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Dan.
Here's some homebuilt P subs with diver lockout
chambers in addition to Carstens sub.
You wrote..." If my sub is rated
for 350 feet I wouldn't likely be diving where the bottom is 600
feet down. In most cases, it's the bottom that your want to
visit. Why even go in deeper water?"
Perhaps you might travel over deeper water to
get to a shallower dive site? What if you sink
enroute?
You wrote..." Leaving your sub and
swimming to the surface may be a futile effort if your down deep, but what if
the bottom is only 60 feet down?"
Remember, I said in my post..."Totally
depends on your depth of course".
I agree with you Dan that it would be a good
idea to have the flood valve for that last ditch "just in case" if your sub is
not constructed with any other alternative and you have no chance to live but to
flood the hull.
But I think there is another alternative.
I think an escape pod is the future and real answer.
Imagine the cockpit of a Psub that has a
hatch built into that cockpit rear that can close it off from the rest of the
boat. Then there is a hatch behind that hatch that is built into the main hull.
Imagine an egg in a tube with a hatch built
into the rear of the egg and a main hull hatch just behind that with an upper
hatch in the tube over the egg. The egg is the cockpit pod and the tube is
the main hull. the egg fits
in the tube but can be floated out
thru the upper hatch.
When in normal operation you have both
hatches open. But in the event of an emergency, you could close off the main
hull hatch, (so the main hull would not flood to be recovered
later)
then also close the hatch just behind your
cockpit after disconnecting your quick disconnect fittings between the cockpit
pod and main hull leaving only the remote control wires for the upper hatch
over the cockpit pod
connected so you can remotely open the upper
hatch when the area around the cockpit pod is flooded and then blow those upper
hatch control wire connections with explosive bolts. Then float the entire
cockpit pod up and out.
In other words make your cockpit ejectable as
your escape pod. We do it with jet fighter cockpits so why not with a Psub? I'm
sure it would be complicated, but then again....this is a sub we are talking
about. They are by nature
complicated. I know mine is and it is just a
simple wetsub. Speaking of which, I started construction of my wetsub canopy
frame recently and have it about 50% finished. It looks a lot like a canopy off
an AT-6 Texan fighter trainer from
the WW2 era. Still got to install the
plexiglass and sliding entrys for both occupants. I built it out of PVC tubing
and fittings and bent the tubing with a heat gun. Maybe one day if I live that
long I might build a dry 1 atmosphere sub with
that cockpit escape pod idea of mine. But
someone will probably beat me to it.
It's all I can do to organize enough time just get my wetsub operational
right now. Ah time. The real enemy.
Kindest Regards,
Bill Akins.
----- Original Message -----
Sent: Saturday, April 23, 2005 11:21
PM
Subject: Re: [PSUBS-MAILIST] Stupid Idea
was Burst Valve
Bill,
Take a look around the PSUBS site and you'll only
find one home built sub big enough to have a divers lockout
chamber, Carstens sub. Most actual personal subs are really
small. There is only ONE chamber, the one your in, and anything else
would pretty much double the size of the sub.
There is much more of a possibility that a sub
pilot wound end up in an emergency situation at the bottom then getting
there. If my sub is rated for 350 feet I wouldn't likely
be diving where the bottom is 600 feet down. In
most cases, it's the bottom that your want to visit. Why even
go in deeper water?
There could be entanglement hazards any where in
the water, but most likely near the bottom where lines and nets settle
to. There are several systems you could use to bring up a sub in
case of a system failure but entanglement may render them all useless.
Leaving your sub and swimming to the surface may be a futile effort if
your down deep, but what if the bottom is only 60 feet down. If stuck
there and you've waited as long as you think you can and help hasn't shown up
to cut you free, your going to want to, TRY anyway, to exit the sub.
I know there are those that say flood valves are
a waste of time, and even a bad thing to have in a sub, but if you already ran
through your emergency procedure check list, also your life support
system time and your still sitting in the dark at the bottom, wouldn't
you feel it was worth the hundred dollars for a few fittings and a ball
valve?
You know you can't push the hatch open once your
down more then a foot. After that you have to bleed off your
HP air into the hull to increase the pressure but if that doesn't bring it up
to ambient, all you can do is let in water and compress the cabin air
more. Remember you most likely already used most of your HP air blowing
ballast tanks at depth to break free. Eventually you can get out.
If you compress the cabin air fast enough and your not down to deep,
you might live to tell the tale. Might, is still better then dying at
the bottom.
I would rather return to the surface any other
way if possible, but in a small P-sub, $100 worth of plumbing
fittings and that one more item on the checklist may someday be the
difference in living or not. It's a VERY VERY last resort, after you
used all your upward thrust, blew all your ballast, dropped your
drop leads and waited for help.
I'll flood and throw away my sub anytime,
for even the chance, to live another day.
Dan H.
----- Original Message -----
Sent: Saturday, April 23, 2005 4:16
PM
Subject: Re: [PSUBS-MAILIST] Stupid
Idea was Burst Valve
Hi forum.
Why not have a diver lock out chamber as
an escape device instead of a burst/scuttle valve for the main hull? The
only reason I can think of that someone would
have a valve to let water into the subs main
hull, is so the pressure inside would equal the outside so you could
open the hatch to bail out. That means the sub would be dropping like a
rock at that point and you probably wouldn't
make it to the surface anyway by the time the sub flooded enough for you to
open the hatch and bail out. But with a
diver lockout chamber you wouldn't need to
flood the sub, just get into the lockout chamber and flood it and then open
the lockout chamber exterior hatch to escape.
Of course you would be lucky to escape anyway
in a situation where you might have to use the lockout chamber because if
you were going down by the time you made the decision
to bail out via the lockout you might be so
deep your body may not be able to stand the exterior water pressure. Also
you probably would only get one person out since there would
not be enough time to blow out the lockout
chamber for another person to use before the sub imploded if you were going
down fast. Totally depends on your depth of course.
Has anyone built a p sub that has an escape pod
built into it that could
jettison from the main sub and has its own
adjustable buoyancy? Just an egg, tube, or sphere that has no motor and
a simple breathing air and buoyancy system, for emergency bailout built to
hold the entire crew capicity of your p sub.
Kind of like an adjustable buoyancy non line
tethered version of the emergency McCann resuce chamber diving bell that
recovered submariners invented and built by Commander Charles B."Swede" Momsen the inventor of the momsen
lung,
Only much more streamline and actually built
into the sub so it doesn't stick out and can be jettisoned. Definately would
increase the size of the sub though to have this. I like this idea much
better than flooding the hull and breathing thru a
regulator while hoping the main hatch will open
and having to endure hypothermia and extreme outside water pressure.
Kindest Regards,
Bill Akins.
----- Original Message -----
Sent: Saturday, April 23, 2005 12:02
PM
Subject: Re: [PSUBS-MAILIST] Stupid
Idea was Burst Valve
I agree that the Burst valve isn't a good idea, which
could end up killing
people.
The flood valve (AKA scuttle valve)
is NO JOKE and is going to save lifes.
That is unless you're spending
so much time and money that you would prefer
to die rather than get
your sub wet and live. Of course this is the VERY
VERY LAST
OPTION (well second last if you count dying as an option). You'd
have
to be a fool not spend the few $$ on way out of your sub in
an
emergency.
For those who choose to death over a flood valve,
make sure you have
enough CO2 absober to out last your O2 supply,
otherwise it's going to
end with a very painful
headache.
Captain goes down with his
ship?
Ian.
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