Re: Pressure compensated thrusters?

["Gary R. Boucher" <protek@shreve.net>]

If you connect a line from the motor to any "air bubble" in a ballast tank
you will get trapped sea water in the line and it will eventually get
inside the motor housing unless extraordinary precautions are taken.  Also
if you have a bubble of air in a tank that is allowed to remain at ambient
pressure the bubble will compress or expand as you change depth.  If the
bubble is not at ambient pressure (sealed ballast tank or "hard tank") then
it defeats the purpose of compensation because its pressure does not track
the pressure at the given depth.

GB

----------
> From: Rick Lucertini <empiricus@sprint.ca>
> To: personal_submersibles@psubs.org
> Subject: Re: Pressure compensated thrusters?
> Date: Friday, May 22, 1998 2:07 AM
> 
> 
> 
> STEVE McColman wrote:
> 
> > >Where can I find information about pressure compensation techniques
for
> > thrusters?
> > >Did anybody oil-filled (or pressure-compensated) a trolling motor?
> > >
> > >Paolo Velcich
> > >industrial designer
> 
> > Since there is always going to be a pocket of air at the very top
> > of my rear ballast tank, I plan on running a tube from my trolling
> > motors up to the top of that ballast tank. That should work shouldnt
> > it???
> >
> > Steve McColman, Canada
> 
> Hi, Steve and all - that's an idea I thought of, too.  It'll work as long
as you make sure that the
> pocket is a true air sump and not just a bubble that will move around
exposing the intake of the
> compensating pipe to seawater.
> 
> Rick in Vancouver.
> 
>