Firing Wire Spool

Fiffvre 41. Dfitructftr, high-exploitive, universal. MIO.

to the full depth by adding boaster cups to the destructor MIO as required.

c. Safety Precautions. Safety distance requirements for preparation of primers and demolition charges as set forth in TM 9-1900 must be observed when preparing the universal destructor MIO for use.

74. Adhesive, Paste, for Demolition Charges, One-Half Pound Can, Ml a. Adhesive compound is a sticky puttylike substance issued in some demolition sets for attaching charges to vertical surfaces or to overhead flat surfaces. It is useful in holding charges while tying them in place or, under some conditions, holding charges without tying.

( 'harges are held in place from several minutes to several days depending on the size and shape of charge and the surface to which it is attached.

h. The adhesive compound will hold a single thickness of explosive blocks to dry, clean wood, steel, or concrete for several days.

c. The adhesive compound will not adhere satisfactorily to dirty, wet, or oily surfaces.

d. The compound becomes stiff and hard at subzero temperatures and loses its adhesive quality.

e. Adhesive compound is softened by water and becomes useless if wet.

75. Bag, Canvas, Carrying, Demolition Equipment

This bag consists of a rectangular canvas receptacle with shoulder strap and adjusting straps. It is used for carrying the components of DEMOLITION EQUIPAIENT SET NO. 5, individual (fig. 49).

76. Boxes for Blasting Caps

Especially designed empty boxes of various capacities are provided for demolition equipment sets and blast-driven earth rod sets. These boxes consist of rectangular wooden blocks with telescoping covers. Holes in the block-like interior of the box are receptacles for nonelectric blasting caps. The boxes are filled with blasting caps when preparing the sets for use. The available blasting cap boxes arc described in a and b below.

a. BOX, Cap, 10-Cap Capacity, Infantry. This box is one of the non-explosive components of DEMOLITION EQUIPMENT SET NO. 5, individual (fig. 49), ROD, earth, blast-driven, Set No. 1 (fig. 51), and DEMOLITION EQUIPMENT SET NO. 1, engineer squad (fig. 47).

b. BOX. Cap, SO-Cap Capacity. Engineer. This box is one of the non-explosive components of DEMOLITION EQUIPMENT SET NO. 2, engineer platoon (fig. 48).

77. Case, Leather, Galvanometer, Blasting, Type I, With Leather

Carrying Strap

This is a leather case with leather shoulder strap for carrying and protecting the galvanometer (par. 81), which is used for testing electrical circuits and their components. This item may be requisitioned separately for replacement purposes when necessary. The case has an opening in one side to register with the scale of the galvanometer. By lifting the cover of the case to expose the terminals, the galvanometer can be used without its removal from the case. The case should be used and stored under as dry conditions as practicable.

78. Chests (Demolition)

a. CHEST % Demolition Squa/l. This chest is used to hold the components of DEMOLITION EQl'IPMENT SET NO. 1, engineer squad (fig. 47). The dimensions of the chest are approximately 40 x 17 x 16. Partitions are arranged especially for keeping components of the set in order.

b. CHEST, Demolition Platoon Engineer. M19S1. This chest is used to hold the components of DEMOLITION EQUIPMENT SET NO. 2, engineer platoon (fig. 48). The dimensions of the chest are 32% x 17% x 12%. Partitions are arranged especially for keeping components of the set in order.

79. Clip, Cord, Detonating, Ml

This is a metal device used to join detonating cord: for application, see figure 25.

80. Compound, Sealing, Blasting Cap, Waterproof, Va-Pint Can

This compound is used to waterproof the connection between safety fuse and a nonelectric blasting cap and to moisture-proof dynamite primers. It does not make a permanent waterproof seal and must not be submerged in water unless the charge is to be fired immediately.

81. Galvanometer, Blasting (W/Leather Case and Carrying

Strap)

a. The galvanometer (fig. 42) is used to test electrical firing wire circuits. It contains an electromagnet, a small special silver-chloride dry cellf and a scale and indicator needle. When the two external terminals are joined by a closed circuit, the flow of current from the dry cell causes the needle to move across the scale. The amount of deflection depends upon the amount of resistance in the closed circuit and on the strength of the cell.

Ik The galvanometer must be handled with care and kept dry. Before using, it is tested by holding a piece of metal across its two terminals. if this does not cause a *vide deflection of the needle, the cell is weak and must be replaced. Only the special cell (silver chloride dry cell battery, type HA 245/U) may be used in the galvanometer, because other cells may be strong enough to detonate a cap. The galvanometer is delicate and must not be tampered with or opened except to replace a weak cell.

r. Dry cells tend to freeze and to cease functioning at temperatures Indow 0° F. When using the galvanometer in a cold climate, protect it from freezing by placing it under the clothing near the body.

<I. A leather carrying case with carrying strap is issued with this instrument. The case may also be requisitioned separately a* a replacement, see paragraph 77.

Explosives And Demolitions
Figure . Galvanometer and carrying cane.

e. For use of the galvanometer to test tiring wires and circuits, see FM 5-25.

82. Machine (Blasting)

The blasting machine is a small electric generator that produces current for firing electric blasting caps. There are. two types in Army use, the 10-cap twisting tyjie and the 30-, 50-. and 100-cap push-down type.

a. Ten-Cap Blunt in/j Machim. The 10-cap blasting machine (A, fig. 43) is standard in DEMOLITION EQUIPMENT SETS NO 1.

and 7. If operated correctly, it will fire 10 electric blasting caps properly connected in series. It weighs 5 pounds. When using this machine, proceed as indicated in (I) through (3) below.

(1) To be sure the machine is working properly and to loosen it up, operate it several times before attaching the firing wires.

(2) Insert the T-shaped handle.

(3) Insert the left hand through the strap and grasp the bottom of the machine very firmly as shown in 0, figure 43. With the back of the right hand toward you, grasp the handle and give it a very vigorous clockwise turn as far as it will go.

b. Thirty-Cap Wasting Machine. The 30-cap blasting machine (B, tig. 43) fires 30 electric caps properly connected in series if operated correctly. It weighs about 20 pounds. Tt is operated by raising the handle to the top of its stroke, then pushing it rapidly and very forcefully downward as far as it will go.

r. Fifty-Cap Blasting Machine. The 50-cap blasting machine is similar to the 30-cap blasting machine, except for size and weight, and is operated in the same manner. Ii weighs 21 ¡»ounds. It will fire 50 electric caps properly connected in series.

B—THIRTY-CAP BLASTING MACHINE

Ww2 Fuse Reel DemolitionDetonator Cord Spool Ww2
TIN-CAP BLASTINO MACHIN!

B—THIRTY-CAP BLASTING MACHINE

C—MKTHOD OF USING 10-CAP BLASTING MACHINIS

ra po 131068

Fi pur? 4-1. Hiattinii machine*.

d. One Hundred-Cap Blurting Machine. The 100-cap blasting machine is similar to the 50-cap machine, except for size and weight, and is operated in a similar manner. It weighs 40y2 pounds and will lire 100 caps properly connected in series.

e. Testing. Blasting machines should be frequently tested for capacity with a rheostat connected in series with the machine and with a circuit of electrically connected electric blasting caps. Sec paragraph 84. for description of rheostats used with blasting machines.

/. Care and Preservation.

(1) Blasting machines are of somewhat rugged construction but they house a relatively delicate, electrical mechanism, hence the machine should be treated with care.

(2) No attempt will be made to disassemble or repair a blasting machine.

(3) Cleaning and oiling will be done only by authorized personnel.

( 4) When not in use, machines will be stored in a clcan, dry, and relatively cool place.

(5) Directions for care and use on metal plates attached to each machine should be followed carefully.

83. Reels and Spools a. REEL, Wire, Firing. 500-foot, RL-39A, With Two Carrying Straps, With Winding Device, Without Spool* Without Wire. This firing wire reel (fig. 44) consists of a spool, a handle assembly, and a crank and axle. Two carrying straps are used to earn- the reel.

(1) The spool is 9 inches in diameter and about. H inches wide. It has a capacity of 500 feet of 18-gage firing wire. The fixed end of the wire is brought from the spool through a hole in the side of the drum and fastened to brass thumb nut terminals*

(2) Two U-shaped steel rods form the handles. A loop at each end encircles a bearing assembly, consisting of a brass housing that contains a steel center to receive the axle.

(3) The axle is a square %6-inch shaft. A crank is riveted to one end and a hole near the other end receives a cotter pin, which holds the axle in place.

b. REEL. Wire, Firing, Mi-foot, With Two Detachable D-shaped Handle*. This tiring wire reel (tig. 45) is a metal drum mounted on an axle, to which two detachable D-shaped handles are fastened. The arm with knob on the side of the drum is used to crank it.

r. REEL. Wire. Firing. 1,000-foot. Empty. This item is similar to I he item described in b above, except that it is empty and has a capacity of 1,000 feet of tiring wire.

Blasting Firing Wire Cable Reels
Figure U. Reel irire, firing, 500-footf RLS»A, irith currying xtrapi. and wire.
Firing Wire Reel

Figure tf. Reel axxembh/. trirc. firing 500-foot, with tin» detachable D-xhaped handle*.

84. Rheostats

There are two types of rheostats used in the Army in connection with testing blasting machines (par. 82), the six-post and the. nine-post (fig. 46). a. RHEO&TA 7\ Blasting Machine. Testing. G-Post.

(1) Description. This rheostat consists of a series of coils of electrical resistance wire in a rectangular block-type case approximately IW2 incites in length. Six brass binding posts with round nuts protrude from the top of the case. The terminals of the resistance coils inside the case are connected to the internal ends of the binding posts. Numbers on the side of the case between adjacent pairs of binding posts indicate the number of caps in series having the same resistance as the internal resistance coil connected to that particular pair of posts. The number of caps in series having a resistance equal to that between any pair of posts is obtained by adding the figures between the pair selected.

6-POST RHEOSTAT FOR 9-POST RHEOSTAT FOR

TESTING BLASTING MACHINES TESTING BLASTING MACHINES

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