"Within this township [Consett] there are two collieries, the Blackhill drift and the Delves pit. The former, situated midway between Consett and Blackhill, is at present working the Busty and Three Quarter seams, the Busty being 4 feet 6 inches thick including a stone band, and the Three Quarter varies from 1 foot 6 inches to 2 feet 6 inches. This drift yields an output of about 3300 tons per fortnight, and gives employment to 207 men and boys. The Delves, a short distance west of the town, is worked by a shaft 130 feet deep, where the Busty seam is met, giving a thickness of 4 feet of good coal, divided by a band, which varies considerably. A good seam of fire clay is also worked in connection with this coal seam, from which are made large quantities of brick for the works. At the pit are employed 123 hands, the output being about 100 tons per day. There are 26 coke ovens, the waste heat from which is utilised in working the colliery."

- Whellan's 1894 Directory of County Durham (via Durham Mining Museum)

NEHL - The pit provided a consistent source of coal and fireclay for the Consett Iron Co., creating bricks for their vast complex.