Ysguborwen Colliery

Overview

A colliery at Trecynon, Aberdare, opened around 1849 by Samuel Thomas, one of the pioneers of the Welsh coal trade, and worked into the family that produced David Alfred Thomas, later Viscount Rhondda. Two explosions killed three men each in 1856 and 1858. Abandoned in 1895 after years of water trouble, its flooded workings burst into the neighbouring River Level pit the following year, drowning six men and boys (see Disasters, below); an inquiry found Ysguborwen's own managers guilty of the deaths. A level of the same name was reopened nearby before 1908 and closed in 1919.

History

Ysguborwen Colliery was opened around 1849 by Samuel Thomas, in partnership with a man recorded only as Joseph, at Trecynon near Aberdare. It had four shafts: a main shaft 86 yards deep to the Graig seam, and three others for ventilation only, and worked ironstone alongside coal. Three men were killed in an explosion on 4 February 1856 -- Benjamin Evans, John Williams and David Thomas, using candles for light, with a door believed left open diverting the ventilation -- and three more died in a second explosion on 15 December 1858: Howell Jones, aged 28, Matthew Cousins, 24, and David Morgan, who lingered a week before dying. Samuel Thomas, described by his own family as one of the pioneers of the Welsh coal trade, ran the colliery as Sam Thomas and Company from at least 1867; he died in 1879 and his collieries passed to his two eldest sons, John Howard Thomas and David Alfred Thomas, the latter later created Viscount Rhondda and a Cabinet minister during the First World War. Ysguborwen was under the day-to-day charge of J.H. Thomas by 1888. The colliery was a very wet one throughout its working life; water that collected in its lower workings drained to the surface through a level known as the Drain Level. About 1892 the colliery worked coal on the dip side of its boundary with the neighbouring River Level Colliery, cutting away the barrier of coal that was meant to separate the two workings without informing River Level of what had been done, and Ysguborwen was finally abandoned in December 1895 for its water problems. On 9 December 1896 the accumulated water in its flooded dip workings burst through the narrowed barrier into River Level Colliery, drowning six men and boys there (see Disasters, below); the official inquiry's barrister concluded that Ysguborwen's managers, Samuel Richard Hopkins and Evan Jones, and its fireman, Thomas Davies, had been guilty of a culpable omission of duty amounting to the manslaughter of the six victims, though a successful prosecution was thought unlikely. A level of the same name was opened about 200 yards south of the original pit by J.H. Thomas before 1908, when it employed 134 men; the Powell Duffryn Group later took over its running, employing 143 men in 1918, before it closed in 1919.

Geology

Worked the Graig seam via the main shaft, 86 yards deep, and also worked ironstone; the colliery's flooded dip workings lay close to a barrier, cut away without record in 1892, separating it from the River Level Colliery workings.

Workings

Four shafts: the main shaft 86 yards deep to the Graig seam, the other three for ventilation only; water draining from the lower workings ran to the surface via the 'Drain Level'.

Closure

Abandoned in December 1895 after years of water trouble; a level of the same name, reopened nearby before 1908, closed in 1919.

What remains

Not established from the sources read for this pass.

Not established from the sources read for this pass.

Redevelopment

Not established from the sources read for this pass.

Related mines

• Bwllfa Dare Colliery — Both opened by the same Samuel Thomas and Joseph Thomas partnership -- Ysguborwen around 1849, Bwllfa Colliery in 1853 -- before the partnership dissolved.
• River Level Colliery, Aberdare — Ysguborwen's own abandoned, flooded workings burst into River Level Colliery in 1896, drowning six men and boys; the official inquiry found Ysguborwen's managers responsible for the deaths.

Nearby mines

• River Level Colliery, Aberdare — 0.3 km NE
• Blaengwawr Colliery — 1.1 km S
• Werfa Colliery — 1.3 km E
• Aberaman Colliery — 2.2 km SE
• Nantmelyn Colliery — 2.6 km W

Straight-line distance, within 15 km. Show on the map.

Disasters & major incidents

• River Level Colliery inrush, 1896
  9 December 1896 · Flooding / Inundation · 6 fatalities
  Water broke through from the abandoned, adjoining Ysguborwen colliery into the Gellydeg seam workings of River Level Colliery on 9 December 1896, drowning six men and boys; an inquiry found the barrier between the two collieries had been reduced to a few feet by unrecorded workings on the Ysguborwen side, and that the case for manslaughter against Ysguborwen's managers was strong but unlikely to secure a conviction.

Recorded claims

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

• Opened around 1849 by Samuel Thomas and a partner recorded only as Joseph, at Trecynon near Aberdare; four shafts, the main one 86 yards deep to the Graig seam, worked ironstone as well as coal. ¹
• Three men were killed in an explosion on 4 February 1856, and three more in a second explosion on 15 December 1858. ¹
• Run by Sam Thomas and Company from at least 1867; on Samuel Thomas's death in 1879 it passed to his sons John Howard Thomas and David Alfred Thomas (later Viscount Rhondda), with J.H. Thomas in day-to-day charge by 1888. ¹
• About 1892 Ysguborwen worked coal on the dip side of its boundary with River Level Colliery, cutting away part of the barrier between the two workings without recording it on the deposited plans; the colliery was abandoned for water problems in December 1895. ²
• The barrister who examined the evidence at the 1896-97 inquiry into the River Level inrush concluded that Ysguborwen's managers, Samuel Richard Hopkins and Evan Jones, and its fireman, Thomas Davies, had been guilty of a culpable omission of duty amounting to the manslaughter of the six men drowned at River Level, though he thought a prosecution unlikely to succeed. ^1,2
• A level of the same name was opened about 200 yards south of the original pit by J.H. Thomas before 1908, employing 134 men; later run by the Powell Duffryn Group, it employed 143 men in 1918 and closed in 1919. ¹
• Samuel Thomas, who opened Ysguborwen, was one of the pioneers of the Welsh coal trade; his family house of the same name, built 1852-55, was the birthplace in 1856 of his son David Alfred Thomas, later Viscount Rhondda. ³

Photographs & further reading

Sources

1. (secondary) River Level Colliery Aberdare (Welsh Coal Mines) — Welsh Coal Mines
2. (secondary) River Level Colliery Inrush - Abernant - 1896 — Northern Mine Research Society
3. (secondary) Ysguborwen (Wikipedia) — Wikipedia

Record created: 14 September 2026 · Last researched: 14 September 2026