Réseau Félix Trombe

3½ days in the Félix Trombe

It all started, as many good things do, in the beer tent at GG. John Helm was spreading the word about a 2011 club trip to the Pyrénées, to the region where the Félix Trombe-Henne Morte system was located. For me this was golden opportunity at last to visit one of the great, classic French caves. Next up was the 2010 Dinner where I described all this to Carmen Smith. Not long afterwards we discovered that Easyjet flew from Bristol to Toulouse, and the trip was on!

There is relatively little information on the Félix Trombe in English. In Cave Men New and Old Casteret describes the siege of the Henne-Morte, and there are some trip reports in journals – the TSG (v 16, pp 42-57) is pretty good – but that's about it. I did however have a well-thumbed copy of Grottes et Canyons which described parts of the Grotte de Pène Blanque and a long through trip from the Trou Mile. Also, Mike Bottomley had been out with Beardy and the Red Rose and had come back with stories about fantastic caving, deep shafts, and rain...lots of rain. It seems that the Félix Trombe region is one of the damper corners of the Pyrénées and I soon realised we would have to plan carefully to avoid being washed out of our long weekend. So it was we started to gather information. It turns out there are two websites that are really helpful. One (lacoume.free.fr) describes the various entrances including rigging notes, and the other (speleologie.free.fr) describes a “traversée intégrale” from the highest practical entrance, the Gouffre de la Coquille, all the way through to the resurgence cave, the Goueil di Her. I also borrowed A Travers le Karst from the CPC library and found more information on the possible through trips. By this stage John had got some replies from his emails to local cavers, so we started to get an idea of what might be feasible.

The first thing that became apparent was the classic Mile → Pène Blanque through trip had been somewhat superseded by the Gouffre des Hérétiques → Pène Blanque option (for mere mortals), or the Coquille → Pène Blanque option (for superhard cavers like Mike and Beardy). Also, we could see that it was almost imperative to rig the Gouffre de Pont de Gerbaut (PdG for short) to gain access to the central part of the system. We also wanted to make sure there were options for people who did not want to do such long trips. So it was that the rope requirements and trip possibilities began to become clear and at this point I volunteered to organise the gear at the UK end. We ended up taking the club 9mm Edelrid, cut to length to rig the Hérétiques and the PdG, plus some 50m+ lengths for pull-through options, and some short lengths for the Trou Mile if we wanted. Carmen, Chris Binding, and I also got ourselves some 8.5mm Beal Unicore as extra lightweight pull-through rope.

In the scouring of the internet for information I had come across some blogs by ULSA caver Paul Fretwell (universally known as Footleg) who we knew from Matienzo. It was from these that I first learnt of a fantastic formation deep within the far recesses of the Pène Blanque, in a system of galleries known as the Réseau du Maillon Manquant (literally, the Missing Link). This "Blanc de Blanc" formation was a huge column of pure white calcite. Not long afterwards, a spectacular photograph of it appeared in the Daily Telegraph (Feb 10, 2011), taken by Robbie Shone. Visiting this unique site was soon added to the top of the trip possibilities.

Then I guess we had a bit of luck. First of all I finally got on loan from Beardy his Félix Trombe library, which consisted of several folders stuffed with information, plus the "Red Book" of surveys, plus the Spéléoguide by Stephane Boyer and Jean Flandin. With some diligent study of the Red Book I finally found the Blanc de Blanc lurking near the end of the Avenue du Futile in the Maillon Manquant. The Red Book contains literally hundreds of 200m x 200m survey squares. I had just started on the laborious task of scanning these into a computer to piece them together to make something more useful for underground when Carmen obtained from Footleg a series of A4 navigation sheets where he had done just that. Undoubtedly this saved me weeks of work! Next, in Matienzo at Easter, Carmen made contact with Martin Barnicott (Barny), an Eldon PC caver who lives within spitting distance of the Félix Trombe. It turned out that Barny was closely involved with Robbie's photographic trip, and they had entered via a new entrance called Serendipity, which drops into the Maillon Manquant. Barny generously said we could use his ropes which were still in Serendipity (it is still being pushed, I think), and he sent us a survey and a Google Earth file of the whole system. Finally, armed with all this information, I persuaded my Liverpool caving friends Becka Lawson and Julian Todd that, yes, the Pyrénées were really just a short dog-leg en route between the UK and Austria where they were heading in August, and, yes, they really wanted to come to the Félix Trombe. It helped, I think, that the NPC was organising a trip to the PSM which they could join between our trip and Austria.

Eventually, all the surveys and notes had been compiled into a big folder; all the rope had been washed, dried, cut, and packed out with various people, and it was time to go. The moment of truth had arrived - soon we would see whether the months of pain-staking planning would pay off.

Friday July 8 : Serendipity → Pène Blanque (Carmen, Chris, Becka, Patrick)

Carmen, Chris and I had arrived in the middle of the previous evening, just after Julian and Becka, and it had been raining all night. Given the weather we decided we should stick with a dry option, and try to find the Blanc de Blanc formation via Barny's Serendipity entrance. We parked at the end of the forestry track above Labaderque and soon found ourselves scrambling over fallen branches and slithering on leaf litter that is the hallmark of the mature forest that blankets the hillsides in this region of France. We were looking for a tiny entrance hole in the middle of this lot, and my biggest worry was that we would waste the day trying to find it. I actually had two GPS coordinates for the entrance – one converted from the Lambert coordinates given on the survey, and one extracted from Barny's Google Earth file. They were only 40m apart, but I soon realised that even searching a 40m x 40m area could take an hour. My attention span was nowhere that long and after 10 mins I gave up on the Lambert coordinates and switched to Barny's coordinates. Thrashing down the steep slope towards the new location, I spotted something from above that looked like a possible entrance – checking this out I was amazed to see the top of a rope concealed within. We had found it! (I don't think my colleagues realised how relieved I was.) It turned out that Barny's location was spot on. The entrance was marked by something of a smiley face in red paint on a 4m high boulder above but otherwise is almost invisible, and there is not really a discernible path.

From the survey it looked like all we had to do was slide down a couple of hundred metres of pitches, saunter along to the Blanc de Blanc, and wander out of the Pène Blanque entrance. As it was, the first five pitches are just like that, then we had to get off on an obvious ledge (just below a hanging rebelay) to what Barny described as a bit of a knarly crawl. It certainly was! SRT gear came off and the first bit was negotiated to a small chamber followed by a trickier bit which was about 10m of crawling in the top of an immature rift, ending in a climb down. Now we had to go down a slope and more pitches, before climbing up and traversing in a rift. Some slightly awkward down-climbing ended with a squeeze opening out over a drop. Below here there was another pitch and then the rope unexpectedly abandoned the large descending continuation and threaded through a small hole near the roof. We followed it, since “it must be right!”. Down another climb then SRT kit off for a body-sized hole dropping onto a climb down to another pitch (SRT kit on!). At the bottom of the pitch there was a further climb down, then SRT kit off again for a more committing body-sized squeeze. I was reluctant to post myself feet-first through this over what I could feel was an unseen drop, without some kind of backup. Becka had a go, and just as we were contemplating making up some kind of lifeline out of a string of cows tails, she got through, and announced that whilst there was a drop there were enough footholds to avoid falling down it. At this point we had worked out from our rather fuzzy copy of the survey that there were "NO MORE PITCHES!". We were at last in the Maillon Manquant, in a side passage known as Recuerdo de Rodellar (Memories of Rodellar). It had taken 2½ hours to get down Serendipity – so much for this being an easy way in, and we took our hats off to Barny and his friends for pushing it in the first place.

Orienting ourselves with a compass, we set off along Recuerdo de Rodellar towards the "Delta" in the Avenue du Futile. An 8m climb up was followed by a 5m rope climb down descended rather inexpertly and out-of-control by yours truly (with the additional embarrassment of being filmed). Then we were essentially on the main route. From here a succession of large passages, short pitches and climbs (both up and down; all rigged), ended at a narrow passage between stal. We briefly misread the passage beyond here, dropping down a 6m pitch and up an 8m pitch, before realising we should have gone up a 6m pitch on the right-hand wall instead. There were two white stalagmites, like sentinels. A shout from the front and we could see the edge of the Blanc de Blanc formation, which appeared almost too large for the passage containing it. There was a rope traverse and a 6m pitch down, right beside this enormous white column. To the sides were more white stal, and round the back a huge curtain aver a drop. Later, I came to understand that the Blanc de Blanc continues for 20m or so down this drop to another equally spectacular chamber. Out came the cameras, needless to say, and we spent ½ hour or so photographing. Eventually Carmen and Chris set off back up the 6m pitch, and Becka and I took the opportunity for a quick look at the passage continuation. It was still large, then around a corner we had an unexpected treat – a lake of pure white calcite crystals spanned the passage, spilling out from the foot of a 4m high mini-Blanc de Blanc. Beyond was a short pitch up, which we left, as the survey shows the Avenue du Futile comes to an end not much farther past this point.

Thus sated, the way back out seemed to be not quite as far as the way in, and we were soon back at the Delta. Now we were in new territory, and out came more of Footleg's navigation sheets and the compass, and a secret weapon too – a magnifying glass to resolve the fine passage details. Suffice it to say that the way out of the Maillon Manquant kept us on our toes, including more pitches, before we got to the Galerie des Méandres in Pène Blanque. A cairn marks the point where the route from the PdG joins at roof level. I briefly explored the 5m climb up to this, then we headed out past the vast Salle du Dromadaire and through the Salle du Bivouac. Here we had a break for 10 mins, then wandered onwards through a part of the system that really does defy description (even with two surveys and the Spéléoguide!). We found the rope leading up to the famous letterbox pitch – the key connection between the upper and lower parts of the Pène Blanque. Then we started climbing out steadily, but soon realised we were missing a bag. After mulling this over for a bit we decided it must have been left in the Salle du Bivouac but that it did not contain anything essential that we might need for the following day. Apart from anything else, it would be a 40 min round trip for someone to fetch it. We went through a short crawl, then up the famous steep "toboggans" in the entrance series to eventually arrive at the level of the entrance passage. This was quite roomy but forced some of us to hands and knees for the middle section, then we reached daylight in the impressive entrance at around 7pm, after 8 hours underground.

From here there was an 8m rope climb down, and a "mere" 200m or so of ascent up the side of the Pène Blanque rock face to a col. Up from the col (on the Pène Blanque side) there was a magnificent view across the French plains to the north, bathed in the evening sunshine. Just south we found a path which took us down to a larger col, then back through the forest to the road.

Saturday July 9 : Pont de Gerbaut → Pène Blanque (Carmen, Chris, Becka, Julian, Patrick)

I had been wondering how the remainder of the weekend would work out when Carmen came up with the smart idea to break the Mile → Pène Blanque through trip into two parts. This made a lot of sense: it would even up the caving balance over the remaining two full days, we would see more of the system, but most importantly we would be able to get to the dinner that John had organised for the trip! The rain of the first night had not made much difference to the water levels so far as we could see, and the weather forecast was quite good, so we decided to do the river section from the Pont de Gerbaut to the Pène Blanque. This saw us retracing our steps of the previous day towards the Pène Blanque col, but veering off at a couple of cairns to climb steeply through the woods to the large and impressive Pont de Gerbaut entrance. The name originates from the French for “bridge of grass” and is very appropriate as there is a rock arch separating the two daylight portions of what looks to be a massive collapsed chamber. On the far side is an opening onto really quite an impressive pitch, which must be some 60m all the way to the bottom, though broken with a steep slope at about –45m. From the base a very draughty low passage leads to a broken series of pitches, then a crawl into the Galerie Bugat and the heart of the Félix Trombe system. The wind blowing through this crawl was sufficiently strong that it seemed we could be blown back out of it! On the far side we found a tackle bag with the letters “CPC” neatly laid out in gravel on top of it. Straightforward caving past a traverse and a short pitch/climb down took us into bigger passages, and soon the well-marked "Entonnoir" or collapse feature that gives access to the river. Here Carmen and Chris changed into pontonnières, or home-made equivalent thereof in Chris's case (the rest of us were in wetsuits).

Downstream was really pleasant going, with the odd small cascade, until the water fell away towards a 60m pitch. A rope on the right indicated a climb up into a fossil high level series. This descended steeply in very dissected rock to an 11m pitch which was our first pull-through point. Below here two small drops (rigged) were followed by a 15m pitch back to the river, downstream from the 60m pitch. Since we had two ropes, there was some leap-frogging, and Chris and I ended up at the back. We found an extra pull-through pitch (about 8m), avoiding a slippery-looking moonmilk climb in the stream, then caught up with the others at the Puits du Trapèze (8m), followed by the Puits de la Douche (10m). The next pitch, the Puits de l'Angoisse (22m), elicited whoops of delight as it was a stunning free-hanging abseil. Then the streamway changed character, becoming wading in a tall rift before the roof lowered to make it a bit gloomy. An easy hole between calcite at the end of this section was followed by the Puits de l'Affluent (11m), and more deep water (out of my depth very briefly), then a last unnamed pitch of 15m. After an easy climb down, an obvious rope on the right led to a balcony, followed by a sensational and hair-raising traverse balanced on a wire over a black space with the sound of the waterfall deep below (Puits du Calvaire) – a fitting end to the PdG river.

Carmen and Chris changed out of pontonnières – I think comparing notes these were not necessarily warmer than a wetsuit but certainly worked to keep clothes underneath dry. A short pitch up and a bit of a crawl lead to a short pitch down and another wire traverse, this time over the start of the puits Arrosés in the Pène Blanque. Shortly after this I found myself at a point I recognised from yesterday – the top of the 5m climb up from the Galerie des Méandres. From there it was steady going, pausing to collect our belongings left in the Salle du Bivoac, to exit at about 5pm (6 hours trip). The “mere” 200m slog up up the side of the Pène Blanque cliffs didn't get any shorter, but the view from the top was just as impressive. Then it was back down the path to the car. Becka and Julian elected to be dropped off in Arbas, to walk the couple of km to Fougaron where the dinner was being held. Carmen, Chris and I opted for a quick shower back in Aspet, before getting to Fougaron at about 8pm. The dinner that night was attended by everyone in camp, I think a total of 34 people, and as broad a cross section of the CPC as you could wish for.

Sunday July 10 : Hérétiques → Pont de Gerbaut (Carmen, Chris, Becka, Patrick)

And so to the second part of the plan. There was much discussion about whether we should start from the Trou Mile or the Gouffre des Hérétiques, but the debate was resolved by proposing that those sufficiently keen to want to do the Trou Mile could have their cake and eat it, by getting up at the crack of dawn and doing it the following morning! Hérétiques it was then. The car parking for both the Hérétiques and the Mile is at the Fontaine de l'Ours, different from the Pont de Gerbaut and the Pène Blanque. We wondered about trying to arrange a car shuffle, but decided it shouldn't be a problem walking between the two parking sites. The track up to the Hérétiques was a very pleasant gradient and we found the entrance easily enough, with the help of GPS and some wayside markings. The pitches seemed awkward but no fault of the riggers as they are break inelegantly and are sloping rather than nice free drops. At the bottom a short length of passage opens into a larger chamber, followed by a bouldery crawl which emerges right at the top of the immense Grande Salle du Trou du Vent (TdV). A steep descent on scree is followed by a flat area then a climb past a huge fallen block which spans the cave, providing a spectacular viewpoint. Below is more steep descent to an area of mudbanks, then a debris cone is flanked on the right to reach the end of the chamber. Right is where the Trou Mile enters, and left is the so-called Pertuis, down to the pitches of the TdV. This short passage certainly seemed like it could get a heavy battering in a flood, and Becka commented it seemed like going down a drain pipe. It ended in a superb 22m pitch (Puits Danielle), which was out first pull-through of the day. Next was a short section to an 11m pitch below which we picked up the stream, then a 27m pitch which required both ropes. Below here one crosses the stream to an obvious dry bypass, and the big pitch (54m). I knew that this was broken by a big ledge 16m down, so we planned accordingly, but about 10m below the big ledge Chris encountered another narrower ledge with another pull-through anchor. This messed up the carefully-laid plans, but I think was worth it to make sure we could retrieve the ropes (so that the pitches are 16m, 10m approx, and 30m approx). There was another short drop to the stream again, then a climb down, and shortly afterwards a nice 10m cascade. I knew that from this point we should look for a rope going into the roof, but at first it was a bit elusive. For the record, the trick is to push on down the stream to the top of the next cascade (do not descend!), and the rope goes up directly above this point.

From the top of the rope we would be in the dry galleries of the Félix Trombe – the backbone of the system, and very pleasant going they were too! We first dodged the Puits Jeannot by a sand bank on the right, then opted to miss the first turn off to the PdG to go and look at the mysteriously-named Cascade des 5 Hippies. The passage beyond this inlet was a big tunnel with a chaotic floor, and a shout echoed twice – once from the immediate neighbourhood, and the second time from the more distant and unseen Salle des Effondrements. At this point too was a second turn off to the PdG, also well marked. From here we lost the plot concerning the survey and I'm convinced there are more junctions than shown, though we were always able to keep on track by heading north with the compass. We picked up the thread again at a 5m climb down. It seemed to me this section of the through trip was basically a link between two distinct systems of larger galleries.

The 5m climb down was followed shortly by an up-along-down rope traverse, to a much more spectacular traverse around the side of Puits de la Jonction. Beyond here the passage became much bigger, especially where we skirted around the side of the Salle Elisabeth Casteret. We ended up at the top of a 10m slope which we roped down, having missed somewhere a climb down to bypass this. Soon afterwards we recognised the Entonnoir from the previous day, then it was just a matter of reversing the route to the PdG entrance and making out way up the pitches, exiting around 4.30pm (another 6 hour trip).

On the surface, Becka and I set off slightly ahead of Carmen and Chris, hiding some of our gear near the parking spot for the PdG, and from here taking a path which climbed directly south up a wooded sort-of ridge. The map showed this path bending parallel to the upper road so it was a really pleasant surprise to find a junction instead of a bend, then shortly afterwards the embankment of the road itself. Then it was easy going for 20 min or so, stopping for the odd wild strawberry, to get back to the car park at the Fontaine de l'Ours. A quick change then down the road and up the forestry track to pick up the gear and Carmen and Chris. The gear was there but no sign of the other two! They must have been quick where we were slow, was the only conclusion I could come to. Sure enough, we found Chris sitting on a couple of tacklebags at a bridge below Labaderque, and Carmen, intent on escaping the flies, on the outskirts of Arbas!

Monday July 11 : Mile → Hérétiques (Becka, Patrick)

True to the plan, Becka and I were up very early the next day, changed, and walking up the track above the Fontaine de l'Ours by 8am. We passed the path to the Hérétiques, then where the track swung left, went down and across the dry stream bed and through an excellent meadow for a camp (which I think was used as such during the explorations of the Trou du Vent). The Trou Mile was just beyond this, and was a large hole between boulders adjacent to the stream bed, exactly where the GPS said it should be. From the surface it starts with a tricky 3½m climb which we put a rope on, then another climb and a short section of passage to a 6m pitch. We were disconcerted to find no trace of a pull-through anchor although there are plenty of bolts. I wrapped the rope a couple of times around a knob of flowstone at floor level protruding over the pitch, and we gingerly descended. On inspection from the safety of the bottom, we realised that the pitch was actually quite an easy free climb. Not much further on the whole scenario repeated itself with an 8m pitch. Again from below this looked an easy free climb.

At this point the Réseau Figaro from the Coquille enters, and it looked like a pretty mean and awkward rift to me. Below here the Trou Mile streamway is often narrow but never tight, and descends innumerable cascades and climbs, passing under some really impressive avens. It levels out for a long section before starting to descend again. A couple of pools are avoided by rope traverses, then eventually the Cascade Laffranque arrives as a 12m pitch (rigged). Too soon, the stream runs off into a shingled-up sump. Amazingly this is at -240m with respect to the entrance, although we have essentially only done one 12m pitch! The way on was a muddy tube on the right just back up from this, followed by a muddy slope to a greasy rope climb, then more climbing to an echoing aven where there is a pitch down. Back over the top of the climb (away from the pitch) soon enlarges to a passage cut by a short rope climb, to emerge in the very bottom of the Grand Salle du TdV, opposite the Pertuis.

From here we retraced our steps from yesterday, only uphill this time. I commented that this style of caving would soon become very familiar in the large chambers of the PSM! The Hérétiques pitches seemed even more awkward to ascend than descend and I can't say that I wasn't glad to see the back of them as we emerged to a hot and sunny morning after about 2½ hours underground. At the car park we met up with a large contingent of CPC cavers. Some were just going to look at the large chamber, and others were heading for the through trip to the PdG.

In Aspet, Carmen, Chris and Julian had done an excellent job drying and packing tents, so it only remained to have a last brew before setting off for our respective next destinations – Toulouse airport for Carmen, Chris and myself, and somewhere near Laruns for Becka and Julian, for a couple of weeks tele-working before joining the NPC for their PSM trip. It seemed like we had crammed everything we possibly could into the weekend, but it was clear we had only scratched the surface of the Félix Trombe and there was plenty left for next time!

BIG THANKS to everyone who made this trip such a success: ferrying gear out and back, and rigging entrances. Thanks also to Beardy, Barny and Footleg for generously providing copious stacks of information and surveys.

Verified GPS coordinates

UTM (WGS84) 31T 0326163 4759250  Hérétiques 

UTM (WGS84) 31T 0325902 4759124  Trou_Mile

UTM (WGS84) 31T 0327560 4759962  Serendipity

Adapted from CPC Record 104, 5-9 (Aug 2011).

Copyright © (2011) Patrick B Warren and Craven Pothole Club Ltd.