Help please with Ebora No. 312

[AleBeHonest]

Hi,

I have just inherited a 4 blade wooden propeller made by the Ebora Propeller Company. I have added photos of the propeller as a whole as well as the hub in detail.

I can make the following out from the hub

Ebora Propeller Company No 312
AD 187
LH
135 CU

All I know of the propeller was that it ended up in a factory built in the 1960s by my great-grandfather on the Kent / Sussex border in South East England. The exact reason of how it became to be stored at the factory is unclear, as the site was previously a pig farm before the factory was built.

All I've been able to find so far is that the Ebora Propeller Company were formed in 1917 in Surbiton and I'm assuming the LH means Left Hand, but I'm not sure what this would refer to.

I look forward to mounting it and have no intention to sell it, but I would appreciate some guidance as to what something like this should be insured for.

[Bob Gardner]

Greetings and welcome to the forum.

Congratulations on finding this prop. It's the first four-bladed Ebora prop I have seen, although the company made several different such props.

The Ebora company was founded in 1912 or 1913 by Jan Schiere, a Dutchman who first worked in the prop shop of Handley Page. In researching WW1 props for my books on the subject I met his son and grandson, who live near Arnhem in the Netherlands and who gave me access to his archives which include copies of around 200 of his plans. My account of Ebora amounts to 45 pages in the second of the five parts of the series.

Could you measure the diameter of the prop from tip to tip, please. Could you take photos of all the data in close-ups. Ebora usually covered their prop hubs with data but it seems to be rather scarce on yours. In your photos, please make sure that the prop is well lit, and your shots are in focus.

May I tell Jan Schiere's grandson about the prop? If you would like it to go back to the family who made it, I think he might well wish to buy it from you.

With kind regards,

Bob

[Dave]

Are there decals on the back of the blades? The left hand rotation at least suggests a pusher configuration, and often with that application the decals were placed on the rear of the blade, where they were more visible.

See this Ebora SPAD propeller that I acquired from Bob years ago for comparison.

[AleBeHonest]

Extra details for you

Thank you for your responses so far. I'm surprised that you haven't seen one of these before, having gathered how much research you have done around this subject. So I'm happy to give you any details you would like to help your research and build the e-museum.

I have taken some more photos this evening, but this is still relying on artificial light, but I hope the results are a little better for you.

What you may be able to see this time round, is that at the 12 o'clock position, almost merging into the bolt hole, there appears to be the number 312 or possibly 342 inscribed upside down. In each of the four corners in a small circle are the letters ADP.

I have taken more detailed pictures of each four corners of the hub, which I could email to you in full size should you wish.

Tip to tip the prop measures 2600mm (102 1/2"). The hub hole 3" circumference and each bolt hole is 1" from the centre of one bolt hole to the centre of the opposite bolt hole is 5.5" and across the hub the prop is 5.5" in depth.

Please feel free to tell Mr Schiere about this propeller, however having only recently taken the prop is as the only person who could find somewhere to display it, I am not looking to sell.

I have also taken a picture of the rear of the hub, where the only inscription appears to be the numbers 1, 2, 3 and 4 going around clockwise.

I have also tried to capture the Ebora decal, though with the poor light I don't feel I have caught this at its best.

Thanks for your interest.

[AleBeHonest]

All decals are on the front. As described above, the only detail on the rear are the numbers 1-4 on the hub.

[AleBeHonest]

One more thing

I had a carpenter come and have a look at it today, with a view of having a wall mount made for it based on your suggestion in the "Storage" part of the site and he was concerned that it would need something stronger than wood to take the full weight of the four bladed propeller off a single wall mounted hub.

Do you have any other suggestions for this?

Thanks

[Dave]

The doweled mounting arrangement will hold an incredible amount of weight, since it is almost all distributed in shear rather than bending or tension. You can use eight dowels and the shear strength is equal to the sum of all 8 circumferences. Using the small split and expansion screw on the upper 2 dowels keeps the hub tight against the hub and prevents bending forces on any of the dowels.

It's extremely effective. I think you'll also be surprised how little the prop weighs if you put it on a scale.

That's a very nice propeller, and I'm happy to see the Ebora decals in place, even if they don't stand out. Be sure not to try to "restore" it in any way!

[Bob Gardner]

Good Morning,

I have identified your prop which is from a British naval sea plane, the Short 830, a variant of the Short 827, which used 200 hp engines, whereas the Short 830 used Salmson or Canton-Unné engines of 135-140hp. It was a recce aircraft with a small bombing capacity. It was introduced in 1914 and remained in service until 1918. Its maximum speed was less than 70mph and it took ten minutes to climb to 2000ft. But it had an endurance of more than three hours which enabled it to be a satisfactory spotter for naval gunfire and a recce aircraft. I believe the total number of Short 830's made was 19.

The data on your prop is atypical and took a little unravelling.

Ebora Propeller Company No 312 Ebora's serial number of the prop.
AD 187 This is the Short Bros drawing number for the prop, always written as S187. Here, the Ebora Co. has used AD to indicate that the prop was made for the Air Department of the Admiralty. I haven't seen this concoction before. It is confusing because it suggests it is an Admiralty drg no, although they begin around AD500.
LH Rotation of the engine.
135 CU 135hp Canton-Unné rotary engine.
ADP Passed as airworthy by the Air Dept of the Admiralty.


The diameter of 2600mm is listed as 8ft 7ins in the table of Ebora drawing nos. where your prop is listed as an Ebora type 41.

The brass sheathing at the blade tips is another indication of a naval sea plane. It protects the blade from sea water and FOD thrown up by the prop wash.

I don't think I shall mention the prop to Jan Schiere. It would be a tad unkind to tell him about this wonderful prop and add that it is not for sale. Incidentally, if offered for sale in the UK at auction it would make around £2000 GBP, about $3200 USD.

With kind regards,

Bob

[AleBeHonest]

Thanks

Bob,

That's amazing to get that much detailed information, it really is much appreciated.

Having weighed it, I make it 24kg (53lbs). I will try and get this mounted and hopefully be able to share a mounted picture before too long.

Thanks again,

Martin

[Bob Gardner]

Delighted to be able to help Martin.

With kind regards,

Bob

[AleBeHonest]

Propeller now mounted

Hi,

As hoped for, I am now back to share with you the propeller as I was able to mount it last week.

In the end I had a carpenter recommended to me who served his national service in the 1950s working with aeroplanes in South Wales, having grown up in the medway towns of Kent watching planes being tested at Rochester, so he was quite thrilled to work with a piece that may have flown on a Short's plane made in Rochester.

You'll see from the picture that he did deviate from the suggested design in taking the weight through the hub, as opposed to the bolt holes and only two dowels have been attached to the mount through the bolt holes to stop rotation. Despite being near 80, the carpenter was happy to demonstrate that once on the wall, the mount could take all of his 13 stone, meaning that the 25kg of propeller wouldn't be a problem.

The one thing I still feel I am missing, is I haven't been able to find any pictures of the Short 830 with a four blade prop to indicate how it may have looked in action.

Does anyone know where I might be able to find one?

Many thanks

[Ebora]

Dear Martin,

Youre propellor is made by my grandfather. If you change youre mind in selling this propellor I am very, very interested. Not only because it is family historie, but also because my company is named Ebora. For more details see the historie part on my company website http://www.ebora.nl/histoire.

If possible I would like to recieve a picture of the whole propellor to add to our website.

[AleBeHonest]

Hi, recently my Dad has been able to find from various ancestry sources that the propeller may have had much more of a family link than any of us knew about. Can you recommend what sources to next try to see if we can get a better picture of where the small number of planes this propeller may have flown from and see if may have been a great grandfather of mine flying it?

I see there is now Cyber Display gallery. Would you like me to try to get some better quality photos of the propeller for this?

Thanks,

Martin

[Dbahnson]

I see there is now Cyber Display gallery. Would you like me to try to get some better quality photos of the propeller for this?

Thanks,

Martin

Do you have a link to the cyber display gallery? I might be able to help.

[AleBeHonest]

Dbahnson This was something I saw on the woodenpropeller homepage and wondered how it worked and whether you were wanting better quality images for putting in a gallery. The propeller hangs in a much easier position to take pictures of now (though currently adorned with tinsel) so please let me know if you'd like more pictures.