RE: Re: [PSUBS-MAILIST] Using a commercially available hatch as an emergency escape hatch.

["Greg Snyder" <snyde032@tc.umn.edu>]

Hi Herve -
Do you think that 2 layers offers a benefit ( they quoted me for 2 layers of
12mm glass).
Thanks-
Greg

-----Original Message-----
From: owner-personal_submersibles@psubs.org
[mailto:owner-personal_submersibles@psubs.org]On Behalf Of Herve
Sent: Tuesday, May 07, 2002 2:16 PM
To: personal_submersibles@psubs.org
Subject: Re: Re: [PSUBS-MAILIST] Using a commercially available hatch as
an emergency escape hatch.


I used in my dry ambient subs, 1/2" tempered glass. cristal clear for ever.
Lexan gets to easy and rapidly worn out, scratched and loses its clearness.
Plexiglass cracks after a while under sun exposure.
I tested my windows in 10 Ft water column when differential pressure never
exceeds 2 Ft of water column.
Herve
----- Original Message -----
From: <rjune@fuse.net>
To: <personal_submersibles@psubs.org>
Sent: Tuesday, May 07, 2002 1:16 PM
Subject: Re: Re: [PSUBS-MAILIST] Using a commercially available hatch as an
emergency escape hatch.


> never use plexiglass ... it is to week
> use polycarbinate also called lexan
> >
> > From: Ray Keefer <Ray.Keefer@Sun.COM>
> > Date: 2002/05/06 Mon PM 06:09:21 EDT
> > To: personal_submersibles@psubs.org
> > Subject: Re: [PSUBS-MAILIST] Using a commercially available hatch as an
emergency escape hatch.
> >
> > Hi Greg,
> >
> > Since your sub is ambient. If this window stays sealed at the surface it
> > should stay sealed at depth. The pressure inside and outside will be
> > even. The strenght of the frame and window only has to overcome minor
> > differences in pressure.
> >
> > My concern is that the window is glass and frontal position of the
window. I
> > would hate to see you run into a rock and shatter the window.
> > The spec says up to 3/4" tempered glass. Don't skimp, use the thickest.
> > Use plexiglass if you can get it.
> >
> > Also keep in mind to use this exit you will have to be on the bottom.
> > Else when you open the window the you will suddenly heavier with water
> > coming in and will sink.
> >
> > If your sub subsides into the bottom silt, sand and stuff might come up
to
> > your opening. Limiting your exit and letting stuff into your sub to add
> > weight.
> >
> > One last concern is you just can't open up the window. Air will bubble
out
> > and water will flood in. How violently depends on how much air will be
> > displaced how fast. Perhaps a valve low down in the sub to let water
flood
> > in and one up high to let air out. Once water level is above the window
> > opening the you can open the window without a large air bubble burping.
> >
> > Regards,
> > Ray
> >
> > > From: "Gregory Snyder" <snyde032@umn.edu>
> > > To: <personal_submersibles@psubs.org>
> > > Subject: [PSUBS-MAILIST] Using a commercially available hatch as an
emergency
> > escape hatch.
> > > Date: Sat, 4 May 2002 13:06:07 -0500
> > > X-Priority: 3 (Normal)
> > > X-MSMail-Priority: Normal
> > > Importance: Normal
> > > X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000
> > >
> > > Dear Psubbers -
> > > I am in need of some advice.
> > > As I refit the sportsub, I wanted to add an additional window that can
> > > serve as an escape hatch.
> > > I thought I would do this in the front lower section (by my knees and
> > > shins when sitting).
> > >
> > > My design can tolerate an oval 27" by 16".  I can fit through if need
> > > be.
> > > I am looking at a commercially available window at the following link:
> > > Model 71111 cut to these dimensions with the hinge removed and bow
> > > handles in their place.
> > >
> > > http://www.beclawat.com/bec71111.htm
> > >
> > > My question is do you think that this will stay sealed in an ambient
> > > cabin at a maximum of 130 feet?
> > > Or am I just fooling myself.
> > >
> > > Open to suggestions-
> > > Thanks-
> > > Greg
> >
> >
>
>
>