♦ Mk 55

Mk 55 is the 2000-lb-class air-dropped bottom mine corresponding to the Mk 52 series; Mods 1-6 corresponded to Mk 52 Mods 1-6. Mod 0 was pressure-fired. Mod 7 used an improved dual-channel magnetic-firing mechanism. Components were interchangeable with those of Mk 52. Dimensions: 23.38 x 89.875 in (142.625 in when faired for high-speed carriage). Weights (Mods 1-6): 2039, 2110, 2120, 2119, 2128, 2118 lb. These mines could be laid by surface ships using portable rails. They were exported to some allied navies.

The Hunting Mine Mk 55 is a recoverable, inert-loaded shape planted by surface craft. It is planted solely to help mine countermeasures personnel develop their mine hunting skills and techniques.

The mine weighs approximately 2,000 pounds, consisting of a mine case and tail cover (flight gear is omitted). The flight gear is shown above only to illustrate how a fully assembled mine appeared when it was once dropped from aircraft. The mine does not contain explosives or target detecting/actuating mechanisms and, therefore, is ballasted with concrete to maintain its necessary negative buoyancy. Two options are available for tail cover use. The standard tail cover may be used, or a modified tail cover designed for MMS Mk 5 recovery may be used. The mine’s case is painted either white with orange stripes or orange with white stripes.


Mk 55 was released for production in November 1955 and became operational in 1961. In FY60 each of 1400 Mk 55 mines procured cost about $5500. Of the versions, Mod 0 was with-drawn from U.S. service in 1963, and Mods 1 and 4 in 1978. The others presumably remain in service; the successor weapon is Quickstrike (Mk 65).



Derick S. Hartshorn - 2009-present
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