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 Actions of 30 September – 4 October 1917 The Actions of 30 September – 4 October 1917 were German methodical counter-attacks ("Gegenangriffe") during the Third Battle of Ypres in Flanders, during the First World War. Hasty counter-attacks () by the German 4th Army during the Battle of the Menin Road Ridge on 20 September and the Battle of Polygon Wood on 26 September, had been costly failures. On 29 September, a review was held at Roulers by Erich Ludendorff the (Quartermaster-General of the German Army, equivalent to the British Chief of the General Staff) with the commanders of "Heeresgruppe Kronprinz