“Holme Bank chert mine was worked from c.1800 up to 1960. There are extensive workings, notable for the large packwalls used to support the roof after the chert beds had been removed. The last company to operate the mine (Smiths Runners) also manufactured davie blocks for building, and continued to do so on site up to about 1995. Much of the surface plant is still on site.
Dry stone pillars as roof supports are a common feature of this mine, usually of single blocks piled in order of size.
On the left you can see the furthest end face of the mine. Because this wall is not packed with deads you can clearly see the streaks of chert running through the rock.”
A Maze Of Stone And Shadows (by jamescharlick)