During the Battle of the Somme, the British Army introduced a secret new weapon intended to break the stalemate of trench warfare: the tank. Developed under the code name 'water carriers for Mesopotamia' (hence the name 'tank'), these armored vehicles were designed to crush barbed wire, cross trenches, and provide cover for infantry. The first model, the Mark I, was slow, prone to mechanical failure, and filled with exhaust fumes that choked the crew. In their first engagement at Flers-Courcelette, only 32 of the 49 tanks reached the start line, and many broke down. However, the psychological impact on German soldiers was immense. While not a decisive 'war-winner' in 1916, the tank's introduction marked the beginning of mobile armored warfare that would eventually render static trench lines obsolete in future conflicts.