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France 1983

The following article has been published in the Axbridge Journal recently but I make no apologies for publishing it here even though the trips described were done four years ago.  My only apology is that I have been unable to copy the main survey and include it with this BB.  Unfortunately it is too complex to be worth reducing, I suggest that anyone going to the Dent-de­Crolles contacts Paul Hodgson and copies the survey. (Ed)

After much deliberation and reminders from friends over several years, I have finally finished this trip report of our visit to the Dent-de-Crol~es and the cave systems of the Trou-de­Glaz.

We had planned this trip over several months and had decided on transport arrangements, the route, how much food, camping kit and the tackle required.  The longest part of the preparations was obtaining BCRA Insurance Cover, I recall it having something to do with the diversity of Caving groups which we individually belonged to.

Suddenly the day of departure arrived and we had to make our final preparations during that day.  An old Bedford van was borrowed for the trip and we stuffed all this kit and five people into it and set off for the late ferry from Dover.  The trip to Dover was uneventful, although we took it in turns to drive the van to get used to it.

Customs passed, we found ourselves travelling through the night towards Paris.  At about three in the morning I was woken by John, who was driving, because the van had started running on three cylinders.  With the Bedford van the engine is easily reached by removal of the engine cover inside the van. So whilst still moving I took it off and woke everyone else up.  With the aid of a caving lamp we found the problem – one of the spark plugs had unscrewed itself and was dangling by the HT lead.  We tried re-fitting it while still travelling and didn't get very far.

After a short break we were back asleep again while John drove on through France.  We hit Paris during rush hour but managed not to get into any trouble.  We continued to the Fontainbleau Forest where we had a couple of hours kip, a late breakfast and then made our way to one of the boulder groups in the Forest and spent several hours "bouldering".

An uneventful journey followed, we travelled along the Autoroutes to the outskirts of Grenoble where camp was set up in a motorway service picnic area.  Early next morning we made our way through Grenoble and along the Isere valley to take a steep road up to the ' Col du cog', which is the closest point by road to the Dent-de-Crolles.  The views across the valley to the Alps were impressive as was the Dent-de-Crolles itself.

The Dent-de-Crolles is part of the Massif de la Grande Chartreuse which is an elongated mountain block some 45 miles long by 15 miles wide and is located between Grenoble in the south and Chambery in the north.  It is flanked by the Isere Valley to the east and south, while the D520 and N6 form the western boundary from Grenoble through Voiron, St Laurent du Pont, Les Eschelles to Chambery.  Beyond the high ground falls away to the Rhone Valley.  Sassenage and the Gouffre Berger are to be found to the south-west about five miles beyond the Isere valley. To the east the ground rises sharply to the Crests of the Massif d'Allevard, a part of the French Alps.

Provisions were picked up in St Pierre de Chartreuse and a suitable camp site located in St Hughs de Chartreuse, a few miles up the valley.  Previous club trips have used a variety of camp sites, especially at perquelin which gives easy access to the Guiers Mort but a long drive or trek to get to the Trou-de-Glaz and P40.

St Pierre de Chartreuse





Our first trip was a 'pull through' trip from the Trou-de­Glaz to the Grotte Annette Bouchacourte.  The van was taken to the Col-du-Cog where we got partially changed before setting off on a well defined track, through the woods, which shortly disappeared leaving us to force a way through to reach the grassland beyond.  We climbed up the steep slope to the track at the foot of the cliff faces and followed this to the Trou-du-Glaz where we found a snow drift in the entrance and a good cold draught.  Once kitted up we descended the large gently descending phreatic entrance tube to a short maze.  A well marked right hand turn leads abruptly to the first "Lantern Pitch" (11 m). This was already rigged with 'bluewater' so we abseiled down on it.

The second pitch (12 m) follows immediately after, again rigged, and after a short crawl the third pitch (13 m) is reached.  Here we met a party from Hadies Caving Club ( Bristol) coming up.  Another short crawl brought us into the main gallery, although wide it was not very tall and the fossilized stal in the roof made it necessary to stoop.  The fourth "Lantern Pitch" (12 m) was reached and quickly descended.

The large dry passage which we were now in was suddenly broken by a shaft which replaced the floor. A short climb into an oxbow on the right took us to a traverse past the "P36" shaft and back into the continuation of the passage via an eye hole.  The passage continued only to be broken by another hole in the floor, this time by " Lake Shaft" (52 m).  An exposed traverse with a bold step was negotiated on the left.  The passage continued.  We noted the Cairn which marked the start of the meanders to "Pendulum Pitch" which we would use for our through trip to the Guiers Mort.

The next shaft to replace the floor was "P60", the traverse on this was larger and on a sloping muddy ledge, fortunately there were plenty of handholds.  Just up a side gallery was "Labour Shaft" (63 m) which was about 10 m diameter and well watered by a small stream from a considerable distance above.

The main gallery was followed to "Fernand Shaft" (25 m) which is an easy broken pitch.  A short way along we found ourselves traversing along an earthen ledge above a deep rift, plenty of handholds but tricky in places when carrying tackle.  A narrow sporting rift followed and ended in a 20m drop which was free climbable, although we abseiled/climbed using the fixed rope at the top of the pitch.  At the bottom were two pots, one was blind, and the other leads to "Gallery 43" (4 m wide, 2-3 m high) a steadily ascending 'railway tunnel'.

"Traverse Shaft" is next.  This is bypassed by a crawl along a ledge on the left with a stretch to distant handholds. The passage is followed to another hole in the floor, "Climbers Shaft". An exposed traverse along the left hand wall leads to a fallen slab across the shaft.  Moving across the slab a 6 m climb on the right wall, with few hand and foot holds, leads to the passage continuation.  At the next fork in the route we turned left and the following two forks the right hand turn was taken, this brought us to the head of "Corog Shaft" (30 m).  This was a pleasant pitch of 10 m to a ledge and 20 m free.





The passage continues, with various side galleries, through five boulder ruckles.  The first of which is the "Cistern".  This is a well concealed hole in the ruckle and the only way on.  The other four ruckles present no real problems, the passage finally leads to a loose spiral stone chute leading to a self blocking squeeze - "The Spiral Staircase".  Route finding was made easier by following orange marker tape and the remains of some cotton thread (first noticed on "Fernand Shaft").  The other side of the squeeze we ascended more loose stones, which were kept back by motorway crash barriers, to exit in the Annette Bouchacourte Grotto.  The Isere valley is 1400 m below, most of which appears vertical.  The view from the cave, exit is impressive.  The Isere valley below and the snow covered French Alps rising the other side.

After de-tackling we trekked along the sometimes non-existent path around the Dont du Crolles and eventually back to the van at the Col du Cog.  Total time underground was somewhere in the region of 8 hours.


We drove the van to the Col du Cog and parked, this time lower down to allow easy access to the usual approach to the steep ascending grass slope to the track along the cliff base. By the time we had got the tackle bags sorted it was about 07-30 hrs.  We followed the same route to the Trou du Glaz as before, and concealed our change of clothes in the entrance.  The path continues upwards, up a couple of chimneys and a few scrambles to the plateau.  By following the red painted arrows we arrived at the summit, took a few photos and then searched for the entrance of P40.  By following the valley down from the summit the entrance was easily found just beyond the first trees.

Pete and I melted snow for the carbides, got changed and rigged the entrance shaft whilst Tony, John and Steve searched for the Gouffre Therese (without much success).  We descended the large fluted shaft (40m) and searched for the way on, a narrow blasted slot.  We eventually found it at the top of the rubble slope and not as the description said, the bottom.

A short crawl leads to "Kid Shaft" (8 m) which we free climbed down into "York Gallery".  This is a mud floored, wide bedding plane with several local collapses.  In places it was possible to walk, otherwise we had to stoop and crawl.  At the end a 'no hold' 30 m climb leads into a short meander to a ledge around a 3 m diameter shaft.  Directly after, a slippery slope, with a fixed hand-line, leads abruptly to the head of the "Three Sisters Pitch" (45 m).  The rope is belayed to a buttress to give a free descent of 10 m to a ledge, then 10 m to another ledge.  Here we met the stream and since little water was flowing we continued to the floor rather than traverse the ledge and rebelay to descent one of the other dry shafts which met at the bottom.

Two ways on were found, one following the stream, and the other through a partially blocked bedding plane into a meander.  Taking the latter we soon found ourselves traversing a deep rift at a high level. The stream dropped rapidly away below and the meander gained a floor at an intermittent level.  The meanders continued and we decided that the description we were following was inadequate so as a precaution we left the odd pitch rigged as we continued until we could verify where we were.  We then had to go back and pull the rope through.

A boulder blockage was next, some went over; some went under to reach a chamber - "Orbitalina Shaft". The meanders continued to a 6m shaft and beyond to two short slippery drops and finally a pitch.  John went down and declared it was "Balcony Pitch" (40m).  The first part of the pitch is descended in three stages, 10m to a ledge, a further 10m to a narrow ledge which has to be traversed for 6-7 m to a re-belay point for the final pleasant 20 m descent to a wide ledge.  The stream cascades down a gully at the side of ledge into the next shaft.  The water is avoided by traversing along the ledge and up an awkward 5 m climb to "The Balcony" a 1 m x 1.5 m ledge. From here we could see the passage by which Chevalier first approached "Balcony Pitch".  It is some 7-10 m lower and in the opposite side of the rift.  The pitch is an easy 25 m drop to a chamber from which a short piece of rift passage is followed to "Shower Bath Pitch" (30 m).  The stream can be avoided for part of the descent, but you get drenched just the same.  Pete tried a bit of aerial bombardment on his way down dislodging a few large rocks.

Two passages exit from the bottom of the pitch and we followed the lower - they both met at a junction of five further along.  After a scout along the passages we took the most obvious route and noted that we passed black painted numbers in descending order.  The route involved a lot of stooping and there were a large number of side passages which were not marked on the survey. 











Eventually we carne to the turn to the "Lantern Pitches" and familiar ground.  Back through the maze and into the main gallery. Just as we approached the exit a large ice stalactite tried, unsuccessfully, to impale itself in Pete, missing him by a mere five feet.

We changed in the late evening warmth and made our way down to the van and back to the camp site. This trip, although enjoyable, was marred by the inadequacies of the description which we had obtained and as a consequence our time underground was much longer than it should have been.


The next day was a day of rest.  The following morning we were up early and on our way through Grenoble and up into the Vercors.  Eventually we started to descend the Bourne Gorge, the road stayed about halfway between the floor and the top of the cliffs.  Just after the turning to the Choranche Show Cave we turned down a narrow steeply descending road which led down to the hydro-electric power station at the bottom. The descent was in the order of 700 ft. After changing in a small car park, we followed a footpath up to, and around, the Bournillon Cirque, ducking under the water feed pipe for the hydro-electric station.  The cave entrance, one of the largest in Europe, is hidden in a corner of the Cirque. The last bend in the path, when you are at last able to see the cave, is practically inside the entrance.

We ascended a large scree slope into a large fossil passage, at one side of the main entrance, and followed it until it degenerated, from about 100 feet diameter with boulder infill, to a boulder ruckle.  Dropping through the boulders we entered a passage which gradually assumed large bedding plane characteristics.  The end of the bedding plane would appear prone to flooding judging by the black deposits over everything.  A short climb through boulders brought us into the main passage.  Turning upstream took us to a large black sump pool.  The way out was to follow the main gallery and the stream.  The passage became vast and had a few attractive formations, the largest of which was the " Negro Village".  We didn't stop to get any pictures because of the swarms of midges and mosquitoes etc. which were crawling up your nose and other places.

The final section involves some relatively easy traverses around some deep pools before reaching the large entrance lake.  This is crossed at its narrowest point by a fixed bridge.  Time taken: about 2 1/2 hours.  After changing we drove back up the narrow road and up to the Chorancle Show Cave car park which is in the 'Cirque de Chorancle' where a number of cave exits may be found.  We dried our kit in the sun and had lunch, then went to the show cave to ask permission to descent the 'Grotte de Gournier', this was given.


The Grotte de Gournier is a resurgence cave and from it issues the larger of the two permanent streams in the Cirque.  Wearing only swimming trunks and boots we set off from the car park and made our way to the entrance, picking up a large crowd of inquisitive tourists.

The entrance arch leads to a large clear lake between 60 and 75 m long, 15 m wide and about 10 m deep and COLD.  After swimming around the left hand wall of the lake for about 50 m we climbed onto a small ledge where John and Tony climbed up 8 m to another ledge which they traversed along to the top of a huge gour.  We swam to the next ledge and climbed up the ladder which had been lowered over the gour.  NOTE: If water is flowing over this gour then the cave is flooded.

We decided to follow the main gallery as far as we could, and not to bother with the stream access points, then return taking photographs.  The fossil gallery starts as a 'railway tunnel' about 10 m wide with a large gour bank starting on the left and eventually dropping over a lip into what may be the lake continuation.  A little way on the passage takes on enormous dimensions, the roof being over 20 m high and the walls in excess of 15 m apart.  The floor was nearly always of boulders, some enormous - the size of bungalows - some distance further in we came across another well decorated section where a series of massive gours stretched across the passage, beyond this the passage size increased and we found ourselves in a chamber strewn with huge stalagmites on flowstone covered boulders.  An oxbow on the left contained some very good formations.  Further on, something like 2 km in, we reached a huge chamber into which we descended and then climbed up a steep boulder slope the other side to find ourselves at roof level with the main gallery choked off.  A hands and knees bedding plane crawl on the right brought us to another parallel (!) passage which shortly gained the same stature as the previous one.









More gours were found when a trickle entered the passage from an aven and the number and quality of the formations increased.  Large boulder heaps now had to be crossed and some of these brought us near to the roof. A 5 m drop halted all of us but John who somehow managed to climb down and have a look further on.

The way out was the reverse of the way in, but I stopped frequently to take photographs, in fact I could quite happily have taken many more.  This gave time for the other members of the party to explore side passages and to find two of the four ways down into the active streamway.  The trip took about 4 hours and was very enjoyable.


Our next trip was the through trip from the Trou de Glaz to the Guiers Mort.  Tony and John went into the Guiers Mort entrance and traced the way back to the bottom of "Chevalier II" the day prior to the through trip, as we had no wish to spend a long time in the labyrinth.

We drove up to the Col de Coq again and unloaded all the kit, including Tony's, who then took the van to a car park in the Forest above Perquelin and joined us at the Trou de Glaz entrance later.

We followed known territory descending all four "Lantern" pitches and the traverses around "P36" and " Lake Shaft".  A short way after " Lake Shaft" we found the cairn marking the meanders to "Pendulum Pitch".  We descended and found that although the passage was not too constricting the shelving made it difficult to haul the tackle bags after us.

After 50 m the passage came abruptly to a shaft, "Pendulum Pitch" (60m).  There are two excellent bolts above a small hole in the floor which give a free 60m descent in the middle of the shaft.  At the bottom the meanders continue for about 220 m which took us 45 minutes to negotiate.  At the end was "Petzl Shaft" (20m) which was free.  A few meters on, at the bottom, was "Trap Shaft" (15m).  The abseil was slightly awkward and made worse by a trickle from above.  By halting part way down we were able to pendulum over to "Dubost Halt" instead of climbing from the bottom. This is a small platform, just big enough for all five of us, overlooking "Chevalier Shaft I" (35m).

The descent was in a large chamber and it-was noted that there were some rock flakes which were very thin and intricate.  We landed on a jagged floor with a huge hole in it - "Chevalier II" (20 m). On our right, looking down the second shaft, we saw a traverse guarded by a heavy duty handline and we think that this is the connection with the "Metro".

We climbed down 3 m to a ledge in Chevalier II before abseiling.  At the bottom we found Tony and John's marker placed there the day before. A short traverse in a rift leads to a sandy crawl to the top end of the Guiers Mort main passage.  On the right the stream sumps to the left, we followed the large abandoned streamway crossing numerous deep water filled potholes. The largest of which being called the "Swimming pool".  Using the fixed handline and a lot of stretching this was passed without getting too wet.

The stream appears shortly after and the gradient steepens.  We came to the remains of a French ladder hanging.  Tony and John free climbed and dropped our ladder down - it was short.  Eventually got a start on the ladder and climbed up into the stalagmite traverse which is a wide bedding plane running on top of the vadose stream canyon and is covered in formations.

A rift begins to develop in places - "Marmite Gallery" - and we maintained our level in traversing along it.  A traverse over a pot requires delicate footwork, fortunately there was a fixed handline.

The passage continues into "Bivouac Gallery" and the main streamway is gained from a wide balcony via a short climb.  Another broken ladder hanging down from "Syphon Gallery".  Again Tony and John free climbed and hung our ladder down. A short way along we found yet another broken ladder hanging in a recess and we used our ladder on this occasion more as a handline to gain "Syphon Gallery I".

Following the obvious way we came to an awkward 2.5 m drop to re-join the river.  The streamway can be followed to a long low duct - " Christmas Basin" - we took the " Christmas Basin" bypass by traversing at a high level into a tunnel ending at a platform next to the "Elizabeth Cascade Waterfall" (6 m).  After abseiling down we followed the stream until it disappeared under boulders while we went over into the " Grand Canyon".  Holes develop in the floor and after about 50 m we ascended (10 m) by ladder into a low roofed tunnel.  This marks the start of the labyrinth and is a series of muddy crawls and crouches. Tony and John picked our way, and we came to the end via the hurricane which was sufficiently strong to keep our Petzl carbide lights from staying lit.  An 8 m drop into "Climbers Gallery" follows, a fixed handline aided the descent.  This regains the main passage the other side of the sump.  A narrow section connects with the "Grande Salle", where a large tree trunk makes the high level escape route when the sump rises to fill "Climbers Gallery".  A series of large chambers lead down to the Guiers Mort entrance which is a 6 m diameter tube exiting 10 m up a cliff face.

Tony retrieved a bottle of wine from the streamway which he had placed there on the way up, to join us at the Trou-de-Glaz.  This went down a treat.

We then walked down to the van.  Trip time about 8 hours.


Since we went to the Trou-de-Glaz quite a lot more passage has been found and some of the trips described have now become non-preferred routes.

The through trip from Trou-de-Glaz to the Annette Bouchacoute Grotte is hardly ever done because a connection has been made with Grotte Chevalier which cuts out the boulder ruckles on the Annette trip.

The preferred trip from the Trou-de-Glaz to the Guiers Mort now uses the "Metro" and by-passes about half of the trip described.

If I get any more details I will pass them on to the Editor for inclusion in a subsequent BB.  Our primary information for these trips came from the following references:-

1.         Survey by G. Grosseil

2.         LUCC journal Dec. 1966

3.         LUCC journal Spring 1969

4.         WCC journal Vol. 16 No 183

5.         CSS journal Vol. 10 No. 6 1980

Letter via the Editor

Graham Johnson,

Hello to all at the B.E.C.

Glad to see (from the B.B.) that you’re still an all-action club.  I’m pretty isolated up here don’t even know how you faired in the ‘Quest for the Rusty Tankard’.  I suspect by traditional devious, sly, and underhand means you regained the trophy. Well done.  The reason for this letter – I’m off to the Canadian Spelofeast, leaving U.K. August 24th and will be happy to take any messages etc. to the cavers out there - nothing that a fork-lift truck can’t handle.  Best of luck.

Yours sincerely,