The Mine Mk 50 series includes the MK 55, a 2000-pound aircraft-laid bottom mine
containing an explosive charge of 1290 pounds of
HBX-1. The MK 55 is an influence mine
specifically designed to actuate on submarine signatures, although
it is also equally effective against most surface ship signatures.
The MK 55 is almost identical to the MK 52, with difference being
its weight (2,000 pounds), its larger explosive charge, the case
is larger and the flight gear is different. Otherwise there are no variations: instrument racks,
color-coded molded cables, and color-coded modular components are
all identical and interchangeable with the MK 52's.
Mod 1
employs an acoustic firing mechanism.
Mod 2
employs a magnetic firing mechanism, efficient over a
wide range of planting depths.
Mod 3
employs a combination of pressure and magnetic firing
mechanisms.
Mod 4
(not used).
Mod 5
employs acoustic and magnetic firing mechanisms.
Mod 6
combines all three influence type firing mechanisms:
acoustic, pressure, and magnetic, making it difficult to
sweep.
Mod 7
The Mod 7, which is unique to the Mk 55 Mine, is similar to
the Mod 2 except that it uses an improved dual channel magnetic
firing mechanism, making it more difficult to sweep.
