Oxford University Cave Club

Extremero Expedition, 1991

Final Report

Contents

Cueva de la Rana (53/5)

Biological find, Description, Rigging

This cave was originally discovered in 1989 by Dave Horsley. It immediately attracted great interest because of the strong draught issuing from the entrance. Unfortunately, 10 metres in, it became too tight. Over the next two years, a number of trips attacked the terminal squeeze with hammers and chisels, but with limited success; the chilling wind meant that few people were willing to work at the squeeze for more than about half an hour before returning to the surface to warm up. Halfway through the 1998 expedition, tactics changed as we started digging down in the floor, hoping to get under the constriction. An intensive effort saw nearly a ton of rock removed from the cave, had but one large boulder blocked the dig.

In 1991 this boulder was soon removed using a pulley system. Ahead were more boulders, but the passage seemed to be opening out beyond. Over the next few days, these boulders were loosened with crowbars and pulled out, until on the 15th of July, the final one, bigger than all the rest, was levered away from the wall and hauled out by Steve Roberts, Tim Guilford and Gavin Lowe. Tim and Gavin pushed through the hole into a small chamber where progress was blocked by more boulders while Steve and Michelle Nickerson shivered above. Tim and Gavin frantically pulled boulders away, working on two leads until one of them became passable. Tim squeezed up onto a coffin lid shaped boulder, and then turned round in the constricted space to follow a narrow passage to another small chamber. The others followed, finding an easier method. A short climb up led to a window overlooking a large chamber. The pitch was quickly rigged, and Tim sent down, being the only one optimistic enough to have brought his SRT kit. Part way down, a Pterodactyl-shaped flank of rock gave its name to the pitch. At the bottom, Tim explored the start of a large rift, before returning to the others.

The next day, the four returned and followed the rift. A route through was found which led to the top of a pitch overlooking a large chamber. Gavin rigged the pitch, Piranas, and then waited patiently for the others to join him. Together they set off along the passage to find... a complete choke after 10 feet. Undaunted, they returned to the top of the pitch and followed a miserably small descending rift. In many places the way was blocked by big, biscuit - like flakes of rock, but these were soon removed with a hammer. A series of vertical squeezes were passed, until the passage lowered to a crawl under two stalactites. A squeeze down over stal flow dropped into a continuing passage, which soon led to a feet first crawl to a tightening boulder pile. Five metres further, progress was halted by a vertical drop.

The next trip rigged a series of three pitches, Witch Doctor, dropping about 30 metres into a chamber. From here, a tight rift was explored to a too - tight section. Subsequent trips passed the squeeze, and continued along the rift to a short pitch. At the bottom, the continuing rift soon closed down to a serious constriction which will require a lot of hammering. An alternative route was forced in the top of the rift; this also becomes too tight.

With the bottom of the cave temporarily impassable, some holes on the far side of Piranas were investigated. A rope was rigged and Tim and William penduled across to find a series of rifts and climbs, most of which eventually become too tight, but may be passable with some work. Its is interesting to note that the strong wind encountered in the entrance passage is lost at the head October Acton pitch, and so it is possible that there is a lot of passage still waiting to be found.

The end of the cave is only 60 metres away from The Mendip Bit in 12/5, on a bearing of 320° and so is expected to join the system at about this point; however, 53/5 is still 190 metres above 12/5 at so it is just possible that the two caves may cross.

Gavin Lowe

Biological find

Contents, Summary, Description, Rigging

Two small arthropods, probably members of the same species, were found in the rift before Pointless Pirhana. One was placed in alcohol and brought back to Britain for investigation. So far we have identified the creature to the family level, and we will send it to the British Museum of Natural History for a more detailed identification.

The animal is in the same class, arachnida, as spiders and mites. It is from the order opiliones, commonly called harvestmen, and the family is ischryropsalidae. It has a body about 10 millimetres long and 8 legs about 20 millimetres long. Unlike spiders, which the opiliones bear considerable resemblance and which have a constriction forming a "waist", the front and back body sections are fused. The first pair of legs are extra long and probably have a sensory function. The chelicerae (the first set of appendages at the front of the head section) are extremely well developed, being nearly as long as the body, and have pincers on their distal end; spiders usually have short, stout chelicerae.

Ischryropsalidae are reported to prey on other small arthropods and molluscs, and to supplement their diet by scavenging. They are found throughout the mountainous regions of central and southern Europe. It is especially noteworthy that they are commonly found in caves in the Pyrenees, although they are not cave adapted and are found in surface environments as well as underground.

Jenny Vernon

Description

Contents, Summary, Biological find, Rigging

The cave is located in the Valle Extremero. A large valley comes down from Jultayu to meet the Valley Extremero, just above a small pond. The cave is an obvious large entrance directly above the pond, in the right hand side of the valley.

The entrance soon closes down to a narrow slot from which a very strong wind blows. Ten metres of stooping passage leads to a drop down into a small chamber. An awkward manoeuvre over a flat inclined slab of rock, the Coffin Lid, follows; climbing up and sticking your head into a slot in the ceiling, it is possible to walk your feet over the slab, and then crawl backwards out, keeping high where the passage is largest. A hole underneath the Coffin Lid is useful for passing gear through. It is soon possible to stand up in a small chamber, where a two metre climb leads to a window overlooking the 10 metre Pterodactyl pitch, named after the rock formation part way down.

The pitch drops into a sizeable rift chamber. To the left, after 10 metres, a hand lined climb leads into a well decorated rift, Silence of the Sheep, leading to a three-way junction; one route doubles back under the rift, and probably reconnects with the passage further on; the other two routes are tight draughting inlets. From the bottom of adaptable pitch, the main route leads to be right along the reasonably sized rift. Part way along, it is possible to climb down to a three way junction. The left hand inlet soon closes down. The right-hand inlet leads to a small chamber with a rift over the top; this probably connects with Silence of the Sheep, but wasn't fully pushed. The other route is a too tight output, which undoubtedly connects further on. Following the obvious traverse level leads to a climb down to a chamber overlooking a pitch. From here there are two ways on.

The 15th metre pitch, Pointless Piranas, drops into a large chamber, where the only passage chokes after 10 feet. It is possible to pendule across the top of the pitch into an obvious hole in the far wall; at present the two sides are connected by a single rope - abseil part way down and then prussik up the other side. This leads to a broken chamber with three possible routes on.

A squeeze through stal leads to a second squeeze into a well decorated rift which closes down and was not fully pushed.

Climbing down through the loose bolder choke leads into a tight rift which was pushed little further than the tight right-hand bend. A fairly exposed, lined climb leads to a ledge overlooking Pirhanas chamber, the Cement Garden. The only way on is a steep muddy ramp leading to a small chamber and a climb up to a possible, but unexplored, route on.

Alternatively, from the top of Pirhanas, doubling back under the approach route and descending the rift leads to the start of Big Biscuits rift. Following the water, a damp three metre descent is made into a chamber. The rift descends steeply to an awkward squeeze, best tackled on your left-hand side about 20 centimetres above the floor, which opens out above a climb of three metres. Another squeeze follows almost immediately; this should be approached feet first, staying high until it is possible to descend. The rift now becomes slightly easier. On the left, a circular hole leads into a blind chamber, Wol's House. Opposite this, a narrow passage leads through to squeezes to an exposed climb; a further crawl leads back into Pterodactyl chamber. Continuing along Big Biscuits rift, the route remains sporting with short climbs and constrictions, to where it allows to a crawl under two stalactites. Beyond, an awkward two metre descent over calcite drops into a meandering rift. At a corner, a mini boulder choke is encountered; this is passed feet first, taking care to avoid dislodging the boulders in the roof above. A few metres further on is the head of the series of pitches, the Witch Doctors.

The first pitch (P15) is best reached by traversing out to a Y - hang off a bolt and spike; two deviations achieve a free hang. This pitch lands on a ledge from where a flake provides the delay for the next pitch (P12); this also lands on a ledge, from where the rope is deviated out over the shaft. Penduling right over the pitch leads to a parallel shaft with a final drop of five metres, into a large rift chamber. Low down to the right, a squeeze and short crawl leads into a chamber at the base of the original shaft. To the left on the bottom of the pitches, an inlet can be followed up an easy climb into a rift, with a route leading back to the base of the pitches; a less obvious route leads straight up, but is very exposed.

The main route from the base of the pitches is to follow the passage to the right into Shagging the Hedgehog rift. This is narrow and awkward, with many sharp, oversuit - ripping spikes. It is possible to descend to stream level at one point. Beyond the worst squeeze, a climb up following the draught leads into a small chamber. The rift continues to a squeeze which opens out above a three metre drop onto a crawl at the top of a 10 metre pitch. At the bottom of the pitch, the rift continues, but soon closes down; it appears to open out ahead, but a lot of work will be needed to pass this squeeze. Alternatively, descending the pitch only two metres, it is possible to squeeze into the top of the rift while lined. A tight vertical squeeze follows; this drops into a narrow rift, which soon closes down at a right-hand corner.

Gavin Lowe

Rigging guide

Contents, Summary, Biological find, Description

The rigging described here is as at the end of the 1991 expedition. Where the rigging should be improved, this is noted. " means that the rope used for the previous pitch is continued for this section. Pitches left rigged are marked *.

Pitch			Rope	Rigging
Pterodactyl (P10)	15m	Thread backup; 2 bolts (bolts need moving higher); 
				deviation at -4m (tape round Pterodactyl's back).
Witch Doctors: P15	40m	Thread backup; spike and bolt Y-hang; spike deviation at -1m; 
				spike deviation at -1m.
": P12			"	Bolt backup; spike belay; spike deviation at -2m; 
				spike deviation at level of ledge (needs another deviation 
				to avoid rub); pendule right to ledge.
": P5			"	Bolt and spike Y-hang.
Final Pitch (P10)	15m	Two spikes
Lined Squeeze*		10m	Two spikes; spike belay on far side of squeeze.
Pointless Pirhana (P15)	20m	Boss backup; two bolt Y-hang; bolt rebelay at -2m.
Pirhana Pendule*		15m	Boss backup; two bolt Y-hang (may need bolt rebelay at 
				-2m and/or more slack in rope); on far side, natural back-up 
				and two bolts.
Climbs above Pirhana*	30m	Natural Belays

Contents, Summary, Biological find, Description