Heaton Banks Colliery, Site of three engines

Three "engines" are shown on an 18th century "Plan of Heaton Estate". A 1733 drawing of the engine used to drain the Knab Pit shows that it was much more sophisticated than the early coffee pot type used at Tanfield. The engine house is a large, two stories, building housing an engine with 42 inch cylinders and a seven foot stroke which was capable of ten strokes a minute and drawing 11,550 gallons of water an hour.