Had a dig through my old PDMHS newsletters and turned this up from short notes no.12:
Edge Rake Sough, Tideswell, Derbyshire SK1442 7662
This sough, enterable via an air shaft with fixed ladder which is about 7.5m deep, has been driven following a thin bed of rotted toadstone (or possibly a clay wayboard). At the base of the shaft it is about 1m thick and its removal has given the sough a flat limestone roof with no sign of a vein. From the base of the shaft, which was entered by the Orpheus Caving Club in 1960 after digging out and repairing the shaft, the passage heading towards the tail is silted but it is possible to crawl along this at least as far as a further air shaft, now capped at surface, about half way to the tail. Progress in the other direction, towards the eastern end of Edge Rake, is easier as the silt here has been removed by Derek Stables. The clay bed rapidly decreases in thickness until it is less than 10cm and the sough is driven through limestone below, while the flat limestone bed immediately above the clay forms the roof. The passage is somewhat sinuous and there are shotholes of 18th/19th century type. The accessible passage ends at a point where its upper part stops abruptly at what is best described as a ‘forefield’. However, at floor level there is a small flooded hole continuing horizontally, now silted and too small to enter. Whether the sough intersected a pre-existing working, or a natural passage as Derek Staples has suggested (Eldon Potholing Club Journal, no. 5, pp 29-31), could not be assessed. It is estimated that the ‘forefield’ is about 75m from the tail.
Present: John Barnatt, Paul Chandler and other PDMHS members.
Follow the horses, Johnny my laddie, follow the horses canny lad-oh!