
Reinforcements of troops were available to blunt attacks or throw back Allied troops with rapid counterattacks.
Mortars and artillery provided support to the front line infantry with firepower from the rear. Machine-gunners and riflemen protected the front lines. Barbed wire slowed or stopped infantry advances. Deep trenches and dug-outs protected against artillery.
The riddle of the trenches was to find a way to overcome the power of the defender. The British turned to armoured vehicles as one way to cross No Man’s Land and break through the enemy trench system.
Barbed wire and machine-guns stopped many Allied attacks with heavy casualties in 1915 and early 1916.