Re: [PSUBS-MAILIST] Re: Some issues -- Sand Ballast

[DJACKSON99@aol.com]

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

 

In a message dated 11/7/2005 4:27:03 PM Central Standard Time, paulkreemer@gmail.com writes:

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

On 11/7/05, Akins <lakins1@tampabay.rr.com> wrote:

Hi Joe.

 

Paul wrote....

"What we need is a clever trick like that used in water ballasted sailboats - just fill the tanks before sailing to increase your displacement.  But of course that doesn't help a sub, unless you look at flooding most of your crew compartment while diving.   Maybe you need a sand ballast keel system.  :-)  Run along in shallow water scooping up sand until you've got the two tons or so that you need.".

 

How do you run in shallow water scooping up sand in a trolling motor ambient sub? How would that be accomplished without the friction of some kind of scoop attached to the sub stopping the sub dead? It would be like running into a sandbar wouldn't it?