Organization

The normal organization of an intrenched position includes the following elements from front to rear:

1. In front of the position and at a variable distance from the first line fire trench there is a line of wire entanglements. (See Obstacles, p. 4.)

2. Close up to the wire entanglements there is an intrenched post known as the "listening post," which is connected with the first line fire trench by a zigzag communicating trench. (See Listening Posts, p. 18.)

3. Then comes the first line fire trench with attached machine-gun emplacements at convenient points. (See Fire Trench and Machine-Gun Emplacements, pp. 24 and 44.)

4. The fire trench is so narrow that lateral communication along it is effected only with difficulty. In order to provide a passageway a communication or supervision trench is provided a few yards in rear of the fire trench. Passageways lead from this communication trench to the fire trench and to the dugouts located along it.

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. 41.)

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. 48.)

7. This whole arrangement of trenches is connected throughout from front to rear, and laterally, by a system of zigzag communication trenches.

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.

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.

This is the typical system now in use in the European war theaters. Circumstances at certain places may render some variations necessary, and it must not be inferred that the trace of the works is the same throughout. As a rule the types of trenches (altered when necessary to meet local conditions) illustrated herein are the ones in actual use on the war fronts.

All of these trenches and their accessories constitute what is known as the first line. At a distance of from 2,000 to 5,000 yards in rear of this first line a second line, organized in a similar manner, is to be found.

At intervals of from 800 to 1,500 yards along the first line-centers of resistance, or what we know as "supporting points," are located. These consist of fortified villages, or a network (labyrinth) of trenches, provided with every defensive device known to modern warfare. The object of these supporting points is to bring a flanking fire to bear on the intervals between them, with the idea that an attacking force cannot advance beyond them without capturing them.

Plate 2 shows the general scheme of the occupation of a sector of the line by a field army of two divisions.