Ynyscynon Colliery

Overview

A steam-coal pit at Aberaman opened in the 1840s by David Williams, the coal owner and poet Alaw Goch; explosions killed five in 1855 and four in 1859, and after its sale to Powell Duffryn it stopped raising coal in 1875 but pumped until 1962.

History

Ynyscynon was opened by David Williams, the coal owner and poet known as Alaw Goch, in partnership with Lewis Lewis of Cefn Coed. One history dates its opening to 2 February 1843, with a lease of 31 December 1847 recording the start of coal digging; another has the pit sunk in 1847. Lewis soon gave up his interest. Two shafts went down to the Seven Feet seam at 132 yards, and a third was added later for pumping and ventilation; winding was at first by water balance and ventilation by furnace. It was also called Scales Pit, and Williams, known as David Williams of Ynyscynon, also held Treaman, Deep Dyffryn and Navigation.

On 20 April 1855 an explosion of gas at naked lights killed five men and boys; the colliery had no rules and the inspector's cautions had been ignored (see Disasters, below). On 2 March 1859 another explosion of gas suffocated four colliers. After Williams's death in 1863 the pit, renamed High Dyffryn, passed with Treaman to the Powell Duffryn Steam Coal Company, in 1866 by one account and for £8,750 in 1867-68 by another. On 14 December 1872 the chain broke as the first dram of the day reached the top, and the cage and dram fell to the bottom; no one was hurt, but 300 men were kept underground all day. Ynyscynon closed in 1875, its coal worked afterwards from Aberaman Colliery, and the pit was kept for pumping until 1962.

Geology

South Wales Coalfield: the Seven Feet seam.

Workings

Two shafts to the Seven Feet at 132 yards and a third for pumping and ventilation; water-balance winding and furnace ventilation at first.

Closure

Stopped raising coal in 1875, its reserves worked from Aberaman Colliery; kept for pumping until 1962.

What remains

Unknown.

Redevelopment

Unknown.

Related mines

• Aberaman Colliery — Ynyscynon's coal was worked from Aberaman Colliery after it closed in 1875.
• Treaman Colliery — Both David Williams's (Alaw Goch's) pits at Aberaman, sold together to Powell Duffryn.

Disasters & major incidents

• Aberaman Colliery explosion, 1855
  20 April 1855 · Explosion · 5 fatalities
  On 20 April 1855 firedamp fired by naked lights in the pillar workings of Aberaman Colliery, Aberdare, killed five men and boys, one of them a sixteen-year-old haulier blown into the sump and drowned.

What's uncertain

Points where sources disagree or the record could not be settled; both accounts are kept. All open questions in the archive.

• Ynyscynon was opened on 2 February 1843 by David Williams and Lewis Lewis of Cefn Coed; a lease of 31 December 1847 records the start of coal digging. (disputed) ¹
• David Williams (Alaw Goch) and Lewis Lewis sank the pit in 1847. (disputed) ²
• Ynyscynon or High Dyffryn and Treaman were sold to Powell Duffryn in 1867-68 for £8,750. (disputed) ³
• The Powell Duffryn Company became the owners in 1866. (disputed) ²

Recorded claims

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

• Ynyscynon was opened on 2 February 1843 by David Williams and Lewis Lewis of Cefn Coed; a lease of 31 December 1847 records the start of coal digging. (disputed) ¹
• David Williams (Alaw Goch) and Lewis Lewis sank the pit in 1847. (disputed) ²
• Two shafts were sunk to the Seven Feet seam at 132 yards, with water-balance winding and furnace ventilation. ²
• On 2 March 1859 an explosion of gas suffocated four colliers. ²
• Ynyscynon or High Dyffryn and Treaman were sold to Powell Duffryn in 1867-68 for £8,750. (disputed) ³
• The Powell Duffryn Company became the owners in 1866. (disputed) ²
• Closed in 1875; its reserves were worked from Aberaman colliery and the pit was used for pumping until 1962. ²

Sources

1. (secondary) History of Aberdare: later coal — Cynon Valley History Society
2. (secondary) Ynyscynon colliery — Welsh Coal Mines
3. (secondary) Aberdare history 8: the Powell Duffryn Steam Coal Company — Cynon Valley History Society

Record created: 17 October 2026 · Last researched: 17 October 2026