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Re: [PSUBS-MAILIST] Stupid Idea was Burst Valve

Bill,
 
Sorry if I got on the band wagon about flood valves.  It's not the first time it has been mentioned in here and I'm sure not the last.  I'll be counted as a vote for every sub having the ability to flood as a last ditch effort.  I agree with you that an escape pod would be a much better and safer ride to the surface, no argument there. 
 
I'm sure that there are many subs around the world that have escape pods or diver lockout chambers.  I haven't scrolled through the PSUBS pictures in a while.  The only sub in it I was aware of that was of a size to have this capability was Carstans. 
 
My point was and is,  a P-sub, although a  big undertaking in time and money for most individuals, is still a toy sub in the corporate world.  Most, not all, but most P-subs that get built can easily afford an escape hood and a method to flood and exit the sub.  It's a cheep addition.  The cost, additional engineering, and construction of an escape pod or divers lockout my very well make many potential builders never see completion or never start at all. 
 
My sub isn't big.  It's a K-350 and believe me, there isn't room for a lockout or escape pod.  In the small hull of most P-subs there isn't room to have hatches that are left opened or room to swing them closed.  One thing that may be applicable in some smaller subs, although still adding some to the cost and construction, is a design with the thrusters and battery pods on a frame that the hull can be released from.  I looked at this idea before I built, but for simplicity, opted not to construct that way. 
 
Yes, it is possible to be over water that is past your subs diving depth, but! 
A P-sub doesn't have a long range if it's battery powered and most are.  If your traveling to a dive site, most likely your sub is doing it behind a surface boat with you on it's deck and not in the sub. Even if you were in the sub, traveling along the surface to a dive site it's a highly unlikely place to get into trouble.  Sure you can always find trouble, look at the Titanic, but in most cases it's a safer place then at the bottom.  Even loosing all three of my ballast tanks while on the surface and not entangled in something holding me at the bottom can be counteracted by dropping my 250 pounds of drop weight.  No, the real danger is near or at the bottom. 
 
Don't make P-sub's so complicated that they don't get built.  Make it as safe as you can afford and know how to build correctly.  A divers lockout or escape pod would be very nice but, like cutting edge alternative power sources for P-subs, they're not always feasible. 
 
Dan H.
 
----- Original Message -----
From: Akins
Sent: Sunday, April 24, 2005 5:11 AM
Subject: Re: [PSUBS-MAILIST] Stupid Idea was Burst Valve

Dan.
 
Here's some homebuilt P subs with diver lockout chambers in addition to Carstens sub. 
 
Take a look at this link to see Peter Madsen's Kraka sub with a diver lockout chamber. I love the look of this one. Check out those torpedo tube viewports!  http://www.vulcaniasubmarine.com/KRAKA.htm
 
Then there's the VAS 525 sub with a diver lockout by Greg Mooney. http://www.psubs.org/psub_pic/vas525.html
 
Here's a really small Psub called baby built by mark with a diver lockout. http://www.psubs.org/psub_pic/SubMark.html
 
Still another one. Scroll down to where it says "Mini Subs (Submersibles) for sale"  http://www.submarines-rovs.com/newsletter_feb_2005.html
 
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 -----
From: Dan H.
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 -----
From: Akins
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.