Re: [PSUBS-MAILIST] Nice Sub Bill!

["Captain Nemo" <vulcania@interpac.net>]

----- Original Message -----
From: <WGif503113@aol.com>
To: <personal_submersibles@psubs.org>
Sent: Friday, June 08, 2001 1:22 AM
Subject: Re: [PSUBS-MAILIST] Nice Sub Bill!


"Pat ....I am sure you have run into problems I haven't foreseen please feel
free to guide me, thats why I joined the group!  Thanks Bill"

Bill,

OK,  then I've gotta tell you:  your conning tower design looks chancy to
me.  I think it could cause you problems.

The flat side walls aren't suited to resisting depth pressure.  I can only
estimate its dimensions from the pictures, but at 132 feet, a rectangular
structure measuring  3 X 3 X 4 feet will encounter something in the
neighborhood of 50 tons pressing in on it from either side.

Then again, there's the question of 50 tons of pressure on top forcing that
tower down into your (roughly) 1/4 inch thick, 48" diameter propane tank.
I'm trying to visualize the internal gussets, trusses, and other
reinforcements the hull would need to withstand that kind of stress without
deforming, and even with those it still doesn't look good to me.

And about your tanks' internal pressure rating: don't equate that with its
ability to resist external compression.  A 2 liter plastic soda bottle can
be pressurized to 120 PSI without popping, but (capped at the surface) will
start to collapse in only a couple fathoms depth.

I think the tank your using could be reinforced to make a pretty fair
shallow water submarine; but scrap the conning tower.  Go to your local
metal fab shop; have them roll you a nice hefty plate (larger than the hole
you cut in the tank); use that to cap the hole; and modify it with a more
conventional "turret" conning tower (check out a Kitteredge Sub).  You could
even install a second one abaft for your passenger, if you wanted to.  This
kind of design will provide MUCH greater structural strength and occupant
safety than what you're building now.

Pat