Trou du Glaz to Grotte Annette



August 2011. Mike Hale (Slug) Tim & Heather Eastwood, Jim Davis, Paul   , Bill Nix, Andy Hall.


Ever since reading Subterranean Climbers by Pierre Chevalier in the early part of my caving career in the 1970’s I had wanted to visit the Dent de Croll system. This "Dent" contains over 50 kilometres of passages and pitches and has been continually been explored on several sections since the 1930’s and has a vertical range of 673 meters. Eight entrances allow you to get into this labyrinth. I was particularly keen to do




the through trip from Trou du Glaz to Grotte Annette, which takes you under the Dent de Crolles massif from one side to the other. When the club decided to organise a summer 2011 caving holiday, I suggested the Chartreuse area as I had passed by on a number of occasions on the way to the Berger, the Alps and Vercors and had heard from a number of cavers over the years what a fine caving area it was.Heather agreed to organise the campsite, insurance etc and thanksshould go to her for drumming up support for the whole event and to various cavers who supplied surveys and descriptions of the system. The club caving holiday got a good deal of support from a large number of members and friends. A few weeks before we set off I was looking through the latest copy of Descent when I spotted an article about the surface route back from Grotte Annette, which seemed to indicate that the route was blocked by a recent landslide and would be too dangerous to attempt. Jonny Braindead came back from a trip to the Petzl factory nearby on the Rhone valley and confirmed the rumours about the state of the exposed path around the south face of the Dent du Crolles. My heart sank as I thought we might not be able to do the trip I had set my heart on all those years ago.


When we first arrived in the area various groups did several other trips in the Dent de Crolles system including through trip from Trou du Glaz to Guiers Mort via Galerie des Champignons where unfortunately Ray Duffy broke his ankle and self rescued from the cave, but that is another story. We tried to make various enquiries about the state of the path from Trou du Glaz to Annette but without much success. Slug had been before some years before so on misty day at the end of July we set off with Bill Nix for a recce trip to find if the route was open and locate the entrances to Grotte Annette and Grotte Chavalier as they are close together under the cliffs below the Dent de Crolles summit. We ascended under the south face of the cliffs across a scree slope that Slug said he remembered and found a path leading below the cliffs. It was difficult to tell if we were at the right level in the mist so after splitting up followed by much shouting and faffing about we located a loose section of traverse with a recent rock fall followed by a newly installed fixed tope traverse. “This must be the way”. We little realised what a spectacular route this is as the mist blotted out the view and the exposed drops. We carried on pleased that we had found the route to be open and the information we had been given to be false. We continued traversing for some time around the east face of the mountain. It was difficult to see where we were due to all the mist! Eventually we decided to look at the map and realised we had gone too far north along the scree slopes. We made our way back several hundred metres and staggered up a loose scree slope to find a large cave entrance with an equally large draft – Grotte Chevalier. Annette lies a hundred metres to the south at the same level. After we had located both we had a quick trip for several hundred metres into Chevalier as it is a large passage boring under the mountain for over a kilometre and well worth a trip. You only need a lamp and helmet to do most of it.


A few days later after a reasonably early start we assembled at the car park at Col du Coq and set off for the steep walk up to Trou du Glaz. Forty minutes later we arrived hot and bothered at the large entrance with its cold outward draft, a place to cool off and get changed. We set off quickly through the entrance series as we had all been through this section before, even so a few of us, me included still managed to go the wrong way at one junction. We all assembled at the first of the three Lantern Pitches (10, 12 and 13 metres) and smoothly descended on tackle already in place. From here a stooping passage gradually enlarges to the top of Puit Lantern 4 (10m). This quickly leads to the top of P36 through a window step up and the way on to Guiers Mort . We did not need to descend this on this occasion but a traverse on an in-situ fixed rope around a deep black hole leads to the way on. I only had a small wobbler here, much to people’s amusement! After this was a mud slope and passage to a traverse with fixed rope around another black hole Puit du Lac. A large passage continues with a trench in the floor and we knew we were on the right route following the large red paint spots on the walls. A right turn at a junction, again well marked leads to Puit Ferdinand a 35 metre pitch with a nice big chain at the top for your pull through rope. Quite a bit of faffing here while the pitch was rigged gave me time for a few photos and a drink. Helen was starting to complain a bout the large split in the arse of her suit; not a pretty site! The pitch was a straightforward abseil with a ledge about half way down. As we were quite a large party there was time for some more photos at the bottom.

We set off from here along a passage that started to get smaller than the big stamping stuff we had got used to. A long rising traverse in a tall rift passage, Gallerie de Sud, again equipped with a fixed rope for protection was the next obstacle. The rope is well placed making the long step over one or two deep black holes less daunting. I was glad to be in front of Heather at this point, as the split in her suit must only be getting bigger. Red spots on the rock showed that we were still on the right track. More milling about in a series of smaller Yorkshire like passages and we seemed to have lost the red spots but not the draft so we pressed on down a climb in a narrower passages, where the tackle bags became a bit of a nuisance. We soon found ourselves at the top of another pitch with a chain Y-hang. This is Diaclase Annette a 23 metre pitch with a small chamber just over half way down. At the bottom we landed in a large phreatic tunnel with at least two ways on.

We stopped to check our copy of the survey here, as the way on was not clear. A decision was made and we set off and soon reached Puit de la Vire. This is an initial traverse on the left wall over a pit, which then goes to a swing over and prussic up an overhang (10m). I found the step off at the top a bit awkward and got a suitable amount of stick from the others, who all had a grandstand view of my antics! We stopped again for a brief rest and food stop while people packed away their SRT gear and then it was on again along a fine, well decorated tunnel, Gallerie 43, named after the year of its discovery. More photos were taken here. There are several junctions but the way on is well marked and well worn.


Before long we reach Puit de la Gnole, the final 75 metre abseil down to Grotte Annette. This is a large open shaft with an easy take off on the right hand wall It took a while to rig the pitch safely for a pull through and to get us all down.

At the bottom a left turn down through boulders leads to a bit of tat hand line over a sloping block into the bottom of a large aven. From here the way is well marked mainly by the big draft. It goes up and down over slippy climbs and narrower passage and the odd boulder pile. It did seem to take longer than I was expecting – probably about half an hour to reach the end and we did go the wrong way once or twice. The tackle bags slowed us down a bit. Eventually a larger choke is reached and the way on is fairly clear here. It soon became obvious that it was the way as we came across the wall of Armco barriers that hold up the wall of the choke, as it has collapsed several times. We now new that we were only a short distance from the entrance. In fact round the next corner you can see daylight shining down the entrance slope.


We climbed up through the choke held up with Armco barriers to immerge in the entrance passage with a short ramp of boulders to the entrance. A magnificent site awaited us with a spectacular view down to the Rhone valley several thousand feet below.  It was still a warm evening so we stripped off our gear and set off for the spectacular walk back around the traverse, fixed rope and back down through the alpine meadows to the car. I scampered down the path like a kid; I was so pleased to have done the trip I had wanted to do for so long even though I had spent a good deal of the trip looking at Heather’s arse!

It took us about 6 hours crossing Trou du Glaz to Annette Cave over 3000 meters of passage with low point at –162m but we were a large slow party and we were in no rush. I always think if you are only going to do a trip once then take your time and enjoy it.

Andy Hall


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