Trench System

• Aircraft can warn of the build up of enemy troops before an attack
• Barbed wire was metres deep and an impassable obstacle for any troops trying to cross
• No Man's Land

  The stretch of land between the trenches of the opposing sides
• No Mans Land is churned up by shell fire. In wet weather it becomes a mass of mud, making it even harder to cross.
• Types of trenches

  Front-line trench, support trench, reserve trench, communication trench
• Front-line dugouts provide protection but not against a direct hit from an artillery shell
• Concrete block house for a machine gun
• Deep dug-outs were too well constructed to be damaged by shell fire; German ones could be as deep as 15m underground
• Long-range artillery is placed about 10km behind the frontline. These guns fire at advancing enemy troops
• Communication trenches were the main form of communication between the front-line and reserve trenches