Dolcoath Mine was once commonly known as “The Queen of Cornish Mines”. Because it was one of the richest and deepest in Cornwall. The surviving Dolcoath Mine buildings have recently been stabilised (late 1990’s), most of my images were taken during the mid 90’s before the work was carried out.
Today 2017, it is sad that such a great mine has so little left on the surface to see. With the addition of a new road through the Wheal Harriet site. also with new houses being built below William’s shaft, there is even less now.
The sett was first worked for alluvial tin during the 1580’s when the ground was leased to the Crane family from the mineral owners the Basset family. By the 1720’s the mine was being worked for copper, during the 1740’s the workings had reached almost 300ft in depth. In the late 1780’s the mine was over 600ft deep with Copper ore production on the increase. During the years 1785-1789 over 15,000 tons of ore were produced.
Cheap copper production from Parys Mountain in Anglesey caused the mine to close during March 1790. However the Anglesey deposit was soon worked out and the copper prices rose again. In 1799 the mine reopened under Andrew Vivian, Richard Trevithick was engaged as engineer.
The early years of the project brought little profit as the lower levels of the mine had proved so difficult to drain. New engines were installed and production increased to a point where Dolcoath was the fifth largest producer in the South West.
As the mine progressed deeper the copper began to run out, in 1832 closure was once again a possibility. However the mine captain Charles Thomas was convinced that Tin would be found deeper in the workings. This proved to be correct and Dolcoath was producing Tin by the 1850’s.
The mine continued to grow and pay huge profits. By the early 1880’s she was over 2000ft deep and had over 50 miles of passage. Some of the lodes were over 30ft wide and very rich in Tin. Over 2,500ft underground was the 412 fathom level. Here the lode had been mined out and the whole structure was supported by a forest of timber.
These timbers of best pitch pine were 20″ square and over 30ft in length. Above this man made forest was over 600ft of broken waste rock. The timbers were set 2ft apart creating what was believed to be the biggest and most secure stull in Cornwall.
In September 1893 the famous 412 fathom level was the site of a disaster when part of this massive structure collapsed. It had been noted underground that several of the timbers were bending under the extreme weight above them.
Whilst 8 miners worked to strengthen the stull it suddenly gave way, thousands of tons of rock fell burying the men. The noise was tremendous and a rush of air swept through the workings. This was so strong that a man on the same level was stripped naked and a wagon was thrown a distance of 20ft.
Miners rushed to the site of the fall which had choked the level for a distance of 28 yards. It is difficult to image their feelings in the heat, danger and choking dust. After 40 hours of digging the miners were recovered. Sadly 7 men were killed, the only survivor Richard Davies who was amazingly unhurt.
In 1895 a new Limited Company was formed which replaced the old “Cost Book” system. A new 3000ft vertical shaft was proposed in the southern part of the mine. The aim was to bypass old workings and intersect known lodes.
A new shaft on the sett called Williams Shaft was started and completed during 1912. The shaft is 17ft in diameter and is 3300ft deep, consequently making it the deepest in Cornwall.
The shaft is vertical to 3000ft where it meets the Dolcoath Main Lode. At the bottom is a chamber which contained a battery of electric pumps. The winding arrangement here was unique, the winder could not be placed far enough from the shaft because it would cross a nearby road.
Consequently a winding engine made by Holman Brothers was installed. This was mounted on rails and could literally move along the walls of the house. This enabled the winder driver to keep a straight approach to the headgear over the shaft. As a result the maximum the engine moved was 16ft.
Also at this time the mine was re-equipped with new suface machinery including 40 heads of Californian stamps along with new winding engines.
Sadly the reserves the owners had hoped for were never found. By 1920 the mine had all but been worked out. That and the collapse in the Tin price brought closure.
When the mine closed there was almost 70 miles of underground passage, which now lie flooded and silent. The production is thought to have been 350,000 tons Copper and 80,000 tons of Tin.
The next few general images were taken around the site. Almost all were taken in the early 1990’s the area is now heavily overgrown. A sad ending to such a great mine.
An attempted re-opening on the northern section of the mine occurred during 1923, a new shaft was sunk at Roskear to 2000ft. Sadly the attempt failed, but had the shaft been further deepened they would have intersected the South Crofty Roskear lodes. If this had happened things might have been very different, the irony of Cornish Mining.