Re: Fw: Re: [PSUBS-MAILIST] Escape Hatch Realities

["Carsten Standfuss" <MerlinSub@t-online.de>]

You wrote : 

Scuttle valves:  It is a generally accepted rule of thumb that most
submarines will have high pressure air for the ballast system.  There is
no need for a Scuttle Valve.  All that is needed is a valve that can be
opened from the inside that will let in high pressure air into the
pressure vessel till it?s equal with the out side.  Then you will be
able to open the hatch.

My answer : 
(will be nice if somebody can convert the figure to feet etc.)

My sub under construction has an inside volume of 48.000 Liters. 
The test deep were the can work is 320 meter equal to 32 atmospheres
adittional pressure. If I want to leave the dammage boat with our diving
equipment (rebreather for 6 hours, heated suits, full-face mask etc..)
via the sail-hatch I have to "flood" the boat with water via the
flood-valve (in this tread wrong called "scuttle-valve"). Water amount
about just under 48.000 Liter in a couple of minutes. 

48000/32 = 1500 cabin air will remain so we need about 46500 liters
of something to fill the rest to get the pressure equal. 

If I want to do the same job with high pressure air from storage
bottles I need : 225 bars in the bottel minus 32 bars comes not out of
the bottle in this deep = 193 bar by 50 liter volume each man high
bottle = 9650 useful liters each bottle. 

Required : 46500 liter x 32 bar = 1,488,000 liters air

1,488,000 divided 9650 in one bottle = 154 man high bottles.. 

I have on board : 30 units (some of them filled with oxygen)

So this short milkcan calculation shows me I have to find place for
additional 124 bottles - and a sponsor for the adittional 37200 USD
it cost - and two much bigger compressors.. , a bigger boat, more engine
power etc.. 

The flood-vale I purchase - was about 120 USD.. 

So from a standpoint of an engineer, an diver and an of course a big
dreamer with a limit amount of money -  I go with a flood-vale. 

Best regards to all members of psub - still the best first hand source
for private submarine information on the net. 

And welcome here. 

Carsten