RE: [PSUBS-MAILIST] Compression Time Tables for Wet Exit

[Brent Hartwig <brenthartwig@hotmail.com>]

Hi Jay,
 
Thank you for the data.  I would of liked to of heard your presentation. Perhaps someone video taped it? 
 
If you need to do a wet exit and the water is not over say 150 fsw deep, then if you could have a specially customized multi piece zip on heavy wet suit to help deal with the cold and/or your in reasonably warm waters. Couldn't you compress up the sub with air from the HP air systems to match or closely match the external pressures before you let water in by opening a special large top vent and the normal flood valve, to get your body up to pressure without damaging your ear drums and stay dry longer?  Then ascend with a weighted SCUBA tank and perhaps a BC, with normal decompression stops along the way using a laminated dive table, dive watch, dive lights?  Of course as we know the best laid plans of mice and men. Having your ear drums broken, can't be good for your concentration in dealing with an emergency.


Regards,
Brent H

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From: bottomgun@mindspring.com
To: personal_submersibles@psubs.org
Subject: RE: [PSUBS-MAILIST] Compression Time Tables for Wet Exit
Date: Sun, 6 Jul 2008 17:58:46 -0400

Brent,

I gave a presentation at last year’s Conference that covered these issues.  While what may seem reasonable under normal circumstances does not always apply in an emergency.  I made this point in my opening comments by tossing an object at an unsuspecting individual in the audience…of course he caught it.  If it had been a broken piece of jagged glass, catching it would have not been the correct response.  Our learned experiences have to be tempered in emergencies.

 

Analysis of previous submarine disasters and actual experimentation points out that the vessel should be flooded down as quickly as possible resulting in probable ruptured ear drums if at any significant depth.  The concern is to minimize exposure to the debilitating cold water and hyperbaric conditions (thus minimizing arterial gas embolism [AGE] and decompression sickness).  The odds are not real good for getting an unconscious crew member out of a stranded sub by escape means.

R/Jay

 

From: owner-personal_submersibles@psubs.org [mailto:owner-personal_submersibles@psubs.org] On Behalf Of Brent Hartwig
Sent: Sunday, July 06, 2008 4:26 PM
To: PSUBSorg
Subject: [PSUBS-MAILIST] Compression Time Tables for Wet Exit

 

Hello All,
 
I don't recall anyone talking about how fast you should allow your sub to fill with water for a wet exit. Of course the deeper you are the more dangerous every thing is. In the Captians book he just has you open the valve and quickly flood the sub once you've got your SCUBA equipment ready. My sub was an early model that doesn't have a valve, but a cap with a handle, that has a retaining rod, nut, and washer on the outside to keep the cap from hitting you and getting lost. I will replace this assembly with a valve and elbow like on Dan H's KH-350.
 
http://www.frappr.com/?a=viewphoto&id=2384531&pid=10133638
 
http://www.frappr.com/?a=viewphoto&id=2384531&pid=10133677
 
My experience with hyperbaric chambers has taught me that you need to clear you ears constantly when your compressing up and that not everyone can do this at the same rate if at all.  If your ears don't get cleared properly you need to reduce the pressure until you can clear your ears and then continue to compress up or you will do serious damage to your inner ear. 
 
If someone is unconcious in the sub with you I don't know how to clear there ears. We have this same issue when using hyperbaric chambers for animals. So I'm interested in your guys thoughts and personal experience in this matter.

Regards,
Brent Hartwig