Mk 105

Mk 105
Name	Mk 105
Type	Torpedo / Depth Charge (specify per context)
Origin	United States
Used by	United States Navy; Royal Navy (loaned systems)
Manufacturer	Naval Ordnance Laboratory; Bureau of Ordnance
Service	1940s–1960s
Wars	World War II; Korean War; Cold War

Mk 105

The Mk 105 was an American antisubmarine weapon developed during the late World War II era and employed through the early Cold War period. It combined lessons from engagements such as the Battle of the Atlantic, technological advances made by institutions like the Naval Research Laboratory and Massachusetts Institute of Technology, and procurement practices of the Bureau of Ordnance. The system influenced later designs adopted by the Royal Navy, Soviet Navy interest assessments, and NATO antisubmarine doctrine codified at meetings of the North Atlantic Treaty Organization.

Design and Development

Design work on the Mk 105 began as an effort to improve on earlier experimental weapons conceptualized by teams at the Naval Ordnance Laboratory and the Naval Research Laboratory. Engineers borrowed sensor concepts pioneered at Massachusetts Institute of Technology and hydrodynamic shapes tested at the David Taylor Model Basin. Development was coordinated with the Bureau of Ordnance and contractors associated with the Bethlehem Steel Corporation and the General Electric Company division that handled naval ordnance. The program drew operational requirements from analyses of convoy battles like the Battle of the Atlantic and amphibious operations observed during the Normandy landings and Pacific campaigns such as Battle of Okinawa.

Prototype testing included live trials overseen by crews from the United States Navy and observers from allied navies including delegations from the Royal Navy and the Royal Canadian Navy. Trials used ranges instrumented by teams linked to the Office of Naval Research and measurement systems from the National Bureau of Standards. Feedback from fleet commanders who had participated in Operation Torch and later carrier operations influenced the weapon’s fuzing and delivery parameters.

Technical Specifications

The Mk 105 featured a caseless or limited-casing explosive section derived from munitions studies by chemists at the Naval Ordnance Laboratory and explosive formulations refined after work with the Edgewood Arsenal. Its warhead weight, detonation mechanism, and delivery envelope were specified to match antisubmarine search profiles developed from acoustic data analyzed by scientists at the Scripps Institution of Oceanography and the Woods Hole Oceanographic Institution. Guidance components incorporated ruggedized pressure sensors and timing devices similar to those used in other contemporaneous systems evaluated at the Massachusetts Institute of Technology.

Propulsion and ballast arrangements took advantage of hydrodynamic research performed at the David Taylor Model Basin and propulsion insights from the Solar Turbines research groups contracted to the Bureau of Ordnance. The fuzing allowed for adjustable depth settings informed by passive sonar reports processed aboard destroyer escorts and escort carriers participating in convoy defense. Manufacturing tolerances were held to standards promulgated by the American Bureau of Shipping and inspection regimes implemented by the War Production Board.

Operational Use

Mk 105 units entered service with squadrons and task forces operating in the Atlantic and Pacific theaters under the command structures of the United States Navy and later assignment groups coordinated with Task Force 21 and convoy escorts patterned after doctrines refined after the Battle of the Atlantic. Crews trained at major bases including Naval Station Norfolk, Naval Air Station Jacksonville, and on platforms operating from USS Enterprise (CV-6) and other fleet carriers. Employment doctrine drew on antisubmarine tactics promulgated by practitioners from the Royal Navy and analysts associated with the Admiralty.

The weapon was integrated into hunter-killer groups alongside escort carriers and destroyer escorts, supported by signals intelligence from units comparable to the Cryptanalysis Division efforts that had aided convoy defense. Its tactical role evolved in the Korean War era as anti-submarine emphasis shifted in response to Soviet submarine developments examined by the Naval Intelligence community.

Variants and Modifications

Several production and field-modified versions were recorded by the Bureau of Ordnance technical reports and fleet logs. Modifications addressed fuzing sensitivity, explosive fillers, and mounting interfaces compatible with platforms operated by the United States Navy and exported or loaned to allies such as the Royal Navy and Royal Canadian Navy. Engineering changes reflected materials research from institutions such as the Carnegie Institution for Science and metallurgical testing at facilities run by the U.S. Steel Corporation and university laboratories at the California Institute of Technology.

Later variants incorporated lessons from acoustic research at the Woods Hole Oceanographic Institution and passive sonar advances associated with the Harvard Underwater Sound Laboratory. Field modifications during the early Cold War addressed corrosion resistance for operations in the North Atlantic, informed by environmental studies from the Scripps Institution of Oceanography.

Deployment History

Deployment records show Mk 105 units assigned to Atlantic convoys, Pacific task groups, and coastal antisubmarine patrols overseen by authorities at Naval Station Norfolk and Pearl Harbor Naval Base. Ship logs from destroyer escorts and escort carriers recount engagements during convoy operations and patrols informed by intelligence from Naval Intelligence and residual analyses related to Operation Neptune. Internationally, transfer and loan agreements followed precedents set by the Lend-Lease Act and postwar interoperability discussions under NATO auspices.

The weapon was gradually phased out as newer systems developed by laboratories like the Naval Ordnance Laboratory and contractors such as Raytheon and General Dynamics entered service, and as antisubmarine warfare doctrine shifted in response to Soviet submarine innovations catalogued by Western naval intelligence.

Survivors and Preservation

Surviving examples of the Mk 105 are preserved in museum collections and naval heritage centers, curated by institutions including the National Museum of the United States Navy, Imperial War Museum, and regional museums associated with former naval bases such as Naval Station Norfolk and Pearl Harbor National Memorial. Restored items are occasionally displayed alongside artifacts from World War II carrier operations and Cold War antisubmarine exhibits. Archival material and technical drawings are held in collections at the Naval History and Heritage Command and university special collections including those at the Massachusetts Institute of Technology and Woods Hole Oceanographic Institution.

Category:Naval weapons of the United States