Gwennap Mining District, Cornwall

Gwennap Mining District is a large area centred on the important Consolidated, United and Poldice mines near St. Day. The Scorrier mines (including North Downs) and Wheal Busy form its northern and eastern boundary, whilst the district extends via the Carnon Valley and the mines which flank it to the port of Devoran on the Fal Estuary to the south-east.

This was the richest mining district in Cornwall during the late 18th and early 19th centuries, and was referred to by contemporary writers as the ‘richest square mile to be found anywhere on the earth’. Most of the mines of this district were shallow, none being deeper than 400 metres below adit.

Their output was remarkable - the largest producers were Poldice (108,000 tons), Great Wheal Busy (100,000 tons of copper ore and 27,000 tons of arsenic), the Consolidated Mines (442,000 tons) and the United Mines (over 350,000 tons). Others to note are Treskerby 32,000 tons of copper ore, North Treskerby (19,000 tons), Hallenbeagle (30,000 tons), Wheal Damsel (37,000 tons), Wheal Gorland (40,000 tons), Wheal Jewel (58,000 tons), Ting Tang (40,000 tons)

Alluvial tin deposited by the Carnon River had been mined from its bed during prehistory, and continued to be worked until the mi 1800's. Poldice was referred to by Hals in 1685 as ‘that unparalleled and inexhaustible tin work which for about forty years space hath employed from eight hundred to a thousand men and boys labouring for tin …’.

Copper eventually overtook tin at Gwennap in importance, once the shallow tin had been mined out. Copper had been worked at Wheal Busy from at least 1718.

Probably the most dramatic engineering achievement within the district, indeed in Cornwall as a whole during the period was the construction of what was to become the Great County Adit. Begun in 1748 by John Williams of Scorrier to drain Poldice, it was extended to include other mines and eventually reached the outskirts of Redruth and extended to a length of 38 miles.

South of St. Day, copper production here appears to have begun in about 1757 at Wheal Virgin. many mines closed in the slump of 1805. The United Mines were restarted in 1811, Consolidated Mines being reopened by John Taylor in 1819.

From 1824, the two mines were worked as a single concern under John Taylor, with Arthur Woolf as his chief engineer. From 1819-1840, nearly 300,000 tons of ore were raised and over 63 miles of development levels and shafts cut. By 1836 over a quarter of the population of Gwennap parish (8,539) worked in this one mine, Consolidated.

John Taylor was not allowed to renew his sett lease with the mineral lords. The mine was reworked as Clifford Amalgamated, but production fell and the mine was abandoned in 1870, the machinery dismantled and many of the buildings demolished. Many other mines of the district had closed not long before.

John Williams of Scorrier also constructed a horse-drawn plateway from his mines at Poldice through Scorrier to a newly-constructed harbour on the north coast at Portreath in 1819 – the first railway in Cornwall. His competitor, John Taylor, replied in 1824 by building a railway from his mines to a new harbour at Devoran on the Fal Estuary. This line – the Redruth and Chasewater Railway - was eventually extended to Wheal Buller and Redruth via Carharrack and Lanner, though was not actually completed to Chacewater. This railway and its extensive wharves at Devoran remained in use well into the 20th century; Williams’ Portreath Plateway closed when the main Gwennap mines closed .

Oddly there are no large towns in this mining area. Gwennap, St. Day, Chacewater, Lanner, Carharrack and Devoran are all just large villages. But the parish of Gwennap had a population of over 8,500 in the early 1830s. Maps indicate that the miners were also small-scale farmers as well, living in isolated cottages with sometimes a row of terraced cottages out in the countryside.

Mines and Mining in Cornwall