Lower Duffryn Colliery explosion, 1858

At about two in the morning of 25 February 1858 an explosion of firedamp in the upper colliery of Thomas Powell's Lower Duffryn, at Cwmpennar near Mountain Ash, killed nineteen men and boys.

Cause

An explosion of firedamp. One account has a large fall of roof in a stall at the extreme rise releasing gas, which travelled down the main road and fired at a naked or defective lamp where men were at their meal; another blames the night-shift practice of letting the furnace burn low while its grate was cleaned, after which it took two hours to regain its heat. The jury found there was not enough evidence to show how the gas was ignited.

Contributing factors

The main return to the furnace was also the main travelling way, which the inspector called most objectionable. The pit was worked with locked lamps, but matches were found on some of the dead; a gauze cap was found some yards from a lamp, and an air-door had been left open.

What happened

The colliery was among the deepest and most fiery in South Wales, and its upper four-feet seam gave off sudden blowers of gas. The dead were from ten to forty-five years old. George Cox died with his son Joseph, fifteen, and William Auberry with his son William, twelve; the door boys Edwin Strong, ten, and George Gale, fifteen, and Henry Salmon, a collier of ten, were among them. Large crowds gathered at the pit mouth.

Rescue & recovery

Unknown.

Investigation & inquiry

The inquest, before Mr Overton, coroner, returned accidental death by an explosion of gas. The inspector, Thomas Evans, criticised using the return airway as the travelling road and wanted air taken to the face of every working.

Legal & regulatory aftermath

Unknown.

Changes to practice & legislation

The jury recommended a larger furnace or two furnaces, that the return air road should not be used for travelling, and strict enforcement of the rules against taking pipes or matches into the pit.

Memorials & commemoration

Unknown.

What's uncertain

Points where sources disagree or the record could not be settled; both accounts are kept. All open questions in the archive.

• The NMRS disaster account dates the explosion 24 February 1858; the colliery accounts give 25 February, at two in the morning. (disputed) ^1,2,3
• A fall of roof liberated gas which exploded at the naked or defective lamp of men having their dinner. (disputed) ^2,3
• The blast occurred while the furnace, allowed to burn low for cleaning, was regaining its heat; the jury recommended a second furnace. (disputed) ¹

Recorded claims

Individual factual claims, each attached to the source(s) that support it below. Where sources disagree, both are kept.

• An explosion occurred on 25 February 1858, killing 19 men and boys. ^1,2
• The NMRS disaster account dates the explosion 24 February 1858; the colliery accounts give 25 February, at two in the morning. (disputed) ^1,2,3
• A fall of roof liberated gas which exploded at the naked or defective lamp of men having their dinner. (disputed) ^2,3
• The blast occurred while the furnace, allowed to burn low for cleaning, was regaining its heat; the jury recommended a second furnace. (disputed) ¹
• Matches were found on some of the victims; the verdict was accidental death, how the gas was ignited not being shown. ³

Related terminology

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

• Blower (hazard involved)
  The seam gave off sudden blowers.
• Gale and Gaveller (contextual relationship)
  Named in this record’s narrative: “…his son William, twelve; the door boys Edwin Strong, ten, and George Gale, fifteen, and Henry Salmon, a collier of ten, were among them. Large…”
• Safety Lamp (contextual relationship)
  The pit used locked lamps.
• Stall (contextual relationship)
  Named in this record’s cause: “An explosion of firedamp. One account has a large fall of roof in a stall at the extreme rise releasing gas, which travelled down the main…”
• Trapper (contextual relationship)
  Door boys were among the dead.

Sources

1. (secondary) Lower Duffryn (Cwmpennar), near Mountain Ash — Welsh Coal Mines
2. (secondary) Lower Duffryn Colliery — Northern Mine Research Society
3. (secondary) Lower Duffryn Colliery Explosion - Aberdare - 1858 — Northern Mine Research Society

Record created: 21 September 2026 · Last researched: 22 September 2026