Sulfur mustard later also against the French Second Army. The name Yperite comes from its usage by the German army near the town of Ypres. The Allies did not use mustard agent until November 1917 at Cambrai, France, after the armies had captured a stockpile of German mustard shells. It took the British more than a year to develop their own mustard agent weapon, with production of the chemicals centred on Avonmouth Docks. (The only option available to the British was the Despretz–Niemann–Guthrie process). This was used first in September 1918 during the breaking of the Hindenburg Line. Mustard agent was dispersed
Tanks in the German Army some areas. Twenty of these tanks were produced, and the first of these were ready in October 1917. The A7V was first used at St Quentin on 21 March 1918. Although some of its features, such as the sprung tracks and the thicker armour, made it better than British tanks at that time, the A7V was less successful as a battle vehicle. The main problems concerned its mechanical reliability and the difficulty it encountered crossing enemy trenches. By the time of the arrival of the Sturmpanzerwagen, the Germans had already successfully developed their own brand of armor-piercing projectile as well.