Gelligroes Colliery

Overview

Old coal workings at Gelligroes near Pontllanfraith, and a pit begun beside Gelligroes mill in 1874 and abandoned in 1875, 1915 and 1918 without being finished.

History

Coal was worked at Gelligroes, near Pontllanfraith in the Sirhowy valley, long before the pit that took its name. The Penllwyn Tramroad served the original Gelligroes Colliery, an old colliery working from the 1840s to the 1870s, and the first Gelligroes Levels were working before 1880 and closed by 1901.

In June 1874 the Western Mail reported that a Swansea company was preparing to sink a new pit near Tredegar Junction, beside the old Gelligroes mill and close to the river, which had to be diverted before sinking could begin. In 1875 the shafts struck the Mynyddislwyn Red Ash vein at 60 to 70 yards, but in October 1875 they were abandoned, unfinished at 90 and 75 yards, because of water.

In 1907 the Cambrian Colliery Company was reported to have acquired the whole Gelligroes undertaking, but nothing seems to have been done. Lloyd's Navigation Steam Coal Company restarted work early in 1914, planning two engine houses, one to sink the old shaft deeper to the Rock vein and one to win the Mynyddislwyn seam; by December the war had stopped work, and the pit was abandoned again in 1915. The Tredegar Iron and Coal Company took it up in 1917, only to abandon it late in 1918. Had it succeeded, the mine was to have been joined by a new railway to the London and North Western Railway's Ynysddu branch above Nine Mile Point.

Geology

The Mynyddislwyn seam of the South Wales Coalfield, whose Red Ash vein the 1874 shafts struck at 60 to 70 yards; the 1914 plan was to sink deeper to the Rock vein.

Workings

Two shafts begun in 1874 beside Gelligroes mill, after the river was diverted, and abandoned unfinished at 90 and 75 yards in October 1875. In 1914 two engine houses were planned, one for deepening the old shaft and one for winning the Mynyddislwyn. Older levels at Gelligroes, reached by tramway, worked before 1880 and closed by 1901.

Closure

Water defeated the first sinking in 1875, the war stopped Lloyd's Navigation's attempt in 1914-15, and the Tredegar Iron and Coal Company abandoned the last attempt late in 1918.

What remains

Tips and a drainage chamber of the Gelligroes levels survive beside Heolddu Lane, and a fenced drainage adit lies beside Tram Road in Pontllanfraith.

Tips and a drainage chamber of the old levels beside Heolddu Lane; a fenced drainage adit beside Tram Road.

Redevelopment

The by-pass covers the final Gelligroes level and its airshaft.

Recorded claims

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

• The Gelligroes pits were started in 1874 and in 1875 struck the Mynyddislwyn Red Ash vein at 60 to 70 yards. ¹
• In October 1875 the shafts were abandoned, unfinished at 90 and 75 yards, because of water. ¹
• Lloyd's Navigation Steam Coal Co. Ltd restarted work early in 1914; work stopped by December because of the war and the pit was abandoned in 1915. ¹
• The Tredegar Iron & Coal Co. Ltd took up the work in 1917 and abandoned it late in 1918. ¹
• Had it succeeded, the mine was to have been connected by a new railway into the LNWR's Ynysddu branch above Nine Mile Point. ¹
• The Penllwyn Tramroad served the original Gelligroes Colliery, an old colliery working from the 1840s to the 1870s. ²
• The first Gelligroes Levels, at ST 1731 9460, were working before 1880 and closed by 1901; the by-pass now covers the final level and airshaft. ²

Photographs & further reading

Sources

1. (secondary) Gelligroes Colliery - Welsh Coal Mines — Welsh Coal Mines
2. (secondary) The Southern Sirhowy Valley: Industrial Archaeology and History — Industrial Gwent

Record created: 1 October 2026 · Last researched: 1 October 2026