Mk 16 Torpedos

By Wally Krupenevich,
U.S.S. Irex (482) Newsletter, March 2005, pp. 8–9

When I reported aboard USS TRUMPETFISH (SS425), I had 6 months in the Navy, was a SA fresh out of SubSchool, and undesignated. Within a few days the Engineering Officer treated me to a cup of coffee in the Wardroom, and tried to talk me into striking for Electrician. One of my classmates, a designated EMFA, had reported aboard a few days earlier than I and was singing the blues about what a rotten job Electricians had on a full four-battery GUPPY, particularly in Key West. I told the Engineer that I thought I was designated as TM because of a few weeks TM training just prior to SubSchool. He bought it, and left me alone after that. As a typical TM striker, I'd spend most of an upkeep topside, then go to the Torpedo Room for the last few days for Field Day. When we'd load fish, I'd start off topside, secure everything up there, and then go to the Room we just loaded for a few more hours. Although some ratings were severely short, TM was overloaded with WWII folks that stayed in. On T-FISH we had 3 TMCs, 3 TM1s, and 3 or 4 TM2 and 3s and me. Two years later, after a fleet-wide exam, I made TM3 (SS), and a few weeks after that my request for rotation to NLon kicked in.

I reported aboard IREX as a newly-minted 3rd class, which was also overloaded with TMs, but not quite as bad as T-FISH was, and generally a better bunch of guys. I made TM2 a year later, and then had to wait 4 years to make TM1. For a few years in there, TM was so overloaded, that they didn't even bother testing for advancement.

Back tracking a little, over the years I'd hear a little about “them damn chemical torpedoes.” Our Navy tried to copy it from Japan's “Long Lance” with little success. Every time they would come out with a new Mod, it would explode, fortunately with no loss of life, and the project would go back on the shelf for a while. Much to my chagrin, in 1955, I was ordered to Newport (RI) Torpedo Testing Station to attend a 3-week Mk 16, Mod 6 course along with three other TM1(SS)'s from other NLon boats.

The Mk 16 was overall the same physical size as the Mk 14. Where the Mk 14 mixed air and water into a combustion chamber to create steam to spin its turbines, the Mk 16 mixed air, water and oxygen with the same results. The oxygen was produced by releasing the extra oxygen atoms from a 95%+ concentration of hydrogen peroxide, which the Navy called Navol. (As a comparison, hydrogen peroxide used at home for cuts and bruises is a 3% solution.)

The huge advantage of the Mk 16 over the Mk 14 was its speed, range and increased warhead size. The Mk 14's speed was 46 knots for 4,500 yards. Originally, the Mk 16 was capable of fantastically higher speeds, but the torpedo's depth mechanisms couldn't control it, and the speed was out of range of the submarine's TDC. Eventually, they brought the speed of the Mk 16 down to equal the Mk 14's, with a range of 11,000 yards.

In an open container, Navol is very stable. When a catalyst is introduced, Navol then breaks down and the extra oxygen atoms escape. On the first day of the Mk 16 course, we were given a demonstration of this. First, the instructor dipped his finger into a beaker of Navol, and licked his finger, with no ill effects. He then put the beaker in a glass~fronted vault, and with remote fingers, dropped a small chunk of cadmium into the beaker. Immediately, there was a small explosion.

From what I've read of the KURSK going down, the first explosion heard was caused by a torpedo's internal Navol leak, causing bad fires in the Torpedo Room, resulting in the second, much larger explosion, caused by the detonation of warheads which ripped her bow apart.

After I returned to IREX in NLon, we were soon blessed with a few Mk 16s to load and shoot. At first they made a point of loading them aft and mooring us up around the Training Tank. If there was a minor problem, we would immediately off-load the Mk 16 and let the base Torpedo Shop handle it. If the decomposition rate became a major problem, we were to shoot the Mk 16 across the Thames, towards the island on the other side. We never had either of these problems to contend with (fortunately.).

There was also a line added to the Below Decks Check-Off List. Because even in an open container, Navol has a natural decomposition rate as it releases oxygen to the atmosphere, the decomposition rate had to be monitored. We were provided with state-of-the-art equipment. The oxygen produced by normal decomposition was lead through a plastic tube, into a Coke bottle filled with water. The Below Decks Watch had to hourly count the bubbles per minute. I forget what the levels were, but if it suddenly got too high, we'd fire the torpedo at the island.

During our next overhaul, a Decomposition Rate Indicator (DRI) was installed in each Torpedo Room. I don't remember where it went Aft, but Fwd it was installed on the starboard side, in a few of the lockers facing the upper bunks. I can't remember ever using it, but maybe so.

IREX was my first and fortunately my last exposure to the Mk 16, but I do know that they went as far as the Mk 16, Mod 8. After the USS GUAVINA (SS 362) was stricken from Navy rolls in 1975, she was sent down with a successful test firing of a Mk 16.

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