♦ Mk 67 (SLMM)

The submarine-launched mobile mine was converted from a Mk-37 torpedo and was designed to be fired into a mine field from a distance. Engineering development began in FY77, and advanced development was completed in FY78. Mk 67 Mod 2 was approved for service use in FY83. A submarine successfully launched a Mk 67 mine (using fire-control panel Mk 281) during FY87; this completed development and introduced the mine into the fleet. The major contractor is the Dewey Corp. of Oak-land, New Jersey, which makes the explosive section. NUWES (Naval Underwater Weapon Experimental Station) Keyport re-furbishes the Mk 37 afterbody and builds up the full Mk 67. The goal, as of early 1988, was to attain the full inventory objective in FY91, using refurbishment money programmed in FY88 and FY89. In 1982, when the mine was approved for service use, the objective was 2421 mines (up from 1729). Procurement: 101 in FY82, 266 in FY83, 242 in FY84, 280 in FY85, for a total of 889. Plans for further procurement were not carried through. As of 1985, they were: 290 in FY86, 284 in FY87, and 266 in FY88, for a total of 840. However, the 1988 statement suggests that some mines have been manufactured using torpedo-refurbishment funds. This weapon uses TDDs Mk 70 and Mk 71.

A SLMM Mk 67 weighs approximately 1,790 pounds and is launched from submerged submarines. The SLMM propels itself to the planting site where it shuts down and plants itself until recovery. Approximately twenty seconds after the end of the run, all propulsion and control functions are shut down and the fuse ejector disconnects the main motor fuse disconnect. This action prevents the motor from restarting after planting.

The Service SLMM is a self-propelled bottom mine with a capability that permits it to be covertly placed in a predetermined bottom planting location. It uses a Target Detection Device (TDD) Mk 57 that utilizes magnetic and seismic sensors to detect stimuli generated by enemy vessels. The SLMM’s purpose is to restrict ship and submarine traffic in an operational role. The Service SLMM employs a modified Torpedo Mk 37 as the propulsion vehicle, designated the Body, Mine Main Assembly Mk 4. Forward of this main body is the Explosive Section Mk 13/Nose Section Subassembly (Loaded) which contains the PBXN-103 explosive mixture, Exploder Mechanism Mk 19, Arming Device Mk 2, and TDD Mk 57 with its Battery Mk 131.

The Body, Mine Main Assembly Mk 4 is painted green, while the Explosive Section Mk 13 retains its galvanized finish.

The Laying SLMM is used to provide a means for submarine personnel to develop the proficiency required to plant the mine in a minefield. The Laying SLMM also uses the Body, Mine Main Assembly Mk 4 for propulsion, modified so it does not flood at end of run and so the energized training battery does not run the propulsion motor when first mated to the main body. The SLMM training “nose” depends on the OA it is to be configured in:

OA-05 consists of an Inert Loaded Explosive Section Mk 13/Nose Section Subassembly. The inert fill material is used in this section to simulate the weight and CG of its explosive counterpart. A weight simulator is also used in place of the TDD.

OA-06 consists of an Exercise Head Assembly Mk 91/Nose Section Subassembly that contains an anchor, weight simulator, Control Box Mk 59, Gel-Cell Battery Mk 140, Float/Flare Launcher Mk 27, and Signal Mk 115/116 (optional, not used in several years).

The Body, Mine Main Assembly Mk 4 is painted green, while the Inert Loaded Explosive Section Mk 13 or Exercise Head Assembly Mk 91 is painted either white with orange stripes or orange with white stripes.



Derick S. Hartshorn - 2009-present
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