On Sat, 15 Dec 2007 09:50:00 +0100, Heikki wrote:

John C. wrote:

Run it as a generator and use it to charge an oversized bank of batteries.
With an electric motor you will gain variable speed and direction without
have an engineering nightmare.

I have been speculating about a diesel-electric propulsion for a smallish
sailboat. Does anyone have links to, or experience with, small electric
motors that are suitable for continuous use - most of my googling finds bow
thrusters and other extra machinery.

I am thinking of a fairly small engine, say 5-10 Hp, to be used mostly in
manouvering in and out of marinas, and occasionally coming home from a calm
sea. Would it make sense to mount the whole engine on the transom-hung
rudder? That way it could turn with the rudder, and give good steering in
both directions. When not in use, it could be lifted out of the water, so I
could use a decent size of propeller for it.

Would anyone care to shoot the idea down before I get too attached to it.
The whole project is on a dreaming level, I won't be building anything for
the next many years. But I still want to design it as if I was going to
build it some day soon...

Regards

Heikki
(Copenhagen, Denmark)

Yes, I guess I'd have to say "why"? With a small diesel engine you
would have a variable thrust device without the added complexity of
the electrical motor, controller, etc., not to mention the "over sized
bank of batteries".

Bruce-in-Bangkok
(Note:remove underscores
from address for reply)