Infantry Drills

3-121: Protective Obstacles

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3-121. Infantry platoons plan and construct their own protective obstacles. For best effect, protective obstacles are tied into existing or tactical reinforcing obstacles. The platoon can use mines and wire, or it might receive additional materiel from company, Class IV or V supply point. The platoon also might conduct any other required coordination, such as needed in a relief in place, to recover or destroy the obstacle:

  • In planning protective obstacles, the platoon leader evaluates the potential threat to the platoon’s position. Then, employs the best system for that threat.
  • Protective obstacles usually are located beyond hand grenade distance (40 to 100 meters) from the Soldier’s fighting position, and may extend out 300 to 500 meters to tie into tactical obstacles and existing restricted terrain. As with tactical obstacles, the platoon leader should plan protective obstacles in-depth and try to maximize the range of his weapons.
  • When planning protective obstacles, the platoon leader considers preparation time, the burden on the logistical system, the Soldiers’ loads, and the risk of loss of surprise.

3-122. The three types of wire obstacles (see figure 3-11) are protective, tactical, and supplementary:

  • Protective wire can be a complex obstacle providing all-around protection of a platoon perimeter. It also might be a simple wire obstacle on the likely dismounted avenue of approach into a squad ambush position. Command-detonated M18 Claymores can be integrated into the protective wire or used separately.
  • Tactical wire is positioned to increase the effectiveness of the platoon’s fires. Usually, it is positioned along the friendly side of the medium machine gun FPL. Tactical minefields also may be integrated into these wire obstacles or used separately.
  • Supplementary wire obstacles can break up the line of tactical wire. This helps prevent the enemy from locating friendly weapons (particularly the medium machine guns) by following the tactical wire.
Figure 3-11. Protective wire obstacles

Next: 3-123: Obstacle Lanes

Go Back To: U.S. Army FM 3-21.8: The Infantry Rifle Platoon and Squad