Lletty Shenkin Colliery

Overview

A steam-coal colliery at Cwmbach in the Cynon valley, sunk in 1843 by William Thomas of Waun Wyllt to work the Four Feet seam and worked until 1922. Its coal was exceedingly gassy and it became one of the most dangerous pits in the South Wales coalfield: an explosion on 10 August 1849 killed fifty-two men and boys in a single afternoon, and further explosions followed in 1853 and 1862. Under Burnyeat, Brown and Company and then Powell Duffryn it grew to over a thousand men by 1910. Nothing of the colliery survives above ground — its two waste tips were regraded in the early 1970s and housing built over the site — but Lletty Shenkin House, built in 1859 out of the colliery's profits, still stands on the hillside above.

History

Lletyshenkin was a farm of about 70 acres on the eastern side of the Cynon valley, owned in 1844 by Edward Morgan, whose family had held the freehold since about 1800. Around 1843 Morgan leased the land to William Thomas, a son of Robert and Lucy Thomas of Waun Wyllt, Abercanaid, and Thomas sank a colliery on the estate a little to the south-east of the farmhouse to work the Four Feet seam. A second, Upper, shaft followed in 1850; both were wound by water balance and ventilated by furnace, with two more ventilation shafts added later. The colliery had been working barely six years when, on the afternoon of 10 August 1849, firedamp ignited in the workings and killed fifty-two of the 112 men and boys who had gone down that morning (see Disasters, below). It was not the last: an explosion in 1853 killed three men and badly burned fifteen more, after an overman ordered a collier to work away a pillar of coal with a naked light near a fall from which gas was escaping, and on 9 August 1862 five died in an explosion of gas at the No. 2 pit — David Griffiths, John Morgan and Richard Thomas, colliers, the boy David Jones, and David Davies, another boy, who died of his burns some weeks later. William Thomas was succeeded by his brother-in-law William Rees, and Rees by his son Daniel Rees; the family became a dynasty of Aberdare mining engineers and colliery proprietors, and William Rees's daughter Anne married William Thomas Lewis, later Lord Merthyr, in 1864. The Lletty Shenkin Colliery Co. Ltd took the pit over in 1865, and in 1872 it was bought by Burnyeat, Brown and Company, a consortium drawn largely from Liverpool and Whitehaven and headed by William Burnyeat, which by 1902 was also sinking Nine Mile Point in the Sirhowy valley. The 1890s were the colliery's leanest years — 317 men in 1900 — but under Powell Duffryn Steam Coal Co. Ltd, which held it by 1908, it grew quickly, employing 1,086 people in 1910 and 918 in 1908. It closed in 1922, and Cwmbach, which had grown up on the pits, emptied into emigration and poverty.

Geology

The colliery worked the steam-coal measures of the South Wales Coalfield on the eastern flank of the Cynon valley, beneath the Pennant sandstone scarp of Craig-y-Duffryn. William Thomas sank it in 1843 for the Four Feet, the seam whose quality had made the reputation of the Cwmbach pits and of Aberdare steam coal generally; by 1910 the returns list six seams worked together — Four Feet, Gellideg, Nine Feet, Seven Feet, Two Feet Nine and Yard — with the Bute added by 1915. Each coal sits on a bed of nearly impervious seatearth, which blocks water draining down through the sequence: the same property that later made the colliery's spoil tips, built on boulder clay over the valley side, a subject of concern after Aberfan. The coal itself was exceedingly gassy, and the leakage of firedamp from worked-out ground into the live workings runs through the colliery's whole accident record.

Geological setting: Sedimentary Beds and Seams (well documented example)

Workings

Two main shafts: the Lower, sunk in 1843, and the Upper of 1850, both wound by water balance and ventilated by a furnace at the bottom of the upcast, with two further ventilation shafts added later. In 1849 the upcast was about 120 yards deep and 13 feet in diameter, and a new air-pit was being sunk six or seven hundred yards away, still unfinished when the explosion came; a shaft of 134 yards is recorded in 1891. Coal was worked in stalls off cross-headings and hauled by horses — eleven were underground on the day of the 1849 explosion. Safety lamps were issued and a fireman examined the workings before each shift, but the colliers habitually put the lamps aside and worked by candle, telling a reporter in 1849 that they could earn twice as much by candlelight. Later working was by longwall, with the roof at the face carried on timber and the mines inspectors' reports full of falls of roof and side. No reliable figure for the full depth of either winding shaft has been located.

Closure

The colliery closed in 1922, the last of the Cwmbach pits to go. The Durham Mining Museum gives 1913 as its closing date, but its own employment returns run on to 1915 and the museum's record of men killed there continues to 1915; 1913 appears to be the year the Four Feet and Six Feet seams were given up rather than the year the colliery stopped. Employment had already fallen from 1,086 in 1910 to 738 in 1915 and 698 in 1918.

What remains

Nothing of the colliery survives above ground. Two waste tips built up from the Upper Lletty Shenkin workings between 1868 and 1927 dominated the site until the Cynon valley was redeveloped: an investigation reported in 1971 by the consulting engineers B. O. Corbett and J. A. Lord found the upper tip — broken siltstone and sandstone, loosely placed on boulder clay over a line of springs — stable at the time but unlikely to remain so, with features in common with the Abercynon slide of 1939 and the Aberfan tips, both within ten kilometres. Some 60,000 cubic metres of spoil were removed to bring the tip down to about 15 metres above original ground level, an extensive drainage system was laid, and the regraded surface was scarified, fertilised and seeded so that it would read as a green hillside against the Pennant sandstone scarp behind. The lower tip, of burnt shale and freely draining, was judged to need nothing beyond local landscaping. Three hundred and sixty houses were built at Rose Row on the cleared ground. Lletty Shenkin House on Cefnpennar Road above the village, built in 1859 for William Rees out of the colliery's profits, still stands; a visitor in October 2011 found it empty for some eight years and on the market, derelict but structurally sound, with its marble fireplaces, servants' bells, stone floors and attic servants' rooms intact and its ceilings down in places.

None of the colliery itself. The regraded and grassed spoil tips form the hillside above Rose Row, and Lletty Shenkin House, the owner's mansion of 1859, survives on Cefnpennar Road.

Redevelopment

The tips were regraded and drained in the early 1970s and 360 houses built at Rose Row, Cwmbach, as part of the redevelopment of the Cynon valley for housing, light industry and recreation.

Related mines

• Nine Mile Point Colliery — Both were held by Burnyeat, Brown and Company: the Liverpool and Whitehaven consortium bought Lletty Shenkin in the 1870s and sank Nine Mile Point in the Sirhowy valley from 1902.

Nearby mines

• Nixon's Navigation Colliery — 3.1 km SE
• Gethin Colliery — 3.3 km NE, Merthyr Tydfil
• Ferndale Collieries — 3.6 km SW
• Tylorstown Colliery — 4.4 km SW
• Ffos-y-Fran — 4.9 km NE, Merthyr Tydfil

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

Disasters & major incidents

• Lletty Shenkin Colliery Explosion, 1849
  10 August 1849 · Explosion · 52 fatalities
  An explosion of firedamp at Lletty Shenkin Colliery, Cwmbach, on the afternoon of Friday 10 August 1849 killed fifty-two of the 112 men and boys underground. Only about five were burned; the rest were suffocated by the afterdamp. The inquest returned accidental death with a rider that the colliery's old workings should be separately ventilated and never connected with the intake air.

Recorded claims

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

• Sunk in 1843 by William Thomas of Waun Wyllt, Abercanaid, on the Lletyshenkin farm estate leased from Edward Morgan, to work the Four Feet seam. ^1,2
• Two main shafts, the Lower of 1843 and the Upper of 1850, both with water-balance winding and furnace ventilation; two further ventilation shafts were added later. ¹
• The coal worked here was exceedingly gassy, and explosions killed men and boys in 1849, 1853 and 1862. ¹
• William Thomas was succeeded by his brother-in-law William Rees and then by Rees's son Daniel; the Lletty Shenkin Colliery Co. Ltd took over in 1865, Burnyeat, Brown and Company bought the colliery in the 1870s, and Powell Duffryn Steam Coal Co. Ltd held it by 1908. ^1,2
• Welsh Coal Mines gives 1872 for the purchase by Burnyeat, Brown and Company; a Cynon valley local history gives 1874, and says the house was bought with the colliery. (disputed) ^1,2
• Employment fell to 317 in 1900 and then rose to 1,086 in 1910, 970 of them below ground; 918 were employed in 1908 and 698 in 1918. ^1,3
• By 1910 the colliery was working the Four Feet, Gellideg, Nine Feet, Seven Feet, Two Feet Nine and Yard seams together, with the Bute added by 1915. ³
• The colliery closed in 1922, the last of the Cwmbach pits. ^1,4
• The Durham Mining Museum gives 1913 as the closing date, although its own employment returns and fatality records for the colliery continue to 1915. (disputed) ³
• Two waste tips from the Upper Lletty Shenkin workings, built up between 1868 and 1927, were investigated in the early 1970s; the upper one was regraded by the removal of some 60,000 cubic metres of spoil and drained, and 360 houses were built at Rose Row, Cwmbach. ⁵
• Lletty Shenkin House on Cefnpennar Road was built in 1859 for William Rees out of the colliery's profits; a visit in October 2011 found it derelict but structurally sound, empty for some eight years and on the market. ^2,6

Photographs & further reading

Sources

1. (secondary) Lletty Shenkin Colliery, Cwmbach — Welsh Coal Mines
2. (secondary) Lletyshenkin House — Cynon Culture
3. (secondary) Lletty Shenkin Colliery — Durham Mining Museum
4. (secondary) Cwmbach — Wikipedia
5. (primary) B. O. Corbett and J. A. Lord, 'Rehabilitation of derelict land: Lletty Shenkin tips, Cwmbach, Aberdare' (1971), abstract in the TRID database — Transportation Research Board / National Academies
6. (observational) Lletyshenkin Victorian Manor, Cwmbach, Aberdare (visit report, October 2011) — Derelict Places

Record created: 3 September 2026 · Last researched: 4 September 2026