Torpedoes

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In the opening months of World War II, U.S. submarines were plagued by faulty ordnance.

By Douglas A. Shireman

On the morning of July 24, 1943, Lieutenant Commander L.R. Daspit and the submarine Tinosa launched what may have been the most frustrating attack of the United States' World War II submarine campaign against Japan. Alerted by cryptanalysts in Hawaii that the 19,000-ton Tonan Maru No.3 was cruising on an easterly course from Palau to Truk, Daspit set a course to intercept the enemy vessel. She and her sister ship, Tonan Maru No.2, were originally built as whale factory ships but had been converted to oil tankers for wartime use. They were two of the largest vessels in Japan's precious merchant marine fleet.

As he manuevered his submarine into a favorable attack position, Daspit calculated Tonan Maru No.3's speed to be 13 knots. Curiously, the heavily loaded tanker had no surface or air escort and was not zigzagging as an anti-submarine measure. After taking up a position from which her torpedo tracks would be nearly perpendicular to the target's course, Tinosa launched a spread of four torpedoes. Only two small geysers of water erupted alongside the vessel, however. To Daspit's dismay, the tanker did not explode or begin to list, but rather turned away and put on speed. Tonan Maru No.3's abrupt course change left the submarine in a poor firing position, but Daspit fired the remaining two torpedoes from his forward tubes by instinct. Both weapons struck the ship aft at obtuse angles and exploded, causing the ship to stop and begin to settle slightly by the stern. Although dead in the water, the well-compartmented tanker was in no immediate danger of sinking. Although fire from Tonan Maru No.3's deck guns forced Tinosa to remain submerged, the Japanese could do nothing to prevent the next salvo of torpedoes.

Repositioning to correct the poor firing angle, Daspit placed Tinosa in a textbook attack position, approximately 875 yards off the tanker's beam, and launched one torpedo. The soundman reported a straight and normal run. At impact, the skipper saw only a disappointing splash alongside the vessel. The torpedo was a dud.

Undaunted, the skipper ordered that every remaining torpedo be inspected before he continued. Each weapon was found to be in perfect working condition. Another torpedo was fired with great precision, yet the submariners were rewarded with only a deafening silence.

After seven more torpedoes were launched at the stationary target without success, Daspit wisely decided to save his 16th and final torpedo and take it back to Pearl Harbor for a complete overhaul. By methodically eliminating all possible factors except the ordnance, Daspit refocused attention on the Mark XIV torpedo, and he even returned with the perfect specimen to illustrate what had been the bane of the submariner's existence for the past year and a half.

For 18 months, several flaws had combined to render the Mark XIV torpedo, upon which submariners' lives and success depended, virtually impotent. From the onset of Mark XIV production, inherent defects had existed within the design of the torpedo and the Mark VI magnetic influence exploder mechanism. Each flaw that was discovered and corrected exposed another malfunction. As Theodore Roscoe, author of the official naval history of submarine operations, put it, "The only reliable feature of the torpedo was its unreliability."

After the initial Japanese naval onslaught in late 1941, the U.S. Southwest Pacific Command was established. Rear Admiral Charles Lockwood assumed command of all former Asiatic fleet submarines and divided the flotilla between the Australian harbors of Brisbane and Perth/Fremantle. Unlike a number of flag officers who held a wide variety of posts during their careers, Lockwood considered himself a true submariner. He proved to be an extremely pragmatic commander and a widely respected leader, which served him and his country well during the dark months after Pearl Harbor.

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