Stainsby’s Shaft
Mendip’s Deepest Mine
Visitors walking from the Blackmoor Reserve car park at Charterhouse towards the causeway road will have noticed a large, fenced mineshaft situated beside the footpath. Named after the company’s manager and treasurer, Peter Stainsby, this was the deepest of four shafts sunk by the Mendip Hills Mining Company in the 1840s, in search of lead and silver they believed existed beneath the ‘old man’s’ workings. Dating mainly to the 17th century, these rarely exceeded 30m in depth.
The Cornishmen’s Venture
Stainsby’s main shaft was sunk using Cornish mining techniques, with platforms and winching equipment installed at stages to aid progress. Research by local caver and historian Chris Richards discovered that the Cornishmen drove two horizontal levels, the first of which was at 33m (108 ft), where large stones of lead were discovered. Optimistic reports were published to encourage investors, and most excitingly for modern cave explorers, it was stated that a ‘cavern’ had also been entered. Later reports stated that Stainsby’s Shaft reached an impressive 108m (355 ft) with a 2nd level being driven horizontally at 69m (226 ft). This level apparently broke into a continuation of the cavern previously entered.
Sadly, for the Cornishmen, results were not as productive as had been hoped. The mineral vein, at depth, did not contain any significant lead content, and for all its early promise, the deep mining venture ultimately failed.
Re-smelting and a Riot
All was not lost for the company, as it was quickly realised that the huge piles of mining waste left behind by earlier miners still contained quite a high percentage of lead, which, using more modern techniques, could be extracted at a profit. Large volumes of water were required, so wooden troughs, known as ‘launders’, were built to carry water across from the adjacent Longwood valley.
Unfortunately, the water, which was heavily contaminated with lead and arsenic, reappeared in Cheddar just a few hours later. Fish and livestock perished, and in 1848 an angry mob marched up the hill with firearms and smashed the launders to pieces. A court case followed, but as no individuals could be identified, the Hundred of Winterstoke was successfully sued instead. Stainsby’s became the preferred drainage option, and tonnes of material were eventually washed away into the shaft.
Rediscovery and the Great Flood
By the 1950s only a handful of mines and small natural caves had been explored. All that remained of Stainsby’s Shaft was a slight depression. However, in 1958, drawn by tales of miners having entered ‘huge caverns’, members of the Mendip Caving Group began digging. They found evidence of an ancient streamway, but when the swallet became too difficult, their attention switched to the depression above. In the decade that followed, a large square mineshaft around 12m deep was reopened, containing plenty of evidence of mining activity, but significant discoveries remained elusive.
That all changed following the Great Flood of 1968 when the huge volume of rushing water revealed several new cave entrances. These new swallets encouraged a spurt of activity, culminating in the discovery in 2006 of Upper Flood Swallet, a 4 km long system containing magnificent formations.
With attention understandably focused elsewhere, Stainsby’s Shaft lay largely forgotten. However, further research rekindled enthusiasm, and attempts are underway to establish a connection. The dig has now reached the 33m level where the miners stated that the first ‘cavern’ had been entered. It seems highly likely that the lost caverns must form an as-yet-undiscovered part of the Upper Flood cave system.
Surveys
Photogrammetry Survey
A modern 3D survey creating a detailed model of the shaft and passages.
Traditional Survey
A sketch survey from 1960 alongside a later sketch from 2011.
Gallery
