The portion of the ground in rear of the parapet and between the parapet and the trench not covered by the parapet is to rest the elbows on when firing, the rifle being rested on top of the parapet.
To obtain head cover in a trench fill a gunny sack or other bag with sand or soil and place it on top of the parapet, aiming around the right-hand side of it, or dig a small lateral trench in the parapet, large enough to hold the rifle. Roof it over with boards, small logs, or brush, and heap dirt on top, aiming through the small trench or resulting loophole.
Figure [5] shows the plan of a section of a rifle trench.[10] Between the portions occupied by each squad there is often placed a mound of earth as high as the top of the parapet and projecting back into the trench. This is called a traverse and protects the occupants of the trench from fire from a flank. Bullets from this direction hit a traverse, instead of flying down into the trench and wounding several men.
Trenches are seldom continuous, but are made in sections placed at the most advantageous points, as shown in figure [6]. A company or battalion may occupy a single section. The firing trenches have cover trenches in rear of them, where the supports can rest undisturbed by the hostile fire until they are needed in the firing trench to repel a serious assault or to take part in a counter attack. Passages consisting of deep communicating trenches facilitate passage from the cover trenches to the firing trenches when under fire. These communicating trenches are usually zigzag or traversed to prevent their being swept by hostile fire.
When troops are likely to remain in trenches for a considerable time drainage should be arranged for, and latrines and dressing stations should be constructed in trenches. Water should be brought into the trenches and holes excavated in the front wall of the trench for extra ammunition.
In digging trenches men usually work in reliefs, one relief digging while the others rest, the proportion of shovelers to pickmen being about 3 to 1. If a plow can be obtained to turn the sod, it will greatly facilitate the initial work of digging.
Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Plate V.