Ponthenry Colliery

Overview

A Gwendraeth Valley anthracite drift mine whose Pumpquart seam made it one of the most dangerous pits in Britain: 37 outbursts of coal dust and methane killed ten miners between 1920 and 1928, five of them in 1924. It closed in 1936 with its reserves unworked.

History

Ponthenry Colliery was an anthracite drift mine in the Gwendraeth Valley, near Pontyates, working outcropping seams deep underground through three slants, the Gwendraeth, Stepney and Glynhir. It may have been working as early as the 1820s, and the Ponthenry Colliery Company was formed in 1865. It worked six seams, the Big Vein, Felin, Gwendraeth, Braslyd, Pumpquart and a little of the Gras, and the Pumpquart made it notorious: its outbursts, sudden inundations of fine coal dust and methane, made Ponthenry one of the most dangerous mines in Britain, with 37 recorded and ten miners killed in four of them between 1920 and 1928. The workforce rose from 192 in 1896 to over 800 at its peak in the late 1920s. Two men were killed in 1911 when a runaway tram ran into a group waiting to ride the slant. William Thomas Williams died in an outburst in February 1920 and two more in March 1923; on 3 September 1924 an outburst in 19 East of the Pumpquart seam in the Glynhir slant killed five men, while more than twenty others survived by lying face down or breathing through wet caps until the gas blew over, and eight rescuers were later honoured by the Carnegie Hero Trust. In June 1927 an outburst with 150 men below gave ten minutes' warning and all escaped, and in July 1928 another killed two and injured over twenty. The company, a member of the Monmouthshire and South Wales Coal Owners' Association and later linked with the Amalgamated Anthracite combine, still raised 200,000 tons a year in 1935, but the mine closed in 1936 with large reserves left in the ground, simply too dangerous to work.

Geology

Anthracite seams of the western South Wales coalfield: the Gwendraeth (Yard), Pumpquart, Braslyd, Gras, Big Vein and Green, with limited work in the disturbed Gras Uchaf and Big Vein; the soft Pumpquart held pockets of gas that released outbursts of fine coal dust and methane.

Geological setting: Sedimentary Beds and Seams (well documented example)

Workings

Three drifts or slants following the outcropping seams, the Gwendraeth, Stepney and Glynhir, the main slant driven down the Gwendraeth seam at 7.5 inches to the yard; a 9-foot Waddle fan from 1894 and a coal preparation plant; the Main Slant was ventilated with compressed air in 1924.

Closure

Closed in 1936 with extensive reserves left below ground because the outbursts had made it too dangerous to work; the company was then in receivership and the colliery was offered for sale by tender in April 1936.

What remains

Unknown.

Unknown.

Nearby mines

• Pontyberem Colliery — 1.5 km S
• Cynheidre Colliery — 2.2 km SE
• Gwendraeth Colliery — 2.8 km NE
• Carway Colliery — 3.6 km SW
• Trimsaran Colliery — 5.3 km SW

Straight-line distance, within 15 km. Show on the map.

People

• John Harris · survivor, 1924 — Fireman, the sole survivor of the men in the slant in 1924, who had survived two earlier outbursts.
• Wilfred Hughes · rescuer, 1924 — Miner of Pontyates honoured by the Carnegie Hero Trust for the 1924 rescue.
• Rees Morgan · rescuer, 1924 — Under-manager in charge on 3 September 1924; led the search and was honoured by the Carnegie Hero Trust.
• George Roblings · manager, 1918–1927 — Agent and certificated manager at the 1924 outburst.

Recorded claims

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

• The mine began with the formation of the Ponthenry Colliery Company in 1865, a drift mine working six anthracite seams, the Big Vein, Felin, Gwendraeth, Braslyd, Pumquart and a small amount of Gras; at its peak it employed over 800 men in three drifts. ¹
• Pont Henry may have been working as early as the 1820s; the Pont Henry Colliery Company Limited, of Brecon, was formed in 1865, and the mine consisted of the Glynhir, Gwendraeth and Stepney slants. ²
• The Pumpquart seam's outbursts of fine coal dust and methane made the mine one of the most dangerous in the UK; there were 37 outbursts, claiming ten lives. ^1,2
• On 3 September 1924 an outburst in 19 East of the Pumpquart seam in the Glynhir slant killed George Buck, Samuel Philip Evans, William Henry Evans, William David Jenkins and Stanley Morris; over 20 men survived by falling on their faces until the gas blew over. ^3,4
• Eight rescuers from the 1924 outburst, among them Wilfred Hughes of Pontyates and under-managers John Morgan and Rees Morgan, were recognised by the Carnegie Hero Trust. ⁴
• An outburst of gas and small coal in June 1927, with 150 men below ground, gave about ten minutes' warning, and all reached safety except two or three slightly gassed. ⁵
• The mine was closed in 1936 with extensive reserves left below ground, having become too dangerous to work; the company offered it for sale by tender through a receiver in April 1936. ^1,2

Photographs & further reading

Sources

1. (secondary) Ponthenry Colliery — Welsh Coal Mines
2. (secondary) Pont Henry Colliery — Northern Mine Research Society
3. (secondary) Ponthenry Colliery Suffocation - Llanelli - 1924 — Northern Mine Research Society
4. (secondary) Ponthenry Mining Disaster — Llanelli Community Heritage
5. (primary) Ponthenry Colliery (Gas Outburst), HC Deb 30 June 1927 vol 208 cc573-4 — Hansard

Record created: 19 September 2026 · Last researched: 19 September 2026