MineArchiveGreat Mountain Colliery outburst, 1958
A sudden outburst of coal at Great Mountain Colliery, Tumble, on the evening of 25 February 1958 killed three men; two escaped. The pit suffered 37 outbursts of fine coal and methane between 1913 and 1959, and the accident was raised in the Commons two days later.
| Date | 25 February 1958 |
|---|---|
| Mine | Great Mountain Colliery |
| Region | Carmarthenshire |
| Type | Gas / Asphyxiation |
| Fatalities | 3 (3 dead, named; two men escaped.) |
| Context | During active mining |
Cause
A sudden outburst of fine coal and methane into the workings.
Contributing factors
The colliery's long history of outbursts in the anthracite seams.
What happened
Great Mountain, at Tumble in the anthracite district, employed over 900 men at nationalisation and had a serious problem with outbursts, in which coal and gas erupt suddenly into the face: 37 were recorded between 1913 and 1959, two of them fatal. On the evening of Tuesday 25 February 1958 an outburst killed Kenneth Melville Jenkins, William Glyn Jones and Ieuan Lewis; two other men escaped.
Rescue & recovery
Unknown.
Investigation & inquiry
H.M. Inspectors of Mines investigated and were to review the special precautions laid down for the colliery, overseen by an advisory committee on outbursts with a full-time inspector.
Legal & regulatory aftermath
Payments to the families were made under a special fatal accidents scheme; two had been made by 27 February and the third was due that day.
Changes to practice & legislation
Unknown.
Memorials & commemoration
Unknown.
People
3 of the 3 who died are named in the archive; the rest are not named in the sources read for this record.
- Kenneth Melville Jenkins (d. 1958) · victim, 1958 — Killed in the outburst.
- William Glyn Jones (d. 1958) · victim, 1958 — Killed in the outburst.
- Ieuan Lewis (d. 1958) · victim, 1958 — Killed in the outburst.
Recorded claims
Individual factual claims, each attached to the source(s) that support it below. Where sources disagree, both are kept.
- On 25 February 1958 an outburst of coal killed three men; another two escaped alive. 1
- Kenneth Melville Jenkins, William Glyn Jones and Ieuan Lewis died in the outburst of 25 February 1958. 2
- Between 1913 and 1959 the mine suffered 37 outbursts of fine coal and methane, two of which caused deaths. 2
- The Parliamentary Secretary told the Commons on 27 February that three men were killed during the evening of 25 February and H.M. Inspectors were investigating. 3
Related terminology
Mining terms this disaster is structurally linked to, with the nature of the relationship.
- Anthracite (contextual relationship)
Outbursts were a particular danger of the anthracite district. - Coal (contextual relationship)
Named 4 times in this record, first in the summary: “A sudden outburst of coal at Great Mountain Colliery, Tumble, on the evening of 25 February…” - Colliery (contextual relationship)
Named 3 times in this record, first in the summary: “A sudden outburst of coal at Great Mountain Colliery, Tumble, on the evening of 25 February 1958 killed three men; two…” - HM Chief Inspector of Mines (contextual relationship)
Named in this record’s investigation: “H.M. Inspectors of Mines investigated and were to review the special precautions laid down…” - Outburst (direct cause)
A sudden outburst of coal and gas.
Sources
- (secondary) Great Mountain Colliery — Northern Mine Research Society
- (secondary) Great Mountain Colliery — Welsh Coal Mines
- (primary) Tumble Colliery, Carmarthenshire (Accident), HC Deb 27 February 1958 vol 583 cc547-8 — Hansard
Record created: 19 September 2026 · Last researched: 21 September 2026