Tom blok Photo collection by Th.Schiöler River and wind powered Windmills Photo 64
Windmills
Gul streg
Photo 511 x 506 pixels, 43,6 K
 
Wind-powered piston pump
The spread of canvas is determined by the speed of the wind. On this illustration, the spread of the canvas is equal to less than 20 % of the circular area. From the shaft, a long vertical connecting rod works the piston pump. The cylinder for the pump is made from a German shell, that was left behind from World War 2.
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Photo 511 x 506 pixels, 43,6 K
 Photo 511 x 506 pixels, 43,6 K

This drawing is by Michael Varming, Copenhagen.
From the data given in the text I have calculated an output of about 70 watt. At full sail it could probably produce four time as much.
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