On Sun, 24 Aug 2008 14:31:35 -0700, Bruce L. Bergman
wrote:

snip

For a steam launch you need to run the oil burner, navigation and
cabin lights, bilge pump and other auxiliaries you need roughly 12V
30A to charge the batteries.

A plain old car alternator would be perfect, now you need a constant
2000 to 4000 RPM power source to drive it - too fast for a piston
auxiliary engine unless you use a step-up geartrain, and adding
complexity is bad. And running an alternator off the prop shaft is
iffy, because the main engine stops - though having two alternators
(like two feedwater pumps) would be perfect.

snip

Stuart Sirius engine possibly.

http://www.stuartmodels.com/inprod_d...ting/mod_id/59

Although it doesn't feature multiple expansion, so you might still benefit
from, say a turbine driven boiler FD fan driven from the exhaust steam.


Mark Rand
RTFM