Grenville United Mine, Cornwall
Camborne: grid reference SW667389
Notable minerals: Chalcopyrite.
The mines of Wheal Grenville lie to the southeast of Camborne on the western extremity of the Great Flat Lode. On 29th December 1845 a lease was granted by the 'mineral lord' Baroness Grenville to work the area southwest of the existing Condurrow Sett. The new 'Wheal Grenville Company', run initially by Captain Lyle and Captain Thomas, took over the workings of previous ventures such as Polgine (1790-1835) and Newton Moor mines and worked for about six years before being purchased by 'John Taylor and Sons' - a company run by the local tramway entrepreneur. Further east, the mines of the South Wheal Frances sett were producing a great deal of copper ore and this helped to promote the general area to potential investors. Wheal Grenville did not however live up to its initial expectations and the new company was sold once more in 1855. The mine was bought for £2040 and the new company set about dewatering the mine and deepening the shafts. The eastern section of the land was hived off in 1859 to become East Wheal Grenville sett. The first real production taking place in 1860 with just under 250 tons of copper ore raised with about 80 tons of tinstone. A new shaft was sunk at North Shaft in 1864 but production was sluggish. Employment at Wheal Grenville at this time was about 240 people, with about a third of these being females and boys working on the surface. Other shafts were deepened especially at New Shaft and at Boundary Shaft where the sett bordered East Grenville.
Towards the end of the 1860's the shallower copper ore was being mined out and the majority of mine owners were, where possible, switching their production to tin found at deeper levels. Between 1869 and 1872 the price of tin was at a high level and this enabled Wheal Grenville to post a dividend in 1870-71. Profits were in general quite meagre as the Grenville Group of mines were quite wet mines and prone to flooding. The cost of pumping out the mines eating severely into any initial profits. In the twenty years since 1855, Wheal Grenville had not really made any significant money from its operations and so later that year (1875), Mine Captains Edwin Hoskin and Captain William Bennetts were replaced by Captain T. Hodge with R. W. Goold Esq. taking over as Chairman in 1876. The initial years of the Goold / Hodge partnership were still a struggle however with problems both financial and natural as the lower levels of the mine continued to flood in periods of heavy rain. The tin price remained depressed between 1872-77, when Wheal Grenville received only £42.551 per ton for its sales of 156 tons of black tin. The East Wheal Grenville venture proved unsuccessful and so that mine was abandoned in 1877 and reabsorbed into Wheal Grenville once more. Captain Hodge understood the need to inject some capital into the mine. It was obvious that the existing pumping engines were not powerful enough to drain the shafts effectively. Something had to be done. An 80-inch pumping engine was aquired and installed in an engine house over North Shaft. It began work on 15th February 1878 with the shaft renamed Goold's Shaft in honour of the chairman.
Despite these hardships the company perservered and explored the area to the east of their sett with miners in Goold's Shaft locating what we now know to be part of the Great Flat Lode some time around 1878. The new management team of the charismatic R.W. Goold and Capt. Hodge as Mine Captain helped to turn the fortunes of Wheal Grenville around. Their expertise and business acumen helped to persuade shareholders and potential investors to part with their money in order to renovate the mine. Captain Hodge's faith was to be repaid as the new pumping engine was more than powerful enough to completely drain the mine. In 1879, the pneumatic rock drill was introduced to the mine as well as a new compressor. These developments helped Wheal Grenville to become viable at last - thanks in no small way to Captain Hodge. Development of the mine continued into the 1880's with the mine actually showing a profit for the first time in the April of that year - £0.17! By July the profit had risen to £517. The trials and tribulations of the last five years had been worth it.
The financial state of Wheal Grenville improved enabling it to pay a dividend for the first time in 1881.The price of tin rose from under £42/ton in 1879 to over £62/ton in 1882. Although that price dropped back to £46.645/ton in 1883 production increased enabling Wheal Grenville to remain in profit. As the tin price began to rise in 1884 Wheal Grenville should of been well placed to make the most of it. In 1885 a new 21-year lease was obtained from the landowner Hon. G. M. Fortescue. 1886 was a bad year however as the winter weather and machinery failures took their toll on production and hence profits. Problems included a runaway skip that damaged the shaft, the pumping engine broke down and a breakage on the whim engine flywheel - caused damage to the structure of the winding house. Some problems were also experienced with water flooding in from King's Shaft of the abandoned South Condurrow. Despite these setbacks Wheal Grenville continued producing tin and as the price rose the company were well placed to reap the rewards. Investors shared in the good fortune receiving a total of £16,500 in dividends in 1887.
The tin price at this time was extremely volatile, fluctuating wildly between £67, £90, and back down to £71 in the space of just a few months. In mid-1889 the influential Captain Hodge died but was ably succeded by Capt. Charles F. Bishop from Wheal Uny - he helped to update Wheal Grenville and the mine operations extended eastwards. A new shaft was sunk at East Shaft and a refurbished 90-inch pumping engine, purchased from Tresavean was installed in the newly built pumping engine house. [The engine was built in about 1873 by Harveys of Hayle initially for a mine in South Wales but it was never delivered. For the next eight years it lay stored at the foundry where it was fitted with an extended beam in readiness for its installation into Tresavean Mine at Lanner. The engine moved to Fortescue's on completion of the engine house in 1892]. It ran for the first time on November 5th 1892 with the shaft renamed Fortescue's. Nearby a 28 inch rotative beam engine (whim) engine previously used at South Roskear Mine in Camborne was installed in the winding engine house again completed in 1892. Incidentally, the engine house on the skyline above is the remains of the Grenville New Stamps (using 136 heads) also built between 1889-92. The long flat concrete building in front of the stamps engine house is the remains of the frue vanner house built in 1900 to house Holman's Vanning (shaking) tables and is worth closer inspection if you are in the area (It may be overgrown in summer!). The year 1893-94 saw Wheal Grenville at its most profitable ever, with production at an all-time high. This year also saw another drop in the price of tin but Wheal Grenville survived and became a limited company. The jagged appearance of the chimmney on Fortescue's Engine house is due to damage caused during a lightning strike in July 1897 causing the chimney to be shortened. Fortecues shaft is 2370 feet (395 fathoms) deep.
In 1906 Grenville United Mines was formed out of the amalgamation of Wheal Grenville, South Condurrow and part of West Wheal Frances. The beam of the Goold's pumping engine house, weighing 25 tons, snapped in the middle in September 1906 causing quite a lot of damage and had to be replaced with a new heavier 38 ton one supplied by the engineering works of Holman's of Camborne. 1914-1918 The First World War was something of a 'double edged sword' for Grenville United - demand for metals to feed the war effort drove tin prices up but the need for troops stripped the company of about a fifth of its workforce. Fortescue's couldn't sustain its viability and closed in December 1920 with the owners formally 'winding-up' the company the following year. The engine was re-used to pump water from New Cook's Kitchen shaft at nearby South Crofty.
The Great Flat Lode is an enormous ore bearing body tilted at an angle of about 45 degrees situated to the south of Carn Brea. Normally lodes are found perpendicular to the ground surface or at best at angles of about 60 degrees. The Great Flat lode got its name as in relative terms it lay a lot flatter in the ground. This, meant that mines could be placed at the optimum locations to extract the tin or copper ore from the ground without digging to excessive depths. The Great Flat Lode Trail encompasses all the major mines of the Camborne-Redruth area running in a 7.5 mile multi-use circular trail around the granite hill of Carn Brea. Follow the hyperlinks for more information and photographs on the main sections of this excellent trail.
'World Heritage' status for this area was granted on 14th July 2006. This should help to provide the necessary funding to improve and interlink all the mineral tramway projects. The majority of the trail is off-road and suitable for walkers, horse riders and cyclists. There are even some parts accessible to wheelchair users.
There is a wealth of information on the mines and miners of Cornwall available. Why not explore Cornwall's industrial heritage through the Bookstore?
Other nearby mines and their main ores
South Condurrow (approx. 0.3 km; TIN & COPPER)
Great Condurrow (approx. 0.7 km)
South Tolcarne (approx. 1.0 km; COPPER)
Pendarves United (approx. 1.0 km; COPPER & TIN)
West Wheal Frances (approx. 1.0 km; COPPER & TIN)
Carn Camborne (approx. 1.3 km; COPPER, TIN, ZINC & ARSENIC)
Camborne Vean (approx. 1.6 km; COPPER 1845-85 & TIN 1857-84)
South Wheal Frances (approx. 1.9 km; COPPER & TIN)
Dolcoath (approx. 1.9 km; COPPER, TIN, ARSENIC & MISPICKEL)
Cook’s Kitchen (approx. 2.1 km; COPPER, TIN & ARSENIC)