NAVAL MINES
The US Navy lays mines principally from aircraft and submarines. There are no surface minelaying ships in the fleet, and very few ships are fitted for minelaying. Attempts to replace the mines described below have met with little success. Several programs begun in the 1980s and early 1990s, the most promising a joint effort with Great Britain, were canceled when funding fell short and mines sank to their usual low priority. Remote Control (RECO) by acoustic signal has been developed for Captor and Quickstrike mines.
Mk 52
The Mk52isa modified 1 ,OOO-lb (454kg) aircraft bomb deployed as an aircraft-laid bottom mine. Mods vary principally in their firing mechanism; in fact, most combinations of pressure, acoustic, and magnetic triggers were deployed: Mod 0 pressure, Mod 1 acoustic, Mod 2 magnetic, Mod 3 pressure-acoustic, Mod 4 pressure-magnetic, Mod 5 magnetic-acoustic, Mod 6 pressure-acoustic-magnetic, and Mod 11 seismic-magnetic.
It was rated as capable of detecting a submarine moving at three knots. Arming delays ran from one hour to 90 days and the mine could count up to 30 ships before detonating. It could also turn itself off between ship passages and self-sterilize at the end of its useful life.
DEVELOPMENT •
The US Long-Range Mine Program began in 1948, with production of the Mk 52 getting under way in 1954 and testing starting in 1956. The
weapon didn’t achieve initial operational capability, however, until 1961. German production followed. Some may still be in service, although it is known that Mods 1 and 4 have been withdrawn.
COMBAT EXPERIENCE •
Mk 52s were laid by US aircraft in North Vietnamese waterways as part of the late-1972 “Christmas offensive” mounted to persuade the government to return to end-of-war negotiations.
SPECIFICATIONS •
weight 1,130 (Mod 1) to 1,235 lb
(Mod 6) (513-561 kg)
warhead 595 lb (270 kg) of
conventional HBX-1
DIMENSIONS
length 5 ft 1 in (1.55 m)
diameter 19 in (477 mm), 2 ft 9 in
(0.84 m) over fins
max DEPTH 150 ft (45.7 m) (Mods 1, 3,
5, 6); 600 ft (183 m) (Mod 2)
SENSORS AND DETONATORS
Mod 1 acoustic
Mod 2 magnetic
Mod 3 pressure-magnetic
Mod 5 acoustic-magnetic
Mod 6 acoustic-magnetic/pressure
Mod 7 dual-channel magnetic
Mod 11 magnetic-seismic
Mk 55
The Mk 55 is the 2,000-lb bomb analogue to the Mk 52 and functionally resembles it. Many of the components were interchangeable.
DEVELOPMENT •
Initial operational capability was in 1961. Probably still in service.
SPECIFICATIONS •
weight 2,039-2,128 lb (925-965
kg)
warhead 1,269 lb (576 kg) of HBX-1
dimensions
length 6 ft 7 in (2.09 m)
diameter 23.4 in (594 mm) max depth 150 ft (45.7 m) (Mods 3, 5, 6), 600 ft (183 m) (Mods 2, 7)
sensors and detonators
Mod 1 acoustic influence
Mod 2 magnetic influence
Mod 3 pressure-magnetic
Mod 5 acoustic-magnetic
Mod 6 acoustic-magnetic/pressure
Mod 7 dual-channel magnetic
Mod 11 magnetic-seismic
Mk 56/Mk 57
The Mk 56 is an aircraft-laid, moored US mine which was specifically designed for use against high-speed, deep-operating submarines. The Mk 56 has a nonmagnetic, stainless-steel case and is fitted with a magnetic firing mechanism. The Mk 57, launched by submarines, has a fiberglass casing.
DEVELOPMENT •
Mk 57 achieved initial operational capability in 1964, the Mk 56 following in 1966.
SPECIFICATIONS •
weight 2,135 lb (968 kg); Mk 57 2,059
lb (934 kg)
warhead 357 lb (162 kg) of HBX-3;
Mk 57 340 lb (154 kg)
dimensions
length Mk 56: 9 ft 5 in (2.87 m) Mk 57: 10 ft 8 in (3.25 m) diameter Mk 56: 23.4 in (594 mm) body
Mk 57: 21 in (533 mm)
max DEPTH 1,200 ft (366 m) , also adjustable from 30-480 ft
sensors and detonator magnetic dual-channel using total field magnetometer as detector
Mk 60 Captor (encapsulated torpedo)
The Mk 60 Captor is the US Navy’s principal antisubmarine mine. Each Captor mine consists of a container that contains a threat analyzer and acoustic signature library, a Mk 46 Mod 4 Antisubmarine Warfare (ASW) torpedo, and an anchor. Captors are laid in a barrier pattern in deep water by aircraft or submarines; preferred drop points are straits and other “chokepoints.”
As the container descends, it pays out the anchor, which drops to the seafloor. The container finds its preset surveillance depth and “floats” vertically at the upper end of its tether. Using a passive acoustic sensor, the Captor detects moving submarines while ignoring surface ships.
When the mine has established the submarine target’s bearing, Captor begins active tracking using Reliable Acoustic Path (RAP) sound propagation. As the target comes within range of the torpedo’s seeker, the container fills with water. The flooding is controlled in a way that tilts the canister to an angle 30″ from the vertical. The torpedo is released, finds its own search depth, and searches with its passive acoustic homing seeker.
Despite its ability to be remotely activated and its “fire and forget” search and attack system, the Captor’s punch is relatively light. This lack of explosive power concerned many in the US Navy during the days of Soviet submarine growth. A Captor would probably succeed in disabling or destroying most likely submarine targets, however.
DEVELOPMENT •
Development of the Captor concept began in 1961; production started in March 1976 after several years of trials. The weapon achieved initial operational capability in 1979.
Produced by Goodyear Aerospace (now a division of Loral, Inc.), Akron, Ohio. Last authorization came in FY1986 at a unit cost of $377,000. Budget constraints cut Captor procurement in FY1985-87 from a planned 1,568 to 450. Total procurement fell short of the 4,109 originally stated as a requirement.
A modification program was planned but has not been funded.
SPECIFICATIONS •
weight 2,321 lb (1,053 kg) warhead 98 lb (44 kg) high explosive
DIMENSIONS
length 12 ft 1 in (3.68 m)
diameter 21 in (533 mm) mine, 12 .4 in (324 mm) Mk 46 torpedo MAX DEPTH 3,000 ft (914 m) MAX DETECTION RANGE 3,281 ft
(1,000 m)
SENSORS AND DETONATOR
passive acoustic monitoring switching to active once target is identified as submarine; monitoring is not continuous but turns on and off according to programmed schedule
Mk 62 Quickstrike
Quickstrike aircraft-laid bottom mines were converted from Mk 80 series bombs. They succeeded the Destructor series of conversions that were used to mine North Vietnamese harbors and rivers.
A Quickstrike conversion includes installation of a modular arming kit containing an arming device, fitting an explosive booster, and Mk 57 magnetic-seismic or Mk 58 magnetic-seismic-pressure Target Detection Devices
(TDD). (Mk 70 and Mk 71 TDDs replaced Mk 57/Mk 58s in production in
the mid-1980s.)
The Mk 62 is a modified Mk 82 500-lb (227-kg) bomb.
DEVELOPMENT •
Began in the mid-1970s to replace the Mk 36 Destructor, achieving initial operational capability in 1980. Plans called for production of almost 40,000 TDDs, but only a small
fraction was actually funded. SPECIFICATIONS •
weight
fixed conical tail
531 lb (241 kg)
low-drag tail
570 lb (259 kg)
warhead 192 lb (87 kg) of H-6
explosive
DIMENSIONS
length 7 ft 5 in (2.25 m)
diameter 10.8 in (274 mm)
MAX DEPTH 300 ft (91.4 m)
SENSORS AND DETONATOR Target Detection Device TDD Mk 57/58 or TDD Mk 70/Mk 71, magnetic-seismic
or magnetic-seismic-pressure firing mechanism
Mk 63 Quickstrike
Successor to Mk 40 Destructor series conversion of 1,000-lb (454kg) bomb. Few of these seem to have been procured.
SPECIFICATIONS •
weight fixed conical tail
985 lb (447 kg)
low-drag tail
1,105 lb (501 kg) warhead 450 lb (204 kg) of H-6 explosive
DIMENSIONS
length 9 ft 5 in (2.86 m)
diameter 14 in (356 mm)
Mk 64 Quickstrike
Successor to the Mk 41 Destructor, a modified Mk 84 2,000-lb (907-kg) bomb.
SPECIFICATIONS •
weight 2,000 lb (907 kg) dimensions length 12 ft 8 in (3.83 m)
diameter 18 in (457 mm)
Mk 65 Quickstrike
Although considered part of the Quick-strike series of bomb-to-mine conversions, the Mk 65 aircraft-laid bottom mine is substantially different from the Mk 84 2,000-lb (907-kg) bomb that is the basis of the Mk 64 and 65. The Mk 65 has a thin-walled mine-type case and several modifications to the arming mechanism, nose, and tail.
DEVELOPMENT •
Production contract awarded to Aerojet Tech Systems, Sacramento, California, in April 1982. Achieved initial operational capability in 1983. 4,479 were produced under FY1983-86, FY1988-89 funding, very close to the 4,500 originally planned.
SPECIFICATIONS •
WEIGHT 2,390 lb (1,083 kg) including
warhead with HBX explosive dimensions length 9 ft 2 in (2.8 m)
diameter body 20.9 in (530 mm), across fins 29 in (734 mm)
max depth 300 ft (91.4 m) sensors and detonator Target Detection Device TDD Mk 58/Mk 71
combination sensor, variable influence (magnetic-seismic-pressure)
Mk 67 SLMM
The Submarine-Launched Mobile Mine
(SLMM) adapts a Mk 37 heavy torpedo to
a self-propelled torpedolike mine that submarines can launch covertly into inaccessible waters. SLMM can also operate as a shallow-water bottom mine against surface ships.
The SLMM consists of a modified Mk
37 Mod 2 electrically powered torpedo with the wire guidance equipment removed and warhead replaced by a mine. The electronics are similar to those of the Quickstrike series. Honeywell Marine Systems proposed an Extended SLMM incorporating the NT-37E torpedo, but this was not developed.
DEVELOPMENT •
Development began in 1977-78 with plans to produce 1,729 mines by the mid- to late 1980s. Delays in development and chronic funding problems pushed the service introduction date to 1992. By then only 889 had been produced under SLMM funding, although others may have been converted using torpedo refurbishment dollars. The prime contractor is Dewey Electronics of Oakland, New Jersey.
SPECIFICATIONS •
WEIGHT
overall 1,759 lb (798 kg)
warhead 529 lb (240 kg) of Mk 13
explosive
dimensions
length 13 ft 5 in (4.08 m)
diameter 21 in (533 mm) MAX depth approx 328 ft (100 m) sensors and detonator Target Detection Device TDD Mk 71 combination sensor, variable influence (magnetic-seismic-pressure)
