Mark 15 torpedo

Mark 15 torpedo. The Mark 15 was the standard anti-surface ship torpedo used by destroyers, destroyer escorts, and light cruisers of the United States Navy during World War II. Developed as a larger, surface-launched counterpart to the Mark 14 torpedo, it entered service in 1938 and saw extensive action across the Pacific War and Atlantic Ocean theaters. Despite sharing the severe technical flaws of its contemporary submarine-launched cousins early in the war, the Mark 15 remained in service through the Korean War before being retired.

Development and design

The development of the Mark 15 was initiated by the Bureau of Ordnance in the mid-1930s to provide a modern torpedo for the new generation of Fletcher-class destroyers and other surface combatants. Designed and manufactured primarily at the Naval Torpedo Station in Newport, Rhode Island, with additional production by the Pontiac Motor Division of General Motors, it was essentially a scaled-up version of the troubled Mark 14 torpedo. It shared the same propulsion system, a wet-heater steam turbine, and was equipped with both a contact pistol and the unreliable Mark 6 exploder, a magnetic influence exploder. The weapon's size and weight required the use of powerful torpedo tube mounts on the decks of ships like the USS Atlanta (CL-51) and USS San Diego (CL-53).

Operational history

The operational debut of the Mark 15 during the early battles of World War II was disastrous, mirroring the failures of the Mark 14 torpedo. During the Battle of Tassafaronga and the Naval Battle of Guadalcanal, numerous torpedoes fired from American destroyers and cruisers failed to detonate or ran erratically, contributing to heavy losses against the Imperial Japanese Navy. The profound defects, including a tendency to run deeper than set and the notorious unreliability of the Mark 6 exploder, were not fully diagnosed and corrected until 1943, after extensive testing at the Naval Torpedo Station Keyport, Washington. Once rectified, the Mark 15 became a effective weapon, used successfully in later engagements such as the Battle of Leyte Gulf and the Battle of Surigao Strait. It also saw limited use during the Korean War before being phased out in favor of anti-ship missiles.

Specifications

The Mark 15 was a large 21-inch (533 mm) diameter torpedo, measuring 24 feet in length and weighing approximately 3,841 pounds. It was propelled by a 46-horsepower wet-heater steam turbine burning alcohol fuel, giving it a speed of 45 knots for a range of 6,000 yards, or a slower 26.5 knots for an extended range of 15,000 yards. Its warhead initially contained 825 pounds of Torpex high explosive, later upgraded to HBX. Guidance was provided by an internal gyroscope, and detonation was intended via the flawed Mark 6 exploder or, later, a reliable contact pistol.

Variants

The primary production variants were the Mod 0, the initial model with all the early-war defects. The Mod 3, introduced during the war, incorporated critical fixes for depth control and exploder reliability. The final major variant was the Mod 10, a post-war modification which likely included updated exploders and propellants. These variants reflected the incremental improvements made to correct the weapon's performance, paralleling the fixes applied to the submarine-launched Mark 18 torpedo and other contemporary weapons.

Operators

The sole operator of the Mark 15 torpedo was the United States Navy. It was deployed from the torpedo tubes of numerous surface combatant classes throughout its service life, including the Gleaves-class destroyer, the Benson-class destroyer, the aforementioned Fletcher-class destroyer, and Sumner-class destroyer, as well as light cruisers like the Cleveland-class cruiser. It was not supplied to allied nations under programs like Lend-Lease.

Category:Torpedoes of the United States Category:World War II naval weapons of the United States Category:Anti-surface ship torpedoes