Ynisdavid Colliery Explosion, Cwmavon, 1856

A firedamp explosion in the Big Vein, deep in the workings, killed nine men and three boys; the colliery's own agent led the rescue and recovery, recorded in detailed inquest testimony.

Cause

A firedamp explosion in the Big Vein; the inquest returned a verdict of accidental death from firedamp with no evidence as to how it was ignited, though it noted that some men were known to raise their safety lamps' locked gauze to light their pipes.

What happened

About 3 a.m. on 24 May 1856, with around seventy men in the mine, those at the pit mouth heard an explosion from deep underground. Men went down at once and found that gas had exploded in the Big Vein workings. David Thomas, the colliery's manager, and W. Gilbertson, the Cwm Avon Works' general manager, were soon on the scene directing the many volunteers who came to help; Gilbertson supplied brandy for those brought out alive and pillows and bedclothes for the injured. Some who reached the surface still living died soon after — Henry Griffiths survived about three hours, Jason Evans about four — while David Thomas (the sixteen-year-old victim, not the manager of the same name) lingered a day and John George died shortly after being brought out. Eight of the twelve were burnt and mutilated; the other four died from gas and their injuries. David Thomas, the mine's agent, gave a detailed account of the recovery at the inquest, held at the Mechanics' Hall, Cwmavon. He described entering the pit himself, working along the Upper Four Feet seam and into the Big Seam's second drift, finding the bodies of Walter Morgan, David Morgan and David King about forty yards in; being driven back by gas further on; finding a cluster of bodies, including the door-boy John George, near an air door; and finally, after clearing a roof fall, recovering the badly burnt body of Hopkin Hill, whose undamaged, still-locked safety lamp was found eight to ten yards away. It emerged at the inquest that the district was known to be dangerous and that safety-lamp regulations were in force, backed by two large ventilating fans, though their installation was not yet complete; the fireman's inspection that morning had found no unusual quantity of gas. It was also stated that some men were known to raise the locked gauze on their lamps to light their pipes. Coroner Cuthbertson summed up, and the jury returned a verdict that the deaths were accidental, from firedamp, with no evidence to show how the gas had been ignited. The victims were buried at Cwmavon, Aberavon, Taibach and Neath.

Investigation & inquiry

An inquest was held at the Mechanics' Hall, Cwmavon, at which the mine's agent, David Thomas, gave a detailed account of the rescue and recovery; the jury returned a verdict of accidental death from firedamp, with no evidence as to its ignition.

Related terminology

Mining terms this disaster is structurally linked to, with the nature of the relationship.

• Drift (contextual relationship)
  Named in this record’s narrative: “…along the Upper Four Feet seam and into the Big Seam's second drift, finding the bodies of Walter Morgan, David Morgan and David King…”
• Firedamp (direct cause)
  The inquest verdict explicitly names firedamp as the cause of the explosion.
• Fireman (contextual relationship)
  Named in this record’s narrative: “…fans, though their installation was not yet complete; the fireman's inspection that morning had found no unusual quantity of gas. It…”
• Roof Fall (contextual relationship)
  Named in this record’s narrative: “…John George, near an air door; and finally, after clearing a roof fall, recovering the badly burnt body of Hopkin Hill, whose undamaged,…”
• Safety Lamp (contextual relationship)
  Named 3 times in this record, first in the cause: “…was ignited, though it noted that some men were known to raise their safety lamps' locked gauze to light their pipes.”

Sources

1. (secondary) Small Collieries in the Afan Valley and surrounding areas — Northern Mine Research Society
2. (secondary) Ynisdavid Colliery Explosion — Cwmavon — 1856 — Northern Mine Research Society

Record created: 15 September 2026 · Last researched: 15 September 2026