With records of mining in the area going back to 1720, South Wheal Frances (SWF) has been active since about 1820. The remains on the Marriot’s shaft site date from around 1897-1900, with the original 80-inch pumping engine being destroyed in a fire in 1895. Initially a copper mine, it gradually moved over to tin from the 1850’s, especially following discovery of the Great Flat Lode in 1886.
In 1896, SWF amalgamated with its neighbours West Wheal Basset and Wheal Basset to become Basset Mines Limited, however there were a lot of continued financial issues and the mine finally closed in 1918.
One the first buildings seen on the way down from the carpark is that of the 2 cylinder compound horizontal whim. This type of engine is unusual in the South West and was intended to speed up its hoisting capabilities.
On the other side of the path are the remains of a miner’s dry, which is considerably larger than the average dry and may have included workshops and storage as well.
The star of the show is of course the main pumping engine house. This beauty was built in the 1897-1900 period and is slightly unusual in that it housed a inverted compound beam engine, one of only three or four in the world. Designed by Henry Davey of Leeds, it housed two cyclinders, one 40-inch and one 80-inch, which stood at opposite ends of the house.
The 80-inch cylinder had been rescued from the fire in the previous house, and was Cornish.
The new engine cost £7,500, which according to the National Archive’s currency converter is approximately £615,369.75 now.
Marriot’s shaft reached a final depth of 340-fathoms (2040-feet/622m), just a smidge short of their 5,000-foot goal.
There was at least one other engine on the site, for which remains no longer exists. This was originally designed as a steam whim to haul from both Marriot’s shaft and Pascoe’s, but stamping was added to its repertoire, and this is all it did in the end.
This building contained a Reidler air compressor which would have powered rock drills down in the mine. This housed a Corliss valve horizontal engine built by Frazer and Chalmers.
Inside the compressor house, with the mounting blocks for the engine still in place; the flywheel and condenser would have gone in the central pit.
Remains of the 1906 steam capstan which was used for moving heavy goods in and out the mine, including installing pumps and pump rods. In its spare time, it also ran a jaw crusher.
The ore sorter above would have originally had wooden walls around the outside. Ore would have come from the shaft in wagons and been tipped onto it; smaller rocks would have fallen to the west, while larger rocks would have gone to the east and onto the jaw crusher.
This building would have held six Lancashire boilers to provide steam for the engine. It originally held four boilers, however when one exploded the number was upped to six.
SWF operated out of a number of shafts, the most well known being Marriots (340-fathom/622m), Pascoe’s (340-fathom/622m) and Daubuz (230-fathom/421m). Other shafts included Richard’s (134-fathom/245m), Broad’s (130-fathom/138m), Pryors (120-fathom/219m) and Harvey’s (65-fathom/119m). These worked a host of different lodes, including the famous Great Flat lode; others were North, Hamley’s, Great/Basset, Fisher, William’s and an unnamed one.
The mine site has a lovely pot-holey car park that is free to use. The whole site is open to the public and has been made safe to visit and traipse around (although access inside the bars of the compressor house is not permitted).
Brown, K. and Acton, B. (2007) Exploring Cornish Mines: Volume One. 4th edn. Truro: Landfall.
Nance, D. and Brown, K. (2014) A complete guide to the engine houses of West Cornwall. Gloucestershire: Lightmoor Press.
Dines, H. G. (1956) The metalliferous mining regions of south-west England. British Geological Survey.
The National Archives (no date) ‘The National Archives – Currency converter: 1270–2017’. The National Archives. Available at: https://www.nationalarchives.gov.uk/currency-converter/#currency-result (Accessed: 13 March 2018).