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Hi Frank , Les Here i made my hatch dogs with u-block seals and on the out
side of the sub , I have 3/4'' nut , insted of handles,, i havent welded them in
yet.,I have to weld the tower on first. I put up one picture of
my legs and weight tray , when i fliped the sub over the tray is 3/8'' off the
floor.. Les
----- Original Message -----
Sent: Saturday, August 08, 2009 2:06
AM
Subject: Re: [PSUBS-MAILIST] Vent
valves
Hi Jon. I agree totally. A psub should be slightly buoyant with the tanks
flooded. We still have the drop weight, but even with that, the sub
should float up. That was one of the first things I picked up on when reading
the ABS stuff years ago. I don't know how much buoyancy is best, but running a
thruster or using dive planes to maintain depth is a necessary evil that a
dependable design should include.
My thinking here is that if a complete failure of the blow system
happens, and you can't drop your weight, you eventually float up. The most
likely scenario for a total failure of all floatation systems coupled with a
failure to drop the emergency weight is the pilot becoming incapacitated
for some reason.
The one thing missing from this on my sub is the means to open the
hatch from the outside. I haven't figured out how to do that yet without
having handles poking through the hatch.
I have considered having an external ball valve, that when opened,
could be used to insert a handle and crank the hatch dogs open. The trick here
is getting a ball valve on the inside too, that keeps the sub from flooding
but still allows access to the center crank. Anyway I look at it, there has to
be a "block V " seal there. Still working on that one. Frank D.
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