The 252nd Tunnelling Company was one of the tunnelling companies of the Royal Engineers created by the British Army during World War I. The tunnelling units were occupied in offensive and defensive mining involving the placing and maintaining of mines under enemy lines, as well as other underground work such as the construction of deep dugouts for troop accommodation, the digging of subways, saps (a narrow trench dug to approach enemy trenches), cable trenches and underground chambers for signals and medical services. 252nd Tunnelling Company is particularly known for creating the Hawthorn Ridge mine during the Battle of the Somme 1916, which formed part of a series of mines that were placed beneath the German lines.