Integral Propeller Co Limited

[wingnutchamp]

Can anyone help me with a propeller I have, the story I have is that it was at Guy Motors Service Department workshop in Wolverhampton where my Dad worked. During a clean up it was going to be thrown away. It was covered with thick black grease but my Dad brought it home. It is 122.5 inches long and has a 8.5 inch hub. attached is some photos. The story dad said was that is was at Guys to test aero engines during WW1? There are markings on the side of the hub, which I think are:
I. P. C.
DC 2338
HP 300 GI
i A F 1A
LE
B 19556

Any help identifying this propeller would be much appreciated, David

[Dbahnson]

I can't find an "IPC 2338" drawing number in the list I have, although there are numbers surrounding that (IPC2303, IPC2330, IPC2360). None of those other numbers seem to be consistent with a prop of that length, and I presume made for a 300 HP engine from the stampings on it.

Yours also appears to be a left hand thread, which might indicate a pusher configuration, but one would have to know the engine rotation to establish that.

I think these drawing numbers that show up and aren't on published lists often do mean that it was an experimental propeller of some sort, and I'm guessing that it is WW1 era.

[wingnutchamp]

Thank you for your information, I think you are right it is an experimental propeller.

I have also found information that Guy Motors during the later stages of WW1 were testing a 9 cylinder ABC engine called the Dragonfly. The engine had resonance issues so was abandoned, but they did make a series 1 and a 1A which may be the marking 1A, this was around 1917/1918.

This may be why the propeller was left at Guys. Here is a photo of the engine on the engine stand with various Guy Motors staff and others.

[Bob Gardner]

Greetings David,

I can't pin your prop down to a specific aircraft either, nor can I find the drg no. IPC2338.

Many large bombers were made by Britain and France towards the end of WW1. Examples are the Handley Page V/1500 with Rolls Royce 350hp engines, and the Vickers Vimy powered by the FIAT and Rolls-Royce engines of 300 hp. These began to be made in large numbers late in 1918 to equip the British Independent Air Force with which it was intended to bomb the industrial centres of Germany, but this never came to pass because of the end of hostilities in November 1918. Your prop is marked IAF which might well refer to the Independent Air Force.

Your prop was made by the British subsidiary of the French Integrale Co, known in Britain as the Integral Co.

Bear in mind that this answer is not a well-researched accurate answer but is based on the coincidence of 300hp engines and IAF stamped on your prop which provide the possibilty that your prop was made for a British bomber with a 300hp FIAT or Rolls-Royce engine such as the Vickers Vimy intended to bomb the Industrial areas of Germany in late 1918 and 1919.

Perhaps our French comrade Monsieur Decombeix will find IPC2338 in his French data.

With kind regards,

Bob

[pmdec]

Hi,

Monsieur Decombeix, there...

Infortunatly, Chauvière (aka Hélice Intégrale, Integral Propeller in English) numbers on props made by IPC (Integral Propeller Company) have nothing to do with Hélice Intégrale ones in France : in France the serial 2338 would be 2.60 meters long (102) but none with this serial number appear to be approved.

Your prop seems to be a pusher because the decals on the flat side of the blades.
The marking "LE" is perhaps LH, for Left Handed. Could you post a clear and large pic of the markings?

Regards,
PM

[wingnutchamp]

Thank you all for the information, here is a photo of the side hub markings.

David

[pmdec]

Perhaps the markings are:
I.P.C.
DC 2338
H.P. 300. GUY.
R. A. F. 1A.
L.H.T.
B. 19556.

Where "HP" could be for Handley Page and RAF 1A for the engine. The "good" thing is that the RAF 1A was geared and using a left handed prop, but the bad thing is I can't find a model of Handley Page which could use the 300 GUY. marking... And another bad thing is the decal at the "rear" of the prop, like on the pushers.
So, perhaps, this post is total crap!!!

Anyway, a very fine prop which seems in original state!

Regards,
PM

[Bob Gardner]

Pierre mon ami,

I think the term to describe our efforts so far is merde!

The RAF 1a engine of 1914 was a British improvement on the French Renault engine of 70 or 80hp and generated 90hp, not HP300. Perhaps this refers to a Handley Page 300? I shall google it. Afternote; it doesn't exist.

To summarise;

The drg no 2338 does not exist in the British and French records.
The RAF 1A aero-engine dates from 1914, and was obsolete long before the Vickers Vimy flew in 1918 with a 300hp engine, probably made by Rolls Royce.
HP300 does not refer to a Handley Page aircraft.

So, the markings on the prop appear to be spurious? And we are defeated!

With kind regards,

Bob

[pmdec]

Hi,
Is it really possible to use a prop with a hub showing a central hole of ~2.5" and a bolts circle of ~5.5" on a 300 HP engine? From the 8 laminations visible, the hub thickness is probably 6 to 6.5", and this a very smal hub for such a power.

About the markings under RAF IA, I am not sure if it had to be read LHT (Left Hand Tractor) or LHP (Left Hand Pusher).

Regards,
PM

[Bob Gardner]

I agree Pierre-Michel,

This prop has the dimensions and size of a prop made for the RAF 1A engine of 90hp.

A quick canter through Lamberton & Cheesman shows that only three major aircraft, the FK3, BE2C and Avro 504K, used the RAF1A engine. Some FK3s were built by Handley Page! This at last provides a connection between the letters HP and the RAF 1A engine.

With kind regards,

Bob

[pmdec]

.../... This prop has the dimensions and size of a prop made for the RAF 1A engine of 90hp. .../...

Hi,

If the markings of the line "RAF IA" is the engine, what could be the line above?

It seems there is no Handley Page "300". Returning to what wingnutchamp said, the 3 last letters could be GUY simply because the prop was made for GUY Factory! And "HP 300" some internal reference of this factory.
It seems compatible with https://en.wikipedia.org/wiki/Guy_Motors
Just my two cents... And, for once, the story come with the prop, a true one!

Regards,
PM

[wingnutchamp]

Thank you all for the information, it seems to be a bit of an anomaly?

My father told me he got it from Guy Motors when he was working there in the early 60s and he understood it had been used to test aero engines Guys were building during WW1.

According to the history of Guy Motors they were building ABC Wasp and Dragonfly radial engines. The Wasp was a 7 cylinder 160hp with the mark 1, and 190 hp with mark 2. The Dragonfly was a 9 cylinder and was supposed to produce 340 hp but accord to Wikipedia it didn't achieve this target and suffered from torsional resonance of the crankshaft so was very unreliable.

The Dragonfly was made as a mark 1 and an updated engine called the 1A. Could this 1A may be the marking on the hub? The 1A was built at the end of WW1 in June of 1918 so with the end of the war and the poor reliability of the Dragonfly engine was discontinued. Could this be why the propeller has no record as it was only for testing purposes and was left in the engineering workshop when the project died?

Do you know what the approximate value of it is for insurance purposes?

Thank you David

[Bob Gardner]

David,

I think we have now uncovered all the possible details and history of your prop.
Incidentally, this prop was not used for testing engines. It is too fragile for constant changes from engine to engine. A purpose built air brake prop is used. It is of substantial construction and small diameter with large metal plates set at right angles to the direction of rotation, which places a considerable load on the engine under test. This allows each engine tested to be calibrated and faulty engines to be identified.

With kind regards,

Bob

[Bob Gardner]

Oh! I forgot that you asked about value. If offered for sale at auction, with its known history, as a BE2C propeller, it is likely to sell for £1500-£2000 GBP. Note that after several deductions by the auctioneer for fees and professional advice, you would probably receive about £12-1400.

I'll send you a bill for my consultancy fees!

With kind regards,

Bob

[wingnutchamp]

Thank you so much Bob, it is a beautiful made propeller and must have been at Guy Motors for some other reason than testing.

We will keep in the family as a bit of my Dads history.

Thank you again and Pierre-Michel for your knowledge and time, the check is in the mail!!

All the best, David