Pit Top Passage, Speedwell - Phil Wolstenholme

Wednesday, 9 December, 2015

Present: Wayne Sheldon, Jess Stirrups, Clive Westlake, Phil Wolstenholme

This trip was a confluence of several members' requirements happily coinciding, and with mine, a deadline looming. Clive wanted to dive the Bottomless Pit lake, Wayne wanted to survey Pit Top Passage and the accessible sections of the main chamber, and I also needed to photograph Pit Top Passage properly for the book, the previous shots being merely 'OK'. Wayne and I had taken time off work, so it had to be 'the day'. As it was a Wednesday, Jess had said that she was free to help as a model, so we had a trip. When we arrived, Clive decided that the water at Peak was too murky, so decided to help Wayne survey instead, and we all got in the first (empty) boat. Climbing up didn't take long, and we all settled into our jobs, only getting stuck at the graffiti, where we all needed to do the same bit! Once we'd crossed over it was easy work, as the passage is fairly clean and easy - all phreatic solution passage along the vein, which is just visible in the roof. Halfway along the passage, on the steepest slope, are masses of smashed calcite, presumably from miners trimming their ore. This is the spot where I found the five brass waistcoat buttons on a wall of deads last year. At the far end, about 50m along, the roof lowers to a proper tube, and the miners have enlarged it slightly, as a few shotholes are present.

The end of the passage is a low arch in the vein, probably higher in mining times, and with a comprehensive vertical choke of rocks and vein material jammed in the roof and wall a metre or so beyond, with water permanently dripping through it, and which always sinks immediately in the floor. This is generally thought of as a choked shaft, but it almost certainly continues as a horizontal passage too. As this is nearly 60m from the Bottomless Pit platform, it's halfway to Pilkington's Series horizontally, though vertically would only reach as high as the inner end of Pilkington's Passage. There is some debate at present as to whether the Bottomless Pit is even formed on Faucet Rake at all, as the cavern is some 40m south of the surface expression of the vein, unlike Watricle Cavern in Pilkington's, the high pitches at the end of the Assault Course, and the end of Whirlpool Passage, which all match the surface almost exactly. Either the chamber is formed on Clarke's Scrin instead, or there is a massive hade to the south on Faucet Rake, between the surface and the canal - possible, but 40m is a pretty large deflection!

We got some very good photos of the breakdown at the entrance to the passage, overlooking the visitor platform, and a great panorama of the vein and stemples from below too - a very good session. Clive and Wayne were down by the lake surveying, including the small fissure opening on the north side, and Clive decided that the water had been clear enough to dive after all, so maybe a return visit will have to be done sometime soon.

Thanks to Jess for the help, and the book content is now almost done.

Pit Top Passage
Breakdown at the mouth of the passage above the Bottomless Pit