Glenbrook Tunnel War One. The first was Chlorine gas which was introduced by the Germans at the Second battle of Ypres in April 1915. This was followed by the use of Phosphene Gas, also introduced by the Germans. These attacked victims' respiratory organs causing coughing and choking. The Germans used Mustard Gas, a more advanced gas, for the first time at Riga (or Yperite) in September 1917. It caused both internal and external blistering in its victims. The blistering was often delayed and remained in the ground for weeks afterwards making capture of infected trenches dangerous. Protection against mustard gas was far
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.