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Old 01-19-2018, 09:50 AM   #5
Bob Gardner
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Join Date: Jan 2006
Location: The North of England
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This is an exciting find!

The pattern of bolt holes is typical of a Rupp fastener, devised by Albert Rupp circa 1916. He was Swiss but conducted his business in Germany until 1919 when he returned to Switzerland. He may have got the idea from Lucien Chauvière via the Imperial Propeller Works which prior to the outbreak of war in 1914 existed as the German subsidiary of the French Integrale Company.

The device was a quick release fastener. The propeller was fastened to the crankshaft by a central nut. The four holes are actually blind conical holes for locating studs. There is no requirement for a central hole for the crankshaft to slide onto. It was also made in a three-locating-hole format for lower powered engines.

Hermann Goring, when commanding the Richthofen Jasta in 1918, saw its potential for quickly replacing a damaged prop on a returning fighter. It was fitted to the BMW IIIa of 200ps, amongst others and Axial, Heine, Reschke and Wollf all made propellers for this fitting.

In 1919 Rupp returned to Switzerland and his device was introduced into the Swiss Air Force. In the 1920's Rupp returned to Germany and his device came into use in both the Luftwaffe and Civil aviation; examples are the Focke-Wulf FW44 Goldfinch Trainer and the Junkers F13 airliner introduced in 1919.

The look of this prop suggests it is from an aircraft such as the FW Goldfinch, which dates it from 1928 to 1945.

I describe the device in fifteen pages in Part Three of my series on German WW1 Propeller Makers which will be published in a few weeks time and can send the owner of this prop the relevant pages now, should he so wish, or the complete book in a few weeks time. If so contact me via the Private Message box which is top right on this screen.

Your propeller is extremely rare and very interesting and I congratulate you on finding such a thing and on showing it on this website.

With kind regards,

Bob
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Bob Gardner
Author; WW1 British Propellers, WWI German Propellers
http://www.aeroclocks.com
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