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
Actions of 30 September – 4 October 1917 were to be replaced by a policy of fighting for every piece of ground. Armin thought that even if counter-attacks failed to recapture ground, the British would keep more troops in the front line and that German infantry casualties were no worse in counter-attacks than under British barrages. On 30 September, the 4th Army issued an operation order for more field artillery bombardments between British attacks and that at least half of the heavy artillery ammunition was to be used for observed fire on captured pill-boxes, command posts and machine-gun nests, duckboard tracks and field railways. Gas bombardments were to