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

[rjune@fuse.net]

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
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> > 
> > 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
> 
>