RE: [PSUBS-MAILIST] Under water lighting: Q for Ron Leonard

[ronleonard <ronleonard@shaw.ca>]

Hi Pat, nice to have you back on the group.
A SportSub hull is 60" tall. The hull was not designed to be used as a
totally dry sub, so there is a lot of wasted space that will have air in
it that will need to be sunk, so yes that makes for a heavy sub. The
fiberglass was also not done to support the lift on the roof or the pull
on the floor from this increased weight. There is a very real
possibility that the roof may tear off, or the bottom may tear away. I
have suggested to Greg that he physically attach from under the floor to
over the roof with external bars. It will be ugly, but should work if
done correctly. 

There are plenty of hatches that can seal that kind of pressure. Should
be no problem with a good hatch. Our R&D sub has had a top hatch for
about 2 years now with no leaks.

Ron


-----Original Message-----
From: owner-personal_submersibles@psubs.org
[mailto:owner-personal_submersibles@psubs.org] On Behalf Of Captain Nemo
Sent: May 16, 2002 2:57 PM
To: personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] Under water lighting: Q for Ron Leonard



----- Original Message -----
From: "ronleonard" <ronleonard@shaw.ca>


> With an ambient sub, you won't get water leaking in, rather air 
> leaking out. Not a problem so long is it isn't too much of a leak. Ron

Hi  Ron,

Been a while.  Trust you're doing well.

If I understand correctly, Greg wants to turn a modified SPORTSUB hull
(used on the surface as a movie prop) into a diving closed-compartment
ambient sub.

Exactly how tall is a SPORTSUB hull?

And considering the pressure differential low / high within the sub
(I.e., since the internal pressure needs to be great enough to push the
water out the bottom of the sub, it will therefore greater than the
external pressure at the roof) , what do you think about the potential
integrity of his roof hatch (which won't have water pressure forcing it
shut): easy to leak air if not well made and tightly torqued down on the
seal?

SPORTSUBS work really well as they were intended to work.  Generally,
what do you think of modifying them into closed ambients, especially
with a roof hatch?

I see a lot of potential buoyancy there.  The hull and components are
light in comparison to a steel dry sub, so it looks like a lot of hard
structural ballast  will have to be added on.  Any suggestions on how to
attach that to a fiberglass hull so as to minimize the possibility of it
tearing loose?

VBR,

Pat