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Re: [PSUBS-MAILIST] Subhuman project



Hi Alec. Yes, a very professional job on the web site.
As far as the efficiency of a tail versus a prop, the tail will win out if the bugs get worked out of the design. It really does take less energy to swish a tail than turn a prop, and props have inherent flaws like the vortices created around and behind the prop. These can rob a lot of power as the rotational speed increases.
    Man kind uses props because our power is based on a rotating machine, be it electric or gas. There are several examples of early sailors using a back and forth motion to drive a boat, like the gondolas in Venice. If it was more efficient to drive a prop, boats would come with hand or foot cranks and gears. Fish would have evolved with propellers. It will be interesting to see what develops in the future.
I would think that a back and forth action would have a slight advantage over an up and down action, because of gravity, and most fish have a vertical tail. I've often toyed with the idea of crafting some type of tail swishing machine, just for fun. Maybe after I finish my sub. Frank D.