Car windshields have 2 layers so that when the glass is broken it doesn't shatter. Safety glass that is, as required on automobiles in the U.S.
pierre&marie <poulin.carrier@videotron.ca> wrote:
Maybe one correction:
The method I saw was to put a thin layer of hard material on an existing
window. The goal of that is to keep all the parts of that window together.
Just like a windshield from a car. That could prevent water from entering
the hull. I don't think it could make the viewport more strong... just more
air-tight. And, the way the viewport is made should also be different
because, if the viewport is broken, the middle is gonna pull the edge inside
the sub...
Pierre
----- Original Message -----
From: "Coalbunny"
To:
Sent: Monday, October 06, 2003 9:47 PM
Subject: Re: [PSUBS-MAILIST] Re: Viewport Toughness
> And unlike in the movies, whent hat baby starts crakin', it ain't gonna
> be in the middle. It's gonna be where the pressure has found
a weak
> spot, and odds are you won't know even then, because it won't just
> crack, it's just gonna go, period. And if that happens while you're
> hanging out at 1,200 feet checking the seafood selection, you'll be part
> of the menu.
> Carl
>
>
> Ron wrote:
> >
> > As Ray said, bullet proof glass is made of polycarbonate, not acrylic.
> >
> > In a sub you are resisting against pressure first, over the entire
> > surface area, and also the sum of that pressure on your
> > sealing/attachment method. Impact resistance is secondary.
> >
> > -----Original Message-----
> > From: owner-personal_submersibles@psubs.org
> > [mailto:owner-personal_submersibles@psubs.org] On Behalf Of Ray Keefer
> > Sent: Monday, October 06, 2003 5:10 PM
> > To: personal_submersibles@psubs.org
> > Subject: Re: [PSUBS-MAILIST] Re: Viewport
Toughness
> >
> > Hi,
> >
> > No such thing as "bullet proof". I have seen banks with "bullet proof"
> > glass (probably polycarbinate) windows an inch thick (1 inch = 2.54
> > centimeters). Seems they have to be thick to absorb the energy of most
> > common projectiles.
> >
> > "bullet proof" glass may be tough but how tough? How tough is enough?
> > The only real extensive viewport research was done by Stachiw on
> > acrylic. Anyone deviating from acrylic needs to take samples of their
> > target material and test it. You must see for yourself if the target
> > material is as tough as you want.
> >
> > Regards,
> > Ray
> >
> > Pierre Poulin wrote:
> > > Could it have been prevented with
> > > the "bullet proof" windows? I don't know... Just a tough.
> > >
> > > Thanks for
the comments!
> > >
> > > Pierre Poulin
> > >
> >
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> --
> "Without deviation from the norm, progress is not possible" - F. Zappa