Mark 14 torpedo

The Mark 14 torpedo was the United States Navy's standard submarine-launched anti-ship torpedo of World War II. This weapon was plagued with many problems which crippled its performance early in the war. It was supplemented by the Mark 18 electric torpedo in the last two years of the war. From December 1941 to November 1943 the Mark 14 and the destroyer-launched Mark 15 torpedo had numerous technical problems that took almost two years to fix. After the fixes, the Mark 14 played a major role in the devastating blow U.S. Navy submarines dealt to the Japanese naval and merchant marine forces during the Pacific War. By the end of World War II, the Mark 14 torpedo was a reliable weapon ultimately remaining in service for almost 40 years in the U.S. Navy, and even longer with other navies. The design of the Mark 14 started in January 1931; the Navy allocated $143,000 for its development. The Mark 14 was to serve in the new "fleet" submarines and replace the Mark 10 which had been in service since World War I and was standard in the older R- and S-boats. Although the same diameter, the Mark 14 was longer, at , and therefore incompatible with older submarines' torpedo tubes. Later in the war, the Bureau of Ordnance (BuOrd) stopped producing Mark 10s for the S-boats and provided a shortened Mark 14. Torpedoes consist of several subsystems, and those subsystems evolved over time. Torpedoes are also tailored for their application. Submarine torpedoes, such as the Mark 14, are constrained by the dimensions of the submarine's torpedo tubes: 21 inches in diameter and a certain maximum length. Submarines are expected to close with their targets, so the torpedoes do not need a long range. In contrast, torpedoes fired by destroyers need greater range because their approach would be under fire from their targets. Improvements in the propulsion engine power output allowed the Mark 14 to have a top speed of compared to the Mark 10 Mod 0's .