Re: [PSUBS-MAILIST] escape question

[MerlinSub@t-online.de (Carsten Standfuss)]

bruno masse schrieb:
> 
> hi ray.
> 
> im talking about lakes dive,the deepest in quebec is about 350' feets
> ok imagine all my electrical component in the sub are pressure isolate

- ok thats is just an imagine.. or a real expensive way to build
electrical instruments.

> and i have a tri-mix diving gear 

- depents on the hatch diameter.. 700-800 mm at least.. 

> in the sub and begin to use the mix 10
> or 15 minute before floading the sub,open the hach get out cut the net
>  (i im already on the bottom) come back in the sub close the hach and
> begin to pump out the waters with hp pump and come back to surface!
> that way is it possible?

and even with trimix - after some 20 Minutes at a pressure equal 300'
you have to decompress the driver/diver. So the boat has to hold some
internal overpressure - and to stop in some depths to decrease the
pressure slow. Not a easy process with ahole boat everthing inside wet 
and full of mallfunction. 

- depents on the HP pump.. how many kilowatts for how many hours.. 

theoretiacl : yes 
practical : difficult

- another question ist to prevent that you as diver catch the net ! 
but this depents on the net ticknesses etc. 

Maybe better : 

- Build the sub in a way that in can not catch a net so easy
- Make an emergency bouy on it, or emergency paint release vale.. 
- make a pre-dive plane with times and give it to somebody onshore

or.. 

build a boat with a diver exit on the bottom.. 

regards Carsten

> thank
> ----- Original Message -----
> From: Ray Keefer <Ray.Keefer@Sun.COM>
> To: <personal_submersibles@psubs.org>
> Sent: Monday, October 13, 2003 12:58 PM
> Subject: Re: [PSUBS-MAILIST] escape question
> 
> > Hi Bruno,
> >
> > Yes, it is possible.
> >
> > The problem I see is if the sub is stuck in a net at 300 feet. The bottom
> could
> > be 600 feet. As you flood the sub it could become heavier then the net
> floats
> > can support. By the time you flood out and egress the sub could be down to
> > 400 feet or 500 feet.
> >
> > At some point you might was to consider getting out alive reward enough
> and
> > cut your losses by letting the hull go to the bottom.
> >
> > As others have mentioned you will need to breath mix gases to work at
> > 300 feet for any length of time.
> >
> > As a design feature you could design your sub to be flooded. Either you
> > have a diving lockout chamber or you flood the interior you are in.
> > In either case your sub will have to be designed to:
> >
> > 1. Blow clear a flooded volume equal to what you want to flood. That is to
> > keep your sub a neutral bouyancy.
> >
> > 2. Protect interior electrics and electronics from sea water. I doubt a
> > typical fuse panel would take well to sea water. Your design will have to
> > some how keep the two seperate.
> >
> > If you let your hull go and you decide to come back and get it,
> > your sub it will be on the bottom with its hatch
> > open. Some how you will have to get down to the sub, close the hatch,
> attach
> > an air hose, and blow your sub dry. The net you got stuck on will still be
> > there. Possibly entangling your recue sub.
> >
> > In any case rescue of anything deeper scuba depth, say 160 feet. Starts
> > to become problematic. What happens if the bottom is 3,000 feet?
> >
> > Some members here in PSUBS recommend never operating in water deeper then
> > you can practically recover your sub in. Others recommend to never dive in
> > water deeper then your crush depth. With your surface support ship calling
> > for help and your 72 hours of life support you have three days to be
> > rescued.
> >
> > Regards,
> > Ray
> >
> > > bruno masse wrote:
> > >
> > > this is my question (maybe stupip!)
> > >
> > > ok imagine im stock in a fishing net at 300' feets and noting to do to
> get out of this shit
> > > is it posible to put my diving gears on ,fload the sub get out cut the
> fishing net
> > > come back in the sub pump the waters out and come back to surface with
> out any problems?