Re: ambient preference

[Rick Lucertini <empiricus@sprint.ca>]

SFreihof@aol.com wrote:

> Hi Alex;
>
> I am also sold on ambient dry design because of simplicity and low cost.  I
> admire the 1atm sub enthusiasts, but to me that is beyond fun.  I like to
> think of a dry ambient sub as a "dive bubble", because that's what it is....

A bubble with an incredible view, that doesn't implode, and that is cheap relatively
speaking.

> My biggest concern with the design is uncontrolled ascent.  I'm don't know
> what preventive measures have been tried or proven.....  I'm listening.

One easy way would be to run down to the plumbing supply store.  Pick up some large
diameter (6 inch) pipe, a screw on cap, a wide but stiff spring and a rubber flapper
valve.  Drill holes in the side of the pipe to allow air to flow up to the flapper
valve from the cockpit.

The screw-on cap would be turned against the spring until it pressed against the
flapper valve.  This is exactly the same principle as a dry suit exhaust valve but on
a larger scale.  As Boyle expands the air in the dry cockpit on ascent, the increased
volume would force the flapper valve back against the spring and allow air to flow
overboard.

Depending on how far you screwed down the cap, the pressure would build or release
accordingly.  I HAVE NOT TRIED THIS MYSELF.  Sounds great in theory.  Works on my
Viking suit at any rate.

My biggest concern would be keeping the cockpit volume reduced as much as possible so
as not to overwhelm the regs or pressure differential valves.  The kayak sock would
go a long way toward this.  Your upper body would bsiclaly be covered by an oversized
diving helmet.

Rick


--
Rick Lucertini
empiricus@sprint.ca
(Vancouver, Canada)