Ogof Ffynnon Ddu 1 to Cwm Dwr Birth Canals and then Fault Aven Series

Saturday March 30th 2024

Members present: Rosie Marshall,  Viki Smyth

The idea to go to the Fault Aven series from OFD 1 had spawned early in the week after Max had cleverly collapsed the Cwm Dwr boulder choke and made it inaccessible for the foreseeable future. This made a Cwm Dwr trip somehow more appealing to me since we’d have to go through the ‘backdoor’ of 1 or Top entrance. Add to this my ongoing leg injury that made any streamway caving painful and a conversation with Ian from SWCC about the Pom-Pom and I was fully set on getting into Cwm Dwr from 1 via the high level, with a possible detour to Fault Aven.

I had recruited Viki and possibly Paulina and Jean-Luc if their 1-Top-1 trip fell through; in the event, Jean-Luc Paulina Sophie Alfie Viki & I caved to the start of Piccadilly, where everyone but me and Viki set off for Top. As their lights disappeared down the dark tunnel, we turned our attention to the huge passage ascending steeply up to Cwm Dwr and were soon in a lofty canyon with a flat sandy floor.

Neither of us had really been to this part of OFD before and we weren’t sure from the survey if you could get into Fault Aven from Cwm Dwr or if it was only accessible from the streamway. I wanted to have a look through the Birth Canals and the Granary as it looked like a series of green/purple/yellow passage might get us there.

We continued walking down rift as it diminished in proportion until we were at a Y-junction, where we took the right into the Birth Canals. Jean-Luc had told me earlier in the week that he had heard (or possibly watched on YouTube) that these were really awful, but I wasn’t to be deterred and besides, we could already hear the dim roar of the streamway somewhere close at hand.

As far as I remember we started off crawling in moderately roomy passage until we reached a junction and turned off sharply right onto our bellies. We continued on this way for a little while until we flopped down a steep slope heading left and soon reached a junction. Or, at least, what I thought was a junction. Looking at the survey now it seems very clear where we were and what we had done, but at the time it was not! I was expecting to turn right, thinking we were quite far along already, but the right turn appeared to be an impenetrably tight rift on a corner, with no way to see what came after. It looked like if I tried to feed myself in I would never come out again.

“Well,” I said finally, “We’re not doing that!”

Feeling sheepish and defeated by the Welsh, we decided to check out the left ongoing passage ‘just in case’ and after a bit of wriggling reached a Y-junction. I wasn’t expecting this.

“Um, maybe don’t follow immediately!” I told Viki (for perhaps the sixth time) as I propelled myself up the left fork.

At the top of the slope was a dead end to the left and a descending passage to the right. I wasn’t expecting this.

I told Viki we were going back and dragged myself to the Y-junction. I stared longingly down the right turn. Then back at the survey. Then at the right turn. Then the survey…

“Wait a second – I’m just testing a theory.”

As I suspected the right passage seemed to connect with the left, forming a roundabout with a new (and tiny) passage going off to the right. It was now easy to identify where we were! To make sure that it was a roundabout, I made a little cairn in the right passage then went back to the Y-junction and looked at it from the other direction. This now seems like an act of lunacy when I could have just done the loop, but I was wary of getting lost or turned around, and in any case it worked.

Back once more at the Y-junction I called to Viki that I had worked out where we were. The noise of rocks grating against each other preceded her feet, which were followed by her legs, torso, arms etcetera after some contorted thrashing around.

We continued on flat out as the booming of the streamway grew louder and louder until the passage grew in size and deposited us into the Granary via a roped climb down. It was amazing to be in a real chamber, even one so drippy, and I hopped around excitedly. For future reference, the ‘red’ passage on the right of the Granary looks very accessible, although we didn’t go up it then.

Running down the left soon got us to the streamway at First River Chamber where it is wide and flat and inviting. This bulge of purple does have an offshoot on the survey that we had thought might be the key to Fault Aven, but we didn’t see it immediately and so put it on the back burner.

Overjoyed not to have to go back through the Birth Canals, we ran upstream laughing with glee and looking for our first prospect: ‘purple’ passage on the true right bank with a pole marked on the survey at the level of flood escape markers. This turned out to be a scaff bar wedged at the foot of a black tunnel; a climb that Viki managed with ease but which I spent a long time looking up in confusion. I could only grasp at the bar with my fingertips and there were no footholds to speak of. Eventually I got a foot up by my ear where the ceiling came down on the left and shoved my weight against the right wall, fumbling at the bar with my hands until I could wrench myself up. I don’t think my stomach muscles had ever done the like before!

“There is no way to get down that except for jumping,” I said to Viki flatly. She seemed unfazed by this.

The passage soon came to a short pitch on the right, with two anchors at the top clearly bolted for pull through and a cord looped through them. The climb up might have been doable, but not climbing down it. ‘You could do it, but we’re not going to’ – the constant refrain of Yorkshire cavers in Wales! Thwarted again, we continued and rejoined the streamway at a much easier climb than the scaff bar.

Our next prospect was a sliver of ‘green’ passage that lay over the streamway. This turned out to be an obvious set of ledges on the true left bank, which went into some sort of passage ahead (upstream). I thought this might just cross over the stream and go nowhere but wanted to check. I turned myself around and around like a cat preparing to sit before finally getting on with it and climbing up to traverse carefully to the passage ahead. I had spent so much time in Top on climbs that I knew were the way on or had done before that I felt unusually cautious and unwilling. The passage did as expected and dropped down to the streamway again; there was something potentially on the other side, but it seemed easier to access from the stream, so I turned around. Meanwhile, Viki had looked at and discounted a climb up to a higher level from the start of the traverse: it went somewhere but not what we thought was the ‘correct’ direction and might have been difficult to get back down.

From the stream what I had seen turned out to be an inlet (on the true right) – an easy squirm up but so badly smelling I wasn’t expecting it to go anywhere.

In fact, it got us up to the level we had seen from the ‘green’ traverse. Directly in front was the climb that Viki had discounted, but turning back on ourselves we could do a set of climbs into a higher level (upstream direction).

Viki headed up these and soon after we reached a larger chamber with a high roof. The floor fell away in front of us into a dark void. H junction…? More intelligent people would have realised that this hole of death was definitely - absolutely not! - H junction, since most ways on from it were inaccessible. But if it was H junction, we wanted to take the first right, which just happened to be the only accessible way on: an extremely exposed step with the hole of death on your side, easy but high consequence.

Left to my own devices, I don’t think I would ever have done this but Viki is made of sterner stuff and once she’d done it I sort of had to follow. “It’s not worse than the Three Traverses,” she pointed out helpfully. Unfortunately for us, the ‘passage’ immediately ended. Shit scared, I stepped back around, nose to the wall and deeply unhappy. I couldn’t watch Viki come across!

But looking back at where we had come from, I noticed that there was a lower route and a higher route. Viki confirmed that we had come up from the lower route, so we decided to give the high route a try. This got us to another climb up (very well worn) into yet another slightly different bit of rift!

At this point, I realised that we had very definitely gone past our turn around time, but going back through the streamway would be much quicker than the high level and I really wanted to reach our objective, so said nothing…

We turned right here (the same direction we’d been heading in below) and encountered some false calcite floor and formations at a pronounced right bend. Our next obstacle was (surprise!) another traverse, this time a dry mud ledge around a hole – not immediately a hole of death, but not immediately not a hole of death. If that makes sense. I eyed this with some trepidation, possibly a symptom of my rapidly advancing age, since again Viki seemed to have no issue with this. “It’s not worse than the Three Traverses,” she pointed out helpfully.

The other side of the hole of possible death had some anchors, though not very close. I hadn’t seen any on the other side, so I think it’s for going down the hole rather than protecting the traverse. Interesting! Possibly part of the route that comes up from the P6 near the scaff bar??

Shortly after we came to a big T-junction. We scoured the survey for passage that matched and realised that we were heading to Fault Aven, which was the exact wrong direction if we wanted to get to the Pom Pom. Still!! We knew where we were!! Probably!!

Around to the left was Fault Aven, a staggeringly grandiose chamber with a steeply slanting floor to a massive drop with all the thunder of the streamway. On the right was a rope. Presumably this was the P8 on the survey, but I disputed this at the time because it seemed to go up for so much longer than that; it seemed to disappear high into the roof of the aven, higher than I could see as I looked up into the spray. An awe-inspiring, intimidating place.

We turned back the way we came. I felt a little forlorn because as I agreed with Viki, we were already past our turn around point, we didn’t really know how to get to where we wanted to be, and we ought to be calling it a day. At least we’ve kind of figured it out, I thought to myself, next year we could come back and probably work it out.

The other factor was exhaustion: after a full week of caving, my muscles were screaming and everything seemed slightly harder than it ought to. Getting back across the easy mud traverse was very tenuous.

(Though I did have a quick foray down the possible hole of death, which you can climb down a little on a sandy slope until it drops off into – something.)

But as we got to the first set of climbs down, we saw across the chamber a very nice worn route that was heading directly towards where we now knew H junction to be… Couldn’t we just have a look?

“Just to see where we should have gone!”

Naturally it was H junction! A cosy chamber with a small stream on the left and an obvious route on our right that clearly went to the Pom Pom. Viki and I looked at each other. Really, we ought to be leaving. But it was so inviting… And if it was easy passage it might only be a couple of minutes away... I gave in. “Okay! Alright! But if it gets even slightly involved or time consuming, we need to turn around!”

Of course, we were immediately traversing over a massive drop! “It’s not worse than the Three Traverses,” I pointed out helpfully. It was easy going, so I continued until we got to a hairier corner, wider and with fewer footholds. But still doable… I edged around it. Aware of Viki’s tension behind me, I said that if she was at all uncomfortable or felt unsafe, she should turn around…

“The only reason I am continuing is that the floor is coming up to meet us here,” I said.

Soon the floor was only a couple of metres below us. “Do you think that climb is doable on the way up?” I asked Viki, no longer really sure of my judgement.

“We’ve done harder this week.”

It looked difficult to me, but I think the setting was responsible for this. This whole section of cave is very atmospheric – the streamway is a low ominous drone; the rifts are narrow and high; the floor often non-existent. It’s really cool, but intimidating and we didn’t ever know what we were about to face. The cave felt hostile.

But she was right, it was a straightforward climb. A little further on was the crystal pool marked on the survey, which takes up the whole width of the rift, so you have to traverse over it. The wear on the rock suggested that people climbed up to ledges about two metres up, so that’s what I tried as this looked the easiest route. But most of the way over, I couldn’t see how I was going to get down on the other side. Certainly I didn’t think I’d get back up! I was exhausted enough I was worried about falling into the crystal pool.

Miserably, I told Viki we’d have to turn back and did a 180 with great difficulty. She had no problems getting down, but the traverse widened at this end and I had issues keeping enough tension on all my contact points… and I was a metre or so from the conservation tape.

“I might have to jump this…”

“Will it help if I catch you?”

Viki moved into position at the edge of the pool.

“Um. Maybe…?”

We looked at each other for a little while.

“You’re kind of where I’m aiming to land…?”

“Oh!”

Viki shuffled back and I leaped towards her, landing just about on the right side of the tape!

We looked at the crystal pool. We were so close!! But we should turn around… But we were so close!

“Can’t we traverse just above the pool?” Viki suggested.

Once suggested, it seemed very obvious. It was a lot more straightforward than the high route and we were across in no time.

And then… the Pom Pom!

I’d seen a lot of formations in the last 7 days, but I did actually gasp at this one. The pool was so clear we couldn’t tell where the surface of the water was and richly decorated with crystals. A singular thin straw came down and a ball of orange crystals hung onto the end, just underwater. The straw was reflected perfectly in the water, as if it went on to the bottom of the pool.

We sat there giggling madly for a few minutes; after all the wrong turns and times we’d come so close to throwing in the towel, it felt miraculous to have actually have made it!

Now all we had to do was make it back. I was worried we’d get turned around, but we got back to the streamway without further mishap. Euphoric, we set a fair pace going downstream. These were parts of the streamway I hadn’t seen for four years and didn’t really remember but enjoyed a lot. I had left my spotlight on accidentally and it turned the water a pale green, eerie against the black rock and the white of the rapids.

When we made it back to Piccadilly it was only 2 ½ hours since we’d departed there, although it felt much longer. It had taken 2 ¾ hours to get there from One on the way in, but I thought it would be quicker on the way out, as we would go through the streamway instead of the high level. Still in high spirits we had the obligatory Maoams (thanks Chris) and sped off into 1.5 and the connection. Route finding didn’t present any issues and neither did Divers’ Pitch or the Letterbox. I’d been concerned about the former as it seemed to require arm strength I was rapidly losing and I’d not gone up it before, but Viki’s climbing route on the left ended up being easier than using the rope.

Back into the streamway and familiar streamway this time! I splashed about for once careless about getting cold and even tobogganed the section after the jammed boulder. I dared Viki to jump in the deeper section at the pronounced bend near Maypole Chain for my last Maoam, which I gave her even though she soft legged it. We had a little dip in Pluto’s Bath and said an emotional goodbye to One, not to be seen again for a whole year. :(


I loved this trip and am very eager to go back next year and see more of the Fault Aven series as we left many passages unexplored. Plus I am unsure how it intersects with the Marble Showers Series. Also I want to do a proper trip into Cwm Dwr as the area around Piccadilly was so cool! It's only now looking at the survey to write this report that I have realised that parts of the Fault Aven series are pretty much the only passage in OFD that forms on the south of the streamway, which is fascinating and in retrospect adds to the special feeling of the place.