The standard barbed wire concertina (fig. 8-12) is a commercially manufactured barbed-wire obstacle made

Figure 8-12.-Standard barbed-wire concertina.

of a roll of single-strand, high-strength, spring-steel wire with four-point barbs attached at 2-inch intervals. Wires forming the coils are clipped together at intervals so the concertina opens to a cylindrical shape 16.4 to 49.2 feet long (depending on structure and build of opening) and 3 feet in diameter. The 16.4-foot length prevents smaller enemy personnel from crawling through the wire because the coils are closer together. Use tanglefoot (discussed later in this chapter) in conjunction with the wire to further increase the effectiveness of the barrier. The concertina is opened and collapsed easily, and it can be used repeatedly. The wire is much harder to cut than standard barbed wire. The concertina weighs about 11 1/2 pounds.

HANDLING

The collapsed concertina is tied with plain-wire bindings attached to the quarter points of a coil at one end of the concertina. When opening the concertina, remove these bindings and twist them around the carrying handle for use in retying the concertina when it is again collapsed. You need four men to open a concertina and to extend it to the 16.4- to 49.2-foot length. Place one man to work at each end and the other two spaced along its length to ensure that it opens and extends evenly. When necessary, two men can easily open a concertina by bouncing it on the ground to prevent snagging as they open it.

Table 8-2.-Material and Labor Requirements for 984-Foot Swtlons of Various Barbed.Wire Entanglements

Two men can collapse a concertina in the following manner:

1. First, remove all the kinks in the coils.

2. Tighten or replace the loose clips with plain wire.

3. Station one man at each end of the concertina and have them place one foot at the bottom of the coil and one arm under the top of the coil to close it.

4. Now, have two men walk toward each other closing the concertina as they go by feeding the wire over their arms and against their feet.

5. After closing, lay the concertina flat and compress it with your feet.

6. The the concertina with plain-wire bindings.

One man can carry the collapsed concertina by stepping into it and picking it up by the wire handles attached to the midpoints of an end coil.

Use improvised staples, approximately 18 inches long and made of 1/2-inch driftpins or similar material, to fasten the bottoms of concertina fences securely to the ground.

Barbed-tape concertina comes in a diameter of 33 inches and an expanded length of 50 feet. It is formed of barbed tape wrapped around a high-strength, spring-steel, core wire. Its configuration, method of handling, and method of employment are similar to standard barbed-wire concertina. One roll weighs 31 pounds.