Mark 14 torpedo

Mark 14 torpedo. The Mark 14 was the standard submarine-launched anti-surface ship torpedo of the United States Navy for much of World War II. Developed during the Great Depression and entering service in 1931, it was plagued by severe technical flaws that crippled the effectiveness of the Pacific submarine fleet in the early years of the conflict. Despite its troubled history, it remained in service for decades, with its final variants retired in the 1980s.

Development and design

The development of the weapon was led by the Naval Torpedo Station in Newport, Rhode Island, beginning in 1931 as a replacement for the Mark 10 torpedo. Designed during a period of severe budgetary constraints, the project was hampered by limited funding for live-fire testing. The design incorporated a sophisticated Magnetic exploder (Mark 6 exploder) intended to detonate beneath an enemy vessel's keel, a Contact pistol for direct hits, and a complex Gyroscope system for steering. Propulsion was provided by a Wet-heater steam turbine engine burning Alcohol fuel, which gave it a theoretical high speed and range. The entire system was more advanced but also more intricate than the torpedoes used by other navies like the Imperial Japanese Navy.

Operational history

The torpedo entered service with the United States Navy's submarine force in 1931 and was the primary weapon at the outbreak of World War II. It saw extensive use from the first day of the Pacific War, deployed by boats of the Asiatic Fleet and later the Pacific Fleet against Japanese merchant and naval shipping. Early combat reports from commanders like Dudley W. Morton of the USS *Wahoo* (SS-238) and John P. Cromwell were filled with accounts of premature detonations, erratic runs, and failures to explode. Its poor performance significantly hampered the commerce raiding campaign against the Empire of Japan until mid-1943. Despite its replacement by newer models like the Mark 18 torpedo, it remained in the inventory through the Korean War and into the Cold War.

Technical specifications

The torpedo measured 20 feet 6 inches in length and 21 inches in diameter, with a total weight of 3,280 pounds. Its Wet-heater engine, fueled by Alcohol, allowed for a speed of 46 knots with a range of 4,500 yards. Later modifications increased its range to 9,000 yards at a slower speed. The warhead initially contained 507 pounds of TNT, but was later upgraded to 643 pounds of the more powerful Torpex explosive. Guidance was controlled by an internal Gyroscope, and it was equipped with both a Magnetic exploder and a mechanical Contact pistol. It was launched from the standard 21-inch torpedo tubes aboard *Gato*-class and *Balao*-class fleet submarines.

Problems and solutions

The weapon suffered from three critical, interlinked flaws: the Magnetic exploder often detonated prematurely or not at all, the Contact pistol frequently failed to fire on a direct hit, and the torpedo tended to run deeper than its set depth. These issues were compounded by extreme secrecy and a culture of disbelief at the Bureau of Ordnance regarding frontline reports. The crisis prompted a major investigation led by officers from the Naval Mine Warfare Test Station at Solomons, Maryland and the New London Submarine Base. Solutions, implemented gradually throughout 1943, included deactivating the faulty magnetic influence feature, strengthening the firing pin in the contact pistol, and recalibrating the depth-control mechanism. These fixes, validated by tests at the Torpedo Station, Keyport, finally made the weapon reliable.

Variants

The primary variant was the **Mark 14 Mod 1**, which was the initial production model. The **Mark 14 Mod 2** incorporated a slower, longer-range setting. The **Mark 14 Mod 3** featured the upgraded Torpex warhead. The design also directly influenced other programs: the **Mark 16 torpedo** was a faster, Hydrogen peroxide-fueled derivative intended for surface ships. More significantly, the desperate need for a reliable weapon led to the rapid development and fielding of the electric **Mark 18 torpedo**, which was based on captured German G7e technology. Post-war, some units were converted for use as the **Mark 32** anti-submarine practice torpedo.