'm delighted to be able to help you.

With kind regards,

Bob

[Lilly6]

Hi Bob
I will do as you say,I think I have some of that very polish in my cupboard as we do have some lovely wood furniture which I look after with beeswax.

Thanks for all your help on this. I am amazed how easy it is these days to get all this information so easily.

Do you know anything about old oars??111

Kind Regards Lilly

[pmdec]

Hi Lilly,

Would you mind to post a pic of the opposite side of the hub (central part)?

Best regards,
Pierre-Michel

[Lilly6]

Hi
Hope this is what you mean,if not let me know.
Regards Lil

[pmdec]

Hi Lilly,

Yes, it is exactly what I wanted to look at. Normally, the side with the "flared" central hole has to sit against the engine. So I think that this prop is a pusher misstamped RHT in place of RHP (with a P for pusher). It makes it more interesting!

Regards,
PM

[Lilly6]

Hi
in what way does it make it more interesting do you think?
I am enjoying finding out about the propeller as we knew nothing about it al all.

Regards
Lil

[pmdec]

Hi,
All props which are not strictly standard ones are the most interesting: yours has perhaps a mismarking, which is not so strange (Bob had often said the workers who stamped the markings were illiterall...), but your new pics show that the way the laminations are glued is also appealing. Could you post:
- one pic of the whole prop on the same side of the flared central hole,
- and one pic of the side of the hub without marking (to look at the laminations and the way they are pilled up)?

Regards,
PM.

[Lilly6]

Hi
Thanks for your prompt reply. All very interesting

I will have to wait for my husband to come home to take more photos as it is propped up in the hall at the moment & too big for me to handle on my own.

Kind Regards Lil

[Dbahnson]

PM,

I think the 80 HP Renault engine must have been normal right hand rotation. Look at this propeller for the DH1 with with 80 HP Renault. It's a left hand thread used in a pusher configuration, which you know because it was used on the DH1, a pusher.

So whatever MF aircraft her propeller was used on, since the prop is right hand thread it would seem to me that it would have to have been used in a tractor configuration. Does that make sense?

(P.S. I just looked at the DH1 prop, which is in my living room, to confirm that indeed it is left hand thread.)

[pmdec]

Dave,

The propeller for DH1 you linked to is a very very fine piece! Is it the very same that the one which made Vanessa Redgrave hold out her ... arms?

But, IMHO, it is a RHP! The 80HP Renault was a RH engine, but the prop was fitted to a shaft at the end of the camshaft, so the prop has to be LH for a tractor, and RH for a pusher. Your splendid prop is a pusher and it has the same geometry (central hole flared on the forward side of the prop) as the one of Lilly6.
Your prop as a faint DG 69 marking which is listed on page 111 of the Bob's book part 3. Five lines below, there is the Lilly6's DG 76.

BTW, the size and pitch of this DG 76 is strange: all the serial I know for Farman using a 80HP Renault are long (2800 to 2950 mm) and have a very high pitch (2300 to 2650 mm) because they are geared x 0.5. But the serial 76 is only 2450 long and has a pitch of only 1750mm. If it was used with the same engine, the plane could not fly with such a prop! Perhaps for "penguin*" used in schools? But how avoid engine too high rev?

Regards,
PM

*For example, see https://www.cradleofaviation.org/his...e_penguin.html

[Dbahnson]

Dave,

The propeller for DH1 you linked to is a very very fine piece! Is it the very same that the one which made Vanessa Redgrave hold out her ... arms?

It's identical to the propeller seen in Blow Up with Vanessa Redgrave, but it's not the exact same propeller. I looked very closely at the movie and determined that they were slightly different. If you look closely right above Vanessa's arms you'll see a notch in the blade. Mine doesn't have that.

That movie was partly responsible for my interest in collecting propellers.

Are you saying that the Renault 80 had exposed shafts at both ends that could accommodate a propeller?



P.S. Hey! I just noticed on the prop held by Vanessa Redgrave that it is a right hand pitch, not a left hand pitch like mine. Now I'm confused. I thought it was identical - until just now.

[pmdec]

Hi Dave,

.../... Hey! I just noticed on the prop held by Vanessa Redgrave that it is a right hand pitch, not a left hand pitch like mine. Now I'm confused. I thought it was identical - until just now.

But they ARE identical. Why do you say yours is a left hand? It is exactly the same as the one in Blow Up, a right hand pitch: When you look from the rear of the plane, as it has to be done, the prop turns same way as a clock hands.

Regards,
PM