Nuns Moor, pillar-and-stall mine shaft

A very spread heap of spoil with a well defined hollow in its centre, measures 4.5 metres in diameter and is 0.5 metres deep. The use of pillar-and-stall mining (cutting horizontal headings out of the bottom of the shaft, leaving pillars of coal to support the roof) meant shafts could be spaced wider apart. The best example of a widely spaced grid pattern of shafts on the Town Moor is on Nuns Moor, where four shaft heads form a square pattern. These shaft heads have larger spoil heaps than the Bell Pits, indicating deeper shafts and a later mining episode. A diagnostic feature of the landscape indicating pillar-and-stall mining is the subsidence of the surrounding ground surface, due to the caving in of the galleries especially after the removal of the roof supports. Such areas of mining subsidence effect large areas of the Moor.