Lady Margaret Colliery

Overview

One of the earliest pits in the upper Rhondda, sunk at Treherbert by the Marquess of Bute in 1853, which grew to over a thousand men under United National Collieries before production stopped in the early 1940s.

History

Lady Margaret Colliery at Treherbert was sunk by the Marquess of Bute in 1853, one of the earliest pits in the upper Rhondda. It was served by the newly extended Taff Vale Railway, with sidings for 160 full, 114 empty and 45 other wagons, and was sunk to the Upper Four Feet. It also worked the Two Feet Nine, Four Feet and Six Feet seams until they were abandoned in 1909.

In 1896 the Marquis of Bute still owned it, with 178 men producing steam and house coal; there were 155 in 1908. United National Collieries Ltd bought it together with Bute Merthyr in 1915 and worked it with the Gorllwyn Level, the unit employing 801 men in 1918. In 1923 Lady Margaret had 613 men in the Six and Seven Feet and the Nos. 3 and 4 seams, with 247 more at the Gorllwyn. The Ocean Coal Company gained a controlling interest in United National in 1926, and by 1938 the workforce had grown to 1,053.

Production ceased in the early 1940s, and plans of the combined Lady Margaret, Bute Merthyr and neighbouring workings record abandonments into 1944. At nationalisation in 1947 the pit was kept only for pumping and ventilation.

Geology

Coal Measures of the South Wales Coalfield. Sunk to the Upper Four Feet; also worked the Two Feet Nine, Four Feet and Six Feet (abandoned 1909), and in 1923 the Six and Seven Feet and Nos. 3 and 4 seams, producing steam and house coal. The combined plans include the Gellideg (No. 5) seam.

Workings

A shaft sunk to the Upper Four Feet, worked from 1915 with the Gorllwyn Level and with the Bute Merthyr workings, which are shown on the same abandonment plans.

Closure

Coal production ceased in the early 1940s; the combined workings' plans record abandonments in 1940 and on 7 February 1944. When nationalised in 1947 the colliery was used only for pumping and ventilation.

What remains

Unknown.

Redevelopment

Unknown.

Related mines

• Bute Colliery — United National Collieries worked Bute, Lady Margaret and the Gorllwyn Level together (801 men in 1918), and one abandonment plan covers both.

Recorded claims

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

• Sunk by the Marquess of Bute in 1853, one of the earliest pits in the upper Rhondda. ^1,2
• Served by the newly extended Taff Vale Railway, with sidings for 160 full, 114 empty and 45 other wagons. ²
• Sunk to the Upper Four Feet; the Two Feet Nine, Four Feet and Six Feet seams were worked until abandoned in 1909. ²
• In 1896 the Marquis of Bute owned it, with 178 men producing steam and house coal. ¹
• United National Collieries Ltd bought it, with Bute Merthyr, in 1915. ²
• In 1923 it employed 613 men in the Six and Seven Feet and the Nos. 3 and 4 seams; 247 worked the Gorllwyn seam at the Gorllwyn Level. ¹
• The Ocean Coal Company gained a controlling interest in United National in 1926. ^1,2
• By 1938 the workforce had grown to 1,053. ¹
• Production ceased in the early 1940s; at nationalisation in 1947 it was used only for pumping and ventilation. ^1,2
• An abandonment plan of the Lady Margaret, Bute Merthyr, Rhondda Merthyr, Tydraw and Ynysfeio workings in the Gellideg (No. 5) seam is dated 7 February 1944. ³
• A photograph of about 1900 shows a group of men by the boilers, among them the colliery fireman David Phillips. ⁴

Photographs & further reading

Sources

1. (secondary) Welsh Coal Mines: Lady Margaret Colliery — Welsh Coal Mines
2. (secondary) Treherbert (Rhondda heritage trail) — Rhondda Cynon Taf County Borough Council
3. (primary) BGS mine plan: Lady Margaret, Bute Merthyr, Rhondda Merthyr, Tydraw, Ynysfeio (Gellideg seam) — British Geological Survey / Mining Remediation Authority
4. (secondary) Lady Margaret Colliery, photograph (c. 1900) — Amgueddfa Cymru – Museum Wales
5. (secondary) Lady Margaret Colliery (NPRN 80498) — Coflein (RCAHMW)

Record created: 8 October 2026 · Last researched: 9 October 2026