Coal mining subsidence, Wemyss villages, Fife

This report describes the results of mining subsidence calculations for the Fife coast around the villages of West and East Wemyss, north of Kirkcaldy. This part of the Fife coastline is well known for the increase in coastal erosion it has suffered in recent years. The reasons for the increase are rooted in past deep mining subsidence, the cessation of the disposal of colliery spoil on the Fife foreshore between Buckhaven and Dysart and the associated loss of beach recharge from heaps of mine spoil (known locally as bings) by longshore drift to compensate for the mining subsidence. The mining spoil at Wellesley Colliery, Buckhaven was eroded by the sea and redistributed southwards by longshore drift depositing up to 5 m of ‘beach recharge material’ on the shores in front of the two villages. Once tipping ceased, coastal erosion (and flooding) re-established itself and retreat of the shoreline accelerated, threatening property and ancient monuments (caves with Pictish and other carvings). The mining subsidence calculations show that the Wemyss foreshore area has been affected by up to 5 m of cumulative and irregularly distributed ground subsidence. The large number of seams (>16) worked and the complexity of the workings will have set up high strains of compression and tension in the strata overlying the worked coal seams. These strains will have caused surface damage and enhanced erosion at the coast. The world famous Wemyss caves have also suffered damage and collapse as a result of mining subsidence and coastal erosion (partial collapse of Court Cave in 1970). Subsidence of up to 2 m, with recent removal of beach material deposits, means the cave system is now even more vulnerable to marine erosion and flooding unless defended.