Trefarclawdd Colliery

Overview

A group of about six horse-powered pits on the Oswestry coalfield, three kilometres south-west of the town, dug around 1780–90 and known in their early years as Sir Watkin's Collieries. Seventy colliers subscribed to the national loan from here in 1798. The pits were abandoned in the 1830s when the water beat them, having never had a steam engine, so their shaft mounds and gin circles survive as the plan of a late-18th-century colliery.

History

Little is recorded of the Trefarclawdd pits, which numbered about six on either side of the Oswestry–Trefonen road and were dug in about 1780–90. In their early years they were known as Sir Watkin's Collieries and Sir Watkin Williams Wynn was closely associated with the enterprise: the Oswestry parish registers record the death in 1792 of John Leach, steward at Sir Watkin's Collieries, and in 1801, during the corn scarcity, Sir Watkin supplied grain at a reduced price for nearly twelve months to his colliers at Trefarclawdd and Llwynymaen. When the national loan for the war against Napoleon was raised in 1798, seventy colliers from Trefarclawdd subscribed £2 14s 6d, against a hundred and forty from the neighbouring and doubtless rival Llwynymaen colliery of John Gibbons and his partners — the two figures are the best measure of the pits' relative size that survives. Historic England's scheduling has the colliery in operation by 1792 and working for around forty years. Throughout its life horse power did the drainage and the winding: Trefarclawdd fell out of use without ever apparently installing a steam engine, and the pits were abandoned during the 1830s, apparently through failure to cope with water. A Geological Survey map of 1918 still showed eight pits in the field west of the Oswestry–Trefonen road and one in the woodland south of Trefarclawdd House.

Geology

The Oswestry coalfield had two worthwhile seams: an upper of about four feet, of tolerably good quality, and a lower six feet thick but of little value in comparison. Mid-19th-century production across the coalfield as a whole ran at some 40,000 tons a year, and working continued in the field until 1891, long after Trefarclawdd itself had stopped.

Workings

The pits survive as a group of well-preserved shaft mounds with their spoil heaps and earthworks: the mounds are typically 2 m high and 7 m across, each with a central depression ringed by a collar of spoil, and on one mound in the centre of the site the collar forms a flattened surface 2 m wide — a gin circle, on which the horse walked round the shaft to work the drawing or drainage gear. A smaller mound in the south of the site is thought to be a ventilation shaft, sunk to help the air circulate in the deeper workings. Spoil heaps of varying size lie across the site, with a dispersed heap about 2 m high in the eastern part, and a flat strip 1.5 m wide running roughly north-north-east to south-south-west between the mounds is a trackway, its line picked out by shallow linear spoil heaps along the north-eastern edge. Deep curving cuts in the northern and south-eastern parts belong to a water-management scheme that took water from a nearby spring, and surface water with it, away from the workings to a brick works and a pottery that stood where the farm buildings are now.

Closure

The pits were abandoned during the 1830s, apparently because the water could not be kept down with horse power alone; no steam engine was ever installed, and the colliery closed after about forty years' work.

What remains

The earthworks and buried remains are a scheduled monument, and the shaft mounds and gin circles are described as unusually well preserved. The site lies under pasture west of the minor road, with further shaft mounds visible to the east outside the scheduled area.

Shaft mounds with their collars and central depressions, at least two gin circles, a probable ventilation shaft mound, spoil heaps, a trackway, and the curving cuts of the water-management scheme.

Redevelopment

The brick works and pottery the mine's water was diverted to are believed to lie under the present farm buildings; the pit ground itself is farmland.

Nearby mines

• Llanymynech Hill Mines and Quarries — 5.4 km S, Powys
• Brynkinalt Colliery — 11.2 km N, Wrexham
• Ifton Colliery — 11.8 km NE
• Black Park Colliery — 12.4 km N, Wrexham

Straight-line distance, within 15 km. Show on the map.

Recorded claims

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

• Seventy colliers from Trefarclawdd subscribed £2 14s 6d to the national loan of 1798, against a hundred and forty from the neighbouring Llwynymaen colliery. ^1,2
• The colliery was in operation by 1792 and continued for around forty years before flooding forced its closure in the 1830s. ³
• Horse power was used for drainage and winding throughout the colliery's life, and it fell out of use without ever apparently installing steam engines. ³
• The pits were known in their early years as Sir Watkin's Collieries, and the Oswestry parish registers record the death in 1792 of John Leach, steward at Sir Watkin's Collieries. ¹
• The Oswestry coalfield had two worthwhile seams, an upper of four feet of tolerably good quality and a lower six feet thick but of little value in comparison, the field producing some 40,000 tons a year in the mid-19th century. ²

Photographs & further reading

Sources

1. (secondary) Trefarclawdd Collieries — Oswestry Borderland Heritage
2. (secondary) The Oswestry Coalfield and John Gibbons (British Mining No. 43) — Northern Mine Research Society
3. (primary) Trefarclawdd colliery remains immediately north of Pottery Cottages, Oswestry Rural (List entry 1016680) — Historic England

Record created: 22 September 2026 · Last researched: 22 September 2026