Westernmoor Colliery inundation, 1878

On the morning of Tuesday 16 April 1878 a stall at Westernmoor Colliery, a small slant near Neath, broke into old workings abandoned more than a century before, and the rush of water and debris drowned three men and a boy of fourteen.

Cause

A stall driven towards a fault broke through a weak barrier of coal into flooded old workings whose existence was not known; the pit had no plans of them.

What happened

Westernmoor was worked by a slant about 100 yards long, made the summer before, with stalls on both sides; about fifteen men were at work that morning. The ground around was marked by old shale tips, but no plans of the old workings existed. Shortly after half past nine John Williams, putting up a post in No. 6 stall on the south side of the slant, saw the water come in on them 'without any sign or any warning'. It carried an immense quantity of debris, striking the men down and covering them. The noise alarmed the others, who struggled up the slant through the water to safety.

Williams escaped, badly injured. His partner Rees Llewellyn, aged about fifty, was drowned with David Williams, John Rees and David Davies, a boy of fourteen who had worked at the colliery for six months. The water soon drained away through the Eastland drift.

Rescue & recovery

An exploring party entered as soon as the water fell, under the manager and engineers including Mr Whittington and Mr Mackworth, and recovered the bodies of John Rees and David Williams within minutes. The boy's body was found two days later; Rees Llewellyn's had still not been recovered when the inquest resumed.

Investigation & inquiry

The inquest was held at the County Police Station, Neath, before the coroner H. Cuthbertson, with the inspector of mines Mr Wales present. The mining engineer who had surveyed the slant, the fireman David Llewellyn and the managing partner Mr Johns all said there had been no sign of water. The jury found that the men died by drowning through the accidental flooding of the colliery and entirely exonerated the managers.

What's uncertain

Points where sources disagree or the record could not be settled; both accounts are kept. All open questions in the archive.

• Welsh Coal Mines gives the date as 15 April 1878. (disputed) ^4,1

Recorded claims

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

• Three men and a boy were drowned at Westernmoor Colliery on Tuesday 16 April 1878. ^1,2,3
• Welsh Coal Mines gives the date as 15 April 1878. (disputed) ^4,1
• No. 6 stall on the south side of the slant broke into flooded old workings of which no plans existed. ^4,2,3
• The water drained away through the Eastland drift. ^4,2
• The jury found the deaths accidental and entirely exonerated the managers. ⁵

Related terminology

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

• Drift (contextual relationship)
  Named in this record’s narrative: “…for six months. The water soon drained away through the Eastland drift.”
• Fireman (contextual relationship)
  Named in this record’s investigation: “…Wales present. The mining engineer who had surveyed the slant, the fireman David Llewellyn and the managing partner Mr Johns all said there had…”
• HM Chief Inspector of Mines (contextual relationship)
  Named in this record’s investigation: “…Police Station, Neath, before the coroner H. Cuthbertson, with the inspector of mines Mr Wales present. The mining engineer who had surveyed the slant,…”
• Slant (contextual relationship)
  Named 5 times in this record, first in the summary: “…of Tuesday 16 April 1878 a stall at Westernmoor Colliery, a small slant near Neath, broke into old workings abandoned more than a century…”
• Stall (contextual relationship)
  Named 4 times in this record, first in the summary: “On the morning of Tuesday 16 April 1878 a stall at Westernmoor Colliery, a small slant near Neath, broke into old…”

Photographs & further reading

This page doesn't try to reproduce everything — these are the best original sources found for this disaster.

Sources

1. (secondary) Welsh Coal Mines: fatalities, 1878 — Welsh Coal Mines
2. (primary) Pontypool Free Press, 20 April 1878: A colliery flooded at Neath. Four persons drowned — National Library of Wales, Welsh Newspapers
3. (primary) South Wales Daily News, 26 April 1878: The Western Moor Colliery accident. The adjourned inquest — National Library of Wales, Welsh Newspapers
4. (secondary) Westernmoor and Gnoll Collieries (Welsh Coal Mines) — Welsh Coal Mines
5. (primary) Pontypool Free Press, 4 May 1878: The flooding of the Western Moor Colliery. Adjourned inquest — National Library of Wales, Welsh Newspapers

Record created: 10 October 2026 · Last researched: 10 October 2026