M86 Pursuit Deterrent Munition (PDM)

(United States), Mines less widely used

Development The M86 Pursuit Deterrent Munition (PDM), also known as the Pursuit Deterrent Mine, was

developed by Alliant Techsystems Inc under the sponsorship of Picatinny Arsenal. The PDM

was primarily designed for use by special forces, who required a small mine that could be laid

rapidly in the path of pursuing enemy forces. In May 1988, Alliant Techsystems Inc was

awarded a contract worth USD11,170,598 for the production of 42,919 M86 PDMs. The mines

were produced in New Brighton, Minnesota, and the contract was completed by late September

1989. Production of a further 9,500 PDMs was undertaken by the Thiokol Corporation at the

Louisiana Army Ammunition Plant, beginning in January 1991.

Description The PDM is based on the wedge shaped mine used in the Area Denial Artillery Munition

(ADAM) (see separate entry in this section). This small anti-personnel bounding fragmentation

mine is coupled to a hand-grenade fuzing system, complete with safety pin and arming lever. To

use the PDM, the safety pin is withdrawn and the arming lever released as the PDM is placed or

thrown into position. After a 25-second delay a small pyrotechnic charge pressurises the seven

spring-loaded tripwire capsules, expelling the wires to a maximum distance of 6 m. Barbs on the

ends of the wires anchor them to the ground and surrounding vegetation. The PDM performs an

electronic self-check programme and is fully armed 65 seconds after the battery is activated. The

mine is initiated by a collapsing circuit when any of the lines are tripped, as the tripwire breaks a

small conductor in the base of the capsule. A liquid propellant charge projects the spherical M43

fragmentation warhead 1 to 2 m into the air where it detonates, scattering approximately 600

steel fragments. The mine will self-destruct after 4 hours, and will detonate if the internal battery

voltage falls below a certain level. Should the initiation functions fail, the battery should become

fully discharged in approximately 14 days, rendering the mine inactive. PDMs are issued in sets

of two carried in a bandolier. As a private venture, Alliant Techsystems developed a one-man

portable dispenser capable of projecting a number of ADAM/PDM type munitions over an area

Plastic and steel, 1.2 lb, approx. 1 Bandolier with 2 PDMs.

M86 Pursuit Deterrent Munition (PDM)

DESCRIPTION: PDM is a manually-activated Area Denial Artillery Munition (ADAM) with a

hand grenade-type release firing mechanism. It deploys up to seven trip wires and possesses the

ADAM self-destruct capabilities. For safety purposes, arming will occur one minute after the

firing mechanism is released.

STATUS: This system was fielded in 2QFY91.

EMPLOYMENT CONCEPT: This munition is employed primarily by Special Operations

Forces to support hit-and-run, ambush, harassing, and urban warfare missions. PDM is also

employed by Infantry, Light Combat Engineers, and Rangers where mission warrants the use of

this device.

BASIS OF ISSUE: The PDM is issued as a Class V item of ammunition.

TRAINING/PERSONNEL: A training support package for PDM is being developed. Since

PDM is used mostly by Special Forces personnel, extensive training is not required.

The M86 Antipersonnel Mine is manually armed by removing the safety clip and then the arming strap

assembly. A camming action breaks the shorting bar and forces the battery ball against the battery

breaking the glass ampule containing an electrolyte which activates the reserve battery and provides

power. The shorting bar hook, attached to the cam, shears the shorting bar (a safety device across the

detonator). After a 60-second (nominal) electronic time delay, a piston actuator in the Safe and Arm

mechanism is electrically fired, moving a slider to align the detonator with an explosive lead in the slider.

At the same time, seven sensor triplines are released. Approximate three or four triplines will deploy up

to 20 feet from the mine, depending upon the at-rest position of the mine. The remaining triplines may

be hindered due to their proximity to the resting surface. After an additional 10- second electronic time

delay, allowing the munition to return to equilibrium, the mine is fully armed electronically. Disturbance

of a tripline, or the mine itself, now triggers a switch which completes an electronic firing circuit. The

S&A electric detonator initiates the S&A firing train which initiates a detonating cord which then initiates

a thin layer of liquid propellant, which by gravity rests under the kill mechanism, shattering the plastic

mine body and propelling the kill mechanism upwards from 6 inches to 8 feet above the ground where it

detonates. The kill mechanism is a spheroid internally embossed and loaded with 21 grams of Comp A5

and when detonated, propels fragments in a high velocity spherical pattern. If the mine is not activated

by tripline or disturbance mode, a factory preset self-destruct feature initiates the mine in 4 hours plus

0-20 percent.