OVERVIEW: The Mk55 is a 2,000 lb air-dropped bottom influence mine developed by the United States Navy for use in deep-water anti-ship operations. It employs magnetic and acoustic fuzes and can operate at depths of up to 180 meters.

DETAILS: Introduced in 1962, the Mk55 mine is based on the Mk84 bomb body and features a modular influence fuze system, including magnetic (Mod 1–6) and dual-channel magnetic (Mod 7) variants. The mine includes programmable arming delays, ship-count discrimination, and sterilization timers for controlled detonation behavior. Designed for deployment from fixed-wing aircraft, the Mk55 is optimized for seabed placement in deeper maritime zones compared to the Mk52. It serves as a strategic denial weapon for channel and harbor defense as well as open-ocean mining operations. Its influence fuzing allows it to passively detect and classify vessel types before activation.

FUNCTION: After being released from an aircraft, the Mk55 descends to the seabed and arms after a preset delay. It then monitors magnetic or acoustic fields for specific vessel signatures, detonating when a qualified target passes overhead.

NOTE:
IOC: 1962
Operators: United States Navy
Platforms: P-3 Orion, A-6 Intruder, F/A-18, other tactical aircraft
Conflict used in: Cold War deterrent minefields; no confirmed combat use

SOURCE: U.S. Navy Mine Warfare Manual ; Jane’s Mines and Mine Clearance ; U.S. Navy Mines Fact File: https://www.navy.mil/Resources/Fact-Files/Display-FactFiles/Article/2167942/us-navy-mines/ ; Federation of American Scientists (FAS): https://fas.org/man/dod-101/sys/sea/mine.htm ; GlobalSecurity.org Mk55 profile: https://www.globalsecurity.org/military/systems/munitions/mk55.htm