Robbins Colliery

Overview

One of the first deep pits sunk at Cyfarthfa in the 1820s and 1830s, when the ironworks it fed was briefly the largest in the world.

History

Robbins Colliery was worked in the mid-19th century by the Cyfarthfa Iron Company. A landscape-archaeology survey of the Merthyr coalfield independently dates the sinking of Robbins Pit, alongside the neighbouring Glyndyrys Pit and Colliers' Row Pit, to the 1820s and 1830s — among the first deep pits sunk at Cyfarthfa, at a time when levels driven into the hillside still accounted for most coal and ironstone extraction in the district (levels supplied about 75% of output at the nearby Dowlais works, for comparison). The main expansion of Cyfarthfa's own ironstone workings took place between about 1806, when the ironworks with its six blast furnaces was briefly the largest in the world, and the 1850s, by which time Cyfarthfa, in decline, had begun importing iron ore from elsewhere.

Geology

Sunk in the 1820s-30s as one of the first deep pits at Cyfarthfa, at a time when hillside levels still supplied most of the district's coal and ironstone (about 75% of output at the nearby Dowlais works, for comparison).

Workings

A deep pit, in contrast to the shallower hillside levels that dominated extraction in the district when it was sunk.

Recorded claims

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

• Worked in the mid-19th century by the Cyfarthfa Iron Company. ¹
• A landscape-archaeology survey of the Merthyr coalfield independently dates the sinking of Robbins Pit, alongside the neighbouring Glyndyrys Pit and Colliers' Row Pit, to the 1820s and 1830s, among the first deep pits at Cyfarthfa — a period when shallower levels still accounted for most coal and ironstone extraction in the district generally. ²
• Cyfarthfa's own main phase of ironstone-workings expansion ran from about 1806, when the works with its six blast furnaces was briefly the largest ironworks in the world, to the 1850s, when the works, in decline, began importing iron ore from elsewhere. ²

Photographs & further reading

Sources

1. (secondary) Small Collieries around Merthyr Tydfil — Northern Mine Research Society
2. (secondary) Merthyr Tydfil - Historic Landscape Character Area — Heneb (Glamorgan-Gwent Archaeological Trust)

Record created: 15 September 2026 · Last researched: 15 September 2026