The Gas attacks at Wulverghem (30 April and 17 June 1916) were German cloud gas releases during the First World War on British troops at Wulverghem in the municipality of Heuvelland, near Ypres in the Belgian province of West Flanders. The gas attacks were part of the sporadic fighting between battles in the Ypres Salient on the Western Front. The British Second Army held the ground from Messines Ridge northwards to Steenstraat and the divisions opposite the German XXIII Reserve Corps had received warnings of a gas attack. From 21 to 23 April, British artillery-fire exploded several gas cylinders in the German lines around Spanbroekmolen, which released greenish-yellow clouds. A gas alert was given on 25 April when the wind began to blow from the north-east and routine work was suspended; on 29 April, two German soldiers deserted and warned that an attack was imminent. Just after midnight on 30 April, the German attack began and over no man's land, a gas cloud drifted on the wind into the British defences, then south-west towards Bailleul.
The gas used at Wulverghem was a mixture of chlorine and phosgene, which had been used against British troops on 19 December 1915 in the phosgene attack at Wieltje, north-east of Ypres. This and earlier gas attacks, beginning at the Second Battle of Ypres (21 April – 25 May 1915) had given the British time to replace improvised gas masks with effective mass-produced versions, obtain other anti-gas equipment and to establish anti-gas procedures. Helmets impregnated with chemicals to neutralise chlorine had been issued in several variants, each more effective than the last. By April 1916, British troops had PH helmets and some specialist troops like machine-gunners, were equipped with box respirators. The German gas attack at Wulverghem on 30 April, caused the defenders casualties and fatalities but German raiding parties, looking for mine entrances to destroy, were repulsed with small-arms and artillery fire. A second attempt by the Germans on 17 June caused about the same number of gas casualties but the British again easily repulsed German patrols.
Background
1915
Second Battle of Ypres
During the evening of 22 April 1915, German pioneers released chlorine gas which drifted into the positions of the French 87th Territorial and the 45th Algerian divisions, on the north side of the salient and caused many of the troops to run back from the cloud, leaving a gap in the Allied line. The German attack was a strategic diversion, rather than a breakthrough attempt and insufficient forces were available to follow up the success. As soon as German troops tried to advance into areas not affected by the gas, Allied small-arms and artillery fire dominated the area and halted the German advance. The surprise gained against the French was increased by the lack of protection against gas and because the psychological effect of the insidious nature of the substance. A soldier could evade bullets and shells but gas seeped into trenches and dugouts and had a ghastly, slow, choking effect. The gas was quickly identified as chlorine and the first Allied mass-produced anti-gas helmet was a flannel bag soaked in glycerine, hyposulphite and sodium bicarbonate.
19 December 1915
On 19 December 1915, the German 4th Army conducted an attack at Ypres using a new gas, a mixture of chlorine and phosgene, a much more lethal concoction. The British took a prisoner who disclosed the intended gas attack and gleaned information from other sources, which led to the divisions of VI Corps being alerted from 15 December. The gas discharge was accompanied by German raiding parties, most of which were engaged by small-arms fire, while attempting to cross no-man's land. The British anti-gas precautions were successful and prevented a panic or a collapse of the defence, even though British anti-gas helmets had not been treated to repel phosgene. Only the 49th Division had a large number of gas casualties, caused by soldiers in reserve lines not being warned of the gas in sufficient time to put on their anti-gas helmets. A study by British medical authorities counted casualties, of whom died. After the operation, German opinion concluded that a breakthrough could not be achieved solely by the use of gas.
