MineArchiveGreat Mountain Colliery outburst, 1935
An outburst of fine coal and methane at Great Mountain Colliery, Tumble, on 31 October 1935 killed two miners, Edgar Owen Collins and Llewellyn Evans: the first of the pit's two fatal outbursts among 37 recorded between 1913 and 1959.
| Date | 31 October 1935 |
|---|---|
| Mine | Great Mountain Colliery |
| Region | Carmarthenshire |
| Type | Gas / Asphyxiation |
| Fatalities | 2 (2 dead, named.) |
| Context | During active mining |
Cause
A sudden outburst of fine coal and methane into the workings.
Contributing factors
The colliery's long record of outbursts in the anthracite seams.
What happened
Great Mountain was troubled throughout its life by outbursts, in which fine coal and gas erupt suddenly into the face. On 31 October 1935 one killed two miners.
Rescue & recovery
Unknown.
Investigation & inquiry
Unknown.
Legal & regulatory aftermath
Unknown.
Changes to practice & legislation
Unknown.
Memorials & commemoration
Unknown.
People
2 of the 2 who died are named in the archive; the rest are not named in the sources read for this record.
- Edgar Owen Collins (d. 1935) · victim, 1935 — Killed in the outburst.
- Llewellyn Evans (d. 1935) · victim, 1935 — 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.
- Edgar Owen Collins and Llewellyn Evans died in the outburst on 31 October 1935. 1
- On 31 October 1935 two miners died in an outburst. 2
Related terminology
Mining terms this disaster is structurally linked to, with the nature of the relationship.
- Anthracite (contextual relationship)
An anthracite colliery. - Coal (contextual relationship)
Named 3 times in this record, first in the summary: “An outburst of fine coal and methane at Great Mountain Colliery, Tumble, on 31 October 1935…” - Colliery (contextual relationship)
Named twice in this record, first in the summary: “An outburst of fine coal and methane at Great Mountain Colliery, Tumble, on 31 October 1935 killed two miners, Edgar Owen Collins…” - Outburst (direct cause)
An outburst of fine coal and methane.
Sources
- (secondary) Great Mountain Colliery — Welsh Coal Mines
- (secondary) Great Mountain Colliery — Northern Mine Research Society
Record created: 19 September 2026 · Last researched: 21 September 2026