ISSN 1756-2988 (Print) ISSN 1756-2996 (Online) Third Series S Newsle Number 9 BS tte U r Charterhouse Extension Mendip Cave Rescue Workshop WW II Archaeology Around the Hut Summer 2008 UBSS Newsletter Third Series Number 9 The Charterhouse Cave Extension The Charterhouse extension looking downstream from the Blades (the stream is flowing under the floor of the passage). Photo: Pete Hann The UBSS team working in Great we sub-contracted the dig to our Graham (another of the 80s Swallet have missed the big prize club mate Pete Hann and set our diggers) undertaking cementing and, now that Charterhouse Cave sights elsewhere on Mendip. Pete trips each fortnight. I was happy to has gone, Bat Dig in GB certainly had dug with Willie Stanton and he give moral support from my does deserve the accolade “Best copied the methods Willie employed armchair. Then in April, with Ali potential in Mendips”, though that at Reservoir Hole. Cement complaining that the team were potential has been rather diminished. everything in sight, remove the having trouble finding enough But it is not all doom and gloop, the boulders blocking the way, move ballast in the splash pools through Society did have a representative forward, cement everything in sight, the cave for the concrete, I foolishly embedded in the successful team of remove the boulders blocking the suggested that instead of wasting Wessex Cave Club diggers at way, move forward and repeat again, an hour or so each trip sieving grit, Charterhouse. What follows is my again and again. It is very effective they bring gravel in from the surface. short summary of the discoveries. but also very slow and tedious. The From then on I become the fairly first assault ran out of steam at the regular fourth member of the team, A brief introduction is perhaps in end of the 1980s after over eighty co-opted to act as a sherpa, helping order. Alison and I were trips. Digging continued sporadically to carry loads to the workface. instrumental in the somewhat for a few years longer with the final Fortunately, after delivering my controversial discovery of cementing session in 1997. burden, with only three people able Charterhouse Cave in 1982. At the Whenever Ali and I discussed to work at the end, unless my time we had little experience in potential dig sites the question of services were required as first tackling boulder ruckles so when we Charterhouse was always raised in reserve, I was usually able to slope found at the end of the cave, the the conversation. Not only was it off back to the surface and the massive collapse beyond the Grotto ‘unfinished business’ but with over sunshine. The new campaign finally of the Singing Stal, was not going to one hundred and sixty metres’ succeeded on the twenty eighth yield to a few furgles of a crowbar depth potential to Cheddar, in an digging trip on 16 February 2008, area of proven cave development, it thirty metres into the choke and really did warrant another go. A twenty metres below Singing Stal Cover Picture: couple of trips were done in 2003 (an average rate of progress from Unnamed Cave, Loser Plateau, Austria with Tony Boycott to pop boulders at 1982 of less than twenty five 2007 Expedition the end but it was not until January centimetres per trip). Another Photo: Andrew Atkinson 2007 that a concerted attack began useless statistic I probably will not again with Ali, Pete Hann and Nigel be thanked for mentioning was that 1 UBSS Newsletter Third Series Number 9 the combined ages of the four of us himself over. was now over two hundred years. When we came out of the Narrows to Description reach the pitch head and saw the The cemented section of the boulder big passage below choke consists of a series of vertical we each thought steps with a final constructed pot of Wow! Below the six metres. The line of attack pitch you climb followed the solid left hand wall. down over Gaps in the choke ahead and off to flowstone coated the right were commonly boulders and encountered but the diggers resisted encounter another their lure and stayed with the wall streamway - GB. heading down into the draught. At This was proved the point of breakthrough the left by a fluorescein wall undercuts and a small stally test in March, the area is entered with the streamway Charterhouse stream, last seen turning bright sinking before the Grotto of the green some thirty Singing Stal, encountered again. five minutes after The stream disappears down beside the dye was the wall but boulders prevent it poured into GB at being followed. Instead, it is the bottom of necessary to move out into the heart Main Passage. of the ruckle, which is now very With Charterhouse open and near vertical in nature. heading straight The way zigzags down and in one for the GB Great particularly dangerous area one has Chamber area we to squeeze through a false floor of were expecting to jammed boulders. The ruckle – Chill have to confront Out Choke - finally ends twenty another boulder metres vertically below the choke but we breakthrough point where a steep have gone below boulder slope leads down into solid and skirted to the passage. Near the base of the rubble east of it. From Looking downstream from the Frozen Cascade (just visible slope are two huge blocks with the Confluence, on the left). curtain draperies horizontal to their after a short Photo: Pete Hann formation. Goodness knows when crawling and they fell or from where they came. crouching section, downstream section of streamway. All credit to continues in fine fashion for most of Andy Farrant for his sketch in the The passage continues as a large rift its length around two metres wide December 1998 Newsletter some five metres high, dropping and averaging 2-3 metres in height. postulating what we diggers might steadily downwards. Aragonite There are many formations; at one find. My only beef is to query where boulders litter the floor. At one point point a pair of stalagmites shaped are those vadose inlets from Bertie’s where the roof lowers all the like twisted broadsword blades have Pot he predicted joining the stalagmites have broken ends - we grown down to almost touch the streamway?! As with GB there has think from boulder strikes during stream. There are several small been a lot of glacial infilling with some mega flood surge. Some down steps, though generally the subsequent re-erosion. In many eighty metres from the choke the gradient is shallow. Some one parts of the extension there are old passage reduces dramatically in size hundred and sixty metres from the cobble banks calcited high up the and becomes a rift very similar to Confluence the passage lowers and passage walls and in the roof. Also Reynolds at the bottom of Longwood further on the stream flows off into you find cobbles and stones jammed August. A couple of metres in height, a tiny crack. However a silt bank to between stalagmites a metre or so it is only negotiable at floor level and the side, which we had to dig above stream level. We hope water has three pinch points, although through, enters a large flood bypass levels this high only occur during nothing is as tight as the gate and the streamway is soon rejoined. exceptional 1968 type floods. squeeze in the entrance series. The Unfortunately only forty metres Narrows is thirty metres long; at the from the silt bank the roof lowers Fifty metres before the dug silt far end a fossil passage – the again, this time to a sump. At about choke there is a fine calcite cascade original stream route - can be 75m OD, the cave currently is a four metres wide and four metres followed back overhead for about smidgen less than six hundred foot high on the eastern side of the ten metres to a wall of calcited deep. streamway (away from GB). At the cobbles. The way on is then down a top there is a letterbox passage with nice little six metre pitch. On the From the breakthrough the a flowstone floor which comes up first exploration I had to return to passages head south and then from almost to meet the roof. Ali the ruckle to collect a ladder, while around the Blades the way turns managed to force her way through Ali had to restrain Pete Hann, south-east, jigs back south, and on a trip on 15th March and found infected with a bad case of then heads purposeful off south-east on the far side that the passage exploration fever, from throwing again along an amazingly straight changed from bedding to rift. With 2 UBSS Newsletter Third Series Number 9 many large sandstone cobbles on the sump today, 3 May, but was Interestingly, in the streamway the floor it had all the signs of being unable to find a continuation below there is a formation which a major fossil passage. Pete H and because everything appears to have appears to have been recently myself, being of less petite frame become blocked by ancient stal. washed with a muddy in-flow, which were unable to follow. However Ali, we speculated might have been being a lady, did not investigate Future potential from Ben Morley’s pumping work at further. Invited to the MCG Dinner Bat Dig. The survey now shows this the following weekend we The possibility of pushing upstream to be highly unlikely so what the speculated about the possibility of from the Confluence and connecting source of the muddy water might an unexplored inlet with over five to GB appears remote.