Re: [PSUBS-MAILIST] Hey, looky, rocket fuel as ballast!

[Ian Roxborough <irox@ix.netcom.com>]

On Tue, 3 Feb 2004 10:55:33 -0600
David Buchner <buchner@wcta.net> wrote:

> 
> On Tuesday, February 3, 2004, at 11:04 AM, Ian Roxborough wrote:
> > I seem to remember hearing that airbags contain lots tiny holes to let
> > the air out (and soften/absorb the blow to your head).  While the holes
> > would be good for letting out the air as it was expanding during the
> > assent, if the assent is too slow then all the air might drain out
> > of the air bags before you get to the surface.
> 
> Oh. I was thinking the bags would be *inside* the tanks. I didn't think 
> of the actual bag-part as doing anything useful: I was focused on the 
> compact way to get a bunch of gas expanded into the tank.
> 
> Regardless, if one had access to some free airbag gizmos, this seems 
> like it would be a fun thing to test down at the lake with an old water 
> heater tank and some long wires...

That doesn't sound very good.  Airbags are one use items, do you really
want only one chance to get to the surface?

It seems like a very complex way of solving a simple problem.  If you've
already got tanks to put air into, then it does seem easier to carry
compressed air in a pressure flask, and use that to fill the tanks.  If
safety is a concern, carry a spare pressure flask that is independently
connected and operated (i.e. doesn't depend on piping and values used
for the primary pressure flask).

If you're concerned about getting air into the tanks really really fast
(I do not know why this would be an issue), this is going to depend a
lot on the size of the openning to let water out of the ballast tank.

Let me know if you do any tests with the air bag and ballast tank, I
am currious what the out come would be.

Ian.