----- Original Message -----
Sent: Monday, January 02, 2006 8:11
AM
Subject: Re: [PSUBS-MAILIST] Compressable
ballast tanks
Bill,
What you describe sound good in principle.
For a SCUBA tank it would way to cumbersome to built it to contain 2000 pound
air for the small benefit of not having to adjust your buoyancy in other
ways.
For your sub it would be more doable, but still,
rather then install a large air tight piston and the mechanism to operate
it, wouldn't you get the same result if you operated a simple small piston
pump and moved water in or out of a sealed tank? A pump would have a
piston, true, but it would be smaller, easier to house and operate. Also
one pump can be connected to and operate more then one tank.
Again, your idea is good but there may already be
easier ways to accomplish what your after.
A note on the topic: Captain Kittredge is
rigging a sub to do what you suggest. He wanted to create a buoyancy
system that didn't require compressed air to operate. I believe he's
using a hand operated water pump and bladder in his dry sub to pump water
into. If you put a bladder in a pod you can do the same thing in
your wet sub.
Dan H.