Cwmmawr Colliery

Overview

Levels and slants in the Cwmmawr valley above Cwmafan, first worked for the Cwmavon copper works by 1869 and reopened in the twentieth century, peaking at 133 men in 1924 and closing about 1944.

History

Cwmmawr Colliery worked the hillside of the Cwmmawr valley above Cwmafan, in the Afan valley. Its first level was probably opened by the Governor and Company of Copper Miners for their Cwmavon Works and appears in a list of 1869; in 1874 the Cwm Mawr Level formed part of the works' Cwmavon Colliery with the Finery Slant, and NMRS has it feeding the works for the English Copper Company in 1876. It worked the Cwmbyr, White, Tormynydd, Clay, Cwm Mawr and Black seams and ironstone. Wright, Butler and Company took it in 1890 and gave it up in 1891, when the Cockshott seam was abandoned; the level is shown disused on the 1899 Ordnance Survey.

The name returned in the twentieth century. A Clay slant was opened, in the hands of the Skewen-Wernafon Colliery Company by 1918 with twelve men, and a new slant, Cwmmawr No. 3, was driven some hundreds of yards further up the valley. The New Skewen Wern Avon Collieries took it in 1920 and were reconstructed in 1922 as Briton Ferry Collieries Ltd of Port Talbot, under whom the workforce reached its peak of 133 in 1924; in 1933 Cwmmawr and Maesmelyn together produced 35,000 tons of house, manufacturing and coking coal.

Most of the old seams were abandoned in 1933. The colliery reopened in 1939 under the Cwmavon Colliery Company and closed again in 1940, when the No. 3 abandoned the No. 2 and No. 3 Rhondda; the Big Vein and Four Feet levels were reopened in 1942 and worked until 1944. A licensed Cwmmawr mine of 1950 lasted less than two years.

Geology

South Wales coalfield, Afan valley: the Cwmbyr, White, Tormynydd, Clay, Cwm Mawr, Black, Golden, Cockshott, New Rider, Big, Four Feet, Five Feet and Lower Clay seams, ironstone, and later the No. 2 and No. 3 Rhondda.

Workings

A first level of about 1869, a Clay slant, the Cwmmawr No. 3 slant further up the valley, and the Big Vein and Four Feet levels reopened in 1942.

Closure

Most seams abandoned in 1933; reopened 1939-40 and, in two levels, 1942-44. A licensed mine of 1950 lasted under two years.

What remains

Unknown.

Redevelopment

Unknown.

Recorded claims

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

• The first level was probably opened by the Governor and Company of Copper Miners for the Cwmavon Works, and appears in a list of 1869. ¹
• Worked for the Cwmavon Works of the English Copper Company in 1876. ²
• Employed 133 men in 1924, its highest workforce. ^2,1
• Owned by Briton Ferry Collieries Ltd of Port Talbot from 1922-23. ^2,1
• Reopened in 1939 and 1942 and finally closed in 1944. ^2,1

Photographs & further reading

Sources

1. (secondary) Oakwood slants, Pontrhydyfen; Cwmmawr Colliery — Welsh Coal Mines
2. (secondary) Cwmmawr Colliery — Northern Mine Research Society

Record created: 7 October 2026 · Last researched: 7 October 2026