Rapid Emergency Ascent

[SailNaked]

Do you just hold the last breath from inside the sub till you breach the surface? there would be no decompression but how deep is the deepest free dive? what would it feel like on your lungs to have only one Atm of air in 18Atm of water? I suppose if you had to you could survive holding your breath for 2 minutes but I would think the Adrenalin would make it very uncomfortable.

Edit: I watched the video, looks like you have plenty of air in the suit. at depth pressure and you breath normally (or as normal as you can leaving a sub on the bottom of the ocean). I guess air at 600ft is ok to breath if you are not staying long? maybe they pump in some Trimix?

 

[Thalassamania]

No, you continue to breathe normally inside the suit using the built in breathing system.

 

[H2O 70]

You can hear the candidate/student doing the 'ahhhhhh' thing on the way up.

I imagine as soon as they open up the sub to the outside, they would then be experiencing that pressure. Since they are still breathing in the bubble suit once they are exposed to the pressure I'd suspect they would still be subject to Boyles law.

 

[Thalassamania]

The feel the pressure as the escape trunk is flooded, you can not open the hatch until the pressure is equalized by flooding.

 

[iztok]

Wonder how they provide pressure inside the suit at the ambient water pressure so quick. If we are talking 600ft we are talking difference of over 18 ata.

 

[Puffer Fish]

I've been thru the San Diego tank after my instructor cert...

Read the comments attached to the video....

But you have to pressurize the suit as the water is coming in if you want to do any one really deep.

I remember the bottom of the San Diego tank being at 120, but they said 100... humm, was a long time ago.

YouTube - Submarine Escape Tank Training(SETT)

 

[bleeb]

Wonder how they provide pressure inside the suit at the ambient water pressure so quick. If we are talking 600ft we are talking difference of over 18 ata.

WWII subs kept large tanks filled with high pressure air, and AFAIK modern ones still do. Primarily used to displace water from the ballast tanks. IIRC in the aftermath of the Thresher loss, most industrialized countries' navies significantly increased the amount of air storable in those tanks, so that in an emergency, they'd have enough air to blow the ballast tanks dry more than once as well as filling all the crew escape suits and hatches, even below normal operating depth.

 

[AndrewA]

As a brief aside. A few years ago I attended a lecture by the physician who supervised the Royal Navy exercise off Norway when the 601ft escape was made.These ascents were made from one of the RNs last diesel boats. During the escape if the submariner had a problem in the escape tube he was to give the alarm by banging on the wall of the chamber with a wrench! During one drill a banging was heard and a full emergency surface of the boat was made (Full blow of the balast tanks and max power from the motors) Aparently the escapee had not given the signal and had an amazing ride to the surface with his head and shoulders half out of the escape hatch. The physician was in a Gemini on the surface when the sub made the very spectacular appearance.

 

[iztok]

WWII subs kept large tanks filled with high pressure air, and AFAIK modern ones still do. Primarily used to displace water from the ballast tanks. IIRC in the aftermath of the Thresher loss, most industrialized countries' navies significantly increased the amount of air storable in those tanks, so that in an emergency, they'd have enough air to blow the ballast tanks dry more than once as well as filling all the crew escape suits and hatches, even below normal operating depth.

I get that part. I was more concerned about big "bounce dive" that pressure will cause to the person.

 

[Bob DBF]

It's all to make mom feel better. Take a map of the worlds oceans and color in the portion that is 600' or less. The Nuc boats I rode went past the 100 fathom (6'/fathom) curve before we submerged. The inside of the submarine is at 1ATM (plus or minus which is why there is an altimeter in engineering) and a pressure hull of thick and strong steel keeps out the water. Most of the ocean is deeper than the crush depth of the submarine.

The people that make the test ascents from 300' and 600' are the best Navy (US or Brit) divers they can train. My understanding is that in actual use at these depths by submariners 50% mortality would not be surprising, more without surface support. That bounce dive would be a bear iztok but would look a lot better than sleeping with Davy Jones.


The only historical emergency ascent was made when the USS Tang was sunk by a circular run of a torpedo in 1944.

"Thirty men had survived the blast. They gathered in the forward torpedo room with the intention of getting out through the forward escape trunk. Only five would survive the ascent and subsequent exposure in the water. In all, eight of the crew survived. They served out the remainder of the war in a Japanese prisoner-of-war (POW) camp."


Bob
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Qualified Submariner