Wheal Jewell

Overview

A Dartmoor tin and arsenic mine on Kingsett Down worked intermittently from the late 18th century to 1924, whose old open-cast workings were built over in 1936 by the large 'S'-shaped reservoir that now supplies the Mary Tavy hydroelectric power station.

History

Wheal Jewell comprises a scattering of workings on Kingsett Down dating to the late 18th century; the mine had already been abandoned by 1797, but was reopened in 1865, then again in 1911 and finally in 1924. From 1912 it was worked as Wheal Jewell and Mary Tavy Mines Limited, consolidating operations here after work at the nearby Bennett's Lode was suspended. The site was worked across three main lodes -- north, middle and south -- with at least six identified shafts, of which No. 3 Shaft (in the south) and the North Shaft were the most productive between 1912 and 1918. Ore was raised using a compressed-air system powered by water piped downhill from the Reddaford Leat to Pelton wheels at a compressor house. Between 1913 and 1924, the combined Wheal Jewell and Mary Tavy operation produced 1,367 tons of arsenic and 288 tons of mispickel (arsenopyrite), alongside tin ore. Mining ceased around 1924, with only limited reworking in the 1930s, 40s and 50s. In July 1932 electricity installers bought the water rights from the Wheal Jewell and Mary Tavy Mining Company, and by 1936 a hydroelectric scheme required the construction of a distinctive 'S'-shaped reservoir, built directly over the mine's old gerts (open-cast workings) and destroying most of the remaining surface evidence of mining in the process. The reservoir still serves as a header tank for the Mary Tavy hydroelectric generators, which had originally drawn on a leat feeding the neighbouring Wheal Betsy and Wheal Friendship mines.

Geology

Three tin and arsenic lodes — north, middle and south — at Mary Tavy on the western edge of Dartmoor.

Workings

Three main lodes -- north, middle and south -- worked via at least six shafts, most productively No. 3 Shaft and the North Shaft (1912-18); ore-raising used a compressed-air system powered by Pelton wheels fed from the Reddaford Leat.

Closure

Abandoned by 1797, reopened in 1865, again in 1911 and finally in 1924.

What remains

Dominated today by the large 'S'-shaped Wheal Jewell Reservoir, built in 1936 directly over the mine's old open-cast workings and destroying most surviving remains; the reservoir continues to serve as a header tank for the Mary Tavy hydroelectric scheme.

Shafts, building foundations and water-management infrastructure survive around the reservoir, though most of the original open-cast workings were destroyed by the 1936 reservoir construction.

Redevelopment

The site was redeveloped from 1932 for hydroelectric power, with the 1936 reservoir still in active use as a header tank for the Mary Tavy generating station today.

Related mines

• Devon United Mine — The Devon United setts were amalgamated at times with Wheal Jewell as well as with Wheal Friendship, which is one reason the production returns for all three run together.
• Wheal Betsy — The Mary Tavy hydroelectric generators drew on a leat that had originally fed both Wheal Betsy and Wheal Friendship.
• Wheal Friendship — The Mary Tavy hydroelectric generators drew on a leat that had originally fed both Wheal Friendship and Wheal Betsy.

Recorded claims

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

• Wheal Jewell had been abandoned by 1797, then reopened in 1865, 1911 and finally 1924, before mining ceased for good around 1924 with only limited reworking in the 1930s, 40s and 50s. ¹
• Between 1913 and 1924, the combined Wheal Jewell and Mary Tavy operation produced 1,367 tons of arsenic and 288 tons of mispickel (arsenopyrite), alongside tin ore. ¹
• In July 1932 electricity installers bought the water rights from the Wheal Jewell and Mary Tavy Mining Company; by 1936 a hydroelectric scheme required a distinctive 'S'-shaped reservoir, built directly over the mine's old gerts and destroying most surviving remains. ^1,2

Photographs & further reading

Sources

1. (secondary) Wheal Jewell — Dartmoor Explorations
2. (observational) Wheal Jewell Reservoir — Treks and Tors

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