Pwllbach Colliery boiler explosion, 1937

Two colliers waiting to go down Pwllbach Colliery, Ystalyfera, were killed on 15 May 1937 when gases exploded in a boiler flue and wrecked the surface buildings around them.

Cause

An explosion of gases in the boiler flue.

What happened

Early on 15 May 1937 eight men were standing near the boiler at Pwllbach Colliery, Ystalyfera, waiting to go down to the workings, when gases exploded in the boiler flue. The blast wrecked the boiler house, store room, power house, smithy and engine house. William Henry Jones died of a fractured skull within ten minutes; William Rees Jones was buried under the debris and suffocated. Three other men were seriously hurt and three more were treated and sent home.

Rescue & recovery

Rescuers worked for an hour to free William Rees Jones from the debris; workers from the nearby tinplate works stopped work to help.

Recorded claims

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

• On 15 May 1937 an explosion of gases in a boiler flue at Pwllbach Colliery, Ystalyfera, killed two colliers, William Henry Jones and William Rees Jones. ^1,2,3
• Eight men were standing near the boiler waiting to go down to the workings; the explosion wrecked the boiler house, store room, power house, smithy and engine house. ¹
• William Henry Jones died of a fractured skull within ten minutes; William Rees Jones was buried under debris and suffocated, and rescuers worked for an hour to free him. ¹
• Three other men were seriously injured. ^1,2,3
• Workers from the nearby tinplate works stopped work and came to help with the rescue. ¹
• The colliery belonged to Henderson's Welsh Anthracite Collieries Ltd. ^2,3

Related terminology

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

• Boiler House (contextual relationship)
  Named in this record’s narrative: “…when gases exploded in the boiler flue. The blast wrecked the boiler house, store room, power house, smithy and engine house. William Henry…”
• Colliery (contextual relationship)
  Named twice in this record, first in the summary: “Two colliers waiting to go down Pwllbach Colliery, Ystalyfera, were killed on 15 May 1937 when gases exploded in a…”
• Engine House (contextual relationship)
  Named in this record’s narrative: “…blast wrecked the boiler house, store room, power house, smithy and engine house. William Henry Jones died of a fractured skull within ten minutes;…”

Sources

1. (secondary) 1937 fatalities — Welsh Coal Mines
2. (secondary) Accident record: William H. Jones, Pwllbach, 1937 — Northern Mine Research Society
3. (secondary) Accident record: William R. Jones, Pwllbach, 1937 — Northern Mine Research Society

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