United Mines

Overview

One of the great copper mines of the Gwennap district, formed around 1780 by the amalgamation of Ale and Cakes Mine, Wheal Cupboard and Poldory, and later expanded to take in several neighbouring setts. Under John Taylor's management from the early 1820s it worked what was, at the time, described as the richest copper lode in the world, part of the ground that gave 19th-century Gwennap its reputation as 'the richest square mile on earth'.

History

United Mines took its name from the union, around 1780, of three smaller workings — Ale and Cakes Mine, Wheal Cupboard and Poldory, the last probably already at work as a small tin operation from about 1760. The combined sett was later extended to take in Wheal Britannia, Wheal Clifford, Wheal Moor, Wheal Squire, Wheal Andrew (Friendship Mines) and Copper Hill Mine, lying just south of the Great Consolidated Mines and bordering St Day and Crofthandy to the west and the Poldice and Carnon valleys to the north.

The mine's most productive era began in the early 1820s when the engineer and mine agent John Taylor took leases on the then-abandoned ground and struck what was, at the time, described as the richest copper lode in the world. The mines were in profit by 1822. Output initially travelled north to Portreath for smelting in South Wales; as tramroad charges on that route rose, Taylor built his own route south through the Carnon valley to the port at Devoran, served from 1824 by the horse-drawn Redruth and Chasewater mineral tramway (later converted to steam haulage), which continued operating for over ninety years until 1915.

At its peak the workings extended to some 80 miles of underground passages served by 22 engines, including Eldon's (Little's) pumping engine house of around the 1830s, built around a 30-inch cylinder, and the pumping engine house at Garlands Shaft, built for an 85-inch engine. A stamps engine house was added as late as 1900 to rework the mine's own dumps. Between 1815 and 1861 the wider United Downs group of mines raised 347,500 tons of copper ore averaging 7.5% copper, plus 250 tons of black tin, alongside smaller quantities of arsenic, pyrite and zinc ore; the closely associated Wheal Clifford alone produced 50,167 tons of 6.5% copper ore and 365 tons of black tin between 1835 and 1861.

Falling copper prices brought United Mines, like most of Gwennap's mines, into difficulty by the mid-19th century. In 1857 it merged with the neighbouring Consolidated Mines to form Clifford Amalgamated Mines, which continued working, increasingly unprofitably, until 1870. A brief episode of prospecting and trial working in the 1940s found nothing commercially workable, and the ground has since been partly overlain by the United Downs landfill site.

Geology

The Gwennap lodes, chief among them the Great South Lode and the Hot Lode, so called for its extreme temperatures at depth — what John Taylor's rebuilding struck in the 1820s was described at the time as the richest copper lode in the world.

Workings

At peak, some 80 miles of underground workings served by 22 engines. Eldon's (Little's) pumping engine house, built around the 1830s around a 30-inch cylinder, handled water from the adit to surface; Garlands Shaft carried a pumping engine house built for an 85-inch engine. A separate stamps engine house was built in 1900 specifically to rework the mine's own dumps rather than raise fresh ore.

Closure

Production ran down after the great copper years; the sett was later folded into Clifford Amalgamated Mines.

What remains

Much of the historic United Mines ground lies within or beside the United Downs landfill site near St Day, and surface remains are correspondingly fragmentary; a permissive path crosses part of the site. Surviving structures include the ruined Bob Wall of Garlands engine house and remnants of the 1900 stamps engine house. The wider United Downs ground has since drawn renewed interest for its lithium and tin potential, currently under exploration by Cornish Metals.

Related mines

• Ale and Cakes Mine — One of United Mines' three founding setts, amalgamated around 1780.
• Consolidated Mines — The two great Gwennap combines merged in 1857 to form Clifford Amalgamated Mines.
• Copper Hill Mine — Absorbed into the wider United Mines group in the 19th century.
• Great County Adit — The Great County Adit's Consols Adit branch was driven in the 1770s-80s specifically to drain the Consolidated and United Mines.
• Poldory Mine — One of United Mines' three founding setts, amalgamated around 1780.
• Ting Tang Mine — Drawn into the 1861 combination with United Mines, Consolidated Mines and Wheal Clifford that formed Clifford Amalgamated Mines.
• Wheal Andrew — Absorbed into the wider United Mines group in the 19th century.
• Wheal Clifford — Absorbed into the wider United Mines group; its own Hot Lode discovery was one of the group's most productive.
• Wheal Cupboard — One of United Mines' three founding setts, amalgamated around 1780.
• Wheal Squire — Absorbed into the wider United Mines group in the 19th century.

Recorded claims

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

• United Mines was formed around 1780 by the amalgamation of Ale and Cakes Mine, Wheal Cupboard and Poldory. ^1,2
• From the early 1820s, engineer John Taylor leased the then-abandoned ground and struck what was, at the time, described as the richest copper lode in the world; the mines were profitable by 1822. ²
• The wider United Downs group of mines raised 347,500 tons of copper ore averaging 7.5% copper and 250 tons of black tin between 1815 and 1861, alongside smaller quantities of arsenic, pyrite and zinc ore. ^1,2
• At peak the mines had around 80 miles of underground workings served by 22 engines. ^1,2
• United Mines merged with the neighbouring Consolidated Mines in 1857 to form Clifford Amalgamated Mines, which continued working until 1870. ^1,2
• The horse-drawn Redruth and Chasewater mineral tramway, opened in 1824 to carry ore south to Devoran, operated for over 90 years until 1915. ^1,2

Sources

1. (secondary) United Mines — Grace's Guide to British Industrial History
2. (secondary) United Mines, Gwennap Cornwall — Cornwall Calling

Record created: 26 August 2026 · Last researched: 26 August 2026