[PSUBS-MAILIST] Re: pressure test

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

Yes - dive your new selfbuild Psub the first time in 
open harbour water and better do not test the hull before in a chamber. 

It will increase your heard beat much more - as with a tested hull
and you never will forget this first dive.. it dosen't matter  
which saftey factor it has. 

Sgt.Peppers first dive was to the harbour bottom - just 7 feet deep
and far away from the crush deep.. Just one vale was leaking - 
but some stupid has put the vale on a position just on top of the 
electric main engine-battery switch - a custom made and 
not watertight box - real fun.. and a lot more of rpm on the
heard beat. 

Shallow diver hulls with a work deep down to 33 foot 
can be easy test - with a vaccum pump conected 
to the hull. Also fun if it fails and implode inside 
your shop.. 

A simple way to test the hull is to sink the boat 
- without a crew but with a additional drop weight 
and a release rope to the surface into a deep lake. 

Some frome the big boys did it this way in the sixties.. 
.. One with automatic relase drop weight for real deep
sea test (no rope to the surface) fails - the release 
automatic - not the hull - and the hull stand there for years 
- some 30 foot above the seafloor on the short rope to the weight. 

Carsten 

rjune@fuse.net schrieb:
> 
> why all the comotion about tank testing a sub.
> 
> I think it would be more wise to desighn/buld a sub
> for 2 times the intended depth (say 200 meters).
> and ony use it at the intended depth (100 meters).
> isn't that what safty factors are all about.
> 
> >
> > From: William Alford <walford@dbtech.net>
> > Date: 2002/04/11 Thu PM 12:53:40 EDT
> > To: personal_submersibles@psubs.org
> > Subject: Re: [PSUBS-MAILIST] Isn't 'Mini book review.'
> >   anymore--pressure test
> >
> > At 10:24 PM 4/10/2002 -0700, you wrote:
> > >I'm less concerned with generating the pressure on a vessel filled with
> > >water, actually, and more concerned with sealing a big tank with a door in it.
> >
> > on the topic, Hyperbaric therapy chambers are often tested by filling with
> > water and then pressurizing with air, however, the above concern of sealing
> > a big tank with *big* door is paramount. Consider that a 30" door of a HBOT
> > chamber pressurized to only 2 atmospheres has a cumulative pressure (add up
> > all those PSI's on the entire area) on the door of around 5 tons! which is
> > equivalent of a dive to only 33 feet of seawater. A testing tank failure at
> > the pressures for modest psub depth and the required diameter of a door (or
> > flange mechanism) for sub admittance could be catastrophic. There is a
> > report in "Hyperbaric Facility Safety"- WT Wortman, of a 30" door failure
> > blowing off the HBOT chamber and through the wall of the building and
> > killing someone in the next room. Of course it was filled with O2, not water.
> >
> > The construction challenges of an enormous test chamber might rival that of
> > the psub itself.
> >
> > William Alford
> > walford@dbtech.net
> >
> > Tout comprendre c'est tout pardonner
> >