British war crimes September 1915 and continued their usage for the remainder of the war. This was done in retaliation for the use of chlorine by Imperial German Army the preceding April. Following the Imperial German Army's use of poison gas at Ypres, the commander of II Corps, Lieutenant General Sir Charles Ferguson, had said of poison gas: Mustard gas was first used effectively in World War I by the German army against British and Canadian soldiers near Ypres, Belgium, in 1917 and later also against the French Second Army. The name "Yperite" comes from its usage by the German army near the
German Type U 93 submarine German Type U 93 submarine Type 93 was a class of U-boats built during World War I by the Kaiserliche Marine. Type 93 U-boats carried 16 torpedoes and had various arrangements of deck guns. As with the type 81 and 87, some had only one SK L/30 deck gun while others had a single SK L/45 gun and some were initially equipped with both. In 1917 some of the boats were refitted with a single 10.5 cm gun and 220 rounds. These boats carried a crew of 39 and had excellent seagoing abilities with a cruising range of around .