RE: [PSUBS-MAILIST] Buoyancy Options During Escape

Hi Jay,

I plan to have a Steike hood in the sub. Those conning towers can be tight. The smaller Kevlar or carbon fiber tank I could escape with, would be in the sub to breath off of during blow down if I don't use air from another source for that. I might just use a standard tank inside the sub to breath off of, and use for back up for the two primary external HP tanks mounted under the stern deck. Then use the smaller Kevlar or carbon fiber tank for exit. The lighter tanks on the exterior are to give me a better CG and CB since they are mounted higher then when they were in the interior. With all I'm doing to the sub, and adding inflatable amas, it very well, might not be needed. So I might whined up just using a pair of smaller galvanized steel tanks that can handle more pressure then the aluminum 80's that have a smaller OD, to better fit under my small aft deck.

For the exit tank, I was thinking I would need it to be positively buoyant. But not so much so that I couldn't deal with it.

Regards,
Szybowski

From: bottomgun@mindspring.com
To: personal_submersibles@psubs.org
Subject: RE: [PSUBS-MAILIST] Buoyancy Options During Escape
Date: Wed, 5 Aug 2009 06:24:51 -0400

Brent,

You want the collapsibility of a typical horse-collar of buoyancy control vest to be able to get out of the sub with it on, then inflate once outside or standing in the con clear of all potential snags. Nothing is gained by going to Kevlar or carbon fiber wrapping a tank. Firemen use this type of tank to decrease weight due to all the equipment they must carry in a trying environment. In the water a regular aluminum or steel tank is neutral or near neutrally buoyant. Depending on your set-up inside your PSUB, you may want the tank stowed inside so you have something to breath off of until flooded down and out side of the sub.

Both of your solution add quite a bit additional cost and do not simplify the escape evolution. KISS!

R/Jay

From: owner-personal_submersibles@psubs.org [mailto:owner-personal_submersibles@psubs.org] On Behalf Of Brent Hartwig
Sent: Wednesday, August 05, 2009 3:45 AM
To: PSUBSorg
Subject: [PSUBS-MAILIST] Buoyancy Options During Escape

If one is not using a Steike hood for buoyancy, one thing comes to mind, perhaps syntactic foam inserts for a vest might be a option. The other option I was asking a SCUBA instructor about, was the use of the carbon fiber or Kevlar high pressure tanks that firemen some times use, and are used for a variety of other applications that require very high pressures in a light tank. This tank could be the one you leave the sub with, and hang onto for dear life. The other use I had for them is to mount them under my stern deck, which will give me some more interior room, and not be heavy higher up on the sub.

Do you guys think those ideas will sink or float? ;}

I think that's a bit Letterman does.

Szybowski