Generally, the farther the C. T. from the enemy, the less necessity to take measures for stopping hostile advance down it, but it is a safe thing when time permits to loophole the traverses facing the long straight stretches either in an ordinary traverse or when time permits the building of island-traverses, especially at junctions. Such loopholes command the straight stretch in front and are reached by narrow trenches very similar to a drainage trench, as indicated at “H.” Here again, as well, the loopholes for at least one or two should be for kneeling fire.
Hostile attacks may also be hampered here by using the rolls of looped wire previously mentioned, or by frames of barbed wire placed at the side of the trench just behind the parapet, so that a man retiring down the trench can easily pull them down into the trench after him. Great care must be taken that C. T.’s running from firing line to support trenches do not obstruct the fire from the supporting trenches.
SECTION IV
SKETCH OF TRENCH SYSTEM
Section IV. Behind the support trenches the C. T. should be constructed on the traverse principle of [Section I], so that the same defensive features existing for the support trenches as should exist for the firing line. In doing this, however, it should be kept in mind to provide rapid transit for troops behind these supporting lines. This is best done by continuing the zigzag system right through support trenches as shown. When necessary, this C. T. can be blocked.
It is always a possibility that support trenches may be lost, but not a probability. Therefore, undue weight should not be given against the convenience of adopting as soon as possible again the zigzag C. T. of [Section II], the latter supplying all requirements of rapid transit and allowing the introduction of straight stretches in loophole traverses wherever required.
TELEPHONE LINES
It is generally found that artillery telephone lines are laid on the north and west side of a C. T.; infantry lines on the south and east. Lines are generally laid about two feet from the bottom of the trench, picketed inter-grooves being cut into the side of the trench. These lines must be given absolutely every protection possible by the infantry and by any one using the trenches. Far too much carelessness has at times existed which destroyed communication with artillery and infantry when it was of vital importance that it should be open.