[Illustration: Fig. 2a

_Intrenching under fire_]

The height of the parapet should not exceed 1 foot. This trench
affords limited protection against rifle fire and less against
shrapnel.

=1145. Kneeling trench.= (Fig. 3.) Time permitting the lying trench
may be enlarged and deepened until the kneeling trench has been
constructed. The width of the bottom should be 2-1/2 feet--preferably
3 feet--and the relief (distance from bottom of trench to top of
parapet) is 3 feet--the proper height for firing over in a kneeling
position.

[Illustration: Fig. 3]

=1146. Standing trench= (Fig. 4) has a bottom width of 3 to 3-1/2 feet
and a relief of 4-1/2 feet which is the proper firing height for men
of average stature. As this trench does not give complete cover to men
standing in it a passage way should be constructed in rear of it not
less than 6 feet below the interior crest. This forms the complete
trench (Fig. 5). Figures 6-7-8 show simple standing trenches used in
the European War.

[Illustration: Fig. 4]

[Illustration: Fig. 5]

[Illustration: Fig. 6

Simple Standing Trench, Parapet Suppressed]

[Illustration: Fig. 7

Simple Standing Trench, Rocky Ground]

[Illustration: Fig. 8

Narrow Firing Trench with Parados]

=1147. Deliberate intrenchments= comprise trenches and works
constructed by troops not in line of battle and are usually intended
to enable a small force to resist a much larger one. It frequently
happens that hasty intrenchments are developed into deliberate
intrenchments and from this stage pass into the domain of siege works.

=1148. Fire trenches=,--the trenches which shelter the firing
line,--are of different types. No fixed type can be prescribed. The
type must be selected with due regard to the terrain, enemy, time,
tools, soil, etc., but all should conform to the requirements of a
good field of fire, and protection for the troops behind a vertical
wall, preferably with some head or over head cover.

The simplest form of fire trench is deep and narrow and has a flat
concealed parapet (Fig. 9). When time will permit the simple trench
should be planned with a view to developing it into a more complete
form (Figs. 10 and 11). In all trenches as soon as practicable a
passage way--2 feet wide at the bottom--should be provided, in rear of
the firing step, for the men carrying supplies, ammunition, etc., and
for the removal of the wounded.

[Illustration: Fig. 9]

[Illustration: Fig. 1