Mine safety in coal mines, which in turn can initiate more extensive coal dust explosions. For this reason, rock dusts such as limestone dust are spread throughout coal mines to diminish the chances of coal dust explosions as well as to limit the extent of potential explosions, in a process known as rock dusting. Coal dust explosions can also begin independently of methane gas explosions. Frictional heat and sparks generated by mining equipment can ignite both methane gas and coal dust. For this reason, water is often used to cool rock-cutting sites. Miners utilize equipment strong enough to break through extremely hard
Gas attacks at Hulluch from whence the gas was being discharged. After thirty minutes, groups of German infantry about equipped with pistols and hand grenades, were seen heading for gaps in the British wire and were repulsed by rifle and machine-gun fire. At about the three mines were sprung and another bombardment was fired, before sending another gas cloud, which caused many casualties to a Black Watch company, whose commander had ordered them to remove their gas helmets after the first gas cloud, under the impression that the helmets were useless after one exposure to gas. Behind the second gas cloud, larger parties of