http://pedalcanoe.homestead.com/index.htmlSubject: Re: [hpv-boats] Re: paddle wheels, twisted chain
Date: Tue, 31 Oct 2000
List-Id: Human Powered Vehicles -- Boats <hpv-boats.ihpva.org>
Here's some observations,
RE: TOP SPEED At the Interlaken event last year, the fastest multi-rider displacement prop and paddlewheel boats were both tandems, both built by university teams, both of similar weight, both designed for speed, and both posted their best racing times over the 100m Sprint to date (AFAIK). "Close To Perfection" is a twin prop catamaran, and "Hydrodynamosaurus" is a monohull with twin eccentric paddlewheels.
The prop boat did an 18.31 second 100m Sprint which equates to 12.2mph. The paddlewheel boat did the 100m in 19.11 seconds, averaging 11.7mph.
Assuming that catamarans are generally slower than similar class monhohulls, and assuming that the two boats are of equal quality craftsmanship, we could conclude that props are faster than paddlewheels. Of course, there are many ways to dispute that conclusion, such as rider fitness levels, racing conditions during the runs, the fact that C2P has posted slower times in the past, Hydrodynamosaurus may not have been mechanically optimized that day, etc., etc..
IMHO, in a pure displacement mode, racing paddlewheel boats can be made to be as fast as prop boats, but the advantage goes to the prop boats. It seems to me that Hydrodynamosaurus is at the top-end of the paddlewheel spectrum, while there's still room for improvement in Close to Perfection (as the name implies :-), such as switching to a long skinny monohull for example.
Now, throw hydrofoils into the mix and the gap widens almost two-fold. Has no-one tried a paddlewheel hydrofoil because it's too tough the change the height of the wheels as the boat lifts, or is it just that props are more efficient at the high-end of the speed spectrum?? ;-).
Bottom line for me is that paddlewheels certainly have great merit in shallow and weedy waters, which are some of the most fun to explore. Props have far more raw speed potential in the open waters. I guess we'll all just hafta get one of each :-).
C-Ya... ...Ron
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