Plate 5a.—Alarm trap.
A portable wire entanglement is constructed by stretching wire loosely around a wooden framework, either circular or square or made on a knife rest, and rolling it into position to close up gaps that may have been made in the entanglement. The illustration shows the wooden framework.
The ordinary repairs to entanglements are made under cover of darkness by working parties detailed for the purpose. Iron posts that can be quickly placed in position are advantageous, their disadvantage being that they may retard bullets that would go through the ordinary wooden posts, thus furnishing just that much cover and protection to attacking parties.
Plate 6.—Portable entanglement. Constructed in the trenches and rolled into position.
In the construction and repair of entanglements care must be taken to see that they are firmly fastened into the ground with numerous stay posts or "deadmen." This is to prevent the enemy from pulling them to pieces with grappling hooks connected to ropes that lead to his trenches and are attached to powerful windlasses or capstans.
Barricades
Barricades are employed for the defense of streets, roads, bridges, etc. They may be made out of any available material such as furniture, vehicles (overturned or with wheels removed), carts filled with stones, bales of goods, etc.