Twyn Gwyn Colliery

Overview

A level in the Mynyddislwyn seams at Newbridge, beside Cwmdows Colliery, whose company took over Cwmdows; it appears on Prujean's map of 1843 and its plans run to 1929.

History

Twyn Gwyn Colliery was a level at Newbridge, a short distance from Cwmdows Colliery, working the Mynyddislwyn seams. Both collieries appear on John Prujean's map of the ironworks and collieries of Monmouthshire, published in 1843.

Cwmdows was in the hands of T. Stroud of Newport by 1880. The Twyn Gwyn Colliery Co. Ltd later took over the running of Cwmdows but concentrated its coal production at Twyn Gwyn, which employed only twelve men in 1896; production restarted at Cwmdows around 1912. A certificate for thirty of the company's £1 ordinary shares, dated 25 August 1915, is in the collection of Museum Wales.

The colliery had a screen at the surface. In November 1904 an eighteen-year-old working there fell from a truck, and a wheel went over his right arm, which had to be amputated.

The Coal Authority holds plans of Twyn Gwyn No. 1 in the Upper and Lower Mynyddislwyn seams, abandoned in 1916, and of the combined Cwm Dows or Twyn Gwyn workings, abandoned in 1929. Cwmdows closed in the early 1930s, and a later working recorded as Woodland New Cwmdows Twyn Gwyn was abandoned in August 1963. The mouth of the Twyn Gwyn level was nearly buried by 2005.

Geology

The level worked the Mynyddislwyn seams, recorded at Twyn Gwyn No. 1 as the Upper and Lower Mynyddislwyn.

Workings

A level with a surface screen; plans survive of Twyn Gwyn No. 1 and of workings combined with Cwmdows.

Closure

Plans of Twyn Gwyn No. 1 were abandoned in 1916 and of the combined Cwm Dows or Twyn Gwyn workings in 1929; a later Woodland New Cwmdows Twyn Gwyn working was abandoned in August 1963.

What remains

The mouth of the level was nearly buried by 2005.

The nearly buried mouth of the level, photographed in 2005.

Redevelopment

Unknown.

Related mines

• Cwmdows Colliery — Run by the same Twyn Gwyn Colliery Co. Ltd, with workings planned together as 'Cwm Dows or Twyn Gwyn' (BGS 21942650).

Recorded claims

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

• Twyn Gwyn is shown, with Cwmdows, on John Prujean's 1843 map of ironworks and collieries in Monmouthshire. ¹
• The Twyn Gwyn Colliery Co. Ltd concentrated production at Twyn Gwyn, which employed twelve men in 1896. ¹
• In November 1904 an eighteen-year-old working at the colliery screen lost his right arm after falling from a truck. ²
• The Twyn Gwyn Colliery Company Limited issued £1 ordinary shares; a certificate is dated 25 August 1915. ³
• Plans of Twyn Gwyn No. 1 in the Upper and Lower Mynyddislwyn seams were abandoned in 1916. ⁴
• Plans of the combined Cwm Dows or Twyn Gwyn workings were abandoned in 1929. ⁵
• A working recorded as Woodland New Cwmdows Twyn Gwyn was abandoned on 10 August 1963. ⁶
• The mouth of the level was nearly buried by 2005. ¹

Photographs & further reading

Sources

1. (secondary) Welsh Coal Mines: Cwmdows — Welsh Coal Mines
2. (primary) 'Sad accident to a Newbridge lad', Evening Express, 2 November 1904 (Welsh Newspapers Online) — National Library of Wales
3. (primary) Twyn Gwyn Colliery Co. Ltd. (share certificate, 1915), Museum Wales item 1999.92/14 — Amgueddfa Cymru – Museum Wales
4. (primary) BGS / Mining Remediation Authority mine plan: TWYN GWYN NO 1, Mynyddislwyn (Upper & Lower), abandoned 1916 — British Geological Survey
5. (primary) BGS mine plan: Cwm Dows or Twyn Gwyn (Mynyddislwyn top and bottom seams), abandoned 1929 — British Geological Survey / Mining Remediation Authority
6. (primary) BGS / Mining Remediation Authority mine plan: WOODLAND NEW CWMDOWS TWYN GWYN, Mynyddislwyn, abandoned 1963 — British Geological Survey

Record created: 9 October 2026 · Last researched: 10 October 2026