120. Trip-Wire Flare Mk 1 Mod 0, Fig. 53, is an alarming device which an approaching enemy unconsciously sets off. It also gives illumination for some 65 seconds. It burns with a bright yellow flame of 75,000 candlepower, resulting in illumination of an area within a radius of approximately 75 feet. The flare is packed in a watertight mailing tube container, which includes the accessories that go with it; namely, 80 feet of wire, two screw eyes, and a belt for attaching the flare to a stake or tree. The flare itself consists of a steel tube 5.5 inches long and 2.5 inches in diameter. Fixed to one end is the firing mechanism, consisting of a pull-type spring to which the trip wires are attached, a pri-mer, and a firing pin. Included in the kit is an instruction sheet outlining the procedure for mounting the flare. When properly mounted, the flare, with is safety pin removed, is fired when the trip wire is pulled. The wire is attached to a plunger with a notched end, which, when pulled, disengages itself from the firing pin. The firing pin, under spring pres-sure, then strikes the primer which ignites a 0.3-gram charge of black powder. The flash from the black powder ignites the pyrotechnic candle. The candle, on burning, creates sufficient pressure to blow off the closure disc on the flare case, and thus exposes the flame.

Figure 53. – Trip-Wire Flare Mk 1 Mod 0

Operation

121. Some amount of ingenuity is necessary for the most efficient operation of Trip-Wire Flare Mk 1. Like a booby trap, its consealment is desirable. The 80 feet of wire can be halved sot that two 40-foot lengths can be attached to the plunger, stretching both aways from the flare, and parallel to the enemy lines. The following steps should be ta-ken:

(a) Secure the flare to a tree or stake by means of the belt and belt loop. It should be mounted about three feet from the ground.

(b) Attach the trip wires to a tree or stake just less than 40 feet on either side of the tree or stake to which the flare is attached.

(c) A screw eye is fixed to the tree or stake on which the flare is mounted. This screw eye should be about six inches from the ground, directly beneath the plunger.

(d) The free ends of the trip wire or wires are then passed through the screw eye and secured to the pull ring on the plunger of the firing mechanism. The wire or wires should be affixed so that there is no sag in the 40- or 80-foot length, but not so taut that it will actuate the plunger.

(e) After the wires and flare are installed, set the device by pressing up on the plunger and carefully withdrawning the safety pin.

(f) Release the upward pressure on the plunger slowly and note its travel downward. This should not be more than 0.25 inch. If, at that point, further downward pressure is felt on the finger holding the plunger, return it to the up position and replace the safety pin. Then slack off on the trip wires. Normally the plunger will not move downward more than 0.125 inch.

(g) If at this point it has been found necessary to replace the safety pin, repeat steps (e) and (f) with caution, each time the safety pin is removed.

(h) After the flare is set, free the plunger from any paint or other substance which may seal it to the wall of the flare. This is done by carefully turning the plunger through a 90-degree arc without allowing it to travel downward.

Packing

122. Each flare, with its accessories, is packed in a watertight container. Ten such con-tainers are packed in wood case. Each case contains an instruction sheet for using Trip-Wire Flare Mk 1 Mod 0.

Stowage

123. General rules for storing pyrotechnic ammunition as outlined in paragraphs 9 to 12, inclusive, apply to Trip-Wire Flare Mk 1. Although the flare and its container are water-proofed, long periods of exposure to rain or excess moisture may result in malfunctioning. Deteriorated flares should be disposed of as outlined in paragraph 20.

Safte Precautions

124. In mounting Trip-Wire Flare Mk 1, the following safety precautions must be taken:

(a) A steel helmet should be worn while mounting and setting the flare. The head must be kept below and away from the flare as far as possible.

(b) When two trip wires are used, each must be attached to the plunger independent of the other, although both may be passed through the same screw eye.

(c) To prevent sellf-illuminating, the flare should be mounted at least 125 yards in ad-vance for the defense position.

(d) It should be remembered that the plunger of the flare is actuated by a pull of six pounds. The plunder should be freed by turning it 90 degrees, after removing the safety pin.