Brynhenllys Colliery

Overview

Brynhenllys was an anthracite colliery at Upper Cwmtwrch, on the Brecknockshire side of the upper Swansea valley, opened in 1872 and worked by two slants, the Top and the Lower. Three waterwheels drove its winding and pumping. Its coal was reckoned fully up to the standard of the celebrated Peacock anthracite. It grew from 145 people in 1894 to 335 in 1933 and passed to the National Coal Board in 1947 raising 50,000 tons a year. Its Waunlwyd slant is claimed as the site of the first stay-down strike in the South Wales coalfield, in October 1934, when twenty-four men stayed below for six and a half hours.

History

The colliery opened at Upper Cwmtwrch in 1872 and worked two slants, the Top and the Lower, with three waterwheels in use over its life driving winding and pumping among other things. The Inspector of Mines list for 1896 gives 121 people under the Brynhenllys Colliery Co. Employment grew steadily — 189 in 1900, 244 in 1905, 270 in 1910, 267 in 1923 and 335 in 1933 — and the colliery was raising anthracite throughout, its coal reckoned fully up to the standard of the celebrated Stanllyd or Peacock coal. The Brynhenllys Anthracite Colliery Company held it from 1925 and the National Coal Board from 1947, when 286 people raised 50,000 tons. The Waunlwyd slant near Cwmllynfell was part of Brynhenllys and is claimed to be the first colliery in the South Wales coalfield to have a stay-down strike: in October 1934 twenty-four men stayed underground for six and a half hours. It was a small working in its own right, employing fourteen people in 1927 and twenty-one in 1928 under the Brynhenllys Anthracite Colliery Company, thirty-one in 1933, sixty-five in 1937 and sixty-seven in 1938.

Geology

Brynhenllys worked the anthracite of the northern outcrop of the South Wales coalfield in the upper Swansea valley, where the coal has been carried to the highest rank in Britain. Its product was judged fully up to the standard of the Stanllyd or Peacock seam, the anthracite the district was known for.

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

Workings

Two slants, the Top and the Lower, rather than shafts, with the Waunlwyd slant near Cwmllynfell worked as part of the same colliery. Three waterwheels were in use over the colliery's life, providing power for winding and pumping among other purposes — unusual survival of water power at a pit still working into the National Coal Board era.

Closure

The colliery was closed in 1955, eight years after passing to the National Coal Board, at which point it had been employing 286 people and raising 50,000 tons of anthracite a year.

What remains

Nothing identifiable of the colliery has been traced on the ground. The upper Twrch valley around Cwmtwrch keeps the chimney and lime kilns of the neighbouring Henllys Vale colliery, which is a separate undertaking despite the similar name.

Nearby mines

• Pwllbach Colliery — 5.2 km S, Neath Port Talbot
• Seven Sisters Colliery — 6.7 km SE, Neath Port Talbot
• Gleision Colliery — 7.3 km S, Neath Port Talbot
• Tarenni Colliery — 7.4 km S, Neath Port Talbot
• Garnant Colliery — 7.7 km W, Carmarthenshire

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

Recorded claims

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

• Brynhenllys opened in 1872 in the Upper Cwmtwrch area with two slants, the Top and the Lower, and had three waterwheels in operation over its history providing power for winding and pumping among other purposes. ¹
• The coal was of very good anthracite quality and fully up to the standard of the celebrated Stanllyd or Peacock coal. ¹
• The Waunlwyd slant, part of Brynhenllys Colliery, was claimed to be the first colliery in the South Wales coalfield to have a stay-down strike, in October 1934, when twenty-four men stayed down for six and a half hours. (uncertain) ²
• The colliery employed 145 people in 1894, 270 in 1910, 335 in 1933 and 286 in 1947, when it raised 50,000 tons of anthracite. ³
• The Brynhenllys Colliery Co. held the colliery in 1896, the Brynhenllys Anthracite Colliery Company from 1925, and the National Coal Board from 1947. ^3,1

Photographs & further reading

Sources

1. (secondary) Brynhenllys Colliery — Welsh Coal Mines
2. (secondary) Small collieries of the Swansea Valley: Waunlwyd Colliery — Northern Mine Research Society (read via a 2024 Wayback Machine capture)
3. (primary) Durham Mining Museum: Brynhenllys Colliery — Durham Mining Museum, from the Lists of Mines

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