Lewis Merthyr Colliery

Overview

Lewis Merthyr, at Trehafod in the Rhondda, grew from two small 1850s pits into one of the Rhondda's major collieries, employing some 5,000 people at its peak. A 1956 firedamp explosion killed nine men and injured five more; the colliery finally closed in 1983, and its surviving pithead buildings and winding engines are now preserved as the Rhondda Heritage Park, with underground tours led by former miners.

History

The Hafod and Coed Cae pits, opened in 1850 by two separate concerns, were both abandoned early on due to difficult working conditions. William Thomas Lewis (later Lord Merthyr) bought and reopened both in the mid-1870s to work the upper household coal seams; Hafod closed around 1893 and Coed Cae in the 1930s. Lewis sank the Bertie shaft (named for his son) in 1880 and the Trefor shaft in 1890, by which point the operation had grown into Lewis Merthyr Consolidated Collieries Ltd, employing around 5,000 men and producing almost a million tons of coal a year. The colliery passed to the National Coal Board at nationalisation in 1947. A firedamp explosion on 22 November 1956 killed nine men and injured five more — see this site's own disaster record. Production was switched to the neighbouring Tymawr colliery after the two were merged in 1960, with Lewis Merthyr continuing mainly to supply materials to the combined workings until mining finally ceased in July 1983.

Geology

The colliery worked Rhondda coalfield seams via the Bertie and Trefor shafts, sunk in 1880 and 1890 respectively, reaching the household and steam coal seams the South Wales coalfield was famous for.

Workings

Underground workings were reached via the Bertie and Trefor shafts; at its peak the colliery employed some 936 underground and 226 surface workers, raising around 1,250 tons of coal a day across three seams.

Closure

Lewis Merthyr merged with the neighbouring Tymawr colliery in 1960, continuing afterwards mainly to supply materials to the combined workings rather than raise coal itself, until mining finally ceased in July 1983.

What remains

The pithead buildings, winding engines and winding wheels survive and now form the Rhondda Heritage Park, a museum of Welsh coal mining where former miners lead underground tours through part of the old workings.

Abandoned workings can be dangerous — unstable ground, uncapped shafts, flooding and bad air are common even where a site looks safe from the surface. This entry describes history and general location only; it is not an access guide.

Disasters & major incidents

• Lewis Merthyr Colliery explosion, 1956
  22 November 1956 · Explosion · 9 fatalities
  A firedamp explosion at Lewis Merthyr Colliery on 22 November 1956 killed nine men and injured five more, after methane that had accumulated undetected in an unventilated roof-fall cavity was ignited by a falling stone striking a steel roof support.

Recorded claims

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

• At its peak Lewis Merthyr employed around 5,000 people and produced almost a million tons of coal a year. ¹
• The colliery merged with the neighbouring Tymawr colliery in 1960 and continued mainly to supply materials to the combined workings until mining ceased in July 1983. ¹
• The surviving pithead buildings and winding engines now form the Rhondda Heritage Park, with underground tours led by former miners. ²

Images

Sources

1. (secondary) Lewis Merthyr Colliery — Northern Mine Research Society
2. (secondary) Rhondda Heritage Park — Wikipedia
3. (primary) Lewis Merthyr Colliery Explosion - Trehafod - 1956 — Northern Mine Research Society
4. (secondary) Plaque marks nine 1956 Lewis Merthyr pit deaths — BBC News

Record created: 20 August 2026 · Last researched: 20 August 2026