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Old 11-03-2019, 05:15 AM   #11
Bob Gardner
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Greetings Skyraider,

The serial number 45145 dates from the late 1920's. The serial number 50,000 occurred during 1930.

I'll do some more research after I have had breakfast.

With kind regards,

Bob
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Old 11-03-2019, 02:21 PM   #12
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Skyraider,

I can't offer any new definitive answers for you but here are a few observations to give an overview of Heine props and the Fok.DVII, for you in particular, and for fellow forumites in general. These observations refer to known serial numbers of Heine props, but apply widely to props made by other makers as well.

Firstly, the good news for present day researchers is that several German propeller makers in WW1 made their props with a characteristic shape which prevailed for a few of the four years of WW1. They changed in size at first, as engine power outputs increased but usually not in shape. This allows an almost certainly correct identification of a maker, even on poor and aged WW1 photographs. Heine, Axial, and Wolff are makers which spring immediately to mind and there are several others. After WW1, increasing power outputs, which sometimes could be exponential, and increasing engine speeds, led to prop designs converging.

Dating or referencing props from WW1 by serial number is scarcely possible and even the assumption that props were fitted to aircraft sequentially from a batch is wrong. Prop makers may not have numbered their prop batches sequentially. Even if they did, they may not have been fitted to aircraft sequentially. For example one batch might have been delivered immediately, whilst others from the batch may have been stored (with the maker, or in a depot) and delivered and fitted later.

In addition, because pilots faced a short life expectancy, they were therefore superstitious, and so, often, had their mechanics fit several props to their aircraft to find the best; to find an extra few rpm, an extra few knots of airspeed. This appears to have been widespread because the Idflieg Propeller Handbook of 1916 produced by the Propeller Office of the Test Institute and Workshops of the Flying Troops (Propellermerkbuch der Luftschrauben-Abteilung der Prudenstalt und Werft der Fliegentruppen) specifically points out that all airscrews are of equal merit. There is (it states) no point in a unit ordering the propellers of a certain maker, nor in trying out several propellers from one batch.

I have recorded two Heine props made for the early Fok DVII using the Mercedes 160ps engine with serial numbers of 35268 and 33035. These numbers are concurrent with the serial numbers of props made for the slightly later Mercedes 185ps powered Fokker DVII (32345, 34361, 35141, 35426, and 35441).

With kind regards,

Bob
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Old 11-04-2019, 07:05 AM   #13
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Hi Bob,

Thanks very much for your time and comments! So my prop is not quite as old as I thought, but still an interesting historical piece. I hope to have confirmation of the origin soon.

Cheers,

Ronnie

PS. You said "Mercedes 185ps" but you mean BMW I assume (D.VIIF)? The Van Berkels were equipped with a BMW IV opposed to the BMW D.IIIa of the D.VIIF, but power output was similar.
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Old 11-04-2019, 12:46 PM   #14
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Hello Ronnie; that sounds so much better than Skyraider !

I was keeping it simple, only referring to Mercedes engined Fok.DVII aircraft.
For the record, I have recorded 42 Mercedes-engined props made for the Fok.DVII by nine different makers.
Wotan x 8
Wolff x 6
Heine x 14
Becker x 1
Bechstein x 1
Axial x 7
Astra x 1
Anker x 1
nk x 3


These 42 Mercedes engines have six different hp.
160ps x 30
180ps x 6
185ps x 4
178ps x 1
220ps x 1

The majority of these props come from the records of German aircraft shot down or forced down behind British lines on the Western Front which are now held by the British National Archives in Kew. The records are comprehensive and include time and location of the crash, the aircraft type and construction number, the engine type and its serial number, the number of laminations in the prop and the types of wood used and the maker.

Several records are from a number of British, French and German museums and a few from fellow forumites who have contacted me.

I only have eight records of BMW engined Fok.DVII, four of which had 185ps and four of 200ps.

With kind regards,

Bob
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Old 11-05-2019, 06:03 AM   #15
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Thanks for the update Bob!

Speaking of updates, I've talked to the seller of the second post-war Heine prop and his hub says "Model B No.52" on the reverse. So his prop and mine are most definitely of the same batch, if that wasn't crystal clear already. That makes it all the more intriguing to find the origin. There were Van Berkel WAs with serials W51 and W52, but I am not sure if aircraft serials were ever stamped into propeller hubs.
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Old 11-05-2019, 11:37 AM   #16
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Ronnie,

Good luck with your research and keep us updated on any progress.

Some random musings about my prop database above, not to be taken too seriously.

1. I know it is nowhere large enough to show a true picture, but the ratio of Mercedes engined D.VII aircraft to the BMW engined ones might give a hint of the relative distributions of these engines.

2. The data also shows that Mercedes produced engines of equal power to those of BMW, but in few numbers.

3. The humorous thought occurs that given the source of this data (shot down aircraft) it might also indicate that the Mercedes engined D.VII aircraft were easier to shoot down!

To be serious, does anyone know of a definitive book on the Fokker D.VII ?

With kind regards,

Bob
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Old 11-07-2019, 09:07 AM   #17
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@ nr.3!

The Windsock "Fokker D.VII Anthology" trilogy is probably the closest to a definite book on the D.VII in WW1. Of course there is so much more to the D.VII post-war and I don't think I ever saw this covered decently. Some years ago a Dutch book was released on Dutch military D.VIIs, so that's something at least. But no, not seen any truly definitive D.VII books.
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Old 11-08-2019, 08:38 AM   #18
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Many thanks Ronnie.

I'll see if I can buy Windsock "Fokker D.VII Anthology" trilogy from Amazon.

On a different note, I live in Yorkshire in the North of England. Our house is cut off by floods caused by what the Met Office called Rain of Biblical Proportions. There are sixty red flood warnings, where 'red' indicates danger to life. We live on a slight hill and are in no danger but all road, motorway and rail links around us for thirty miles are flooded and shut.

This makes a change from watching on TV the awful and endless footage of California fire storms! Climate change is going to be exciting!

For Rhett only, I expect the floods might have gone down by 17 November when you are coming to see us, but we'll need to check the met before-hand. I have strapped the two props I bought for you to four empty oil barrels, for use in the last resort!

With kind regards,

Bob
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Old 11-08-2019, 10:42 AM   #19
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O wow, good luck there Bob! That sounds exciting, but not the right kind of exciting...

Although I guess this isn't really the place to discuss climate change, the news is full of bizarre weather. Australia is on fire again as well. Here in Holland we had a record heatwave in 2018 (essentially 3 months almost uninterrupted, while normally after 3 days of sunshine we usually speak of a good summer ) and this year the 75-year old heat record was smashed by a massive 2.1C (40.7C). The future could be interesting... Keep your props safe!

If you have trouble finding the D.VII Anthology, these guys in France might still have them. They advertise them in their 2019 catalogue, although their website doesn't have it any more so they may have sold out meanwhile.
https://www.aircraft-navalship.com/
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Old 11-09-2019, 05:18 PM   #20
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Quote:
Originally Posted by Bob Gardner View Post
Many thanks Ronnie.

I'll see if I can buy Windsock "Fokker D.VII Anthology" trilogy from Amazon.

On a different note, I live in Yorkshire in the North of England. Our house is cut off by floods caused by what the Met Office called Rain of Biblical Proportions. There are sixty red flood warnings, where 'red' indicates danger to life. We live on a slight hill and are in no danger but all road, motorway and rail links around us for thirty miles are flooded and shut.

This makes a change from watching on TV the awful and endless footage of California fire storms! Climate change is going to be exciting!

For Rhett only, I expect the floods might have gone down by 17 November when you are coming to see us, but we'll need to check the met before-hand. I have strapped the two props I bought for you to four empty oil barrels, for use in the last resort!

With kind regards,

Bob
Bob, I may have that publication at home, and if so you are welcome to it. I bought it when I owned two D VII propellers but since I've disposed of them I don't really need it.

I'll check early next week. It's really nice that you've been able to help Rhett out with his endeavors. I'm envious of his ability to travel so easily around the world.
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