In The Navy (Sub School), Part 4

Sub School is designed to separate the guys who can handle Subs out from those who cannot. One of the first really physical tests we had to get through was the hyperbaric chamber. It’s about 10 feet long and 6 feet wide. When you went in, it was at room temperature. You were locked in this tank with about 8 or 10 other guys and an instructor/diver. It’s the kind of chamber they use to decompress people who had been diving very deep and came up too fast, causing the Benzes. Before entering, we are told anyone with a cold has to leave, as stuffed up sinuses can lead to broken ear drums.

So we are crammed in there like sardines, shoulder to shoulder. They start slowly raising the pressure inside by releasing high pressure (HP) air into the chamber from an external tank. There is a gauge that shows you what the equivalent depth would be. By the time we passed 200 feet, it became noticeably a bit warmer. The pressure kept going up steadily. At 500 feet it was like a sauna in this thing, and it only took about 15 minutes to get there. Down, down down, we virtually continued. One guy (or more, inevitably I am told) popped an eardrum and had to be bailed out into the adjoining chamber to decompress immediately and head up to the Hospital. It seemed very painful.

http://www.answers.com/topic/pressure-chamber-jpg-1

We reached a max depth of 750 or 800 feet and everyone was sweating. We got a quick refresher in “clearing our ears” which is a divers trick where you pinch your nose shut and close your mouth and then push from the diaphragm. It forces your ears “pop” like they do when you are flying in an airplane or going over a large hill in a car, which equalizes the pressure on both sides of the ear drums.

All the way up, we all kept popping our ears. It started getting very cold now and at one point, the water in the air actually turned into little snow flakes and fell to the floor. The windows of the tank were frosted. As we neared normal atmosphere, they slowed the pressure release. It seemed to take forever. We had no one bail out because of claustrophobia, but I hear it’s a common occurrence. If you do bail out, you get a ticket to the Surface Navy (no offence…really).

Getting shipped off to the Surface Navy was the same thing that happened to guys that failed the now mandatory piss tests we had to take “randomly”, based on a letter in the last name.

After the Tank, we were warned to not take any flights for a few days, because we had been subject to more than enough pressure for a while. Apparently it’s bad for the heart. I unfortunately had a flight booked to go back home for the Labor Day long weekend and I went anyway. I can report that everything went fine.

So the first big test was done, we had two more to go through, the Dive tank and the Damage Control tank. Each one was a very serious test that could seriously hurt you if you freaked out and panicked. Even though they take safety precautions, this is not kids play.