Cwmtillery Colliery explosion, 1866

An explosion of firedamp at the Cwmtillery pits on 18 May 1866 burned three men, a father and son among them, who died over the following weeks; the inquest jury blamed a canvas ventilation door left open.

Cause

Gas accumulated in Bagnell's stall and was fired; the overman believed a canvas door ('sheet') in the ventilation had been left open, cutting off the air.

What happened

At about four in the afternoon of Friday 18 May 1866 firedamp exploded in the Cwmtillery pits of the South Wales Colliery Company. The overman, Joseph Wallace, had been in the pit through the night and morning and had found only a little gas. John Bagnell and his son Emanuel had been waiting on the roadway for trams for about an hour when Emanuel went back into his stall and fired the gas. After the explosion several of the canvas sheets that directed the air were found blown down, and the workings full of afterdamp. John Bagnell died on 24 May, and Emanuel and Thomas Parry, both badly burned, died in June.

Investigation & inquiry

The inquest before the coroner W. H. Brewer at the Castle Inn, Abertillery, was adjourned twice; a second jury had to be sworn when Emanuel Bagnell died. The overman thought a sheet or doorway had been left open, and evidence was heard that the sheet the men passed through had no frame and was flapping about. The jury believed the door had been left open by someone passing through; the coroner told them this amounted to a finding of manslaughter, and a verdict of manslaughter against persons unknown was returned.

Recorded claims

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

• An explosion of firedamp at the Cwmtillery Pits of the South Wales Colliery Company on 18 May 1866 killed John Bagnell, who died on the 24th, and seriously injured two other men. ¹
• John Bagnell, 56, his son Emanuel, 19, and Thomas Parry, 27, died of the explosion; a main ventilator door had been left open, and the jury returned a verdict of manslaughter against persons unknown. ²
• At the adjourned inquest the foreman said the jury believed the doorway had been left open by some person, and the coroner observed that this amounted to manslaughter against some person. ³
• The overman, Joseph Wallace, thought the accident was caused by a sheet or doorway being left open, and found several sheets blown down afterwards. ¹

Related terminology

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

• Afterdamp (contextual relationship)
  Named in this record’s narrative: “…directed the air were found blown down, and the workings full of afterdamp. John Bagnell died on 24 May, and Emanuel and Thomas Parry, both…”
• Firedamp (contextual relationship)
  Named twice in this record, first in the summary: “An explosion of firedamp at the Cwmtillery pits on 18 May 1866 burned three men, a father and…”
• Overman (contextual relationship)
  Named 3 times in this record, first in the cause: “Gas accumulated in Bagnell's stall and was fired; the overman believed a canvas door ('sheet') in the ventilation had been left…”
• Stall (contextual relationship)
  Named twice in this record, first in the cause: “Gas accumulated in Bagnell's stall and was fired; the overman believed a canvas door ('sheet') in the…”
• Tub (contextual relationship)
  Named in this record’s narrative: “…John Bagnell and his son Emanuel had been waiting on the roadway for trams for about an hour when Emanuel went back into his stall and fired…”

Photographs & further reading

This page doesn't try to reproduce everything — these are the best original sources found for this disaster.

Sources

1. (primary) Fatal explosion at Cwmtillery pits - Monmouthshire Merlin, 2 June 1866 — Welsh Newspapers (National Library of Wales)
2. (secondary) Glamorgan colliery fatalities, 1866 — Welsh Coal Mines website
3. (primary) The Cwmtillery colliery accident: the adjourned inquest - Monmouthshire Merlin, 9 June 1866 — Welsh Newspapers (National Library of Wales)

Record created: 2 October 2026 · Last researched: 2 October 2026