Ten years in the dark

Chapter 5 of 13

Caverns measureless to man

Adam Whitehead, Huw Groucutt and Tarquin in Old Illtydian's chamber, Ogof Draenen. Flash by Huw Groucutt, Tarquin and Adam Whitehead, camera by Ian Wilton-Jones, setup by Tarquin and Ian Wilton-Jones.

This is the dream of every cave digger, to find a cave so big that even using the most modern and sophisticated techniques, it would be impossible to measure it. Of course, this could never happen, as even the largest known cavern in the world - Sarawak Chamber - has been measured. Still, cavers live to dream. In reality, most new cave exploration in Britain is in small passages, and often in very short sections. It has to be said though, there is very little that can compare with the knowledge that you are the first person to ever see this piece of cave. An ancient stream flowed through this passage, maybe a hundred thousand years ago, creating these beautiful sculpted shapes in preparation for this one moment. For you. Never before has a light shone on that rock, and the sound of your footsteps is the first human sound that has ever broken the silence of these majestic caverns.

I had always dreaded the thought of finding new passages, there are usually so many junctions, you never know which ones are the important ones, and you never know if you have just walked past the important passage and dismissed it as being not worthwhile. My uncle had been one of the first explorers of Ogof Ffynnon Ddu. That would have been a nightmare. Thousands of junctions. You would be almost certain to miss the important passage and then you would have to go back again and again until you had explored every bit just to make sure you didn't miss the important bits. I had really missed the point. All the things I didn't like the thought of were the very things that make it so exciting and worthwhile.

Cave digging usually falls into two categories. The most easy is where silt has been washed into the passage and filled it to the roof, or sometimes leaving a small gap. Digging here would simply mean removal of the silt. The second, and often more difficult form of digging is through chokes. These occur where the roof of the passage has collapsed over thousands of years, and the rubble that has fallen has blocked the passage. Digging through chokes often requires tunnelling through gaps between the rocks and boulders, sometimes using scaffolding to hold the rocks up and stop them from falling further. Even now, new chokes are forming and occasionally chokes slip and re-block the passage.

In my first few years of caving, I was lucky enough to meet Bill Gascoigne, geologist, hydrologist, and a very patient cave digger. It was mostly through Bill's ten years of hard work that Ogof Carno had finally been found. Carno Adit itself is a masterpiece of engineering; a tunnel was driven for over 3 kilometres into the Llangynidr mountain, in attempt to tap into a large water source. The project was finally abandoned when the shale band that the end of the tunnel ran through became too unstable to maintain. This was a major oversight on the part of the geologist involved, and near the end of the tunnel, he had the engineers make futile attempts to dig around it.

The first two kilometres of the adit are perfectly straight, at which point the tunnel turns sharply to the left and then runs in a straight line to its end. Standing at this corner, daylight can be seen as a speck in the distance, where it streams through the entrance. For the first kilometre, the two metre high and over one metre wide tunnel is lined with bricks to prevent the walls from collapsing. Several times throughout the rest of its length, the tunnel breaks into both open and silt filled passages. Some of these were originally covered in cement to prevent water leaking into them. Many of the silt filled passages were dug out by Bill, but these invariably led nowhere.

One passage that did finally 'go' was later to become known as Suicide. The dig here began where bricks had been used to line what would normally have been an un-bricked section. Suspicious, Bill dug out the filler rubble that lay between the bricks and the solid wall. A large, rubble filled shaft was entered beside the main tunnel, where the tunnel diggers had dug down to find out if they would intersect the local water table. About ten metres down they had intersected a cave passage, but had continued downwards, stopping several metres below. Taking many years, Bill removed all of the rubble in the shaft, finally reaching the bottom. The cave passage may be as much as 100 metres long in one direction, but boulders had fallen in the other, blocking the way on. This boulder choke was very loose, and just 'tickling' the boulders with a crowbar would cause boulders to fall in an unseen chamber beyond for several seconds.

In order to remove the boulders, Bill resorted to using explosives. Several cavers used to be licensed to use a low power explosive known to cavers as bang, sticks or chemical persuasion. More recently, Hilti-Caps have become popular. These are similar to blanks - a charge without a bullet - used in handguns. These are drilled into the rock and set off, cracking the rock where they were. With Bill's approach, the charge was placed in the choke and, while standing out of the way, Bill set it off. He could not have foreseen what happened. The choke shot passed him, emptying the chamber where it had been and filled the bottom of the shaft, up to the level of the passage. Suicide was abandoned as it had become too dangerous.

Later, Bill managed to find a hole in the floor of an aven (a pitch going upwards) that the tunnel had intersected and, over several trips, chemically persuaded a narrow passage to enlarge, allowing access to the main Ogof Carno.

It was with Bill that we started digging in Carno Adit. Our first dig was in an area like that where he had found Suicide. Spurious was dug over a couple of trips, but it seemed that this bricked section had no real reason for being there. Maybe the engineers were worried about the stability of the adit. Our second attempt also looked futile; exactly on the corner in the adit, a silt filled alcove could be seen in the roof. We leant some railway sleepers against the wall and used them as a step ladder, allowing us to scrape the silt out of the alcove. The alcove became bigger than we had expected, and soon, the pile of silt we were making was making it easier to reach the alcove. The problem was that the roof of the alcove was getting further and further up. Just over a metre up, the roof became solid except at one end of the alcove, where a circular hole appeared to rise vertically. This, we quickly realised, was an aven.

This dig, named Beyond Spurious, became the target of many digging trips. In the space of about half a year, about twenty trips removed several tons of silt. The aven levelled off about three metres up, and a silt filled passage headed back along the adit. Slightly offset, the aven continued through a small hole. The hole was forcibly enlarged with a crowbar to enter the continuation. Excavation here showed the crawling sized passage we were in headed in both directions. Digging back along the adit, this eventually joined the lower passage, which had been dug separately. Continuing past the connection, a few metres further on, we gave up. Metal bars pushed into the mud ahead passed over a metre without breaking into open space. We knew that in order to find open passage, we would have to go upwards, above the level of the silt.

Digging in the other direction led to what we really did not want to find. The passage closed completely, rounding off without even a narrow crack left behind. Attempting to explain how the passage formed, we hit on the idea that maybe the water had welled up through the floor. We had found solid walls and roof but had not found a solid floor. Scraping all of the mud out that we could, we noticed a low passage hidden under the left wall. Several trips later, this had been passed into a human sized passage, without a solid roof, and we began to dig upwards. This was very tiring on the arms so we developed an 'interesting' digging technique. Using a normal garden spade, we lay on our backs, pushing the spade into the mud with our feet. The problem came when the lump of mud detached itself, falling in the most painful place possible. After several trips, Cabbage Balls At The Foot Of An Aven was abandoned, as it had risen to about two metres high and the metal bars still did not break surface after a further metre.

So we moved to another project. Bill had been walking along a new forestry track above the Nant Maelor valley, a tributary of the Afon Lwyd, south of Blaenavon. In a small cliff, he noticed two cave entrances, one fairly large and one very small. The small entrance gave about two metres of passage before becoming far too tight, but the other entrance was the start of a relatively large circular passage, about five metres long and one metre in diameter, becoming about two metres in diameter in the middle. At the end, mud filled the passage and was clearly a run-in directly from the surface. Not much cave but it had some promise.

The problem was that the mud run-in would prevent any progress in that direction. In the floor, Bill noticed two holes, covered by large rocks. The rocks in the second hole looked more difficult to remove but the hole was larger than the other. After attempting to remove the rocks, we could see passages leading off from the bottom. The problem we had was that one of the rocks was too firmly wedged in the hole. Now, I would probably crack the rock with Hilti-Caps, but they were not available at that time. With permission from the local authorities, Bill set up two sticks to blast the rock into little pieces. The detonator was set and the wires trailed outside where we all stood clear of the entrance, bracing ourselves for the small shock waves that the blast would produce.

'Ready? ... Three, two, one, firing!'. Nothing happened. I will now take this moment to describe the area. Below us, trees covered much of the view, but on the opposite side of the Maelor valley, we could see the mountains continuing. To our left, we could see across the Lwyd valley to the mountains that lined its other side. Below, the Nant Maelor flowed into a small, unused reservoir, where locals were swimming, frequent playful screaming breaking the silence of the forest. A better battery now on the wire, we tried again. 'Ready? ... Three, two, one, firing!'.

I have heard bang explosions underground before. Normally, the length of passage dulls the sound and all you hear is a dull thud, accompanied by a small but sudden shake of the rock. This was different. This was like firing a large cannon. The shape and short length of the passage helped to amplify the sound, sending it roaring across the hillsides. A few seconds later, we heard it echo back from across the Maelor valley. Whoops of amazement were emitted by all cavers present, and a silence from the reservoir below. There was no more playful screaming. Almost twenty seconds later, a roar echoed back from the mountains on the other side of the Lwyd valley, rolling like a thunder clap.

The rock was almost completely intact, most of the blast wasted on the sound and a small amount of mud that we had not realised was there. Resorting to older techniques, we wrestled with the boulder, trying various methods of attaching slings to it and hauling it from all directions. Eventually, the rock was removed and the hole was opened, where it dropped into a small junction. Heading under the passage in the direction of the other entrance was a descending rift which was deemed too tight - by Phil Jane - while one on the other direction was deemed far too tight by all present. A third passage was large enough to follow and turned right, paralleling the second passage. This quickly became choked with rocks. Ogof Pen Maelor was giving away secrets but only slowly.

With all of us now lying in The Rat Run, the third passage, Bill began to dig upwards into a small enlargement. Once through he started muttering something about a chamber, ten people, and biggest yet. None of us believed him, having sat in such small passages for such a long time. Finally convinced, we all entered the chamber, which was as big as Bill had suggested. To the left, a rift passage - tall and narrow - leaning sideways, led for about five metres, where several branches all became too tight. To the right, three passages down a small drop all ended quickly. Later, my dad and brother found a small passage ahead-left, which ended after a few metres.

After several futile attempts to expand the cave, I gave up digging here, leaving just my brother and dad to dig in there. Many trips later, my brother entered the first of the original passages. Phil, it seems, had a larger body than the rest of us and had not realised the potential of the passage, or how easy it would be to enter it. At the bottom of the slope was a chamber almost as big as the other. Four passages led off, each choking fairly quickly. One of these had a vocal connection with the other entrance. The rocks and walls of part of the chamber were covered with botryoids, tiny toadstool like stal formations, each a drip of calcite, held on by a hair-thin calcite crystal. Crystal Mushroom was never extended.

Another passage was found in the first chamber, opposite the way in. This led into a rock filled chamber, which was emptied by poking the boulders with a pole and ducking out of the way as they fell. My dad and brother developed a 'buddy-buddy' system where each would help the other by pulling them out of the way when they twitched. Not exactly safe, but it worked without any injuries at all. The rocks they cleared were stacked in the first chamber, burying the hole into the short passage.

When I was asked back to help survey the cave, at the end of the leaning rift, I poked my head up through a hole in the roof and found about three metres of extremely low passage that we had all somehow managed to miss, Squashed Banana. I could feel a slight draught here. Caves respond to changes in barometric pressure outside, 'breathing' in or out to equalise the pressure. For this reason, a draught will usually mean that there is more passage ahead, large enough for the 'breathing' to be noticeable. In this case, it meant that if I were to dig ahead, I would create another entrance.

Back at the first junction we had found, I decided to also look at the second passage. Now more confident in my own caving, I pushed through into a wider section where I could easily turn around in. Ahead a passage sloped up and filled with mud. To the left, a too tight hole entered The Rat Run. All leads now pushed, I turned around to leave this passage. Somehow, the tight section seemed to have shrunk, and I required the assistance of all present to lever me out through the squeeze. Well, at least I never had to go in there again. And I had found about eight metres of passage, taking the cave to just over 80 metres long.

Just a few months before this, my dad and I had been invited by some members of Morgannwg Caving Club to dig in a small cave that they had been digging for three years. The first reports were that the cave had been found by Cwmbran Caving Club and ignored and that Brynmawr Caving Club had dug it to about five metres in length. The extensions since then were significant. We slid down a very steep hillside to the entrance trying not to loose control. On a later date, a caver was to break their ankle doing just that and a new, safe path was created. Beyond the Brynmawr Caving Club limit, Morgannwg had dug down through a choke, following a draught. The choke had been shored well with scaffolding and at the bottom, a crawl entered a bedding - a wide, low passage. At the end, an upper passage led into a second choke, while a lower passage contained a stream that also entered the choke. A hole down between a solid wall and large rocks entered a chamber, although the hole down poured water all over any passing caver.

The chamber was low and my dad and I started digging to the left. To the right, a drop down entered a passage that could be followed back under the climb for a short distance. In the other direction, the choke was impassable, but in the floor, a scaffolded shaft dropped almost eight metres and was the most promising. The water fell down this and there were signs that the bottom was the way on. A good draught could be felt, but the bottom was loose and needed to be left to settle before digging there could continue. Needless to say, we did not proceed far.

Just a few weeks later we heard the reports. The shaft had been passed less than half a metre from its previous limit. The cave had gone, and it had gone big. The story of Ogof Draenen is one of the greatest fables in the history of South Wales' caving. This cave surpassed all expectations, and confirmed the beliefs of hundreds of cavers that there was a master cave draining the mountains of The Blorenge, Gilwern Hill, and the pass of Pwll Du. Within a month, there was one metre of cave for every caver in Britain, over 20'000, and the cave was still going.

This was the mystery cave that I had been searching for on that trip into Ogof Ddwy Sir. It passes fully from the north end of Gilwern Hill to beneath Blaenavon, five kilometres away. One tantalising prospect is still the borehole. Passages have been found on three sides of the borehole, but as yet, the passage it intersected has not been entered. My first trip into here was shortly after the breakthrough, although even by then, the cave was nearly twenty kilometres in length.

Phil Jane led myself, my brother and my dad along the bypass that had been found to the Darling Rifts, an awkward traverse that had already claimed the ribs of two tired cavers. Spare Rib was easy. Eventually, we reached a rope climb down. On a later trip here, my dad and I watched a female caver having problems on this climb, not really having had enough experience to be in this very awkward cave. My dad asked her if she was climbing up or falling down and with an irate look, she proceeded to try just that. Her feet apart, she hung upside down with one foot on each wall and her hands on the rope. 'Oh Fleep' she said calmly. Her two companions, realising that they should not have brought her into the cave quickly helped her up and left.

Beyond the rope climb lay Cairn Junction. This was the first major passage in the cave. To the right, Beyond A Choke led off but we headed left. We passed under the Big Bang Pitch, the original way in via the Darling Rifts, and headed up the choke leading into Upstream Passage. The choke here had been passed only a few times and we were to quickly learn that less cavers means less stability. Walking up the choke, I dislodged a large boulder which spun on its small pivot. I managed to hold it for long enough to shout a warning to my dad who jumped out of the way before the boulder tumbled down the steep boulder slope to where he had been. Another lesson learned, we all proceeded more carefully.

This very large passage eventually fills up with stal and we took the smaller inlet. This ended after a short distance where the stream emerged from the left. The stream passage could have been regained by climbing a simple and short climb above the stream into a walking sized passage, but due to the number of large passages still left to be explored, it was to be years before this too-small-to-be-significant passage was to be properly explored to enter the many kilometres that make up Waterfall Series.

We turned back and headed downstream. This trip taught me just how well I couldn't cave. It was like learning to walk all over again. I learned a great deal from Draenen. It certainly improved my balancing skills. The large boulders that littered the floor were awkward enough on their own; many of these boulders had never been stood on before and were still in need of passing cavers helping them to settle. The boulders also had a thin coating of mud making sure we all slipped and slid all over the place. By the time we reached Tea Junction, all of our legs were aching slightly. We were learning how to firmly place our feet on the narrow edges of boulders without falling off while simultaneously being prepared for them to move or to be too slippery to get a firm foothold.

We headed up the large, draughting White Arch Passage. We were walking like monkeys, dragging our hands, trying to use them for balance. Eventually we reached the large Lamb And Fox Chamber, amazed by the enormous boulders stacked up providing a ramp for us to walk up. They did not look at all safe but none have ever been known to move.

Finally, a comfortable passage. Indiana Highway starts easy, but the trench soon develops in the floor and the traverse continues, with fairly easy ledges on both sides. At the end of the passage, a hole suddenly appears in the floor, dropping over twenty metres. Beyond, some climbs up entered Megadrive. I remembered this passage as being very easy with a sand floor. This is not the case. It has a very bouldery floor, but it was easier than the others, as the boulders did not move when you stood on them and the mud coating them was more sticky than slimy. The passage swung left into the nunnery.

For the purposes of conservation, routes through the cave are marked with brightly coloured tapes. Cavers should not cross them in order to protect the delicate stal, mud and gypsum deposits on the floor. In this section of passages, these tapes had not been laid so we laid them there ourselves, before taking a crawl through Perseverance.

We turned around at the Balcony Pitch, looking into the Arms Park chamber. Back at Tea Junction, we had a quick look at the Giles' Shirt formation in Gilwern Passage, before heading out of the cave. The trip lasted over nine hours. Without Phil, we would be able to complete this in less than two. I will not complain. At the time, that was the correct speed. In an unfamiliar cave it is always better to be safe than sorry.

I had acquired the grade 2-3 survey (fairly low quality) of the cave along with which came a one page description. I was not impressed as it offered very little guidance through complicated sections and having remembered most of the details of the trip we had done, I wrote my own, taking three pages. Over the next few years, this cave quickly became my favorite, you might almost say that I developed a love affair with it, and I have continued to maintain the description. It is now over 25 pages long, covering over sixty five kilometres of passage. I have probably visited between fifty and sixty kilometres of the total length of passage. Those that I have not visited, I get from friends who visit the cave, from maps that the original explorers produce, or best of all, from the original explorers themselves.

Several groups became involved in the exploration of the cave, the most important being Morgannwg Caving Club themselves, followed closely by Oxford University Caving Club. Other groups involved are Grwp Ogoffedd Garimpeiros, Wessex Caving Group, Brynmawr Caving Club and finally the Chelsea Spelaeological Society, who have generally made finds while surveying the cave to high quality.

The finds made by Brynmawr Caving Club were generally by me, my dad, my brother and those cavers that we were with, as well as about two kilometres of passage found by Charles Bailey whilst on a trip with some Oxford cavers in a new find of theirs.

Our first few finds were very short. We had not yet learned how to read Draenen, and could not predict where hidden cave might lie. A recent find had been made at the end of Elliptic Passage; Lucky Thirteen series contained two large passages, with several smaller ones. At the end of one of the large passages, an extension had been made by Tim Guilford, which contained an unusual 'Snowball' made of compacted gypsum crystals, about 15 cm across. Gypsum decorated many of the passages in Draenen but this was unheard of. Gypsum crystals normally cover the passage walls, like they had been squirted from the rock. This in fact is not far from the way that they are created.

Tim was a cave genius, and seemed to be able to predict exactly where cave passage would be found from patterns in the crystals, tiny shapes in the walls or roof, or geological projection. His team also found Going Somewhere, a passage that headed back towards the other of the large passages. These were connected through the Midwinter Chambers where vast quantities of gypsum crystals adorned the walls and ceilings, and great 'snowdrifts' of fallen crystals covered the floor. The midwinter chambers connected to each other through eight small chokes. With our discoveries in this area, we were to grow to dread these chambers, where we grew to counting each choke just so we could see the number decreasing, nearly there ...