Yorkstone has been quarried since the 1400’s and in the 18th and 19th centuries a very large industry developed exploiting the sandstones (Yorkstone) of the Millstone Grit ‘Namurian’ and the coal measures ‘westphalian’ for Masonry, Flagstones and for Roofing know locally as thackstones or Grey Slate.
The Yorkstone Quarries or Delves first worked the outcrop on the valley sides where there was little or no overburden to remove, the Yorkstone rock was sometimes followed underground into large chambers or galleries. old workings and mine shafts can still be seen in the Southowram area.
The mines took advantage of a thin layer of soft shale underneath the stone blocks called the “pricking” when the rock above was left to “weight” and fall by gravity.
When the quarries or delves were shallow, the blocks of Yorkstone were carried to the surface by “huggers”. Hugging continued until about 1870 though gins and hand cranes capable of lifting a ton were used earlier in some quarries. The development of deep Yorkstone quarries and mines came only with the intoduction of gins and steam cranes and in Hipperholme the earliest shafts were sunk about 1860.