Monday, March 23, 2009

Jerk Drive

I've always been somewhat of a student of unidirectional drives. These involve methods to redirect force into a single direction, which can be sideways, down or UP. There is much literature on the subject and several patents but I won't go into those, leaving you to do your own research.

I found something in an old book which I'd not seen before and so am sharing it with you;

In certain curious boat races held at some English regattas as explained by Professor W.W. rouse Ball, in his 'Mathematical Recreations and Problems', he says;

" affords a somewhat curious illustration of the fact that commonly a boat is built so as to make the resistance to motion straight forward less than that to motion in the opposite direction.

The only thing supplied to the crew is a coil of rope, and they have (without leaving the boat) to propel it from one point to another as rapidly as possible. The motion is given by tying one end of the rope to the afterthwart and giving the other end a series of violent jerks in a direction parallel to the keel.

The effect of each jerk is to compress the boat. Left to itself the boat tends to resume its original shape, but the resistance to the motion through the water of the stern is much greater than that of the bow, hence, on the whole, the motion is forwards. I am told that in still water a pace of two or three miles an hour can thus be attained."

A practical experiment to show how redirected centrifugal force can produce drive is seen here;

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