Chemical weapons in World War I in Palestine during the Second Battle of Gaza. Russia began manufacturing chlorine gas in 1916, with phosgene being produced later in the year. Most of the manufactured gas was never used. The British Army first used mustard gas in November 1917 at Cambrai, after their armies had captured a stockpile of German mustard gas shells. It took the British more than a year to develop their own mustard gas weapon, with production of the chemicals centred on Avonmouth Docks. (The only option available to the British was the Despretz–Niemann–Guthrie process). This was used first in September 1918 during the breaking
German Type U 151 submarine U 139 "U-cruisers", designed from the outset as military submarines. "Deutschland" made two successful commercial voyages before being commissioned into the Kaiserliche Marine on February 17, 1917 as "U-155". Max Valentiner commanded a Type U 151 U-boat, , and undertook the longest cruise in the war from 27 November 1917 to 15 April 1918, a total of 139 days. High-scoring Waldemar Kophamel also commanded a Type U 151 U-boat, in late summer and fall of 1917. Seven Type U 151 submarines were built, of which six were commissioned into the Kaiserliche Marine. German Type U 151 submarine Type U 151