Tirtwmbwl Colliery

Overview

Tirtwmbwl Colliery was a small level at Merthyr Vale that abandoned the No.1 Rhondda Rider seam in September 1912.

History

The NMRS's Merthyr roundup records only that this small level, at grid reference 080994 near Merthyr Vale, abandoned the No.1 Rhondda Rider seam in September 1912; no owner, employment figures or further working history survive in the source. The British Geological Survey's district memoir for Merthyr Tydfil describes the No.1 Rhondda Rider as a thin seam, traceable throughout the district by its associated 'slack' feature, that was thick enough to have been worked on a small scale in the Taff Valley -- which Merthyr Vale lies within -- though the memoir does not name Tirtwmbwl itself.

Recorded claims

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

• Tirtwmbwl Colliery, a small level at Merthyr Vale, abandoned the No.1 Rhondda Rider seam in September 1912. ¹
• The No.1 Rhondda Rider is a thin seam traceable throughout the Merthyr Tydfil district by its associated 'slack' feature, and was thick enough to be worked on a small scale in the Taff Valley. ²

Sources

1. (secondary) Small Collieries around Merthyr Tydfil — Northern Mine Research Society
2. (primary) Geology of the South Wales Coalfield, Part V, the country around Merthyr Tydfil (Memoir, Sheet 231) — British Geological Survey

Record created: 15 September 2026 · Last researched: 16 September 2026