Fitzgerald’s Journal

This is an old post from my old journal.

They don’t make submarine sailors go through “Pressure and escape” training any more.  I don’t think, I’m not really sure because I retired from the Navy back in 2000, and I got out of the sub Navy after getting a commission as a Naval Officer and becoming a cruiser sailor back in the nineties (that is another story).  But back when I attended submarine school in the early eighties they did.  

It was one of the most awesome moments in my life.  I know people throw the word awesome around like it’s nothing, but when I say awesome, I mean like jumping out of an airplane kind of awesome.  But people jump out of airplanes all the time, not too many people get to try to escape from a submarine.

First to give you a little background, you know the drill, I have to try to put this stuff in context (and I hope not to bore you either).

I could not even swim when I joined the Navy at eighteen.  As many African Americans could not back in those days, and as many do not today.  But a testament of how well the Navy trains people, I learned not only to swim but made the buoyant assent that was a part of pressure and escape training.  All within the span of a couple of months.

It was those Navy Seals that made me sat on the bottom of the pool (underwater) and proved to me that, (a) they were not going to let me drown, and that (b) you can’t really drown in a swimming pool (according to them it was not deep enough), and that if I did drown, (c) they would pull me out of the pool and resuscitate my sorry ass and throw me back in the pool for more training.  

You will not believe how motivated you can be when you think you are about to die.

Pressure and escape training was a three stage training event that all submariners had to go through.

1. Valsalva maneuver or equalizing your inner ear.

The first thing that you have to be able to do is equalize the pressure inside your head by exhaling air, while blocking off you nose and mouth.  This cause your inner ear to pressurize.  Some people can’t do this, and the ones who can’t, can never become submariners.  

The reason that it is important to be able to do this is because in the older submarines you could be exposed to rapid air pressure fluctuations.  As air moved about the submarine the pressure would (and often time did) change very quickly, due to the opening and closing of hatches and the starting of equipment and other things that effected the air pressure inside the sub.  

If these rapid pressure changes happen and you can’t equalize the pressure in your inner ear then your ear drum will rupture.  Not good!

2. Pressure testing or time spent in a pressure chamber.

Then there is the actual pressure testing.  This was so much fun.  You are placed in a pressure chamber and exposed to increased air pressure to simulate the pressure that you could be exposed to if you had to exit the submarine at depth.  

One of the really cool effects of this are that as air is compressed it gets hot, so the temperature in the pressure chambers rises.  I love being warm and it was a little intoxicating also because I think that as the air is pressurized your lungs take more of the oxygen out of it.

But the depressurization part of this test is also very cool (and I mean that literally), as air pressure in the camber is released the air begins to cool off.  We had been sweating as the pressure was increased but as the pressure was decreased our sweat turned into frost.  Quite and interesting effect to be exposed to.  If your mustache has ever been frozen, then you have experienced that part of it (growing up in the south, this was the first time I ever experienced that sensation).   It was like going to a spa and going from a sauna and then into a refrigerator, within a few seconds of each other.

3. Escape Training or you mean you want me to swim all the way up there

Actual escape training is the simulation of escaping from a submarine.  The building in the picture above is the escape trainer that is located in Pearl Harbor HI and there is also one located in Groton Connecticut.

It is basically a swimming pool that is over 300 feet deep.  With a diving bell on the side.  How cool is that?  If I could, I’d have one built in my back yard.

Now what really made this an exhilarating experience was that when you are underwater, your lungs are being exposed to water pressure.  So if you breath some air that is pressurized for a certain depth, as you rise your lungs will be under less and less pressure.  And the air that is in your lungs will expand.  This is a really cool fact of escape training, and I hope I am making sense here, because what this means is that as you rise from the lower depths, you need less air.

That is correct, you need less air.

This is counter intuitive to what you would think, and you have to be trained to not try to breath in, but to exhale all the extra air that you will have in your lungs due to decreased pressure as you rise.  Make sense?

OK if not, then think of it this way, your lungs are two balloons.  And as they are exposed to less and less pressure they get bigger.  If you do not exhale as you are rising from depth your lungs will explode.  And this, by the way, has happened to people. Not good! Actually this would be bad!

That is what made this training awesome, just wondering if your lungs were going to explode or not.  I am happy to tell you that mine did not. And that was good.

And when I reached the surface, I actually left the water and shot into the air.  I mean I was flying upwards like a cork.  It is like falling upwards, or skydiving underwater.  Those who have gone underwater diving and made rapid assents probably know what I am talking about.

So if you are wondering, I can take the pressure and I know how to escape ; )

You can read more about it here

Submarines in the US Navy