The colliery had two shafts only apart. The downcast shaft was used for access and coal extraction. The upcast shaft was provided with ropes and pulleys for use if the downcast was blocked. The shafts passed through four shallower "mines" that were not worked in 1885 before reaching the Dow, Five-Quarters and Trencherbone mines. The shafts terminated at the Cannel mine which at the time of the explosion was not being worked. The Trencherbone seam is about high. Above it is around 6 feet of "white metal" a rock forming a fair roof, and above that some low grade coal which was not worked. Above this poor coal is "good solid rock" thick known as the Trencherbone rock. All the strata in the colliery sloped down from the north to the south at about 1 in . A horizontal tunnel ran from where the downcast shaft met the Trencherbone mine southward until it intersected the Five-Quarters and finally Dow mines.