Hendreforgan Colliery

Overview

An anthracite colliery on the Afon Llynfell near Cwmllynfell and Cwmtwrch Uchaf, developed from 1816 by James Cox into what was called 'the most complete and valuable colliery in the Principality', with a George Stephenson engine underground and early steam-jet ventilation. It was worked on for a century under a string of owners, employed nearly 500 men in 1896, suffered a firedamp explosion that killed six in 1869, and closed around 1924.

History

Richard Jenkins of Coity was working coal at Hendreforgan early in the 19th century, but surrendered the workings in 1812 to John Jones of Brynbrain. A lease of 1814 went to John and George Evans of Llansamlet, and James Cox, a native of Shaftesbury in Dorset, replaced George Evans in 1816; from the end of 1818 Cox was sole proprietor. Two shafts were sunk 150 feet to the Great Vein in 1818, with a steam engine over the downcast for winding and pumping and a ventilating furnace at the foot of the upcast. Because the seam dipped sharply away from the shafts, a second engine built by George Stephenson hauled coal to the pit bottom. In 1827 one shaft was deepened to the Milford Vein at 250 feet and divided by brattice into upcast and downcast, the draught aided by steam from the Stephenson engine; the system lasted until 1833 and was copied elsewhere. Coal went by tramroad and the Swansea Canal to Cox's wharves at Swansea, and 'Cox's Milford Vein' was sold to London maltsters and hop driers. When the colliery was offered for sale or let in December 1831, some £35,000 had been spent on it and it could raise 120 tons a day. Evan Jones held the colliery in 1855, Swan and Company in 1858 and the Hendreforgan Colliery Company from the 1860s. On 11 November 1869, with the mine under Alexander Bain, an explosion of firedamp killed six men and boys (see Disasters, below); the inquest jury asked the coroner to reprimand Bain for leaving the colliery in incompetent hands. A petition to wind up the Hendreforgan Colliery Company was presented in December 1879. By 1878 a drift had become the main coaling adit. The Gwaun-cae-Gurwen Colliery Company of Rotherham owned it in 1893-96, when it employed 386 men underground and 103 at the surface under Daniel Meredith, and in 1896 a runaway journey killed two boys (see Disasters, below). A Waddle fan was fitted in 1880. The workforce fell to 33 by 1908 under the British Anthracite Colliery Company, and from 1917 the New Coedffalde Colliery Company worked it with some 37 men, perhaps together with the neighbouring Coedffalde. The Black seam was abandoned in 1900 and 1911, the Brass Vein in 1904, and the New Hendreforgan or Spion Kop working abandoned the Brass seam in 1927; the colliery closed around 1924.

Geology

Anthracite from the Great (Big) Vein, about five feet thick at 36 yards, the Milford Vein, four feet thick 67 yards lower, a third three-foot seam below, and later the Little, Black and Brass seams.

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

Workings

Two shafts to the Great Vein (1818), one deepened to the Milford Vein at 250 feet (1827) and divided by brattice; an underground Stephenson haulage engine; furnace ventilation, with steam-jet ventilation recorded by 1828, and an 8 ft 9 in Waddle fan from 1880; by 1878 a drift as the main coaling adit. A 400-yard slant intersected six seams. Coal went by a three-quarter-mile tramroad to the Swansea Canal.

Closure

Welsh Coal Mines gives closure around 1924, when it may have been absorbed into the neighbouring Coedffalde; NMRS last lists manpower in 1924, and a New Hendreforgan or Spion Kop working abandoned the Brass seam in May 1927. No reason is recorded.

What remains

Unknown.

Unknown.

Redevelopment

Unknown.

Related mines

• Gwaun Cae Gurwen Colliery — Both owned by the Gwaun-cae-Gurwen Colliery Company in the 1890s.

Nearby mines

• Cwmllynfell Colliery — 0.3 km N
• Gilwen Colliery — 2.1 km SE
• Brynhenllys Colliery — 2.4 km NE, Powys
• Tirbach Colliery — 3.1 km SE
• Cwmteg Colliery — 3.5 km NW

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

Disasters & major incidents

• Hendreforgan Colliery Explosion, 1869
  11 November 1869 · Explosion · 6 fatalities
  A firedamp explosion shortly after thirteen men and boys started work killed six of them, the youngest an eleven-year-old door-boy. The pit was worked with open lamps and poorly ventilated, and a change to the airways days before had left three workings on one air current. The inquest jury asked the coroner to reprimand the owner, Alexander Bain, for putting the colliery in incompetent hands.
• Hendreforgan Colliery Runaway Journey, 1896
  15 August 1896 · Haulage / Transport · 2 fatalities
  Nine boys riding illicitly up a steep incline in an empty journey of trams were thrown back down when a drawbar broke between the fourth and fifth trams. Two were killed, a 17-year-old collier boy and a 13-year-old haulier, and the other seven were all injured.

Recorded claims

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

• Richard Jenkins of Coity worked coal at Hendreforgan early in the 19th century and surrendered the workings in 1812 to John Jones of Brynbrain, who in 1816 demised them to John Evans and James Cox; Cox became sole proprietor at the end of 1818 and by 1831 had spent £33,500. ¹
• The colliery opened in 1814 under a 99-year lease to John and George Evans of Llansamlet; James Cox replaced George Evans in 1816 and two shafts were sunk 150 feet to the Great Vein in 1818. ²
• NMRS gives the colliery, also called Cox's, as opened in 1817. (disputed) ³
• A steam engine built by George Stephenson hauled coal to the pit bottom; in 1827 a shaft deepened to the Milford seam at 250 feet was divided by brattice, ventilation aided by steam from the Stephenson engine, a system that lasted until 1833 and was copied elsewhere. ²
• Alan Hill records steam jet ventilation at Hendreforgan as early as 1828; a pumping engine was ordered from the Neath Abbey Iron Company in 1830 and a Waddle fan installed in 1880. ³
• In December 1831 Hendreforgan or Cox's Colliery was offered for sale or let: 95 acres, three seams including 'Cox's Milford Vein', capable of 120 tons a day, £35,000 expended, coal carried by railroad to the Swansea Canal. ¹
• In 1896 the Gwaun-cae-Gurwen Colliery Company of Rotherham employed 386 men underground and 103 at the surface under Daniel Meredith; in 1908 the British Anthracite Colliery Company employed 28 underground and 5 surface; in 1918 the New Coedffalde Colliery Company employed 29 underground and 8 surface. ^3,2
• The colliery closed around 1924 and may have been integrated with the nearby Coedffalde colliery, under whose name it appears on maps from 1918. (uncertain) ²
• The Black seam was abandoned in December 1900 and May 1911, the Brass Vein in August 1904, and the New Hendreforgan (Spion Kop) abandoned the Brass seam in May 1927. ³
• The BGS mine-plans catalogue holds Mining Remediation Authority abandonment plans titled 'Hendreforgan' dated 1900, 1904 and 1911, matching NMRS's abandonments of the Black and Brass seams, and a 1925 plan covering Brynmorgan and Hendreforgan. ⁴

Photographs & further reading

Sources

1. (secondary) Coal mining in Gwauncaegurwen and Cwmgors and local area (Glyn-Moch Colliery; Ystrad, Glanaman) — Gareth Hicks, GENUKI
2. (secondary) Hendreforgan disaster (Hendreforgan Colliery) — Welsh Coal Mines
3. (secondary) Hendreforgan Colliery — Northern Mine Research Society (Ray Lawrence)
4. (primary) BGS / Mining Remediation Authority mine plans: HENDREFORGAN (1911) — British Geological Survey / Mining Remediation Authority

Record created: 16 September 2026 · Last researched: 16 September 2026