#35: UNESCO World Heritage Sites – Cornwall & West Devon Mining Landscape
The Cornwall and West Devon Mining World Heritage site comprises ten separate areas, featuring the remains of tin and copper mine workings, associated industries and supporting industrial infrastructure. Mining appears to have been somewhat ad hoc until the 1700s when the introduction of gunpowder made deeper mines possible. The deeper the shafts were sunk, the more water needed to be pumped out of them and it was in rising to these engineering challenges that Cornish mining came into its own. During the 18th and early part of the 19th century, Cornwall was the world’s leading supplier of tin, copper and arsenic. The development of steam pumping engines industrialised and revolutionised Cornish mining, making it the world leader for around 200 years and driving the creation of significant infrastructure for transportation of the metals and housing of the workers as well as the operations of the mines themselves and the establishment of subsidiary industries such as foundries and smelters. The World Heritage listing reflects the fact that the area dominated world supply of tin, copper and arsenic for a significant period, making a huge contribution to the British Industrial Revolution and influencing mining around the world.
When you know what you’re looking for, the Cornish landscape is literally littered with mining remains.
I visited over Easter and had a packed four days taking in the key mining sites, landscapes and seeing the prosperity brought by the mining. I learnt about the processes of mining and the conditions of work for the miners and their families, visited the remains of the infrastructure which supported the industry and made profit from waste products, saw the impact mining architecture has had on the landscape, and watched a steam beam engine in operation.
The basic premise of tin and copper mining appears to have changed little over the years, only the equipment used to achieve it has advanced. The rock has to be cut out and crushed to release the ore it contains which then has to be separated from the rock in order to be melted down and used. Ore is lighter than rock, so methods of separation focus on this. Originally the backbreaking work of crushing the rock was done by hand, often by women, but with the advent of steam machinery stamping engines took over this task and are still used in mining today.
I was fascinating to learn that the arsenic industry grew from what was originally a waste product of tin mining. Waste rock containing arsenic pyrite was thrown out until it was realised that heating it changed the arsenic from a solid to a gas state (it being one of the few elements which doesn’t exist in a liquid state) and that passing the smoke containing the gaseous arsenic through a labyrinth of chimneys meant that arsenic crystals formed on the sides of the chimneys as the smoke cooled.
The arsenic could then be collected and used for domestic, agricultural and industrial purposes, particularly to protect American cotton from the boll weevil which was decimating crops, and therefore protecting British interests in the cotton trade (which I learned about when visiting the world heritage site of Liverpool last Easter). The remains of the arsenic works were particularly interesting to see. Another ‘spin off’ industry was the supply of lime, which like arsenic, was produced by heating the rock to extreme temperatures.
During its heyday, mining was clearly physically demanding and dangerous work, although I was interested to learn that in tin mining there are no issues with gas underground as there are with coal mining. Fatalities were more normally a result of mechanical breakdowns or physical problems due to constant inhalation of rock dust. The average life expectancy for a Cornish miner was 35 years. Surprisingly, arsenic workers could expect to live to the age of 45.
It was amazing to see the sheer number of crumbling engine houses dotting the Cornish landscape. These engines drove either water pumps to keep the mines dry, lifting engines to bring the rock and ore up out of the ground or stamps, to crush the rock. There are also counting houses
– built to demonstrate the wealth of the mine to attract investment, where the accounts were done and where the mine companies hosted lavish dinners for the ‘adventurers’ who invested and ruined transport infrastructure including canals, railways, viaducts, tramways and the specially constructed harbour at Charlestown.
It felt like a whirlwind tour, so here’s a run down of the sites I visited:
Luxulyan Valley and the Treffry Viaduct: The viaduct was built to as both an aquaduct and a horse drawn tramway.
Some of the rails of the tramway can still be seen along with the Wheelpit – the machinery which lowered and raised the trams to different levels in the valley. Also crisscrossing the valley are numerous ‘leats’ (created narrow waterways) which provided water both to power machinery, to sluice the harbour at Charlestown.
Charlestown : now a pleasant village with a dinky harbour, in its heyday Charlestown was a busy port, exporting copper and china clay and importing coal as well as supporting complementary industries such as rope making, lime burning and boatbuilding. The harbour and wet dock were constructed in the late 1700s for Charles Rashleigh, the local landowner, who wanted to benefit from the industries in the area. The leats in Luxulyan Valley fed the wet dock and also kept the harbour silt free.
Wheal Trewavas: one of the best examples of a submarine mine – where the workings extended far out under the sea bed. The engine houses for these mines, perched perilously on the edges of cliffs, are particularly iconic.
Botallack: The ruins on the cliffs in this area are especially dominant in the landscape. This area was full of submarine mines, and also developed infrastructure to support associated industries. Access shafts were dug down into the rock and the mine workings spread out from these.
Around Botallack can be seen the remains of tin dressing floors, arsenic smelters, engine houses and chimneys. The Botallack Count House has also been restored. The area is very beautiful now and it’s hard to imagine how noisy, industrial and busy it would have been during the key mining period.
Levant: Just along the coast from Botallack, Levant features a steam restored beam engine, so it was possible to see how the engines revolutionised the mining industry by enabling far greater output through access to deeper shafts, lifting material out of the mine and crushing the rock to release the ore.
Geevor: This site was a working mine until relatively recently, so here I learnt a lot of about modern mining techniques and machinery. There was also an opportunity to explore an old tin working – complete with hard hats!
Hayle: The town was a key mining port and also became home to the foundries that manufactured the steam engines for the mining industry. Originally, Cornwall had no foundries so the mines had to buy engines from elsewhere in the country but this was rectified in the early 1800s. The town was prosperous because the foundry workers were paid in tokens which could only be used in company shops. Eventually, they had to open up to competition and ‘front garden shops’ were built to supply customers – I was fascinated by these.
Gwenapp Pit: A tranquil part of the world heritage site, this is a natural amphitheatre which was used by John Wesley, the founder of Methodism, for preaching. I walked all around each circle of the pit, descending as I went, and then all the way back up again – apparently that’s a mile. The Pit is in a tiny hamlet and is literally shoehorned in amongst houses and gardens. But it was a very special and restful place. Methodism was popular among miners.
King Edward Mine: After ore extraction ceased at this site, it became a school of mining, so now features examples of historical mining equipment and more modern kit. Here we learnt more about older methods of tin dressing (separating the ore from rock using water) – and the great stone buddles I’d seen at Botallack suddenly made sense!
The Great Flat Lode: This area marks part of Cornwall which had extremely rich tin deposits. These were at a shallower angle to the surface than is normal, hence the name; a ‘lode’ being a mineral seam. There were mines and engine houses all across the lode, the ruins of which form a key part of the landscape.
The mining heritage is a side of Cornwall that I suspect most tourists won’t see and certainly won’t appreciate the prosperity it brought during its boom. Once again, the 40 before 40 has taught me something and taken me places I probably wouldn’t have gone otherwise.