Rob,
Welcome and enjoy, you have arrived at the right place. As my design is an ambient one, I can not speak to the issues you raised except the buoyancy question. I found this link extremely helpful. http://www.maritime.org/fleetsub/chap5.htm#5A in grasping the basics. Refer also to the online Busby manual through the PSUBS links.
Some of the gentlemen on this list are true professionals in the field, from Johnson Sea Link pilots, R.O.V and manned sub manufacturers, to some really intrepid individual hobbiests. Enjoy!
Joe P
From: Robert Ossian <rob_neptune@yahoo.com>
Reply-To: personal_submersibles@psubs.org
To: personal_submersibles@psubs.org
Subject: [PSUBS-MAILIST] Advice for a newbie?
Date: Fri, 30 Dec 2005 09:36:59 -0800 (PST)
>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
>
>
>
>
>__________________________________
>Yahoo! for Good - Make a difference this year.
>http://brand.yahoo.com/cybergivingweek2005/
>
>
>
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