MineArchiveLewis Merthyr Colliery explosion, 1956
| Date | 22 November 1956 |
|---|---|
| Mine | Lewis Merthyr Colliery |
| Region | Rhondda Cynon Taf |
| Primary type | Explosion |
| Associated types | Collapse / Roof Fall |
| Fatalities | 9 (Nine men died of burns received in the explosion, including colliery manager A. R. Fox (41); two men, turbine attendant E. Howells (37) and overman S. Thomas (69), were killed immediately, with the other seven fatally injured.) |
| Injuries | Five further men were injured. |
| Context | During active mining |
| Status | Researched |
A firedamp explosion at Lewis Merthyr Colliery on 22 November 1956 killed nine men and injured five more, after methane that had accumulated undetected in an unventilated roof-fall cavity was ignited by a falling stone striking a steel roof support.
Cause
Roof falls on 8-9 and 19-20 November 1956 left an unsupported cavity above the centre road of the N4 district, Two Feet Nine seam. Methane accumulated in the upper part of this cavity, reaching a concentration of around 80%, undetected because the cavity itself was never ventilated even though systematic gas monitoring continued in the active working areas around it. In the early hours of 22 November a roughly three-ton stone fell from the cavity and struck newly erected steel roof arches; the impact produced a spark that ignited the accumulated gas.
Contributing factors
The unventilated roof-fall cavity was the critical gap: routine gas monitoring in the working faces gave no warning of what had built up in ground that was no longer being actively worked or checked.
What happened
The explosion and resulting flame travelled around 70 yards along the centre road and across both working faces of the N4 district. Nine men died of burns; five others were injured.
Investigation & inquiry
HM Divisional Inspector of Mines T. A. Jones OBE investigated and reported to the Minister of Power, Lord Mills, on 8 November 1957, concluding the explosion was caused by firedamp ignited when the fallen stone struck a steel support. HM Coroner for North Glamorgan, T. Alwyn John, held an inquest with a jury on 1 March 1957; the jury found all nine men died of burns accidentally received in the explosion.
Memorials & commemoration
A plaque commemorating the nine men who died was unveiled at the site, now Rhondda Heritage Park.
Recorded claims
Individual factual claims, each attached to the source(s) that support it below. Where sources disagree, both are kept.
- Methane accumulated undetected (to around 80% concentration) in an unventilated roof-fall cavity above the N4 district centre road; a falling stone striking a steel roof support on 22 November 1956 produced the spark that ignited it. 1
- Nine men died of burns and five were injured; victims included colliery manager A. R. Fox, turbine attendant E. Howells and overman S. Thomas. 1
- HM Divisional Inspector of Mines T. A. Jones reported to the Minister of Power in November 1957; a coroner's inquest with a jury in March 1957 found all nine died of burns accidentally received in the explosion. 1
- A plaque commemorating the nine men who died was unveiled at the site, now Rhondda Heritage Park. 2
Sources
- (primary) Lewis Merthyr Colliery Explosion - Trehafod - 1956 — Northern Mine Research Society
- (secondary) Plaque marks nine 1956 Lewis Merthyr pit deaths — BBC News
Record created: 20 August 2026 · Last researched: 20 August 2026