Ogof Dan yr Odyn and Ogof Ffynnon Ddu trip 27/08/2020
Unless otherwise stated, camera, setups, lighting, edits and gallery effects by Tarquin. Modelling and lighting at various points will be Garry Evans, Gareth Davies and Jules Carter.
This was the second day in a row that I had inexplicably recorded a body temperature of 34.5°C, having woken up feeling like the inside of a glacier. I normally have a low temperature, but this was definitly too low; technically hypothermic. The good part is that this wasn't COVID, it was just a broken internal thermostat. The bad part is that I couldn't risk getting myself too cold or wet. But a good dose of SWCC digging week helped get the blood pumping, and bring my temperature back up.
Walking up in the rain, between Clogau Bach (left) and Clogau Mawr (right). Ogof Dan yr Odyn lies in an old quarry on the flanks of Carn Pen-y-clogau (523 metres) in the Black Mountain, immediately behind the tree in the middle of the picture.
Modelling by Gary, Gareth and Jules
The entrance sits at the tip of a rock projection that somehow survived the quarrying. It looks almost surreal to have a passage in such a narrow strip of rock.
Modelling by Gareth and Gary
The entrance crawl.
Modelling by Gary, lighting by Tarquin, Gary and Sol
The passage suddenly increases to its largest size. Down to the right is a wriggle between rocks into a short and very muddy wallow, which closes down. It swallows the pittiful dribbles from the passage ahead.
Modelling by Jules and Gareth, lighting by Tarquin, Jules and Gareth
Gour pools as the passage shrinks to its normal size.
Modelling by Gareth and Jules, lighting by Tarquin and Gareth
Stal, made from that rather crumbly, rapid-forming calcite, that you tend to find near limekilns and under lime mortared structures.
Stal in the crawl, which has to be carefully avoided.
Decomposed stalagmites, exposing the layers.
Enlargement. To the right here is the outflow, which is the most promising passage.
Modelling by Gareth, lighting by Tarquin and Gareth
Tiny false floor in the main passage.
The passage then passes through a pool. In the water on the left is a sump which might be an undercut, or another possible way on. The pool ends in a chamber filled with spoil, after which is a short passage leading to a choke. Sadly I was still far too cold to want to crawl through the water.
Modelling by Gary, lighting by Tarquin and Gary
The others sludged along through the very muddy outlet, reporting that there was a junction with a side passage pinching out towards the other side passage. The amount of passage here seems to match the main passage's length, so the quoted total length of 61 metres is clearly too short. The outlet may simply feed into the marshy ground below the cave, and may therefore have no prospects.
Modelling by Gareth, lighting by Tarquin and Gareth
We switched to Ogof Ffynnon Ddu instead, with this superb view from the Top Entrance (on the left). To the left are the Carreg Lwyd crags on Carreg Cadno (538 metres), then Mynydd Marchywell (418 metres), Cribarth (428 metres), Carreg Goch (558 metres), Disgwylfa (544 metres) and Fan Hir (761 metres).
Modelling by Jules and Gareth
Shortly inside the entrance, just after the passage grows to huge size, this flowstone on the left wall signifies a climb up to White Arch Series. That climb is through an eyehole just after the flow.
Just before the flow is a narrow rift that is not on the survey, so we took a look.
Modelling by Gareth, lighting by Tarquin and Gareth
The rift is long enough to deserve a place on the survey, but pinches out after not too far.
Modelling by Gareth, lighting by Tarquin and Gareth
We took the fork towards Big Chamber Near The Entrance, then through the choke to the left just before the chamber itself. That quickly becomes this large passageway.
Modelling by Jules and Gareth, lighting by Tarquin, Jules and Gareth
The passage splits, with both routes being a way onwards, and the upper requiring a climb.
The upper passage has a distinctive whitewashed aven.
A climb back beside the aven reaches a dead end.
A very tricky climb above the dead end reaches a narrow passage leading over the top of the aven, which enters the next chamber via a pitch.
Modelling by Gareth, lighting by Tarquin, Jules and Gareth
The lower route is the usual way onwards, which enters this chamber.
Modelling by Gareth and Jules, lighting by Tarquin, Gareth and Jules
The passage ahead passes through a choke into a couple of collapse chambers. The space is made by rocks peeling from the ceiling into a passage, and the passage itself is lost below. It would connect to known passage, so there is no point digging here.
Modelling by Jules, lighting by Tarquin and Jules
The way to the left from the chamber reaches a junction with a pool.
Modelling by Jules, lighting by Tarquin and Jules
Ahead over the pool is a longer side passage.
Crawling sized
Modelling by Jules, lighting by Tarquin and Jules
Dried crystal pool in an alcove.
Dried crystal pool.
The survey shows a rift to the right, but it's impossibly narrow.
Modelling by Gareth
The side passage ends at a stal blockage.
Modelling by Gareth, lighting by Tarquin and Gareth
Following the main passage, the next passage stub on the right ends in a chamber with a superb white flow down the wall.
It looks like someone spilled a can of paint.
Even the rocks are coated.
Continuing ahead at the junction, the main way on leads past more whitewash.
Modelling by Jules, lighting by Tarquin, Jules and Gareth
There is a choice; over or under. Over looks a lot more inviting, a big passage. Under is a drop into the slot, and crawl forwards. The way on is under, as over requires a short pitch which cannot be free climbed.
Modelling by Jules and Gareth, lighting by Tarquin, Jules and Gareth
Pool in the upper passage.
Modelling by Gareth, lighting by Tarquin and Gareth
The lower route reaches the last major junction, with two passages on the left, and a tube ahead.
Modelling by Jules, lighting by Tarquin and Jules
Stalagmites on the wall of the tube ahead.
The tube ends at a junction with a blind aven above, and a gate down below. The gate is only open on days when trips to the Columns are permitted - typically bank holidays.
Modelling by Jules and Gareth, lighting by Tarquin, Jules and Gareth
Beyond the gate, the passage splits. On the left is an ascending tube that used to be the highest known passage in the cave. On the right is a 16 metre pitch down directly into Column Hall.
At the last major junction, the two passages on the left form a loop, adorned with this stal in the lower passage.
The upper passage of the loop contains these stalagmites, very similar to The Minicolumns.
Modelling by Jules, lighting by Tarquin, Gareth and Jules
The passage leading off the loop is a superb phreatic tube
Modelling by Gareth, lighting by Tarquin and Jules
The passage then reduces to a crawl, heading away from the cave, towards the hillside.
Modelling by Gareth and Jules, lighting by Tarquin, Gareth and Jules
The passage then reaches a junction, with all ways on choking at the surface. A stream with a lot of water enters from the right, and sinks into the floor. The spoil and retaining wall are how they appeared before our trip.
Modelling by Gareth and Jules, lighting by Tarquin, Gareth and Jules
Stal at the junction.
The floor has been dug before, to a depth of just over a metre, trying to follow the water. There are no known passages below this point, and the nearest inlets in the known cave are quite a long way away.
We set to work at this authorised dig, painstakingly freeing each boulder from the mud, lugging boulders and loose choss out of the hole, and stabilising the edges so it was safer to work. Several of them were in the 50 kg range.
Modelling by Sisyphus (Jules), lighting by Tarquin and Jules
At this end, we only added enough spoil to raise the wall by one line of rocks.
But we completely built out the other end, so that the spoil heap was 50% larger than before.
The largest boulders were too big for the wall. All of the muddied boulders (not the three in the water, or the clean one) here came from the dig, and many of them were from our work during this day. The heaviest couple were as heavy as a human, and as large as a human torso. They were raised with ropes for safety, but most of the work had to be done with an Atlas Stones approach, manually lifting a rock out by hand while standing in the pit.
The pit as it was when we left. It looks disappointingly similar, but now nearly 2 metres deep.
Modelling by las botas de Jules, lighting by Tarquin and Jules
The stream will do some more of the work, cleaning the mud off the rocks, and exposing more of them.
Walking up in the rain, between Clogau Bach (left) and Clogau Mawr (right). Ogof Dan yr Odyn lies in an old quarry on the flanks of Carn Pen-y-clogau (523 metres) in the Black Mountain, immediately behind the tree in the middle of the picture.
Modelling by Gary, Gareth and Jules
The entrance sits at the tip of a rock projection that somehow survived the quarrying. It looks almost surreal to have a passage in such a narrow strip of rock.
Modelling by Gareth and Gary
The entrance crawl.
Modelling by Gary, lighting by Tarquin, Gary and Sol
The passage suddenly increases to its largest size. Down to the right is a wriggle between rocks into a short and very muddy wallow, which closes down. It swallows the pittiful dribbles from the passage ahead.
Modelling by Jules and Gareth, lighting by Tarquin, Jules and Gareth
Gour pools as the passage shrinks to its normal size.
Modelling by Gareth and Jules, lighting by Tarquin and Gareth
Stal, made from that rather crumbly, rapid-forming calcite, that you tend to find near limekilns and under lime mortared structures.
Stal in the crawl, which has to be carefully avoided.
Decomposed stalagmites, exposing the layers.
Enlargement. To the right here is the outflow, which is the most promising passage.
Modelling by Gareth, lighting by Tarquin and Gareth
Tiny false floor in the main passage.
The passage then passes through a pool. In the water on the left is a sump which might be an undercut, or another possible way on. The pool ends in a chamber filled with spoil, after which is a short passage leading to a choke. Sadly I was still far too cold to want to crawl through the water.
Modelling by Gary, lighting by Tarquin and Gary
The others sludged along through the very muddy outlet, reporting that there was a junction with a side passage pinching out towards the other side passage. The amount of passage here seems to match the main passage's length, so the quoted total length of 61 metres is clearly too short. The outlet may simply feed into the marshy ground below the cave, and may therefore have no prospects.
Modelling by Gareth, lighting by Tarquin and Gareth
We switched to Ogof Ffynnon Ddu instead, with this superb view from the Top Entrance (on the left). To the left are the Carreg Lwyd crags on Carreg Cadno (538 metres), then Mynydd Marchywell (418 metres), Cribarth (428 metres), Carreg Goch (558 metres), Disgwylfa (544 metres) and Fan Hir (761 metres).
Modelling by Jules and Gareth
Shortly inside the entrance, just after the passage grows to huge size, this flowstone on the left wall signifies a climb up to White Arch Series. That climb is through an eyehole just after the flow.
Just before the flow is a narrow rift that is not on the survey, so we took a look.
Modelling by Gareth, lighting by Tarquin and Gareth
The rift is long enough to deserve a place on the survey, but pinches out after not too far.
Modelling by Gareth, lighting by Tarquin and Gareth
We took the fork towards Big Chamber Near The Entrance, then through the choke to the left just before the chamber itself. That quickly becomes this large passageway.
Modelling by Jules and Gareth, lighting by Tarquin, Jules and Gareth
The passage splits, with both routes being a way onwards, and the upper requiring a climb.
The upper passage has a distinctive whitewashed aven.
A climb back beside the aven reaches a dead end.
A very tricky climb above the dead end reaches a narrow passage leading over the top of the aven, which enters the next chamber via a pitch.
Modelling by Gareth, lighting by Tarquin, Jules and Gareth
The lower route is the usual way onwards, which enters this chamber.
Modelling by Gareth and Jules, lighting by Tarquin, Gareth and Jules
The passage ahead passes through a choke into a couple of collapse chambers. The space is made by rocks peeling from the ceiling into a passage, and the passage itself is lost below. It would connect to known passage, so there is no point digging here.
Modelling by Jules, lighting by Tarquin and Jules
The way to the left from the chamber reaches a junction with a pool.
Modelling by Jules, lighting by Tarquin and Jules
Ahead over the pool is a longer side passage.
Crawling sized
Modelling by Jules, lighting by Tarquin and Jules
Dried crystal pool in an alcove.
Dried crystal pool.
The survey shows a rift to the right, but it's impossibly narrow.
Modelling by Gareth
The side passage ends at a stal blockage.
Modelling by Gareth, lighting by Tarquin and Gareth
Following the main passage, the next passage stub on the right ends in a chamber with a superb white flow down the wall.
It looks like someone spilled a can of paint.
Even the rocks are coated.
Continuing ahead at the junction, the main way on leads past more whitewash.
Modelling by Jules, lighting by Tarquin, Jules and Gareth
There is a choice; over or under. Over looks a lot more inviting, a big passage. Under is a drop into the slot, and crawl forwards. The way on is under, as over requires a short pitch which cannot be free climbed.
Modelling by Jules and Gareth, lighting by Tarquin, Jules and Gareth
Pool in the upper passage.
Modelling by Gareth, lighting by Tarquin and Gareth
The lower route reaches the last major junction, with two passages on the left, and a tube ahead.
Modelling by Jules, lighting by Tarquin and Jules
Stalagmites on the wall of the tube ahead.
The tube ends at a junction with a blind aven above, and a gate down below. The gate is only open on days when trips to the Columns are permitted - typically bank holidays.
Modelling by Jules and Gareth, lighting by Tarquin, Jules and Gareth
Beyond the gate, the passage splits. On the left is an ascending tube that used to be the highest known passage in the cave. On the right is a 16 metre pitch down directly into Column Hall.
At the last major junction, the two passages on the left form a loop, adorned with this stal in the lower passage.
The upper passage of the loop contains these stalagmites, very similar to The Minicolumns.
Modelling by Jules, lighting by Tarquin, Gareth and Jules
The passage leading off the loop is a superb phreatic tube
Modelling by Gareth, lighting by Tarquin and Jules
The passage then reduces to a crawl, heading away from the cave, towards the hillside.
Modelling by Gareth and Jules, lighting by Tarquin, Gareth and Jules
The passage then reaches a junction, with all ways on choking at the surface. A stream with a lot of water enters from the right, and sinks into the floor. The spoil and retaining wall are how they appeared before our trip.
Modelling by Gareth and Jules, lighting by Tarquin, Gareth and Jules
Stal at the junction.
The floor has been dug before, to a depth of just over a metre, trying to follow the water. There are no known passages below this point, and the nearest inlets in the known cave are quite a long way away.
We set to work at this authorised dig, painstakingly freeing each boulder from the mud, lugging boulders and loose choss out of the hole, and stabilising the edges so it was safer to work. Several of them were in the 50 kg range.
Modelling by Sisyphus (Jules), lighting by Tarquin and Jules
At this end, we only added enough spoil to raise the wall by one line of rocks.
But we completely built out the other end, so that the spoil heap was 50% larger than before.
The largest boulders were too big for the wall. All of the muddied boulders (not the three in the water, or the clean one) here came from the dig, and many of them were from our work during this day. The heaviest couple were as heavy as a human, and as large as a human torso. They were raised with ropes for safety, but most of the work had to be done with an Atlas Stones approach, manually lifting a rock out by hand while standing in the pit.
The pit as it was when we left. It looks disappointingly similar, but now nearly 2 metres deep.
Modelling by las botas de Jules, lighting by Tarquin and Jules
The stream will do some more of the work, cleaning the mud off the rocks, and exposing more of them.