Brent,
He was operating under conditions that were not an emergency in nature so the blow down could be controlled. One of the reasons for a fast blow down is that they have to get up to 120 (or more now) crew members off of the stricken sub at a rate or two or three at a time. If they could get 3 out each time, that would be 40 total escape cycles at lets optimistically say 10 minutes per cycle to enter, close up and check seal, press down, escape out the inclined escape tube from the trunk, remotely close the outer hatch from inside the sub, drain down the trunk, and prepare for another escape cycle. So we are looking at least 400 minutes…close to 7 hours if everything went perfectly. In reality this doesn’t happen and bodies have had to be removed from the trunk during most other real emergencies.
As the Navy’s escape paper noted, people experience more difficulties with a “press down” that involves an air bubble vice a completely flooded chamber. I would support this based upon my observations during numerous chamber runs with inexperienced personnel.
R/Jay
Resepectfully,
Jay K. Jeffries
Andros Is., Bahamas
Save the whales, collect the whole set.
From: owner-personal_submersibles@psubs.org [mailto:owner-personal_submersibles@psubs.org] On Behalf Of Brent Hartwig
Sent: Wednesday, August 05, 2009 4:03 PM
To: PSUBSorg
Subject: RE: [PSUBS-MAILIST] Escape from sub
Hi Jay, It's interesting you mentioning the HO-HO-HO technique. Just two days ago I was over on the far west side of Lake Pend Orielle in Idaho just off shore of the deepest part of the lake where the US Navy plays all the way down to the bottom at 1,150 feet. I was picking up a 16 foot Hobie Cat from a friend that wants me to do my subs first test dives off in front of his dock. He has a retired US Navy Seal neighbor that came over to talk to me about diving my sub, and being my first test dives safety diver. He was telling me about how they would routinely blow and go from 150 feet and yell GO-YO-HO or some thing like that as they ascended. I'll be speaking with him again soon, and will write it down this time. But the effect is the same in any case.
He said they would be in control of the blow down speed, so they could better clear there ears as they went down, and if they went to fast, they would stop and go back until they could clear, then continue on with the mission. He said they didn't usually have any issues with blowing there air drums. He did damage one ear on a dive that they pushed him to far on, and ever after that, he would have to have the dive tech pierce that one ear drum with a needle before some ops, so he could clear. He wasn't very happy with the US Navies disregard at the time for there long term well being.
Regards,
Szybowski
From: bottomgun@mindspring.com
To: personal_submersibles@psubs.org
Subject: RE: [PSUBS-MAILIST] escape from sub
Date: Tue, 4 Aug 2009 22:13:26 -0400
The Brits used buoyant thermal suits and you will need some controlled buoyancy to get up to the surface during an emergency ascent. Being slightly negative and with lots of drag added from clothing it will probably be impossible to get to the surface without added buoyancy….you are going nowhere (and sometimes even sinking) without buoyancy. You want to make this as simple as you can. You are going to find trying to deal with a plastic bag impossible in the most stressful emergency situation you will ever deal with. You want to get to the surface as fast as you can…submariners practicing escapes shoot out of the water up to their knees. You will flare your body out on the ascent by outstretching your arms and bending your head back, this opens your airway and allows you to HO-HO-HO.
Keep the solution simple using as little equipment possible otherwise you are task overloaded and will screw up. You are correct in noting that if you feel the pressure in your lungs, it is probably too late. You will have a pneumothorax which can lead to an embolism.
Respectfully,
Jay
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