Re: sailing upwind

["John S. Denker" <jsd@MONMOUTH.COM>]

At 12:32 PM 12/31/99 -0500, Ludwik Kowalski wrote:

> Was it a tab with water in it and an air blower of some kind?
> How large was his boat and how fast it moved? How large
> was the mechanical advantage and how was it achieved?

Actually it was on wheels.  The air-turbine used the propeller from a model
airplane.  The linkage was implemented using his kid's construction-toy
kit, which included a couple of what I'm guessing to be 4:1 gearbox pods,
for an overall mechanical advantage of 16:1 if vague memory serves.  I
can't remember the brand name of the kit, and AFAIK it's not made
anymore.  I don't see it on shelves.  Another option would be to do it with
chains and sprockets, but the kits containing such things have disappeared
from the local toy stores as well.  Sigh.

The air came from a blow dryer.

The result was quite impressive.  It took a pretty stiff breeze to overcome
static friction and turbine blade stall, but once the thing started moving
it moved quite smartly.  Everyone who saw it couldn't help but smile to see
the thing attracted to the blower.

It left no doubt that the aquatic model would work just fine, especially if
it had some angle-of-attack control on the turbine blades to help with
starting.