Tincroft Mine, Cornwall

Tincroft Mine

Tincroft Mine was first mentioned in in the 1680s as 'Penhallick Vean & Tyn Croft'. Tincroft was worked for copper originally, but the mine changed to tin in 1865. 1896 Tincroft and Carn Brea Mines amalgamated. In their lifetime Carn Brea and Tincroft mines produced 460,000 tons of copper and 53,000 tons of tin.

1794, an extract from the Watts Letters "Murdock & Me called at Tincroft on Monday, & found the Engine working 12 Strokes p[e]r minute under a load of 15.3lb [pound] on the Small Cyl[inde]r they now leave a Continual open road for Steam to pass upon the large Cyl[inde]r, the water is increased to 10 Strokes p[e]r Minute, & they now burn 30 Bushels p[e]r day; the water is not kept in fork 1/8 of the time"

1859 A 'man engine' was installed on Dunkin's shaft, connected to a 26-inch rotative beam engine at South Tincroft Mine - Grid reference

1850-1870 As copper production fell tin production increased with advances in mining technology allowing the tin to be worked at greater depths.

1891 The compressor house was constructed at South Tincroft with a horizontal steam-driven compressor made by Harvey's of Hayle which powered the underground rock drills.

1896 Tincroft and Carn Brea Mines amalgamated - records show that in this year the mine employed 466 workers underground and 607 on the surface.

1921 South Tincroft mine closed.

"The chief lode exploited here is the Tincroft North Lode. The granite-killas junction at the surface runs E.N.E and underground the general subcrop of the granite surface dips 25° to 35° N. Several elvan dykes, traversing both granite and killas, are located in the north of the area" (Dines, 1956).
" The central part of the Tincroft North Lode was worked from South Shaft; the workings are all within killas and greenstone. The western part of the Tincroft North Lode is cut by Price’s Lode. Specimens from this lode consist of quartzose breccia with quartz grains in a fine-grained quartz-tourmaline matrix that has itself been rebrecciated and invaded by vein quartz that carries well-crystallised and zoned cassiterite. Both tin and copper ore were reported to occur to a depth of 200m, dominant lode fillings below this depth consist of finely divided chlorite with grains of cassiterite and arsenopyrite. The lode passes from
killas to granite at 210m in the east and 150m in the west. Lodes in the Tincroft area were closed early in the 20th century "(Dines, 1956).

Illogan Area Mines, Cornwall