Glenchass Mine

Overview

A minor Manx copper working near Port St Mary, also known as Glensash, worked in fits and starts from before the 19th century until a fatal-to-the-mine shaft collapse in 1865.

History

Glenchass -- also recorded as Glensash -- lies in the north-western corner of Perwick Bay, about half a mile south-west of Port St Mary on the Isle of Man, one of the island's mines alongside the much larger Laxey, Bradda and Foxdale workings. The date of the first working is uncertain but was probably before the end of the 18th century; Macculloch mentioned the place in 1819 as 'Glensash, near Port la Marie' and as then abandoned. Work was resumed toward the middle of the 19th century, at first as part of the Bradda mining sett and afterwards as an independent company, but the mine never yielded ore in paying quantity. The first workings were an adit level driven into the cliff along the lode, and a shaft was later sunk from the surface 200 yards inland to 50 fathoms, with levels driven chiefly southward under the sea at 15, 23, 38 and 50 fathoms. Small bunches of argentiferous galena of high quality, and kupfernickel, the only known occurrence of that nickel ore on the island, are said to have been found in the floor of the day-level.

Glenchass was in operation in 1857, work was then suspended, and it resumed in 1861 when the 15-fathom level was being driven; by 1862 the shaft had reached 50 fathoms, and by 1863 a three-foot lode was carrying steel-grained galena. In 1865 the shaft -- sunk among old workings -- collapsed, 'subjected to a sudden pressure by the fall of their walls', and the accident brought operations to a close. The failure of the mine is locally held to have been due to this cause alone, although the mine inspector had written in 1864 that the lode 'has always appeared to me a hopeless blank'.

Geology

A lode running N 18-20 degrees W with an easterly underlie, intersected by the cliff in the recess known as Cotlooway, carrying small bunches of argentiferous galena and kupfernickel and, by 1863, a three-foot band of steel-grained galena.

Workings

An adit driven into the cliff along the lode, then a shaft sunk from the surface 200 yards inland to 50 fathoms, with drivings chiefly southward under the sea at 15, 23, 38 and 50 fathoms; the shaft was sunk among old workings.

Closure

A shaft collapse in 1865, the shaft having been sunk among old workings, brought operations to a permanent close.

What remains

Twin chimneys and heaps of mine waste survive at the site.

Twin chimneys and deads heaps, around grid reference SC 200 670.

Related mines

• Bradda Head Mines — Glenchass was first worked as part of the Bradda mining sett before becoming an independent company.

Recorded claims

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

• Glenchass was worked in 1857, suspended, then resumed in 1861 (15-fathom level); by 1862 the shaft reached 50 fathoms and by 1863 was raising galena from a 3-foot lode; a 1865 shaft collapse ended operations. ¹
• The first working at Glenchass is uncertain but probably dates from before the end of the 18th century, and the place was described as abandoned in 1819. ¹
• Glenchass is grouped alongside Laxey, Bradda and Foxdale as one of the Isle of Man's worked mines. ²
• The first workings were an adit level driven into the cliff along the lode; a shaft was later sunk from the surface 200 yards inland to 50 fathoms. ³
• Macculloch mentioned the place in 1819 as 'Glensash, near Port la Marie', abandoned at that time. ³
• Operations resumed toward the middle of the 19th century, first as part of the Bradda mining sett and then as an independent company, but the mine never yielded ore in paying quantity. ³
• Kupfernickel, the nickel arsenide, is said to have been found in the floor of the day-level, the only known occurrence of that ore on the Isle of Man. ³
• Twin chimneys and deads heaps survive around grid reference SC 200 670. ⁴

Photographs & further reading

Sources

1. (primary) Chapter 12 The metalliferous veins of the island (Geology of the Isle of Man, Lamplugh, 1903) — Scottish Geology Trust / British Geological Survey
2. (secondary) Mining activities - Isle of Man — Derbyshire Caving Club
3. (primary) Geology of the Isle of Man (Chapter 12) — G.W. Lamplugh, HMSO, 1903
4. (secondary) Industries — Mines, Quarrying & Extraction — Manx Environmental Records / MERS

Record created: 31 August 2026 · Last researched: 30 September 2026