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Best way to add ballast via sand "on the fly" for
any sub is simply suction. Salvage operations do it all the
time, only they suck the sand away and get rid of it. Not a difficult
thing to rig actually, all you need is a motor/impeller and a semi-permeable
membrane to let the water and light silt pass through, leaving the good, heavy
stuff behind. It could be set up as a bladder system within an
ambient/vented tank. Later, the sand could be expelled if
needed.
----- Original Message -----
Sent: Monday, November 07, 2005 10:52
PM
Subject: Re: [PSUBS-MAILIST] Re: Some
issues -- Sand Ballast
Boy it's really true that there aren't any new ideas out there.
:-) Thanks for that great website of yours Doug; that is such a well
documented project!
On 11/7/05, DJACKSON99@aol.com <DJACKSON99@aol.com> wrote:
If I remember sand varies depending on the type of sand, but is about
100 pounds per cubic foot, whereas lead is over 700 pounds per cubic foot,
meaning you need a lot of sand storage area. I actually went down that
road with a design. But I figured on just using a
dredge or shovel to load the sand. http://www.submarineboat.com/sub/Sub_H2_files/h2.html
-- No tongue in cheek :) Doug
Bill, yeah the sand ballasting was kind of a tongue in cheek
suggestion. I was trying to get creative and spur some discussion on
ballasting a large air volume and still make it trailerable. Also I
haven't looked up the density of sand but expect that it wouldn't compare
well to lead or even concrete. :-)
Way more practical to go
with a semi-dry compartment like you suggested.
Paul
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