Hollybush Colliery

Overview

Two house-coal levels at Llwyncelyn in the Sirhowy valley, between Blackwood and Tredegar, with a shallow shaft sunk about 1860 to lift their coal to the railway. Four men died there in 1881 raising steam in an underground boiler. It closed in 1921, but the Tredegar company reopened the old level in 1929 to drain water from its pits, and it was still pumping for Markham in 1947.

History

Hollybush Colliery lay at Llwyncelyn in the Sirhowy valley, between Blackwood and Tredegar. Two levels, Old and New Hollybush, worked the Brithdir house-coal seam, and a shaft only just over 100 feet deep was sunk about 1860 for one purpose: to raise the coal from the level mouth to the height of the railway wagons for tipping. E. D. Williams, High Sheriff of Monmouthshire, bought the colliery in 1868.

On 18 December 1881 four men were suffocated while raising steam in an underground boiler (see Disasters, below). New Hollybush was developed in the early 1890s. After Williams died in 1895 his executors ran the colliery; in 1896 Hollybush employed 125 men and New Hollybush 49, and in 1908 the two together employed 171. The workforce had fallen to 89 by 1918, and the colliery closed in 1921.

In July 1929, expecting water trouble, the Tredegar company began reopening the old Hollybush Level. It cleared 700 yards and installed low-lift centrifugal pumps, which started work in November, to protect the Llanover, Abernant and Waterloo pits. In 1947 the level was still pumping for Markham Colliery.

Geology

The Brithdir house-coal seam; Welsh Coal Mines records both levels on the Pontygwaith seam in 1896.

Workings

The Old and New Hollybush levels, with a shallow shaft just over 100 feet deep that raised the coal from the level mouth to the railway; an underground boiler raised steam.

Closure

Closed in 1921. The Tredegar company reopened 700 yards of the old level in 1929 and pumped from it to protect its pits; it was still pumping for Markham in 1947.

What remains

Unknown.

Redevelopment

Unknown.

Related mines

• Abernant Colliery (Argoed) — Hollybush Level was reopened in 1929 to protect Abernant from water, and the old workings share a plan with it.
• Markham Colliery, Sirhowy Valley — The reopened Hollybush Level was pumping for Markham Colliery in 1947.

Disasters & major incidents

• Hollybush Colliery boiler suffocation, 1881
  18 December 1881 · Gas / Asphyxiation · 4 fatalities
  On the morning of Sunday 18 December 1881 four men working on a pumping engine and its boiler underground at Hollybush Colliery, between Blackwood and Tredegar, were suffocated when the workings filled with fumes.

Recorded claims

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

• A shaft just over 100 feet deep was sunk about 1860 to raise coal from the level mouth to wagon height. ¹
• In 1896 Hollybush employed 125 men and New Hollybush 49. ¹
• Fatal accidents were recorded at New Hollybush in 1907 and at Hollybush in 1912. ²
• The old Hollybush workings in the Brithdir are recorded on one plan with Abernant and Llanover. ³
• The Tredegar company reopened the old level in 1929 to pump water, and it was still pumping for Markham Colliery in 1947. ¹

Photographs & further reading

Sources

1. (secondary) Welsh Coal Mines: Hollybush Colliery, Tredegar — Welsh Coal Mines
2. (secondary) NMRS coal mining accidents and deaths database — Northern Mine Research Society
3. (primary) BGS / Mining Remediation Authority mine plan: ABERNANT & LLANOVER, HOLLYBUSH OLD (Brithdir) — British Geological Survey

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