Gethin Colliery

Overview

William Crawshay sank it in 1849 to make coke for the Cyfarthfa furnaces, and within sixteen years it had killed eighty-one men and boys in two explosions — after the first of which a Merthyr jury returned a verdict of manslaughter against the manager, and a grand jury threw it out.

History

Gethin was sunk at Abercanaid in 1849 by William Crawshay, the Cyfarthfa ironmaster, to supply coking coal to his own furnaces — the classic Merthyr pattern, in which the pit existed to feed the ironworks rather than to sell coal. It grew to six pits on two levels employing around 800 people. On 19 February 1862 an explosion in the Lower pit killed 47 men and boys, the first serious mining accident in the Merthyr district; on 20 December 1865 a second explosion, in the Upper pit, killed 34 more. The manager, John Moody, was held responsible by the jury on both occasions and prosecuted on neither. The colliery later passed to Powell Duffryn and turned to steam coal, working the Seven Feet, Nine Feet, Gellideg and Upper Yard seams by 1896. Employment rose from 308 men that year to 703 by 1918. Coal production ended in the 1920s, though the site was kept on as a pumping station until 1947.

Geology

Gethin worked the coals of the northern rim of the South Wales coalfield, where the measures outcrop along the heads of the valleys and were the reason the ironworks stood where they did — coal, ironstone and limestone all within reach of one another. These are gassy coals, and the 1862 inquest turned on exactly that: firedamp accumulating in a heading that the ventilation could not clear, in a pit where naked lights were still in general use.

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

Workings

Six pits on two levels. The two winding shafts, the Lower and Upper pits — Nos. 1 and 2 — were each about 120 yards deep, with separate shafts for ventilation and pumping. Ventilation was by furnace, the standard arrangement of the period and the one the 1862 inquest found deficient. Naked lights were in general use, with safety lamps issued only to men working in stalls where gas had already been found.

Closure

Coal winding finished in the 1920s and the site worked on as a pumping station until 1947, keeping water off neighbouring workings.

What remains

Nothing survives. The colliery site at Abercanaid has been cleared and the hillside above is now forestry — Gethin Woods, which carries the name and nothing else.

None on the ground. The dead of both explosions are commemorated locally and the disasters are well recorded in the Merthyr historical literature.

Redevelopment

Forestry and open ground on the valley side south of Merthyr Tydfil.

Abandoned workings can be dangerous — unstable ground, uncapped shafts, flooding and bad air are common even where a site looks safe from the surface. This entry describes history and general location only; it is not an access guide.

Disasters & major incidents

• Gethin Colliery explosion, 1862
  19 February 1862 · Explosion · 47 fatalities
  Gas ignited at a naked flame in the No. 19 heading of Gethin's Lower pit on 19 February 1862, killing 47 men and boys. The inquest found the ventilation deficient and returned a verdict of manslaughter against the manager; a grand jury then found no case to answer.
• Gethin Colliery explosion, 1865
  20 December 1865 · Explosion · 34 fatalities
  Three years and ten months after the Lower pit killed 47 men, Gethin's Upper pit exploded on 20 December 1865 and killed 34 more. John Moody, the manager held responsible for the first explosion and never tried for it, was found culpably negligent again — and acquitted again.

Recorded claims

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

• Gethin was sunk in 1849 by William Crawshay to produce coking coal for his Cyfarthfa furnaces. ¹
• The Lower and Upper pits, Nos. 1 and 2, were each about 120 yards deep, with separate ventilation and pumping shafts; ventilation was by furnace. ¹
• The colliery worked six pits on two levels and employed around 800 people at the time of the 1862 explosion. ²
• An explosion on 19 February 1862 in the Lower pit killed 47 men and boys — the first serious mining accident in the Merthyr district. ^2,1
• A second explosion on 20 December 1865, in the Upper pit, killed 34 men and boys. (disputed) ¹
• The 1865 death toll is given as 36 elsewhere. (disputed) ³
• Employment rose from 308 men in 1896 to 500 in 1908, 703 in 1918 and 684 in 1923, working the Seven Feet, Nine Feet, Gellideg and Upper Yard seams. ¹
• Coal production ceased in the 1920s and the site operated as a pumping station until 1947. ¹

Photographs & further reading

This page doesn't try to reproduce everything — these are the best original sources found for this mine.

Sources

1. (secondary) Gethin Colliery, Abercanaid — Welsh Coal Mines
2. (primary) Gethin Colliery Explosion, Merthyr, 1862 — Northern Mine Research Society
3. (secondary) The Gethin Pit Explosion, 1862 — Merthyr Tydfil's History and Culture

Record created: 24 August 2026 · Last researched: 24 August 2026