40mm Smoke Shoulder Fired

A-2. Safety procedures pertaining to the M136 AT4 are as follows:

Backblast

A-3. Because the M136 AT4 has a closed chamber, it produces a slight recoil. When the weapon is fired, pressure from the warhead propellant builds up in the chamber and ruptures the baseplate. Once the baseplate ruptures, propellant gases exit with tremendous force from the back of the weapon. The resulting backblast can damage equipment or seriously injure personnel who are too close to the rear of the launcher. When operating temperatures fall below freezing (0 degrees centigrade or 32 degrees Fahrenheit), the dimensions of all backblast areas and safety zones double.

Training

A-4. The total backblast area extends 100 meters to the rear of the launcher in a 90-degree fan (Figure A 1). During training, the entire backblast area limit must be marked off and kept clear of personnel, equipment, and obstructions. This weapon must not be fired from an enclosure or in front of a barrier (TM 9-1315-886-12). Neither the M136 AT4 nor the M141 BDM is to be fired from a fighting or prone position during training.

Shoulder Launch Munition Training
Figure A-1. M136 AT4 backblast danger area.

Surface Danger Zones

A-5. The surface danger zone (SDZ) requirements for the M136 AT4 are shown in Table A-1 and Figure A-2 and Figure A-3 (page A-4).

Table A-1. M136 AT4 SDZ criteria in meters.

DISTANCE X

MINIMUM

AREA A

AREA B

AREA F1

TO TARGET

DANGER ZONE DEPTH

CAUTION AREA DEPTH

84-mm HEAT M136

2,100

50

227

488

52

953

9-mm Trainer, M939

1,600

N/A

N/A

N/A

N/A

N/A

NOTES:

Area F is 90-degree angle (45 degrees left and right) of rearward extension of launcher target line.

2Danger zone occupation could result in fatalities or serious casualties including severe burns, eye damage, or permanent hearing loss. The hazards are baseplate fragments, debris, fireball, high noise levels, and overpressure.

3Caution area is an extension of the primary danger area. Occupation of this area could also result in severe casualties due to backblast, debris, high noise levels, and possible baseplate fragments. Primary danger area and caution area are conditions that may not be modified.

Increased dud rates may occur when firing HE (M136) at impact angles of 10 degrees or less.

DISTANCE X

Cal Surface Danger Zone
Figure A-2. SDZ for firing M136 AT4.
Shoulder Launch Munition Training
Figure A-3. SDZ, area F, for firing M136 AT4.

Minimum Target Engagement Range

A-6. Fragments formed by the detonation of the tactical warhead can be hazardous to the gunner and other personnel who are on, or close to, the firing line. The velocity of these fragments increases with target hardness.

Training

A-7. For safety reasons, the minimum safe engagement range for training is 50 meters. Combat

A-8. In combat, no targets will be engaged within the 15-meter minimum arming range.

Operating Temperature Limitations (Training and Combat)

A-9. No shoulder-launched munition should be fired when its temperature exceeds its operating limit range.

Minimum Operating Temperature

A-10. When a weapon temperature is below freezing (0 degrees centigrade or 32 degrees Fahrenheit), overpressure increases and may prevent some of the propellant from burning during the firing sequence. This could cause portions of the remaining propellant to be directed onto the firer's face or upper body as the projectile leaves the launch tube. Therefore, in cold weather, the firer should wear a protective mask. The M136 AT4 must not be fired when its temperature is below its minimum operating temperature of -40 degrees centigrade (-40 degrees Fahrenheit).

Maximum Operating Temperature

A-11. When the weapon temperature is above 60 degrees centigrade (140 degrees Fahrenheit), propellants and warhead compounds can destabilize. In hot weather, weapons should be stored in a shaded area, whether they are located at training sites or at fighting positions. The M136 AT4 must not be fired when the temperature exceeds its operating limits of 60 degrees centigrade (140 degrees Fahrenheit).

Firing Limitations

A-12. The extreme overpressure and noise created when the M136 AT4 is fired requires special precautions during training. To reduce these hazards, firers must observe the range firing limitations shown in Table A 2.

Table A-2. M136 AT4 daily individual training firing limitations.

Three times (total)

if the M136 AT4 is fired from either

Within a 24-hour period, a Soldier may only

the standing or kneeling position.

fire, observe fire, or act as safety NCO for

-------------OR-------------

the M136 AT4 one to three times,

depending upon the firing position used.

One time (total) if the M136 AT4 is fired from the sitting position.

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