WIRE OBSTACLES

H-154. The platoon or squad normally employs wire obstacles as part of the protective obstacle plan in the defense. Wire obstacles include barbed-wire, triple-standard concertina, four-strand cattle fences, and tanglefoot. Construction methods for two of the more common wire obstacles the platoon or squad employs, triple standard concertina, and tanglefoot are shown in figures H-21 through H-25. (Refer to ATTP 3-90.4 for more information.)

TRIPLE STANDARD CONCERTINA FENCE

H-155. The most common wire entanglement a platoon or squad may build is the triple standard concertina fence. It is built of either barbed wire concertina or barbed tape concertina. There is no difference in building methods. The material and labor requirements for a 300-meter triple standard concertina fence are─

  • Long pickets – 160.
  • Short pickets – 4.
  • Barbed wire, 400-meter reels – 3
  • Rolls of concertina – 59.
  • Staples – 317.
  • Man-hours to erect – 30.

H-156. First, lay out and install pickets from left to right (facing the enemy). Put the long picket’s five paces apart and short (anchor) picket’s two paces from the end of the long pickets. (See figure H-21.) The enemy and friendly picket rows are offset and are placed three feet apart. Now lay out rolls of concertina. Place a roll in front of the third picket on the enemy side, and two rolls to the rear of the third picket on the friendly side. Repeat this step every fourth picket thereafter. Install the front row concertina and horizontal wire. (See figure H-22.) Place the concertina over the pickets. Install the rear row of concertina and horizontal wire. Install the top row of concertina and join the rear horizontal wire. (See figure H-23.)

Triple standard concertina fence

Figure H-21. Triple standard concertina fence

Installing concertina

Figure H-22. Installing concertina

Joining concertina

Figure H-23. Joining concertina

CONCERTINA ROADBLOCK

H-157. The concertina roadblock is placed across roadways and designed to block wheeled or tracked vehicles. The roadblock is constructed of 11 concertina rolls or coils placed together, about 10 meters in depth, reinforced with long pickets five paces apart. The rolls or coils should not be tautly bound allowing them to be dragged and tangled around axles, tank road wheels, and sprockets. Additionally, wire is placed horizontally on top of the concertina rolls or coils. (See figure H-24.)

Eleven-row anti-vehicular wire obstacle

Figure H-24. Eleven-row anti-vehicular wire obstacle

TANGLEFOOT

H-158. Tanglefoot is used where concealment is essential and to prevent the enemy from crawling between fences and in front of emplacements. (See figure H-25.) The obstacle should be employed in a minimum width of 32 feet. The pickets should be placed at irregular intervals of 2 ½ feet to 10 feet. The height of the barbed wire should vary between 9 to 30 inches. Tanglefoot should be sited in scrub, if possible, using bushes as supports for part of the wire. On open ground, short pickets should be used.

Tanglefoot

Figure H-25. Tanglefoot