Re: Double Hulled Sub

[SJSVOB@aol.com]

In a message dated 99-02-24 19:03:55 EST, you write:

<< At depth, the external pressure would press in the outer hull, compressing
the
 air, or pressurising the water, which would press on the inner hull.  >>

That would only be true if the outer hull were not a pressure vessel.  So
let's say you are at 20 atmospheres, 660 feet, and you have the outer hull
pressurized to 10 atmospheres and your inner hull is at 1 atmosphere.  The
differential pressure on the outer hull is 10 atmospheres, the differential
pressure on the inner hull is 9 atmospheres.  For your sub to achieve a
maximum of 660 feet depth each hull must therefore be capable of withstanding
10 atmospheres or 330 feet.

For the sub to benefit from surviving a breach of the outer hull though, the
sub must be within the maximum depth of the inner hull.