Take A Good, Deep Breath. End of a Gosport Era.

capnsensible

capnsensible

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Those of you who use or have sailed in/out of Portsmouth will probably recognise the Submarine Escape Training Tank at Fort Blockhouse, ex HMS Dolphin.

As of earlier this year, training there has finally ended after a long and amazing career. I think wet training finished a while ago but the whole facility was still used. However with the Submarine Flotilla moving to Faslane, it certainly was a waste to send the chaps back to Gosport. Seems a new trainer is opening at HMNB Clyde with the latest generation of submariners being taught the new stuff.

Its a listed building so will remain as a familiar landmark and will always be remembered by those who 'did the tank'.

End of era for Gosport’s iconic submarine escape tower

Submariners do it deeper! :cool:
 
capnsensible said:
Those of you who use or have sailed in/out of Portsmouth will probably recognise the Submarine Escape Training Tank at Fort Blockhouse, ex HMS Dolphin.

As of earlier this year, training there has finally ended after a long and amazing career. I think wet training finished a while ago but the whole facility was still used. However with the Submarine Flotilla moving to Faslane, it certainly was a waste to send the chaps back to Gosport. Seems a new trainer is opening at HMNB Clyde with the latest generation of submariners being taught the new stuff.

Its a listed building so will remain as a familiar landmark and will always be remembered by those who 'did the tank'.

End of era for Gosport’s iconic submarine escape tower

Submariners do it deeper! :cool:
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Have they built a tall chamber, or just rely upon the heavy rain?
 
It will be interesting to how they preserve the Gosport tower. My sources in Fort Blockhouse tell me they can't drain the water out as the tower will then collapse so they are thinking of replacing the water with sand which will be a very slow and laborious exercise as they would have to put some sand in then take some water out and repeat until all the water has gone.
 
Giblets said:
It will be interesting to how they preserve the Gosport tower. My sources in Fort Blockhouse tell me they can't drain the water out as the tower will then collapse so they are thinking of replacing the water with sand which will be a very slow and laborious exercise as they would have to put some sand in then take some water out and repeat until all the water has gone.
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Fish breeding?
 
Poignard said:
... and keep breathing out or someone will grab you and give you a thump in the stomach!

Did they still use the twill trunk?
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Loong ago since that was practised. The 30' and 60' ascents were via a side chamber into the main tank.

Compartment escape was, IIRC, practised as a demonstration but the into the 100' one man escape tower ascent.
 
Happy days in the dunker but we all felt deep, deep respect for the guys that did the escape training from the bottom.

I wonder why they say it would collapse if the water was drained out? It must have been built before they ever put water in it.
 
JumbleDuck said:
Are the ear-drum bursting knives still issued?
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.

:eek: I don't remember that particular horror but it was almost 60 years ago. I do remember being told we would be issued with some kind of very large thick nappies to put on before a real escape because, if I remember correctly, it is the cold around the lower back that hastens death by exposure .
 
I’ll confess now that I did the SETT nearly twenty years ago. The 100’ ascent was in a escape suit ‘breathing all the way to the surface’. The chamber was at the top of the tower and before you went anywhere near the water you got pressurised to check a few things. I remember taking the lift up and looking down into the column of water for the first time. Then watching a escape instructor jump in and swim to the bottom free diving (ie with no tank.). There was a little inverted bell at the bottom they could duck underneath and breath in. On the last run (from the bottom) as the hatch opened youbcame out on a tether. The diver came over and checked you were ok before releasing you and monitoring you all the way to the surface.

I loved the whole training and thought you could have sold tickets for it as it was better than a theme park. (But with a serious side).
 
Slowboat35 said:
I wonder why they say it would collapse if the water was drained out? It must have been built before they ever put water in it.
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It's quite common for old swimming pools to be undrainable because water has penetrated the tank concrete behind the tiles and without the water in the pool hydrostatic forces push the tiles off. My local pool uses divers to do grouting for this reason - they had to do an emergency drain some years back and were closed for a month while they stuck a huge number of popped tiles back on. Perhaps something similar has happened to the escape tower.

Poignard said:
I don't remember that particular horror but it was almost 60 years ago.
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My father-in-law did the course fifty years ago when his employment as an engineer took him on a submarine for a while. They were shown neat little tubes: you stuck them into your ear and then pressed a button on the end, releasing a small sharp knife which made a neat hole in the eardrum to avoid busting it completely in the escape. Only used for really deep escapes, apparently, no he didn't have to use one ...

john_morris_uk said:
The diver came over and checked you were ok before releasing you and monitoring you all the way to the surface.
Click to expand...

My f-i-l says they were told to breathe out all the way up to avoid busting a lung, and lurking swimboys would punch you in the stomach if they failed to see bubbles coming out of your mouth as you rose.
 
Not sure why any would want to pierce there ear drums, The main danger is to your lungs if you don’t exhale, You can’t feel them being damaged, or so I am told,
I was never a submariner so I wouldn’t know.
As a diver I have practiced free assents, and have had to do one for real. From about 20m
Equalizing my ears was never a problem coming up. Going down it’s the first few meters which could be painful.
At 30m narcosis is really quite noticeable,
Free assent from much deeper and decompression will probably be an issue.
 
JumbleDuck said:
My f-i-l says they were told to breathe out all the way up to avoid busting a lung, and lurking swimboys would punch you in the stomach if they failed to see bubbles coming out of your mouth as you rose.
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Exactly what we were told and the reason we were monitored all the way to the surface from the deep escapes. The practice ones from shallower were for us to ‘purse your lips and make a hole the size of a pencil and breath out through it all the time.’

We also had demonstrations of a balloon inflated at the bottom of the tank and released to float to the surface but burst en route. “And this is what will happen to your lungs if you hold your breath and forget to breath out... AND YOU WILL DIE”.

I understand that they stopped using the SETT because too many trainee submariners did die when things went wrong... but that might have been just a story/gossip doing the rounds. They’d certainly stopped doing the mass escape practice run where you form a line and the whole compartment is pressurised to allow continuous escapes rather than individuals in the escape suits.

For those who are interested, the MUCH preferred option would be for the submersible LRV5 to come and latch onto the escape hatch and for the trapped submariners to be taken to the surface a few at a time in comfort and the dry...

(I hope I’ve remembered the name of the submersible correctly.)
 
If I remember correctly we were trained to use the two different systems then in use:

System 1. A trunk of strong twill cloth, 2 to 3' diameter, supported at intervals by steel hoops was let down from the hatch surround to which it was attached at the top with a watertight seal. It had guy ropes to keep it in place.
This trunk extended down to within a few feet of the deck.
Both doors of the compartment were shut.
Water was allowed to flood into the compartment until no more could enter because the pressure inside equalled that outside.
By that stage the lower end of the trunk was underwater.
We were then breathing pressurised air.
Somebody, previously detailed off, opened the hatch above, giving access to the sea.
This was easy because there was equal pressure both sides of it.
One at a time, we took a deep breath, ducked under the twill trunk and floated to the surface. Breathing out because the air we had taken into our lungs at high pressure was expanding all the time.

System 2. A cylindrical chamber was permanently mounted inside the hull. Large enough to stand in.
At the top it had a spring-assisted hatch opening to the sea.
There was another horizontal hatch at the bottom end.
The hatches and valves could be operated from inside or outside the chamber.
The first escapee climbed into the chamber through the lower hatch and it was then shut.
The chamber was then flooded until the pressure equalised and no more flowed in.
The upper hatch then opened and he floated clear.
The process was repeated as necessary.
The last man had to operate everything from inside the chamber.
Presumably each had to wear some kind of equipment that gave him an air supply. I can't remember now, it was a very long time ago.

One thing I can remember that surprised me was that the water in the tank was warm. Perhaps it was a hot day or maybe it had to be kept warm for the instructors!
 
JumbleDuck said:
My father-in-law did the course fifty years ago when his employment as an engineer took him on a submarine for a while. They were shown neat little tubes: you stuck them into your ear and then pressed a button on the end, releasing a small sharp knife which made a neat hole in the eardrum to avoid busting it completely in the escape. Only used for really deep escapes, apparently, no he didn't have to use one ...
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Total wind up Im afraid. Bet the lads had fun with that one!

For free ascents, you have to breathe out all the way up, forcefully, as the air in your lungs expands as water pressure reduces. Deaths in the tank were extremely rare. But unfortunately, I knew a chap quite well who was the last one.

Compartment escape using a Submarine Escape Immersion Equipment suit is different. Once in the tower, you breathe air via a tube into a hood thats open under your chin. The tower is flooded to about the top of your head. The tower is then pressurised to 100' and your air supply is kept a couple of psi above that. Hatch opens, diver tethers you to a taut wire and off you go. You breathe normally (only need to do a couple of exhales, its quick) as excess pressurised air vents from the gap under your chin. Its quite quick and quite exciting.

The tank safety divers do a demonstration ascent from the bottom of the tank using an inverted bucket. They are Very Good.

Still although those days are now gone, the Tank Staff are the hardcore blokes that form the Submarine Parachute Assist Group. Nutters. :D
 
For Poignard. Yup the first method is compartment escape. Whole compartment flooded then pressurised. Big problem with that is 'time spent under pressure'. Its gonna be fairly slow to get mebbe 50 blokes out so near the back of the queue, survival chances diminish very rapidly.

One (or for some classes of boat 2) man escape towers meant very little time under pressure and enhanced survival. The last escaper has to be able to pressurise the escape tower from inside so is provided with the interestingly named 'last man vent cap'.......

The 'nappy' bit is true. Urine floating around inside your suit will gather by your lower spine and will chill to cause problems.
 
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