Chapter V: Section II: The time and claims of rapid transit will not allow the

traverse system as employed in Section I to be continued, the narrow single-traffic C. T.’s, from wear and tear and shell fire, soon become wider, and as the width would allow rapid transit to friend and foe alike, it is of the utmost importance that some means be adopted to deprive the enemy of this advantage. Moreover, the enemy may have successfully advanced down on traversed C. T., say, at “C,” and our own bombers might still be fighting in another traversed C. T., say, at “D,” and their needs demand protection. This may be obtained if, before the single C. T.’s merge into the double, each of them be quite straight for approximately 15 yards, and island-traverse, “E,” be placed at the junction. In the rear of this island, “E,” is a large and substantial recess, into which one or two Lewis guns or automatic rifles can be placed, firing through loopholes and rendering hostile advance down both “C” and “D” communication trenches almost impossible. The recess in “E” must allow ample room in which to operate. Overhead cover is provided, and one rifle would require one long loophole, so that it could fire along either C. T. without more than a moment’s interruption. In the case of two rifles being available, there could be two such long loopholes, each covering both C. T.’s, one for kneeling and one for standing. The lower loophole gives the advantage of it being impossible for any of the enemy to get out of danger beneath it. The fact that the traverse is an island one, with passageway either side, would allow friends to advance round the traverse and up “D” to the support of friends still fighting there, and without obstructing the fire directed from the traverse at enemy advancing down “C.”

A type used to control long, straight stretches of trench.]

An island-traverse so constructed and manned should be unapproachable along either trench “C” or “D,” but precautions must be taken to prevent the enemy avoiding it by coming out into the open, as in active moments C. T.’s become as mutilated as fire trenches and the enemy may leave the C. T. before reaching the 15-yard stretch and approach the traverse from above or flank. In anticipation of this, the position “H” is selected slightly in rear and to flank of the traverse, and in this position one of the automatic rifles may take up, either originally or by retirement from “E,” and deliver the required traversing covering fire across the front of “E” and giving adequate protection to the garrison manning the island-traverse. Barbed wire is also generally placed in open ground such as this described, say, for instance, between “K” or “L” on either side of the 15-yard stretches to impede hostile exit and advance. The overhead traverse just in front of the island gives protection against bombs thrown down on C. T.

When covering fire is not required, the position “H” will form an alternative position should the island-traverse be destroyed by shell fire or taken by the enemy; but the latter will be of little use to the enemy as their progress passed it is blocked by a loophole placed at “H” and covering the trench “M” down which they must advance. It also covers a dummy trench, shown as “N,” down which there is a fair chance that the enemy would naturally go if a misleading notice were placed at the junction of “M” and “N.” The slight turn at the end, “O,” will prevent premature knowledge as to the real nature of this trench. The enemy’s progress may also be blocked for a short time by having rolls of looped wire, sometimes known as concertina wire, so placed in recesses in the side of the trench, and so arranged that when a man retiring down a trench can catch hold of the roll as he passes a recess, uncoils it as he runs, leaving it in the trench in a badly tangled mass.

SKETCH OF TRENCH SYSTEM]