The United States submarine Tang (SS- 563) lay on the bottom in one hundred and forty-two feet of water off the island of Maui, Territory of Hawaii. Three men were in the submarine’s flooded forward escape trunk, the water up to their chins.
“Ready to pressurize, Commander?” Bob Newby, commanding officer of the Tang, asked.
I nodded my head. Newby turned to Schneph, Gunner’s Mate 1/c, from the submarine rescue vessel Coucal.
“Ready to pressurize, Schneph?” Newby asked again.
“Yes, sir,” Schneph replied.
“Commencing to pressurize!” Newby reached out for the high pressure valve to the compartment and turned it. Air hissed into the twelve inches of space between the water under our chins and the steel overhead of the Tang’s escape trunk. Instinctively the three of us held our noses with our right hands. We felt the pressure hit our ear drums. We blew out, straining against our fingers clenched tightly to our noses. We blew against our fingers so our eardrums wouldn’t burst. The needle on the pressure gauge was going up fast. Thirty pounds, forty pounds, fifty pounds. So was the heat. The compressed air being forced into the tiny air space raised the air temperature. It was over a hundred and forty degrees now. Suddenly, there was a great gurgling in the compartment and the pressure against our eardrums ceased. A column of light reflected in the water under the metal skirt to the hatch above us.
“I’m going to duck out and see if the hatch is fully opened,” Bob Newby said to me. He ducked under the metal skirt and disappeared. Seconds later he was back.
“Was it opened?” I asked. He shook his head.
“Not fully,” he replied, and added, “It is now.”
I began to blow up my yellow fabric lifejacket through the oral inflation tube. At that depth and pressure, the CO2 cartridge wouldn’t inflate the lifejacket fully. Newby and Schneph watched me, puff by puff. At last the jacket bulged out around me, pinning me to the steel beams of the overhead. I could hardly move.
“Ready, Commander?” Newby asked.
I felt for the bottom of the metal skirt leading up to the open hatch and replied, “Ready.” I took a deep breath and pulled myself down under the metal skirt. On the other side the buoyancy hit me and I had to struggle with both hands to hold on. My head was clear of the hatch. I could see the line leading to the life raft on the surface and up above, far away, the sheet of light that was the surface itself. I pursed my lips and blew out my air. Then, I let go of the metal skirt. The inflated lifejacket took charge. I began to gain velocity. Faster and faster I went. At fifty feet, I passed the aqua-lunger stationed on a line as safety man, so quickly that he had difficulty following me with his eyes. I broke the surface of the sea like being shot out of a gun. The observers in the photographic boat said I came out of water clear to my knees. It had taken only twenty seconds to come up from the submarine Tang lying on the bottom one hundred and forty-two feet below me. I put my face in the water. I couldn’t see the submarine. If I had held my breath on the way up, I would have been dead.
This wasn’t a stunt, this escape from a bottomed submarine in the open sea with no breathing apparatus of any kind. When I went out through the forward escape trunk hatch of the bottomed submarine Tang with only a lifejacket on, it was the climax of months of training. It was the final proof of a new method of escape from sunken submarines. The United States submarine forces have recently adopted this new method. It is called buoyant escape. The wonderful part about buoyant escape is that it places the main reliance for escape from a sunken submarine on the man himself and not on some artificial breathing device. It will permit men trapped in any compartment of a submarine sunk in salvagable waters to make an escape if they remember their training and carry it out correctly. In teaching this technique, we use an inflatable lifejacket but in an actual disaster anything which would provide positive buoyancy, such as an inflated pillow case or an inflated pair of trousers with the legs tied, would do just as well. We also use a nose clip or a face mask in training but these are not necessary. They simply prevent the discomfort of getting water up the nose. Let’s take a run in the escape training tank at the Submarine Base, Pearl Harbor, to see what the technique of buoyant escape is and how it is taught.
The escape training tank at Pearl Harbor is 100 feet deep and 18 feet in diameter. It holds 209,331 gallons of water. Up and down the side of the tank are compartments having locks from which escapes at various depths are made. We start out by going into the eighteen foot lock. It is called that because the lock from which we are going out is eighteen feet below the surface of the water in the tank. The compartment itself is small. When we stand up, the steel overhead is only six inches above us. We close the outside door to the compartment. The instructor shouts into a waterproof microphone to the safety personnel in the tank outside, “Starting to flood down!” The instructor begins to turn the handwheel to a large valve at his right. Water starts to seep in around our toes. In order for the water to come in faster, the instructor also opens a small vent valve. Air hisses, escaping from the compartment. The water continues to rise. Soon it is to our knees. Then to our waists. The water is coming in from the escape training tank and it is warm, due to the heat of the bright Hawaiian sunlight. When the water gets up to the top of the watertight door which forms the lock into the tank, the instructor turns the handwheel to the large valve again, closing it. The water stops rising. It is up to our chests. The instructor looks around. “Now I’m going to pressurize the compartment,” he says. “If anybody has trouble with his ears, just hold up your hand and I’ll stop until your ears are equalized.” We suddenly remember that we are 18 feet below the surface of the water in the tank and for every foot we go down, the pressure increases .44 pound per square inch. That means that the pressure in the compartment is going to increase by 7.92 pounds per square inch or about 50% more pressure than the normal atmospheric air we have been breathing. The instructor shuts off the vent valve and opens an air valve. “Topside! Starting to pressurize!” he shouts into the microphone above the noise of the inrushing air. We hold our noses and blow against our eardrums. They pop, relieving the pressure building up against them. It doesn’t take long for the compartment to pressurize. Eighteen feet isn’t very deep. Suddenly, the watertight door to the lock blows open. Air from our small compartment bubbles out the door frame and we can see the inside of the escape tank.
“First man,” the instructor says. That’s you! You are wearing a yellow inflatable lifejacket and hold a nose clip in your hand.
“Put your nose clip on,” the instructor says. “Now remember what you are going to do. As soon as you step through that doorway, blow out all your air! And keep blowing it out all the way to the surface. You have fifty per cent more air in your lungs now than you would have on the surface and if you hold your breath on the way up your lungs will rupture. There’ll be an instructor outside the door in a shallow water diving mask who is going to hold you down until you blow out all your air. If you don’t blow it all out, he will push you back into this compartment. We don’t want you to upset our safety record.”
You nod your head and put your nose clip on. The instructor reaches out for an air hose attached to the bulkhead. You grab the oral inflation tube to your lifejacket and point it at him. He inflates your lifejacket with the air hose. Saves time. There are other trainees behind you. In seconds your yellow lifejacket is bulging around you.
“All set?” the instructor asks. You nod your head again. “OK,” the instructor says, “Take a deep breath and out you go. And remember, when you get outside, keep blowing out that air.”
You take a deep breath and duck your head under water. The instructor helps you fight against the buoyancy of the inflated lifejacket. At last you are through the doorway. Unseen hands grab you and hold you down. You feel someone pushing you in the stomach. You blow out your air. The hands let go. You shoot toward the surface. Exactly four seconds later you bob up, your head held high above the water by the straining lifejacket. Why didn’t the lifejacket burst? It has relief valves in it. Like you, it has been letting off air all the way to the surface. You swim over to a ladder at the side of the tank and climb out. Another instructor says to you, “Stand right over there until the others come up. You’ll be going down to the fifty foot lock as soon as the last trainee is on the surface.”
Simple? Of course, it is simple. That’s the beauty of the system, its simplicity. All you have to remember is to blow out air all the way to the surface. If you continue to blow out all the way to the surface there is absolutely no danger. And this is a good thing for any skindivers who have to ditch their aqualungs under water to remember. If you don’t blow the air in your lungs out as you come up, you are in great danger. The lining of your lungs is one cell thickness. Four pounds differential pressure will rupture that lining and then an air bubble will go into your blood stream. When the bubble passes to your brain or some vital organ, you die. In other words, if you should hold your breath for over ten feet in coming up, you would be a very lucky man if you lived long after getting to the surface. The medical term for this casualty is “air embolism.” But if you continue to blow out your air completely as you come to the surface, there is absolutely no danger. This is borne out by the fact that since August, 1956, more than 9,800 buoyant escapes have been made in the escape training tank at Pearl Harbor and no one has been hurt. There was one casualty during that time, a minor air embolism. It was caused by a small cyst on a man’s lung that had not shown up clearly on the X-ray taken during his last annual physical. The man has since completely recovered and has returned to duty. Ninety-eight hundred buoyant escapes in the escape training tank at Pearl Harbor with only one temporary casualty testifies to the safety of the system and the excellence of the training given at the submarine base.
How did the United States Navy come to adopt this system of submarine escape training? Well, it was noticed in going through the records of successful escapes from submarines sunk during World War II that the majority of the handful of survivors who reached the surface came up without any escape device, such as our Momsen Lung or the British Submarine Escape Apparatus. Most of the men who got out of a sunken submarine and lived to tell about it were either blown to the surface in a huge bubble of air or came up holding onto something that would give them positive buoyancy, like a life ring or an empty ammunition container. The record of escape devices was not good. There were too many things to remember when using an escape device to get out of a sunken submarine and it took too long to reach the surface. With buoyant escape you travel up at a rate of 260-300 feet per minute. So the experts, both British and American, put their heads together and advanced the present technique. The British adopted it first and the United States Navy followed shortly afterwards. During the summer of 1956, our submarine force began training using buoyant escape on a volunteer basis, and in October the Chief of Naval Operations sanctioned this method as the official means of escape from a sunken submarine. Since then, training has been pushed hard in the submarine escape training tanks both at New London and at Pearl Harbor.
But it is one thing to make a buoyant ascent in the escape training tank and quite another thing to make an escape from an actual submarine in the open sea. In the tank at Pearl Harbor, every possible precaution is taken against accidents. From the hundred foot level, fifteen instructors are stationed at various positions on the way up to insure that the man making the ascent does not get into trouble. Obviously, such precautions would be exceedingly difficult to achieve in the open sea. On the other hand, conditions at sea in a bottomed submarine can not be simulated in the training tank. And finally, the escape training tank has one serious limitation. Buoyant escapes in the training tank cannot be made at a depth greater than one hundred feet.
When we went out into the open sea to try out this new system, I ran into an interesting series of coincidences. The one submarine available at the time to test the technique of buoyant escape was the USS Tang (SS- 563). This submarine was built during the Korean War and was named after a very famous submarine of World War II. The first USS Tang sank a total of seventeen Japanese ships on her first four war patrols. Then, September 24, 1944, she left Pearl Harbor on her fifth and last war patrol. It was for this patrol that her Skipper, Commander R. H. O’Kane, received the Congressional Medal of Honor. O’Kane sailed the Tang to Taiwan Strait between Formosa and China where he sank two freighters soon after arrival. On the 23rd of October, the Tang ran into a convoy of two transports and three tankers. O’Kane torpedoed all five ships. The next night, the Tang made contact on another convoy. In the leading column were three ships, a tanker and two transports. O’Kane eluded the convoy’s escorts and fired his bow tubes at the three ships, aiming two torpedoes at each ship. All torpedoes hit and exploded. O’Kane brought the Tang around so the stern tubes bore on the second column of ships. Just as he fired the aft torpedoes at the leading two ships, a destroyer raced by, astern of him. One of the torpedoes hit the destroyer and the other fish went on to reach their mark. Incredible luck for one night’s work! Six ships for ten torpedoes. But wait. The last ship, a transport, was still afloat. The Tang had two torpedoes left in the racks forward. O’Kane ordered a reload and closed for the kill. Fire One! Torpedo number twenty-four left its bow tube. The Tang’s luck ran out. Torpedo number twenty-four, last of the submarine’s torpedo load, began to circle.
O’Kane kicked the Tang ahead and tried to avoid it. No use! It hit the Tang in the stern and the submarine sank in 180 feet of water in Taiwan Strait. Commander O’Kane and eight others were washed off the bridge as she sank. Minutes later, Lieutenant Savadkin reached the surface. He had come up from the sunken submarine without a Momsen Lung or any escape device. He had found a pocket of air remaining in the conning tower after the Tang hit the bottom. He took a deep breath and swam up through the hatch. All the way to the surface he blew out air, the same technique as in buoyant escape.
There was still to be even more coincidence. The officer in charge of the escape training tank at Pearl Harbor, the officer who trained us in buoyant escape before we took the new Tang out in the open sea to try the new method, was Lieutenant William R. Leibold. Among the ten survivors the Japanese picked up that night in Taiwan Strait when the Tang was sunk by her last torpedo, was William R. Leibold.
Up to what depths should buoyant escape be successful? Some of the medical officers say 300 feet in a pinch. They say that if you had to get out of a sunken submarine on the bottom at 300 feet you would have a very good chance of survival, providing you weren’t exposed to pressure too long. The danger lies in getting caisson disease, more commonly known as the bends. Caisson disease is caused from the body’s tissues absorbing nitrogen under pressure. About 80 per cent of the air we breath is made up of nitrogen. The longer you breath compressed air, the more nitrogen your tissues absorb. If you are under pressure too long and then reduce the pressure too fast, bubbles of nitrogen are formed in the blood stream instead of being passed out naturally through the lungs. It is like opening a coke bottle fast on a hot day. Bubbles suddenly appear in the bottle. When this happens in your blood stream, you have bends or caisson disease. The main thing, the doctors say, in preventing bends when using the buoyant escape principle at deeper depths is to spend only the shortest possible time under pressure. Theoretically, you would have a reasonably good chance of survival with only a minor case of skin bends if you could cut the time under pressure at 300 feet to only a minute. This is all well and good in theory. I’m conservative! If we work down to 200 feet a few feet at a time and still have no trouble, there is where I’m going to stop.
It seems ironic to me that after fifty years of submarining in the U. S. Navy we have found that the safest, fastest, most reliable of all apparatus ever invented for escape from a submarine sunk in less than two hundred feet of water has finally proved to be the well trained man and that most wonderful of all devices, the human body. It makes me wonder if, in this nuclear, electronic age of ours, the greatest asset in any line of endeavor is not well trained people and healthy bodies.