5. At a variable distance in rear of the fire trench (100 to 200 yards) the emplacements for bomb-throwing apparatus and trench mortars are located. These are connected up laterally by a communication trench which joins with the main communication trench running from front to rear through the position. (See Emplacements for Trench Mortars, p. 51).
6. From 100 to 400 yards to the rear of the first line fire trench, and generally parallel to it, is the supporting trench or cover for the supports. This trench is invariably provided with strong overhead cover and a system of dugouts for the protection of the troops. (See Cover for Supports, p. 53).
7. This whole arrangement of trenches is connected throughout from front to rear, and laterally, by a system of zigzag communication trenches.
PLATE 1.
PLAN OF THE ORGANIZATION OF AN INTRENCHED POSITION
Take this brief description together with Plate 1, the drawing that accompanies this volume, and study the two until you get the entire system fixed firmly in your mind; that is, until you get a mental picture of all the elements included in the system.
Organization of a Sector of the Battle Front occupied by a Field Army of Two Divisions.
Plate 2.
After you have done this, study on through the book in order that you may know the purpose of each of these elements and how one links up with the other.