New Tredegar Colliery explosion, 1858

Firedamp exploded in New Tredegar Colliery before dawn on 11 September 1858, when a haulier took a naked light into gas while the pit was being readied after a strike; two or three men died.

Cause

A naked light carried into accumulated firedamp; the Durham Mining Museum records that a door had been left open.

What happened

New Tredegar pit had stood idle for a fortnight in September 1858 while its owner, Mr Powell, and his colliers argued over the tonnage rate. Most of the thirty-odd men had left; about a dozen gave in, and some of them went down on the night of 10 September to get the pit ready for work.

At about four on the Saturday morning the engineman at the top of the upcast shaft heard a loud report and a rush of wind that damaged the winding machinery. The manager, Mr Nasmyth, had water poured down the shaft to clear the afterdamp and went down with three men. Near the bottom he found three colliers, John Jones, John Griffiths and William Davies, burned and bruised where they had been cutting coal for arching. Further along the level the fireman, Llewellyn Pierce, was found dying near a fall, and beyond him the haulier William Davies, badly burned, with his open lamp lying ten yards in front of him. He had gone with a naked light into a part of the level where gas had gathered.

The inquest returned a verdict of accidental death. The Durham Mining Museum and Welsh Coal Mines both list a second William Davies among the dead; Welsh Coal Mines says he died some days later.

Rescue & recovery

The manager had water poured down the shaft to clear the afterdamp before going down with three men; three injured colliers were found near the shaft bottom.

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 New Tredegar Colliery early on 11 September 1858 killed the fireman Llewellyn Pierce and a haulier, William Davies. ^1,2,3,4
• The Durham Mining Museum and Welsh Coal Mines list a third man, another William Davies, among the dead; Welsh Coal Mines says he died days later. ^1,2
• The haulier had gone with a naked light into a part of the level where gas had gathered. ^3,4
• The Durham Mining Museum records that gas had accumulated because a door had been left open. ¹
• The pit had been idle for a fortnight over a wage dispute, and only about a dozen men were preparing it for work when the explosion happened. ^3,4

Related terminology

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

• Afterdamp (contextual relationship)
  Named twice in this record, first in the narrative: “…manager, Mr Nasmyth, had water poured down the shaft to clear the afterdamp and went down with three men. Near the bottom he found three…”
• Firedamp (contextual relationship)
  Named twice in this record, first in the summary: “Firedamp exploded in New Tredegar Colliery before dawn on 11 September 1858,…”
• Fireman (contextual relationship)
  Named in this record’s narrative: “…they had been cutting coal for arching. Further along the level the fireman, Llewellyn Pierce, was found dying near a fall, and beyond him the…”
• Haulier (contextual relationship)
  Named twice in this record, first in the summary: “…in New Tredegar Colliery before dawn on 11 September 1858, when a haulier took a naked light into gas while the pit was being readied after a…”
• Naked Light (contextual relationship)
  Named 3 times in this record, first in the summary: “…Colliery before dawn on 11 September 1858, when a haulier took a naked light into gas while the pit was being readied after a strike; two or…”

Sources

1. (primary) Durham Mining Museum: New Tredegar Colliery — Durham Mining Museum
2. (secondary) Welsh mining fatalities, 1858 — Welsh Coal Mines
3. (primary) Rhymney: fearful explosion at the New Tredegar coal pit (Monmouthshire Merlin, 18 September 1858) — Welsh Newspapers (National Library of Wales)
4. (primary) Terrible explosion at New Tredegar coal-pit (Cardiff and Merthyr Guardian, 18 September 1858) — Welsh Newspapers (National Library of Wales)

Record created: 8 October 2026 · Last researched: 8 October 2026