Booby traps laid in and along paths and trails are both delaying and frustrating obstacles to foot troops and patrols. Improvised shrapnel charges use either pressure-release or pull or pull-release firing devices. Pressure-release devices are placed under stones, wood, or other objects, and pull or pull-release firing devices are tied to a trip wire stretched across the path. Fragmentation hand grenades are often used for this purpose. One use is to place the grenade (with safety pin removed) under an object, so the safety lever is released when the object is moved.

Other uses include the following:

GRENADE TRAP. A fragmentation grenade is attached to low underbrush, an anchor stake, or a tree trunk alongside the path. One end of a trip wire is tied to an anchor stake across the path, then stretched to the fragmentation grenade where the other end is tied to the grenade safety ring. A pull on the trip wire removes the safety ring, firing the grenade.

HAND GRENADE IN CAN. A C-ration can is attached to an anchor stake or tree trunk alongside the path. A hand grenade is placed base first into the can so the can retains the safety lever in the safe position. One end of a trip wire is tied to an anchor stake across the path, and the wire is stretched across the path and tied to the hand grenade. The grenade safety pin is then removed. A pull on the trip wire pulls the grenade from the can, thus releasing the safety lever and firing the grenade.

MUD BALL MINE. The safety pin is removed from a fragmentation hand grenade and replaced with a 10- to 12-inch wire. A base of mud is molded around the grenade, leaving the ends of the wire exposed. When the mud has hardened enough to hold the grenade safety lever in place, the wire is removed, thus arming the grenade; however, the grenade cannot detonate until its mud case is broken. The mud ball is placed on a trail or anywhere troops may walk Stepping on the ball breaks the dried mud and releases the safety lever, detonating the grenade.