Nunnery Colliery opened in 1868, sunk on land that took its name from a long-vanished medieval nunnery. The mining company - the Waverley Coal Company - also worked High Hazels Colliery, three miles further east. At its peak Nunnery's coal supplied the bulk of the trade within Sheffield itself, fuelling the city's domestic fires, its railway sidings, and the steelworks growing along the lower Don. The pit had two shafts, an arrangement that proved its worth on 12 July 1871 when a fire broke out in one of them. Every miner underground was able to climb out through the second shaft. The fire was put out within hours and work resumed within days. Such fortunate outcomes were not always to follow.

The Paddy Mail was the underground commuter service of British coal mining. Wooden benches or open tubs were coupled into a short train, hauled along the haulage road by a continuous steel rope that ran on a return loop powered by a stationary winding engine on the surface. The strain on the rope was greatest when it was pulling loaded coal tubs back up the gradient, not when it was carrying miners. That made the December 1923 failure all the more puzzling. The 500-yard rope was nineteen months old. The men were riding back to the surface at change of shift, not hauling coal. The strain should have been the lightest it would be all day.

After the bodies had been brought up and the injured carried to the hospital, the company submitted two-foot lengths of the broken rope to Dr C. H. Desch, Professor of Metallurgy at Sheffield University, and to a local testing works run by James Hoyland. The Mines Act of 1842, the management noted in evidence, said nothing about how long a haulage rope was allowed to remain in service or what strength it needed to retain. Hoyland's tests did not prove the rope had materially weakened. Desch examined the fracture faces and could not explain why a rope under what should have been light load had broken in tension. The jury at the inquest, with no metallurgical explanation and no clear regulatory breach, returned a verdict of accidental death. The seven dead - and the fifty injured - went into the long unmarked register of British mining casualties between the wars.

Mining continued at Nunnery for another thirty years. When the Labour government nationalised the British coal industry on 1 January 1947, Waverley Coal Company's locomotives - a mixed roster from Andrew Barclay, Hunslet, Hawthorn Leslie, Kerr Stuart and the rest of the British industrial-locomotive trade - passed to the National Coal Board. The pit closed in August 1953, its reserves declared exhausted. The shafts were capped, the buildings demolished. The land was absorbed into the industrial sprawl of Darnall, and there is little left above ground today to mark where ninety men and thirty boys once climbed into a Paddy Mail on a winter morning and seven of them did not come home.