Glanddu Colliery

Overview

A Mynyddislwyn-seam level near Pengam, worked from the 1840s, whose mile-long main road was shared by several coal owners. A roof fall on it killed two men in 1875, and a coroner's jury found one owner guilty of manslaughter. A later Glanddu mine closed in 1931.

History

Glanddu was a level near Pengam, in the Rhymney valley, working the Mynyddislwyn seam for red-ash house coal. It was at work in the 1840s, when Lewis and Rosser Thomas owned it, and the Children's Employment Commission of 1842 recorded at their colliery one man with a fractured leg, another not expected to recover and ten other accidents in twelve months, none fatal. Cope and Latch owned it from at least 1851, J. Latch and Company in 1860-65 and Latch and Cope in 1870. Newspapers in 1875 said the level had been worked for forty or fifty years.

The main level, about a mile long, had been driven by the Carngethin Colliery Company as the outlet for its coal, and is also called the Carngethin level. The landowner, Captain Edmund Williams, later leased other parts of the ground to Latch and Company, to Davies and Sons and, in 1873, to James, Williams and Davies and to Richard Clayton Evans, each with a way along the level; Latch's company laid new tramplates and charged the others a halfpenny a ton. Three or four owners brought their coal out of the one mouth, and none of them examined the main road. On 21 May 1875 a stone fell from its roof onto a tram carrying men to work, killing two (see Disasters, below).

W. and E. Beddoe worked the mine from 1877 to 1880, closing Upper Glanddu and starting a new level in 1878; the Glanddu and Pentreporth levels abandoned the Mynyddislwyn seam in 1898. In 1920 the Glanddu Colliery Company opened a mine at Tir-y-berth, listed by the Great Western Railway as Glanddu. Offered for sale in March 1928, it was bought by the Welsh Coal and Coke Company, which employed 29 men there in 1929-30 producing 25,000 tons, but went into liquidation and closed it in June 1931. The seam was abandoned in June 1932. At least three entrances are attributed to the mine.

Geology

The Mynyddislwyn seam, described in 1875 as the well-known Mynyddislwyn red-ash house-coal vein.

Workings

A main level about a mile long, arched for some distance from the mouth, through which three or four separate owners brought their coal to a single entrance; men rode in to distant faces in empty trams drawn by a horse. At least three entrances are attributed to the mine.

Closure

The first period of working ended about 1880, and the Glanddu and Pentreporth levels abandoned the seam in 1898. The Welsh Coal and Coke Company closed the later mine in June 1931 on going into liquidation, and the Mynyddislwyn seam was abandoned in June 1932.

What remains

Unknown.

Redevelopment

Unknown.

Disasters & major incidents

• Glanddu Colliery roof fall, 1875
  21 May 1875 · Collapse / Roof Fall · 2 fatalities
  A stone of about five tons fell from the roof of the shared Glanddu level near Pengam on 21 May 1875, killing two colliers riding in to work and injuring three. The coroner's jury found their employer guilty of manslaughter for leaving the road unexamined; the grand jury threw out the bill.

Recorded claims

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

• In 1842 Lewis and Rosser Thomas owned the colliery, where the Children's Employment Commission recorded ten non-fatal accidents in twelve months. ¹
• Cope and Latch owned it from at least 1851, and J. Latch and Company in 1860-65. ¹
• In 1875 three or four separate coal owners brought their coal out through the one mouth of the Glanddu level. ^2,3
• The Glanddu and Pentreporth levels abandoned the Mynyddislwyn seam in 1898. ^1,4
• In 1929-30 the Welsh Coal and Coke Company employed 29 men at Glanddu producing 25,000 tons of coal. ¹
• The Mynyddislwyn seam was abandoned in 1932. ^1,5

Photographs & further reading

Sources

1. (secondary) Welsh Coal Mines: Glan Ddu level, Pengam — Welsh Coal Mines
2. (primary) 'Fleur-de-Lis: verdict of manslaughter against a colliery proprietor', Monmouthshire Merlin, 11 June 1875 — Welsh Newspapers Online (National Library of Wales)
3. (primary) 'The late fatal accident at Pengam', The Cardiff Times, 5 June 1875 — Welsh Newspapers Online (National Library of Wales)
4. (primary) BGS / Mining Remediation Authority mine plan: GLANDDU AND PENTREPORTH (Mynyddislwyn) — British Geological Survey
5. (primary) BGS / Mining Remediation Authority mine plan: GLANDDU (Mynyddislwyn) — British Geological Survey

Record created: 11 October 2026 · Last researched: 11 October 2026