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
Battle of Arras (1917) the Western Front, in Operation Alberich. By the spring of 1917, the German army in the west had a strategic reserve of "Experience of the German 1st Army in the Somme Battles", ("Erfahrungen der I Armee in der Sommeschlacht") was published on 30 January 1917 by Ludendorff but new defensive methods were controversial. During the Battle of the Somme in 1916 Colonel Fritz von Loßberg (Chief of Staff of the 1st Army) had been able to establish a line of "relief" divisions (), with the reinforcements from Verdun, which began to arrive in greater numbers in September. In his analysis