Inclined roadways were driven to exploit shallow coal which would be uneconomic to be worked by shafts. Due to the geology some of the North Staffordshire coal seams, the drift mine was introduced to extract the coal. The photograph shows the 1260 yard long main intake drift at Silverdale which 16ft wide, 12ft high and equipped with a 48in conveyor belt capable of discharging 750 tonnes of coal an hour.