Mark 14 Torpedo - Development

Development

The Mark 14 was designed in 1930 to serve in the new "fleet" submarines, replacing the Mark 10 which had been in service since World War I and was standard in the older S-boats. Although the same diameter, the Mark 14 was longer, at 20 ft 6 in (6.25 m), and therefore incompatible with older submarines' 15 ft 3 in (4.65 m) torpedo tubes.

The Mark 14 was designed at the Newport Torpedo Station (NTS), Newport, beginning in 1922 under the direction of Lieutenant Ralph Waldo Christie. It had a fairly small warhead and was intended to explode beneath the keel where there was no armor. This required the sophisticated new Mark VI magnetic influence exploder, which was similar to the British Duplex and German models, all inspired by German magnetic mines of World War I. The Mark VI was intended to fire the warhead some distance below the ship, creating a huge gas bubble which would cause the keel to fail catastrophically.

The Mark VI exploder, designated Project G53, was developed "behind the tightest veil of secrecy the Navy had ever created." Small quantities were produced in extreme secrecy, and at a cost of US$1,000 per unit, by General Electric in Schenectady. The exploder was tested at the Newport lab and in a small field test aboard USS Raleigh. At Christie's urging, equatorial tests were later conducted with Indianapolis, which fired one hundred trial shots between 10°N and 10°S and collected 7000 readings. Inexplicably, no live fire trial was ever done. Chief of Naval Operations William V. Pratt offered the hulk of Cassin-class destroyer Ericsson, but prohibited the use of a live warhead, and insisted the Bureau of Ordnance (commonly called BuOrd) pay the cost of refloating her if she was hit in error. These were strange restrictions, as Ericsson was due to be scrapped. BuOrd declined. A service manual for the exploder "was written—but, for security reasons, not printed—and locked in a safe."

In 1923, Congress made NTS Newport the sole designer, developer, builder and tester of torpedoes in the United States. No independent or competing group was assigned to verify the results of Mark 14 tests. NTS produced only 1½ torpedoes a day in 1937, despite having three shifts of three thousand workers working around the clock. Production facilities were at capacity and there was no room for expansion. Only two thousand submarine torpedoes were built by all three Navy factories in 1942. This exacerbated torpedo shortages; the Pacific Fleet Submarine Force had fired 1,442 torpedoes since war began.