T20A Silvestre Pot exploration log

Extract from various sources on exploration of Silvestre Pot (Alistair Gott)

Part 1

Sobra valley is part of the stream catchment for cueva del marniosa, very little was known about the stream sinks until 5 days ago. Cueva del marniosa is one of the two well known stream caves in the Tresviso region.

Imo furlong, Stu coxon, Derek Cousins and Alastair Gott started the ball rolling by doing some gorse, bracken, karst and bramble wading. Finding various areas of interest. Aided greatly by stu’s verbal sonar “boop” and imo’s “cooweep”. Both of these sounds really carry in the woods.

A return was on the cards for the next day, without a drill, we descended a cave named cueva donga. Down various sections to a constriction. Kelda Jones, stu coxon, bob the juggler, Adam Spillane and Alastair Gott were present on this day.

The third day we returned with a drill, 5 ropes of various sizes, a keen biologist called Will Burn and breaking gear. With 2 objectives descend IM2 “practice pot” and cueva Donga. AG descended practice pot and placed 2 bolts in plain clothes and SRT gear, realising his rope did not reach the bottom, he returned to the surface and kitted up.

Whilst AG and SC descended practice pot, the “other two” KJ and WB had a dig to connect donga via the stream sink and collect biological samples, putting many bugs into alcohol for further analysis.
After getting bored with that they went for a wander and found another hole which needed investigating. Rigging a rope from a tree Kelda fearlessly descended…

Practice pot was going well, bolts being placed and the Derbyshire digger (AG) doing what he does best and digging at 30m depth, (after surveying) finding approx 6m more passage to a mixed mud and rock constriction. AG and SC got bored with this, surveyed it and returned to the surface.

KJ1 “silvestre” had reached a leafy ledge and needed some bolts, AG and SC joined Kelda (KJ) and Will (WB).

Part 2

About 4.30pm AG and SC were teaching KJ how to place a bolt. KJ was desperate to descend.

AG found himself at the base of the shaft, I would say the shaft is approximately a tenth of the size of eldon hole, similar width to length proportions. At the base approx 10m down, AG then put a bolt in to rebelay the rope to help rigging the y-hang. The rock here was quite hard to place a bolt, but in two places it was possible to place. despite the cherty conglomerate. Below this, AG rigged a rebelay and told KJ and SC that it was ok to descend. Three leads were immediately obvious. A wet lead “upstream”, a dry lead and the downstream lead. The chamber leading to these leads was approximately 10m by 10m.

All upstream leads have been left to further expeditions.

KJ was still keen, despite AG’s protesting. Rigging a handline down a 3m climb, her first bolt placement, the drill ran out of battery for further bolts.

KJ climbed down even though AG said if she descended he would leave her, AG soon excitedly followed, keen not to miss out. “Fear of missing out”

KJ, SC and AG then found themselves in a bit of stompy stream cave approximately 30m long. Ending in a gaping hole to the unknown. With no battery they returned to the surface.

All four of us returned to the hut, including Will Burn our callout. AG had a celebratory shower, 1st shave of the Expedition (Gott to look good for the photos!) and wolfed food down, lovingly cooked by the other members of the expedition. Potentially Helping with the washing up (can’t remember) AG was feeling pleased with himself. But tired.

Part 3

We returned again on Monday. The trio were together again Kelda Jones, Stuart Coxon and Alastair Gott, this time as surveying team.

Sir Phillip of Thirsk had said we needed some “adult supervision” so we were joined by Bob the Juggler and Jason Gotel, who immediately became the rigging team. Storming through the cave they excellently rigged 7 pitches, of varying length. At the start of the day, sir Phillip said we could only take the Crap rope. So we left 200m of brand new rope at the “hut” and cracked on. As it happens, JG and BTJ (Bob Cockeram) did a very good job, all the ropes were actually the right length.

The surveying team only followed the way on and did not survey the numerous sinks joining the flow on the way. They caught up with the rigging team at the head of the seventh pitch, “electronica pitch” the PDA ran out of battery at this point and the rigging team had swapped batteries in the drill to ensure they could reach the bottom. Rigging style by Jason Gotel was classic “by the book” rebelays to keep the cavers out of water. Top work.

The 58m rope landed on a ledge with space for 5 or more people, the pitch remaining was estimated at 17m by Bob the Juggler. At this point drill battery was low, it was suspected that the drill batteries were cold, and could get the remaining half a hole needed to rig the pitch. Therefore JG and AG each had a drill battery under their armpits to warm up. It worked, and a bolt was placed to complete the 70m ( ish) “electronica pitch”.

Part 4

Electronica pitch is a fantastic pitch, with white lines running through the rock, and approx 14m wide and 30m long chamber, straight down not unlike some of the Yorkshire style places, i would say the equivalent in Derbyshire would be the NCC shafts in terms of vertical walls, except electronica is bigger.

Without surveying, the team continued downstream, the dimensions of the chamber close down to a rift type development with cherty conglomerate ( approximately 1 and a half body widths wide) much like the entrance pitch. The team found an ethical problem with a bridge of rock glued together by mud and calcite, the team decided it was quite dodgy, so two sandstone boulders were chucked at it to see if it would collapse. It didn’t, but there’s a video made by Stuart Coxan, which may get posted up later.

The team, then continued downstream to a point where the stream drops down a pitch. The remaining 50m rope was left for futher exploration the next day.

Part 5

A return was in order for Tuesday, objectives were to continue exploration and survey electronica pitch.

AG did a sterling job of forgetting the drillbit and also forgetting the waterproof protection for the surveying tablet he had borrowed from “sir Phillip”. Eeeeep!

AG ran back up the hill via the muddy track when he realised he’d forgotten the drill bit and called “sir Phillip”, who dispatched Adam Spillane in a car to deliver the drill
Bit. The team then descended to the head of electronica pitch, where AG realised his error with the tablet and tried to “make do” with a zip-lock sandwich bag.

Having no experience with surveying pitches AG then tried to survey on the way down, but soon realised that he wouldn’t be able to download the shots till the base of the pitch. The team today consisted of Alastair Gott on tablet and Stuart Coxon on disto shooter. Bob and Jason continued the rigging.

At the base of electronica, AG tried to download the shots from the disto with a damp tablet. Every time he tried to select the download button the sandwich bag decided to touch the first shot collected at the top of the pitch to start the survey. Needless to say this method was dispatched rapidly. Mars bars were extracted from what looked like a dry bag, and the tablet was turned off and enclosed within, it turns out this was a “damp bag”. So the tablet was not much better in here. Rice to the rescue for the second time on “the holiday”.
Surveying continued with disto and book, noting the legs of the mostly north trending rift. Any bad LRUDs (left right up down) or forward legs were noted for deletion later.
AG picked a permanent marker which it turns out is not as good as pencil! Another lesson learnt!

We had done so well the day before of hiding all the old rope in the cave, so “sir Phillip” deemed that we could take 100m of New rope. Mmm, we hid this in the cave as well!

At the base of the “water fall junction” pitch we found at the continuation of electronica, we found three ways on.

Straight on, 23deg is the direction of hall of the mountain king in cueva de la marniosa. Some 300m distant from the head of electronica, we were closing the gap…

Behind left (dry but descending) and behind right (wet pitches) were also leads.

We progressed two leads, picking the dry options, straight on and back left. Leaving the wet option for the end of the day. JG and AG went for straight on and BTJ and SC picked back left.

BTJ rigged with SC as support, and used up the rest of the 50m old rope, phew! The pitches ended in a sump.
JG progressed the straight on lead, with AG stopping at a climb he didn’t like, JG reckoned 180m of passage, paced. The lead took a slight trickle of water, but nothing more, it was exceptional fossil passage with popcorn formations.

The team made a decision to exit the cave, it being after 7pm.

It has been reported that hall of the mountain king only takes a slight trickle of water…

Part 6

Today was a day off for Alastair Gott, Stuart Coxon, Kelda Jones and Jason Gotel. AG getting up at midday + 30mins. Coffee and tea straight off then a spot of brunch in the bar before decamping computer, tablet and disto to the bar for investigation. Some data sorting required. A lovely leisurely day starting in the sun, turning to mist/cloud.

Bob the juggler, Dave “mate” Collins and “Gay” Dave powsland were dispatched today to investigate the wet lead and the dry 23 deg lead (to marniosa).

The wet lead was pushed by bob the juggler to land in water. It is assumed this is a sump.

Dave Powsland entered the 23 degree passage, and investigated for some way before retuning to some hot food cooked by Dave mate. The three returned in time for dinner, rather than the 10pm time that we’ve been returning on other days.

Tomorrow Jason Gotel plans a return for the through trip, a team will probably be assembled. Otherwise we will savor the treat for next year…

Part 7

Silvestre through trip to marinosa, did the lead killers make the through trip? Find out at hidden earth 2018 in one week.

Silvestre Pot (Sobra Valley)

An early start was arranged, which would normally mean an early night. 2am was the actual bedtime for most on the trip. The agreed start time of 9am was fairly well stuck to and saw us at the cave by 9.45am. Upon arrival at the track, AG decided to put his caving kit on and walk down. As we walked away the shout of ‘Oh no, these aren’t my wetsuit socks!’. Bob cast his sceptical eye over the previous days rigging and gave it a rating of ‘Misplaced, must try harder’. In actual fact the bolting was fine and the rigging was good, but we thought we may need any extra rope lower down and not around the entrance. Bob re-rigged with Jason following ready to add a bolt to the next rope and continue. Kelda then followed on to mark the survey points, Stu followed with the Disto and Alistair brought up the rear with a PDA to draw up. This was working well, until the request for more rope came fairly quickly in order to rig more economically. The survey team quickly caught the rigging team who were discussing the best way to rig with some less than inspiring rock to go at, whilst crucially staying dry! This pitch dropped us about 15m (see survey) into a large chamber. Onwards from here we continued through a selection of boulder slopes and short pitches which brought us into some large clean washed passageway with very little in the way of stooping or obstructions. The one obstruction that we did come across was a small puddle that we had to duck down to cross. Jason said when he first got there it was knee deep. We all got wet feet. Upon the return journey we broke the plug on this puddle and its has now dropped to just below ankle deep. After this another couple of pitches and passageway led us to a big pitch into a large hall. At the top of this pitch is where the PDA ran out of battery so we stopped surveying. Whilst waiting for Jason to bolt down the pitch, a lot of chatting happened. One of the more notable comments was from AG who said ‘why did we spend all that time digging?’ Jason did a sterling job of the bolting on the large pitch, putting several rebelays in place to keep us all out of the water. At the bottom of this pitch a ledge was reached, followed by another short drop of a laser calibrated Bob’s arm length of 17m. The rope reached, so we assumed this was correct. A quick potter around the chamber to take in its size led us on to a rift passage and another short pitch. We left it there, having run out of drill battery at the top of the short pitch. 2 hours saw us all back at the surface, with a nice walk back to the road in the dusk. Toby was contacted and we watched the stars whilst waiting. A good end to a top days holidaying.

Silvestre Pot (Jason Gotel)

Practice Pot (IM2) Cueva Donga (AS 1) & de Silvestre (KJ1)   

By Stu Coxon

 We left the hostel with the intention and kit to look at the tight section in Cueva Donga and hopefully enlarge it. Our secondary objective was to have a look at the pitch in the entrance of what is now known as Practice Pot. Alistair and Dreads went over to Practice Pot to start the day. Alistair quickly donned his SRT kit, tied a rope around the tree above and took everything he needed to bolt down the pitch. Very quickly a shout from the hole came asking for a hammer. The hammer was lowered. A sound of drilling commenced. Tapping of the bolt followed. Another shout came. This time asking for a screwdriver. Much amusement on the surface followed and the request was rejected on the grounds we didn’t have one and Alistair should not be doing D.I.Y when on holiday. Instead we lowered down a rachet spanner, which on the whole was more useful. Alistair placed another bolt and then returned to the surface, muttering about the rope not being long enough.

Stu then took the sharp end and re rigged the rope off a sling round the tree, creating enough extra rope to place one more bolt and reach the bottom on a second rope. Alistair followed on surveying in. Upon reaching the bottom Stu voiced that we were at the end of the cave for us as it narrowed off into a muddy rift. Alistair disagreed and promptly got stuck into a dig. We made a few extra metres with the use of Alistair’sshovel hands and a hammer.

Upon returning to the surface we were greeted by Kelda and Will.  Will had been down Cueva Donga looking for insects and had also been digging and extended Cueva Donga 4m (unsurveyed) upstream. Kelda had been prospecting.

After looking down several large shakeholes with no obvious entry points one had a large tree stump with the rest of the tree down the shakehole with just a small section of it exposed above the mud and leaf that has fallen into the hole. This had no entry point but just to the side as heading up out of the shakehole is an entry rift going down 10m to a large ledge of rock, mud and leaf. KJ went to get the rope and kit to descend the hole and see if it went. KJ met WB and he also came. KJ descended to the ledge and dropped a rock down the continuation of the rift which gets considerably tighter for a section. The rock hit the bottom and then rolled – an estimate of 30m so KJ came back up and went to find SC and AG to see if they had finished investigating the hole they were in and if could get some help and kit from them.

KJ and WB had also been wandering around prospecting and had looked at a few holes and were very excited about one in particular.

 

We wandered over and logged the hole as KJ1. KJ went down first and wasn’t confident in the rock for placing her first bolt. AG then took the lead, followed by KJ and SC. Upon descending we became quickly aware we were into a big hole. The start is an open shaft to a leaf, mud and boulder ledge. From here the cave changed into narrow rift down to a boulder slope with lots of animal bones!  That was not the only thing of interest! The cave opens into a rift chamber with 3 onwards leads. We explored the dry rift to the right upto a boulder jammed in where the passage changes from walking to hands and knees crawling. Not explored beyond the boulder. Boulder is marked. A little further on from the rift chamber is a streamway. Upstream we explored 10/15m to a wet crawl but did not go into the wet crawl. Downstream from the rift chamber we quickly found a cascade (6m) which we handlined down due to running out of drill battery. Downstream from this a short section of passageway leads to another pitch. Due to not having any drill battery we did not descend this pitch.  We returned to the surface to meet WB with tales of caverns measureless to man (mainly because AG would not let us survey!) a top days holidaying had by all!

 

Cueva del Marniosa – Upstream avens (Part 2)

by Dan Workman

The planned trip as of Monday eve was Sam and I to continue the climbing whilst Dave and Derek resurveyed the upstream passage behind us. However, in the morning Derek was not feeling up for caving and we were reduced to a group of three. We set off slightly later than planned but with a later callout we decided we should still be able to get a good amount done. The trip down to the streamway went by at a good pace and we arrived at the water after 40 minutes. After arriving at the bottom of the climb we moved all the climbing gear up to the next level whilst Dave stripped yesterdays hangers and maillons beneath us. As Sam had climbed the day before it was my turn to don the buckaroo suit. With a shaky start whilst I tried to remembered how to climb without tying myself in knots I pushed on up for about 8m to a suitable ledge where I rigged an “adequate” pitch off calcite stal for Sam to jug up and join me. Dave was pretty cold by this point so we hastily bolted a Y-hang and short traverse so Dave could also come up. Moving around a large boulder we were greeted by a sizable chamber which was probably 20m across and 30m high in places. The biggest stuff Sam and I have ever aid climbed to!

This is almost certainly the older mature passage above the immature streamway below. A muddy ramp dropped down lower toward what was probably the boulder choke and then streamway. Sam rigged a quick single bolt handline using our climbing rope and we dropped down to have a look. Once he returned I went down whilst Sam’s brew kit was assembled for some noodles. It is at this point that I should probably state that this was Sam’s brand new, very lightweight, and untested stove. As I almost reach the top of rope with my hand jammer I nearly have a heart attack as I look over to see Sam engulfed in a propane fireball with blobs of    burning hell spitting off in all directions covering both Sam and our gear. I rapidly down prussik and take cover behind the nearest the large boulder whilst Sam’s screams and efforts to extinguish it fail entirely. He throws it down and both him and Dave take cover themselves. It is at this point I notice how beautiful the chamber roof looks lit up in a wonderful orange light. We discuss for some time what the next course of action should be as the gas ganister has plenty of gas in it still. After about minute or so the large fire resides and it is evident the stove is now burning normally. I jug up and peek round the rock to see that it is probably safe to turn off and gingerly reach down to stop the flame which was currently doing a very good job of drying mud. Crisis averted. For a good while we all thought it might explode and I wasn’t looking forward to the resulting tinnitus (or missing limbs). Sheepishly we packed up our gear and made do with a few cereal bars to eat instead of same tasty hot noodles. We made good time on our way out and we were back to the entrance in 50 minutes. As there were diving bottles left at the bottom of the 22m pitch I picked up two loose 3’s to drop off in the entrance chamber (not lugging them back up the hill). We arrived back in Tresviso happy to still be alive with a good story to tell.

 

Alterntive take by Dan Collins

So my story starts gibbering on a ledge in Marniosa waiting for Sam and Dan to aid climb and rig so I could come up. It probably wasn’t that long a wait but minutes seem like hours, hours seem like days, days seem like months, it was probably 1 hour. So they got up the climb and sounded really excited to find a massive chamber but apparently it wasn’t safe to come up yet so I carried on sat down at the bottom of the pitch gibbering. Finally they rigged the pitch and could finally take of Dan’s down jacket, put my wet caving kit back on and start ascending the pitch. After finally ascending the pitch I got to the massive chamber which was very impressive and probably worth the wait. After being convinced that they weren’t going to be much longer and the promise of hot food I decided to stick around and put the down jacket back on.

After Sam came back up from looking around the chamber he got out his brand new light weight brew kit with 25 gram stove. He attached it to the top of the stove where it started to hiss gas, and after getting it connected then lit it. This however then produced a massive fireball, lighting up the newly discovered huge chamber and also setting fire to Sam’s arm and the dry bag. Sam tried to frantically put out his arm. I tried to pat out the dry bag. The stove was still spewing fire, and in his panic Sam tried to throw the water over the stove. This did nothing. We then both decided to run and shouted for Dan to do the same. Now hidden behind two rocks we watched as the orange fireball still spewing out of the stove lit up the chamber. Sam repeatedly asked dan if he had any ideas while trying to form mud patties with some idea of using them to smother the stove. Eventually the orange glow from the stove died down but me and Sam did not want to approach the stove in case the gas canister had got too hot and exploded. Dan on the other hand, saw the stove was burning normally, rather than spewing fireballs went back to the stove and turned it off. After calming down and having a good chuckle about what happened all decided to have a cigarette. Whether this was the best idea after a massive gas leak also made us chuckle. Now with only cold noodles we each had a chocolate bar and headed out of the cave and to tell of our discoveries and incident at the bar.

Cueva del Marniosa – Upstream Avens (Part 1)

by Sam Deeley

Having been driven down to the entrance by Joe, we entered the cave at 1300. Bob and Dave led the way to the streamway, after which we split into two parties.

Following the directions of Dave, specifically details of the climb over a calcite flow, we reached the first boulder choke. Quickly, we made the decision to climb the first aven before the choke, in an effort to avoid any misery associated with ‘choke-finding’. Before we could even flip a coin to decide who would lead first, Dan had his down jacket on and was ready to belay. I kitted up to climb first, scrambling up a first short section, under drip, to a level false floor. Our intention was to climb directly up a flow-stone/calcite wall, chasing the voids above. Very quickly, it became apparent that the flow-stone/calcite wall was utter sh*te. It was more suited to ice-axes, rather than bolting. After many wields of the hammer, the occasional suitable bolt placement was found, generally hidden by and inch or two of moonmilk (read: calcite j!zz). Eventually, I made it up to a false floor level, where a pitch could be rigged back down to the level of the main passage, approximately 12m below. The rift continues above, where it would appear to open up. The false floor continues along the same level, where a small traverse needs to be negotiated – although this is not considered the preferred lead.

All in all, a successful, friendly trip to begin the 2018 expedition. All kit was left at the base of the climb so that it can be continued tomorrow.

Cueva del Marniosa – Sump 2 push         

   Josh Bratchley, Rob Middleton, Joe Daniels, Arwel Roberts

A late start saw us in the cave not long after 13:00 (much better via Land Rover) and good progress was made down the entrance series to the 1st Pitch in the downstream passages where we’d left our 3 bags of cylinders the day before. Here we met Bob and Dave who had kindly diverted from their aid climbing trip upstream to re-rig the damaged rope and check the other two streamway pitches. Fortunately, the other pitches were unscathed and good progress was made to Sump 1 having lugged 7 bags between the 4 divers. The trip in was warmer than last year as we’d chosen to wear wetsuits the whole way, compared to last year when we opted to get changed at Sump 1.

At the sump, kit was sorted (Josh & Rob taking 1 x 3L cylinder each, with Joe and Arwel taking 2 each) and Josh dived first and inspected last years line. All was well, so all divers soon passed the sump without issue. Kit was again sorted, with 2 cylinders, 1 x 30m rope, slings/tat and regulators in a drum packed into 3 bags to be taken to Sump 2 between the 4 divers. Good progress was made through the often-awkward stream passage, past the two pitches and to the start of the traverse/rifts where SRT kits were dropped.

Slow progress was made through, in and over the sharp traverses with only a few small navigation errors – Josh luckily managing to remember most of the route and way down from last year. Eventually the main rifts were reached where the team squeezed, thrutched, clambered and grunted through, passing bags between them regularly. The deep pool halfway was no warmer than last year! This section of cave felt much better than last year as a larger team allowed longer chains to be made for bag passing.

After the rifts and boulder choke marking the end of the hard stuff, the lovely roomy stream passages were enjoyed down to Sump 2. Josh and Rob kitted up and Josh dived first with a single 1.5 L cylinder, laying a 9mm rope as line and a tape to measure the sump length and survey. The old thin line from last year was still intact, but didn’t feel secure enough. A bag of rocks on the back ensured that Josh sank enough to complete all tasks. Rob unattached the tape afterwards and Josh reeled it in before Rob followed through with a single 3 L cylinder, a drum of survey kit and compulsory rocks.

On the other side, kit was dumped and surveying commenced into the passage explored last year to the limit of exploration. The two leads from last year (left hand rifty stream passage and right hand stal climb) were investigated. The left-hand route led to a loose choke which was bypassed via the right-hand climb (a rope would be useful here 8m), with a drop back down on the other side of the choke to ongoing streamway. This sadly ended in another choke, so a retreat was made to a side lead noted further back towards the first choke. This was large, and continued in impressive fashion to a few down climbs, ending in a 6.5m pitch. With no ropes or SRT kit a retreat had to be made. Diving back through Sump 2, Josh removed the old thin line and Rob followed both passing the sump without issue. Joe and Arwel who had been keeping themselves occupied in the chambers and climbs further upstream were found with their bothy feeling rather cold after 3.5 hours alone.

 After Josh and Rob had gone through sump 2 Joe and Arwel waited and listened for the sound link but there was nothing to be heard. After waiting a few minutes to make sure Josh and Rob would not return imminently Joe and Arwel moved back up the stream way to look at a ramp on the stream right a few bends before sump two. Arwel climbed the muddy ramp to discover some old boot prints and decided it was too exposed to continue without a rope. Moving back to ‘Steve and Colin’s Aven’ a short free climb led to a moon milk flow of about 60m. There appeared to be evidence somebody had previously tried to ascend but we did not follow. There was a lot of surface debris in the area including worms, leaves and plant matter. Joe and Arwel then returned to the sump, collected the bothy and made for a sloping soft mud ledge around the bend from sump 2 to try and make home for a few hours.

A slow, tired return was made upstream, with Sump 1 being passed by all without issue, and back to the bottom of the entrance pitches. All divers struggled up these and through the between-pitch obstacles with all kit (two bags each, including cylinders) before giving in and having to leave the cylinder bags at the bottom of the 20m pitch near the entrance. A return was made to collect the remainder of these and get a few photos two days later. Surfacing after 15 very tiring hours of effort to the Land Rover was welcomed by all. Great trip!

P.S. Thanks to Dan and Sam for pulling 2 cylinders out from here to the entrance chamber the next day.

Updates

Pozo del Castillo

After 30 years of a blocked snow plug, preventing access to the lower reaches of Castillo, the snow plug has melted.  The previously scary boulder held up by snow, is now held up by air and luck.  A 100 year old winch has now been revealed, and more large scary boulders.  The ‘pitch’ has been dropped down under the snow plug into continuing passage, but not currently bearing any relation to the descriptions from the 1980’s French description.

A second trip explored further under the snow plug to arrive at some Screwfix through bolts…. FT16 explored in 2017.  It’s not clear how this has happened, no survey detailing such a connection, quite possibly a link revealed by the receding snow.  More work to do….

Cueva del Marniosa

Following a successful set up trip by 2 divers, a team of 4 passed Sump 1 to reach Sump 2 and get 2 divers into the new passage found last year.  The 2 divers explored 185m of passage before hitting a 6m pitch.  Logistics of exploration at such a remote site prevented further exploration.

SUSS updates: https://ukcaving.com/board/index.php?topic=23537.0

Tresviso 2018

Prospecting for caves (Sam Deeley)

Expedition Dates

  • 1st September to 15th September 2018 – main expedition dates

Objectives

The expedition has a number of goals.  The following are a few primary objectives:

Cueva del Nacimiento

  • Jurassic World – Terror Firma – multiple avens and climbs,
  • Pina Colada Bypass – a 3-10m rift leads off from the Pina Colada sump.
  • Joe’s Crack – un-descended shaft behind Death Race camp.
  • Teeth of Satan – Wet Aven – +30m aven with draft and calcite squeeze, requires enlarging.
  • Dan’s Big Room – unexplored section of maze in area of Dan’s Big Room and Winter Gardens
  • Parting Friends – a dive of the Parting Friends sump is planned.
DR traverse (Chris Jones)

Cueva de la Marniosa

  • Beyond Sump 2 – a dive of sump 2 and exploration beyond is planned

Pico Boro (SUSS)

SUSS are also involved and will take on responsibility for exploring either  Flowerpot on the Pico Boro area.

  • FlowerPot – re-rigging and exploration of leads
  • Surface sweep and logging of entrances in Sara Depression (around camp)
  • Surface sweep and logging of entrances in Pico Boro area


Secondary Objectives:

Time and resources permitting there are a number of secondary objectives that will be attempted:

Sistema Castillo

A large mine and natural cave complex in the Minas de Mazarrasa area.  Pozo del Castillo series was explored to -292m depth in 1983, with either a howling draft or roaring waterfall beyond a constriction at the limit.  The potential of the cave is significant but currently a collapse prevents getting to the end. Pozo Natacha series ends at -309m depth and is close to the same point in Castillo.

  • Pozo Del Castillo shoring and bypass of rock collapse Castillo remains a major lead, if we can get past the blockage!
  • Pozo del Castillo – other entrances. FT16 entrance snow plug would appear to be the same blockage in lower Castillo passage.  Snow plugs are reported further into the cave, so another entrance must exist!
  • Pozo del Castillo – surveying of Natacha upper series and locating possible surface entrance,
  • Pozo del Castillo Natacha 1983 series. Attempt to get small, skinny person through current limit, otherwise derig and survey.
Pozo Castillo (Chris Jones)

Valdelafuente / Sobra Valley

  • Re-locate draughting surface entrance on Valdelafuente, close to 80m aven beyond Sump 1 in Cueva del Marniosa,
  • T20 (Sobra Valley) – sandstone sink above Hall of the Mountain King in Cueva del Marniosa,
  • Yorkshire Inlet in Cueva del Marniosa. Exploration of col above aven (also close to T20),
  • Upstream series in Cueva del Marniosa. Large black voids above the streamway,  if leads head to the South this is up the Valdelafuente

Sierra del a Corta

Above the furthest reaches in Nacimiento is the Sierra del Corta.  A heavily wooded area with a number of promising leads, that could potentially drop into Nacimiento and provide an easier route into the back-end to aid exploration at the far reaches.

  • T554large 100m shaft on the Sierra del a Corta, this requires some digging at the bottom,
  • Al2a drafting shaft not yet bottomed.  Jurassic World in Nacimiento appears to be heading directly towards this site,
  • T294 Oh What Pot (La Gobia) – continuing passage,
  • Surface prospecting close to vicinity of Terror Firma in NacimientoTerror Firma is only 40m vertically and 200m horizontally from some parts of the surface in the Sierra del a Corta region.

Other

  • Locate and survey General This may be another way into T87 Mazarrasa, bypassing entrance collapse. (most likely T88 Suerte or T89.  T88 draughts strongly at junction inside)
  • Locate and descend FT43, this draughts strongly. It is almost directly above Boulder Chamber in T87 Mazarrasa and would provide bypass to collapse at T87 entrance.
  • Surveying of Nacimiento top entrance series. There are a number of unsurveyed and minor leads in the area,
  • Prospecting on Hoyo Oscuro and Hoyo Evangalista. Highest entrances on the mountain range.
  • Mine 2.32a – there is large unexplored level (with tram lines) leading to unexplored passage.

2017 Summary

Cueva del Nacimiento – Jurassic World – Terror Firma

The ‘final’ aven at the end of the cave was climbed to over 40m, a split in the aven was followed to a new height of 534m above the entrance, but closed down.  The second aven remains unclimbed and is ongoing 

Cueva del Nacimiento – Jurassic World – Pterodactyl Crumble

Another aven at the end of the cave was explored upwards before reaching horizontal passage for another 60m, then finally closing down. 

Cueva del Nacimiento – Death Race 2000 – Joe’s Crack

Initial constriction was passed and the passage continues down another 35m, to head of undescended 12m pitch.  The passage heads under the Death Race chamber, toward the Death Race pitches.

Cueva del Nacimiento – Teeth of Satan – Wet Aven

The Wet Aven was not attempted on this trip, in part due to 2 trips getting lost on the way to the far end and running out of time to climb.

Cueva del Nacimiento – Other

180m of passage found near Death Race passage.

A new aven (+30m) found near P Chamber in Death Race passage, continues.

Cueva del La Marniosa

Sump 1 was dived and the 80m aven beyond was climbed to approx. 47m.  The rock is extremely poor and no obvious continuations could be seen at the top of the aven, using powerful lights.

The Marniosa team diverted attention to trying to dive Sump 2,  an undived sump, discovered in 1987 and unvisited since.  A rather ambitious trip saw two cavers reach sump 2 and allowed one diver to pass sump 2 (30m long t 5m depth) to surface in stream passages.  A further 40m of cave was explored and still continues, before safety concerns forced a retreat.

 Pozo Del Castillo.

Pozo Castillo continues to be surveyed (2km +) and leads explored, attempting to bypass the 1987 snow collapse.  The rediscovery of FT16 and the lower snow levels, allowed further progress in the system, but a sump was encountered at -110m.

Pozo Natacha (a series of pitches in Castillo, rather than a separate cave) was pushed past it’s 1983 limit, down a tight right to the head of a tight 20m pitch.  This pitch head would need serious enlargement before further exploration can continue.

Other exploration

Torca del Carneros was (re)discovered and surveyed.  This lies on La Mesa, above Tresviso, and probably would be connected to caves draining away from Tresviso toward the San Esteban valley.

Fallen Bear was also rigged ready for further exploration in 2018.  The bulk of the cave is a steeply descending ramp, similar to Nacimiento, and contains a number of leads of potential.

Summary:

In total over 2km of cave was surveyed in 2017.  Exploration of Nacimiento continues and has now pushed the height to over 534m from the entrance.  A logistical challenge that is not proving to get any easier, despite fixed camps toward the end of the cave.  Trips to the far end require 4-5 nights of camping, and advanced camps at the far (far) end now need to be considered.  Passing the second sump in Marniosa is a major achievement and unexpectedly has surfaced in passage heading away from Nacimiento and into the mountain, possible towards a hypotheses trunk route that may also feed the upstream sump in Nacimiento.  The rigging of Fallen Bear, and discovery of some new leads, opens up further possibilities of closer deeper systems lying between Nacimiento and the deep potholes high on the mountain.

Cueva de la Marniosa – Terminal Sump 2 dive

Gareth had been having trouble sleeping over the few days previously, possibly due to the heat. This meant going on a push trip to the end of Cueva Marniosa to the Terminal Sump 2 would not be sensible. Josh was still determined to go but was not keen on the idea of a solo trip to the end (with or without dive kit), based on various reports of the cave suggesting a hard trip was in order (see reports from Boothroyd et al.). Therefore Josh persuaded Arwel to join him since Arwel, despite not being a cave diver, had previously passed Sump 1 without issues to help Gareth in the 80m aven beyond. Thankfully Arwel agreed and an uneventful trip down to Sump 1 was had in good time (45 mins) where both dived through, Josh carrying a bag with SRT kits plus other bits and bobs in a Daren drum (floaty!). On the other side Arwel started to brew a hot chocolate whilst Josh sorted equipment for the Sump 2 dive, including a makeshift dive harness (etriers), a single full 3L cylinder (one of two left on that side of Sump 1 by Josh two days prior), some bolting kit and general dive accessories.

The journey down to the limit explored by Josh on a solo trip two days before was much nicer this time, with company, and the obstacle turned out to be an awkward squeeze between a fallen block and the passage wall (which Arwel climbed on the way back, whereas Josh squeezed back up). After this, relatively pleasant stream passage with the usual climbing, traversing, rifts and stooping was followed for some time, via some large chambers, passing a sump pitch to the left noted on the survey, to the 14m pitch into the “bear pit” obstacle. This area had been the site of frustration for multiple previous explorers, as evidenced by equipment left behind, including Brian Judd’s lead and diving cylinders. Multiple lengths of rope were left on or near the pitch, and the first attempt to descend by Josh was shaken by one of the Y-hang “anchors” failing, when a natural rock flake inconveniently broke away. During the subsequent fall/swing encountered by Josh, an impact onto an extended left arm caused some pain and aches for the remainder of the trip. The anchors were re-rigged and the pitch descended into a large resurging pool, likely the regained streamway after it is lost in one of the aforementioned chambers. A swim across this and a short section of walking passage lead to a tight rift and a climb above.

This area is not well represented on the survey, no climb is specified in this large walking section however having communicated with MadPhil Rowsell previously, who had bolted up this climb, Josh was aware that a rope should be nearby. This was found to be about 4m up, anchored to a bolt. Josh went back to cut a short section of excess rope from the bottom of the previous pitch before Arwel, being by far the better climber, clipped it onto the 4m bolt and continued up, carefully, to the top. Midway AR found another rope from across the void attached to the rope he was climbing, which turned out to be the main hang rope installed by MadPhil for the pitch after climbing the corner. This ascending pitch is around the same height as the previous descending pitch (15m or so) and is not on the survey, despite having been climbed by the 80’s explorers (dive line was found above and below the pitch).

There are a couple of ways on at the top, and given the inconsistency of multiple descriptions a long while was spent looking around for what matched the descriptions and survey best. A retreat to the bottom of the pitch to explore the rifts below was carried out, to cover all routes, until after a discussion on whether to continue or not, it was decided to choose the ongoing large passage at the top (which didn’t match survey direction or description). This continued into sharp, snaggy, nasty traversing at high level and became obvious that it was the way, where there was no possibility of staying at the same height, with lots of up and down climbing on extremely weak and sharp rock (a fall would NOT be conducive to life). A point high up, on an S-bend was reached where progress began to look bleak and dangerous. More discussions were had where Arwel seemed happy to turn around, with Josh agreeing subject to one more attempt to bottom the rift. This turned out to be fruitful, where an exposed, cautious, but relatively straight-forward series of descents led to rifted streamway and eventually the difficult, tight, friable jagged rifts that were expected based on prior reports.

With the bag of dive gear, the journey through this rift had to be methodical, slow and careful. Everything snagged, at all levels, with multiple restricted and resistive climbs up and down, chest-tight squeezes and a deep pool midway through, requiring a cold swim across. Finally the rift widened slightly, leading to a boulder choke (easily passed) and more pleasant streamway. This got appreciably easier until stomping streamway lead off, with periodic obstacles, to the final chamber with the large, clear blue Terminal Sump 2 at the far end.

Without wanting to waste time, Josh kitted up into his dive kit and entered the water, buoyant, using two compact reels (i.e. search reels) as dive line. The crystal clear underwater passage dipped gradually down to a shallow 5m depth, where it continued to an elbow. Surface was visible ahead and was reached after approximately 25-30m, using both reels with only a metre to spare to tie off on the far side. Approximately 40m of open, lightly cascading stream passage was explored, after removing some kit, to a calcite/mud climb on the right and rifted stream passage on the left. The climb was pushed until it became too exposed for the divers’ situation, but was seen to choke ahead. Down on the left, a very short foray into the narrow stream passage saw an ongoing rift continuation, relatively pleasant with no sign on an imminent sump. Aware that Arwel was waiting on the far side and would be getting cold/feeling isolated, Josh began a return. The security of the join between the two line sections was inspected once more, in doing so, due to very positive buoyancy, Josh found himself stood upside down near the far side of the elbow of the sump with feet on the roof and head on the gravel bottom – an amusing situation in such a place. The line was left in place, and an exit was made to a pleased Arwel.

The trip back to Sump 1 was a long, uneventful journey, where Arwel got a brew on and heated some ration packs, while Josh prepped all kit for bringing back through the sump (it was at the time improbable that either Gareth or Arwel would return with Josh to Sump 2, hence all kit was due to exit from the diver-only section of the cave). This included all kit used to aid the aven downstream, plus cooking and excess dive kit. This amounted to three large bags for Josh to exit with, which were tied together and made as neutral as possible for the return, which was successful and unhindered. AR being uncomfortable in deep canals (which are extensive on the exit side of Sump 1) continued through after the dive to warm up at the dryer Sump 1 dive base, whilst Josh ferried the remainder of kit through the canal and up the cascade to meet him. Kit was then sorted, a brew was heated, and a further uneventful exit was made, reaching the surface 16 hours after entering the cave (at least 12 of which beyond Sump 1). Thanks to Arwel for enduring yet another Marniosa Sump 1 cave dive!