John Darling Colliery was owned by The Broken Hill Proprietary Co Ltd and was situated 12 miles south of Newcastle. The sinking of the two 22ft diameter shafts commenced in 1925. Both shafts were lined with concrete apart from 20ft at the surface. The Victoria Tunnel seam was reached on June 10, 1927, at a depth of 650ft, with a thickness of 10ft 3in, of which 5ft 9in was workable. In all, eight seams were proved, with a total thickness of 130ft.
The average daily output in 1937 was 2,400 tons hand mined from the Victoria Seam (2,150 tons) and the Borehole Seam (350 tons). Pillars were worked simultaneously with the bords, resulting in almost the whole of the seam being extracted.