Millbank Pit tunnel

This tunnel was discovered during excavations for a carrier drain associated with road improvements. The brick-built arched structure was investigated by the mechanical excavation of test pits along its projected alignment which were subject to a watching brief (event 5193 report 2017/154). It consisted of two parallel brick walls, set 0.8m apart, which survived to a maximum height of 1.8m, and the remains of a brick floor. The walls and capping of the structure were two brick courses wide and comprised hand-made bricks bonded with a lime-based mortar and laid stretcher bond. Two upright wooden planks were set against the south-east facing wall. The structure lay at approximately 2m below ground level and had been damaged during past groundworks. It was tentatively interpreted as a drift, providing access from the pit shaft to a coal seam or another shaft.