Re: Visibilty / Safty or Safty / Visibilty ?

[shawl@torchlake.com (Jonathan Shawl)]

Phil Nuytten wrote:

>  [snip] The point is, you can make a sub out of damn near anything that is
> impermeable
> to water . .it's just that some materials and shapes are more efficient that
> others. Sub design, like life, is a series of trade-offs and compromises.

I agree with that totally. My first sub was made from an aluminum wing tang
(hull). one half of a 275 gallon oil tank, the end of a water tank (hatch), the
hatch gasket came of a washing machine tub, and 4- 100 lb size propane tanks
(ballast tanks), and it worked to 12'. Then I tested it later and it crushed at
15'.
So if you want to work full time all summer or longer to build something like I
did just to find out it was a waste of time and money, go ahead. If you want
plywood or fiberglass or what ever (I can't imagine why), that won't hurt my
feelings, but you better make two and test one to destruction so you know what
you have.
Again I will have photos of my first sub (mistake) that I rebuilt into a boat,
because it looked to cool to scrap.
My point is, take your time, save a little more money, learn more, then build,
once!
How deep are they going in the successful fiberglass dry 1 Atm, subs?
Do they know the crush depth? Are they operating them close to crush depth and
don't even know it?
Is there any way to reliably predict the crush depth of the one off subs you
are talking about?
I can't think of any tradeoffs that would make it worth while to build a flat
sided pressure vessel or to make one out of anything other than time proven,
cheep, strong, steel.
Maybe someone can enlighten me? I like to think I have a open mind. But I will
always stick to safety first over all other thinking. After all, what is the
point in making a unsafe sub, or one that is only safe to, lets say 30'? Might
as well go diving.
I think we are agreeing. If not, how long before we get to the part where
people start beating the dead horsie? What type of club or whip do I buy?  Just
asking, I'm new here. ;-)

Jon Shawl