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.