The Mystery of Wheal Trewavas Mine

Wheal Trewavas

Precariously perched on towering cliffs Wheal Trewavas Mine is a special place to visit. These huge engine houses are just as impressive as the world-famous Crown Mines at Botallack on Cornwall’s North Coast. And, just like the Crown Mines, Wheal Trewavas was once famous for it’s temeritous tunnels that stretching out from the coast beneath the seabed. But this mine is definitely not on the tourist trail, and as a consequence you are likely to have the place all to yourself.

The history of Wheal Trewavas is a short and profitable one but how the mine came to suddenly close when it was still producing large quantities of precious ore is one of the enduring mysteries of Cornish mining history.

Trewavas mine

Dramatic Scenery

Even in Cornwall there are few stretches of coast which offer the stunning scenery and the dramatic industrial archaeology that the cliffs near Rinsey Head do. The obvious comparison is the Penwith coast around Levant Mine and Botallack but Trewavas is completely untouched by tourism.

Wheal Trewavas

The views from the coastal path are just epic and spans most of Mount’s Bay as far as Lizard point. Close by is the hidden gem of Porthcew, a gorgeous sandy beach accessed via a steep windy path from the cliff top and you will also pass the impressive rock stack known locally as Camel Rock (although I think it looks like a skull with a cap on when approached from the Porthleven direction).

The construction of the two engine houses themselves is a staggering feat of engineering. From certain angles it is interesting to note, that because of the steep gradient of the cliffs that they cling to, the buildings are exceptionally tall on their seaward side. They were also constructed from stone that was quarried from the hills just above the mine, you can still see the scar in the earth to this day.

Amphibious Creatures

The story of Wheal Trewavas begins in about 1834. That year the Mining Journal reported that profitable lodes had been discovered there “by some of those amphibious creatures who obtain their livelihoods by fishing in the summer and mining in the winter”. Work began slowly with a small pumping engine and a whim powered by horses to haul the ore to the surface.

Wheal Trewavas

By 1836 the discovery of a large seam of copper meant that more men were employed and a new larger pumping engine was purchased from Harvey & Co of Hayle. The shafts began to stretch ever deeper and ever further out to sea.

“During the last few days there has been a large copper lode discovered, which from its appearance will yield great quantities of copper in depth – there is an adit bringing up from the cliff which will cut this and many other large and promising lodes from thirty to forty fathoms under the surface.”

Royal Cornwall Gazette, 11th November 1836

Beneath an Angry Sea

Wheal Trewavas continued to grow throughout the 1840s. Although no official plan of the mine and its shafts and tunnels has survived we know that it worked four copper lodes and one tin, all of which ran out under the sea bed. Those lodes were called the Trewavas Old Lode, North Lode, Sowan Lode and Nimble Cutter Lode. At its height of its industry the mine was employing around 160 men below the surface as well as around 40 bal-maidens working above, all from the surrounding area.

Wheal Trewavas

By 1842 the mine was making annual profits of £4000 per year. At this time it was recorded as being around 70 fathoms deep, which is around 130 meters. What a strange and frightening world it must have been for the men working in those tunnels, to be not only so far underground but under the sea as well! An article written after the mine’s closure goes some way towards describing the conditions:

“When the mine [Trewavas] was worked men drove tunnels out under the sea in search of copper ore and whilst at work they could hear the big rocks washing about a few feet above their heads by the angry sea!”

The Cornishman, 15th July, 1880
  • Wheal Trewavas
  • Wheal Trewavas
  • Wheal Trewavas

There were occasional rumours of flooding over the years, which were denied by the Captains and, as is so typical of this dangerous occupation, a number of fatal accidents, including the death of sixteen year old Henry Richards who fell down one of the shafts to his death. In December 1842 a boiler exploded and the following year a miner called Richard Gilbert was brought before the courts accused of stealing a large quantity of ore. But none of these accidents or incidents was the cause of the closure of Wheal Trewavas.

Suspicious Closure

There are a number of rumours and local legends as to why Wheal Trewavas closed suddenly in 1846, but it was almost certainly not due to a lack of profitable ore. Between 1834 and 1846 the mine was said to have brought up 17,500 tons of copper ore valued at just over £100,000 which works out as around £6 million in today’s money. And it is said that there is still plenty more precious metal down there.

So what could have caused the owners to suddenly advertise the whole concern, all its kit and caboodle, for sale in the newspapers in May 1846? Some say despite all the profits that the mine company’s financial affairs had begun to raise suspicion in 1845. It was rumoured that they were paying their shareholder’s dividends with an overdraft from the bank. The December before Trewavas closed another diagonal shaft was sunk to a depth of 96 fathoms (175m), presumably following another lode. But for some reason the mine’s bankers were nervous and demanded that at least £2000 of the overdraft be repaid immediately. It seems as if the owners didn’t have that money; or did they . . .?

Wheal Trewavas

Another often repeated story is that the mine was suddenly flooded in a rather dramatic and poorly timed fashion. Each year the mine Captains would hold a celebratory dinner for the mine’s shareholders. But this was not an ordinary meal. The food would be set out on long table deep inside the mine, far out underneath the sea. According to local gossip some recent excavations had taken the workings very close to the level of the sea floor and when the final checks were being made to the decorations for the party water was noticed leaking from the roof of the tunnel. The waiters beat a hasty retreat and within minutes the water had broken in. The mine was breached and, with no little exaggeration, the dinner was ruined!

Dispute with the Duchy?

This is not the end of the story however, there is one more reason that has been suggested as the cause of the closure of Wheal Trewavas, while it was still producing so much valuable ore. It is thought that the owners may have owed money to the Duchy. You see, the Duchy of Cornwall owns the seabed around the coast of Cornwall and it is thought that they may have made a claim for dues owned on any ore being mined at Trewavas beyond the shoreline. That was certainly what appears to have been reported in 1859 when there was talk of reopening a number of mines in the area.

” . . . the celebrated Trewavas Mine which is said to have been abandoned in consequence of a dispute between the Lord and the Duchy, although it is well known that the lodes were rich at the time of stopping.”

Royal Cornwall Gazette, 9th December 1859
Wheal Trewavas

It was suggested that the mine was deliberately flooded by Captains N and J Vivian in order to avoid paying the Duchy of Cornwall their backdated dues by concealing any evidence of the extent of the tunnels. This may also be why no plan of the mine survives either.

Whatever the case advertisements appeared in the local newspapers in May, June and August 1846 informing the public of auctions for all the mining machinery and fittings.

Final Thoughts

Wheal Trewavas is part of the Cornish Mining World Heritage Site and is also looked after by the National Trust. The easiest way to reach it is to walk from the Rinsey Head carpark, which will also take you past the impressive remains of Wheal Prosper. I have also attached a link to a longer circular walk from Porthleven below. As with all old mine workings in Cornwall please be very cautious when visiting and keep dogs and children close.

Walking Opportunities

Circular Walk Porthleven to Rinsey Head

Further Reading

DROSKYN POINT PREHISTORIC GALLERIES – CORNWALL’S OLDEST MINE

SOME CORNISH MINING HISTORY – THE GROUND BENEATH OUR FEET

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7 thoughts on “The Mystery of Wheal Trewavas Mine

  1. On this occasion I hope many read your posting but decline to visit. As you say it is remarkably quiet. You may also think about linking your article with the reintroduction of the Chough. There have been many sightings of the Chough as well as Kittiwakes and Peregrine falcons here making it a place to visit and sit quietly.

    1. I know what you mean, its always a difficult question for me when I am writing about places I love. I do avoid posting about chough sightings though the conservation groups prefer that their nest sites aren’t advertised.

  2. Many thanks for the tour! One branch of my family (Tregaskis) came from the Truro area – and your terrific photos give me a great idea of views they must have had!

  3. Thanks fascinating post. I’ve never been to the Rinsey area although I at one time lived just up the road at Rosudgeon, but I certainly will visit the place in the near future!
    The idea of a mine stretching out under the sea is pretty daunting, what must it have been like to work thewre! Worse than tunneling out under the sea would have been the Wherry mine in Penzance where the miners had to walk on a gantry for some 200 yards out from the shore before descending into the workings…

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