"Richard Casady" wrote in message
...
On Sun, 19 Apr 2009 15:58:09 -0400, "Wilbur Hubbard"
wrote:

"Capt.Bill" wrote in message
...
http://www.windvinder.com/index.php?id=14&L=1


Nobody's seen it because it doesn't exist. It is a pipe dream. Notice on
the
site there are no photographs of it in action. Just drawings. It can't
work.
You cannot harness enough wind power with a windmill on a boat to make the
entire untethered vessel proceed directly upwind. It isn't going to happen
because it defies the laws of physics.

Wilbur Hubbard

The usual windmills around here put out 2000 hp.

Casady


The reason a windmill can put out that kind of horsepower is because they
are firmly attached to the ground. In other words they cannot be blown
backwards by the wind. The ground and tower pushes back against the wind
thus providing a vector's worth of power to the system.

Put one on a catamaran and it will be blown backwards until it experiences
little or no apparent wind. If it were 100% efficient the best it could do
is stay in place against the wind. We all know there is no 100% efficient
machine. That would be a perpetual motion machine which the laws of physics
say cannot be.

Wilbur Hubbard