Originally started by Ebbw Vale Steel Iron & Coal co Ltd mining commenced as quarries in 1915 however in 1918 the company engaged in driving the huge underground mine here the likes of which had never been seen in Ironstone mining in the Midlands.
The mines were worked by Pillar & stall and had an overhead electrified railway in the mine of 3 foot gauge. This emerged from the adit at the GR given and had fully wired sidings. The main tunnel was extended by Richard Thomas & Co in 1938 (3 years after purchase from Ebbw vale co) to the Finedon Quarries. the ore works for these extensive working was near the adit entrance at Irthlingbro itself and had its own 2 foot gauge internal railway worked by steam.
The final phase of operation was by Richard Thomas & Baldwins Ltd from 1945.
The electric locomotives employed are interesting 4 wheel electrics, 2 built by GEC (US) in 1938 and 6 by Greenwood Batley in 1941, these had a HP of 240-260 and operated from a wire voltage of 250v. Initially the mine was worked by 4.8hp Battery locos which were retained to work the stalls and galleries.