[PSUBS-MAILIST] Advice for a newbie?

[Robert Ossian <rob_neptune@yahoo.com>]

Hello Everyone,

Let me first say that I am very impressed by the
success that the members in this group have had
building their subs and the innovations all of you
have made to conquer problems with limited resources
and budgets.  Also, let me assure you that since I am
so new to this field I will have ANY and ALL plans I
come up with checked out by a structural engineer
prior to any construction, testing or use.  I'm
enthusiastic, not stupid. ;-)
 
This site has been very encouraging to me as I begin
to design my own first sub, but I have been coming at
it from a slightly different perspective than the
traditional design views.

Like many others, I was inspired by Hawkes and his
Deep Flight subs and am also trying to follow his lead
and design a different style of submarine than the
traditional lines allow.  Obviously I must trade depth
for speed and aesthetics, but I think I can deal with
that (at least for my first sub).

For these reasons, I would like to ask some questions
of the sub builders in this group regarding some ideas
that I think are slightly radical and possibly
suicidal:

1.  Hull shape
I realize that the traditional shape of the sub has
been a tube for obvious reasons (equal exterior
pressure on all 360 degrees), but this limits sub
design a great deal.  Does anyone know of anyone who
has designed a dry 1 ATM sub with alternative hull
shapes?  It is my thought that as long as the frames
are rated to support more weight than is pressed upon
it at the weakest point, structural integrity should
be secure.  

For example, I am designing a wedge shaped submersible
that at 7 ATMs I would expect about 103 psi (7 * 14.7
psi = 102.9 psi) of pressure on my subs exterior.  If
the ovalic frame is rated to support 150-200 psi, then
there should not be a problem, right?

I am comforted by the fact my research has turned up
that Northrup Grumman is also experimenting with
similar design alterations.  Here is a press release
that is actually quite similar to what I have been
working on:
http://www.nn.northropgrumman.com/news/2003/031202_nnemo.html
 
2.  Bouyancy
This sounds stupid even as I write it, but I'd rather
ask the esperts here than make an even dumber
assumption.  
If a submarine has x amount of bouyancy (let us say
+1) at surface level, and then is somehow submerged to
a depth of 200 feet without anything changing, is that
bouyancy still the same?  With SCUBA, the BC vest is
always under external prssure and the flimsy bladder
walls of the BC allow the air within to become
slightly compressed by the pressure of the water
around it, causing the bouyancy value of the air
within the BC to diminish slightly between surface
(arbitrary value of +1) to 200 feet (arbitrary value
of +0.5).  With a sub I would assume (thats usually
where trouble begins) that the air would retain the
same volume and hence the same bouyancy value.  
Is this accurate?  

3. Thruster waterproofing
Is there a good primer or schematic out there for
explaining to a novice how this is done?  Preferebly
with images for us visual learners?

Again, thanks for all the great information in this
forum!

Sincerely,
Rob


	
		
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