The 2018 expedition was
undertaken with collaboration between a number of UK based caving clubs and the
Spanish AD KAMI club, under the name of the Tresviso
As per previous years the
majority of work was concentrated on the resurgence cave of Cueva del Nacimiento, a 13km+ cave
system with a height gain of over +535m from the entrance. The catchment of this cave totals 37 km2 and, if linked with known cave systems high in the Eastern Massif, would create
a potential 1500m+ deep underground traverse.
The main effort in 2018 was to continue work in the furthest reaches of the cave, around the areas known as Death Race 2000, Die Hard and Jurassic World. A series of steep ramps lead to the highest known points in the cave and a number of leads were investigated at these highest points. In addition, a re-investigation of some of the caves on the higher Andara range was continued.
The 2018 expedition has continued
to build on the successes of previous trips advancing exploration in line with
objectives and discovering over 2.5km of new cave and a number of new leads. Over 3km of existing cave was also resurveyed
to improve accuracy of old data and provide a better picture of the
Cueva del Nacimiento
Exploration in Cueva del Nacimiento still remains a
challenge. The distance and nature of the cave has prevented numerous cavers
from reaching the end and thunderstorms during the expedition produced some
unexpected reactions at the far end.
The large Pina Colada sump was crossed to give
access to an ascending rift / climb that led to another 150m of passage, and an
aven at the end remains unclimbed. Given the ramp like nature of the system this
area is of particular interest, not only has it dropped back down to
stream-level, it is now heading back up and in large fossil phreatic passage.
Terror Firma, at +534m the highest point in the cave,
was climbed once more but the lead closed down with no further progress.
Although it did
not produce new passage, the re-rigging of the Death Race traverse and other climbs opens up the
possibility of increased success over future expeditions as the time to the end
of the cave from the Death Race camp has been
reduced from 3-4 hours to a mere hour.
Cueva de la Marniosa
2 was dived again to the previous limit of exploration. Another 150m of cave was explored over a
3-hour trip beyond sump 2 by 2 cavers and was stopped after encountering a 6m
pitch into the continuing streamway.
Logistics for diving at such a remote site (with full SRT and rigging
equipment requirements) prevented further exploration.
T20A Cueva de la Silvestre
An unexpected discovery was a surface sink in the Sobra Valley. Sites have been known in this area since the early 70’s exploration but with no real systematic exploration occurring. One site in particular provided a series of pitches into an active stream. The location and direction of the cave pointed to an obvious connection to Cueva de la Marniosa.
The cave was explored over 4 trips reaching over -230m depth and 780m long. Finally, on the last trip a connection with Cueva de la Marniosa was achieved. This has created a through trip and increased the length and depth of the system to 5.5km long and -463m deep, the 7th deepest cave in the Andara range.
T169 Flowerpot (Torca del Picu Boru)
The BEN series was re-bolted and resurveyed to a depth of -304m, of the -723m total known depth. Neither Boulder Bluff or Aerial Antics were found to be ongoing, but there remain several unclimbed avens throughout the BEN series. The alternative route onwards from Pozo del Lago led to around 100m of new fossil passage with two pitches (Bottom of the Barrel – 10m and Tequila Sunrise – 8m). There remains an undescended pitch with the sound of water suggesting this re-joins the active streamway and possibly the known route.
In the BILL series an alternative route around the previously abandoned constriction at around -150m led to over 100m of pitches and a new maximum depth of -260m. There remains an unexplored continuation above Elephants Trunk pitch, as well as a inlet part way down the final Invasive Species pitch which was unexplored. It is thought that the chamber closes down at the bottom of the final pitch however this is worth investigation.
the higher-level Deflowered Chamber was discovered and pushed upwards where it appears to head towards the surface,
although this eventully closed down.
The snow plug that has prevented access to the main cave for the last 30 years had receded over the hot summer in Spain. A 5m pitch was dropped to tight rifts against the remaining snow. Unexpectedly the passage popped out to connect to the lower section of FT16 (explored in 2017). This now suggests that the snow plug is the centre of a very large entrance chamber / shaft, at least 60m deep, with the snow plug almost 30-40m high. The way on into Pozo del Castillo ‘proper’ remains elusive and is probably still beneath the centre of the snow plug. Further work in the chamber next year may be successful.
undescended 20m pitch at the bottom of Pozo
Natacha was also passed, to a further 5m pitch and another impassable rift
T516 Cowshead Cavern (Cueva de la Cabeza de Vaca)
1 was dived and an unclimbed ramp, just after the sump, was scaled leading to
159m of new passage. The passage heads
T190 Torca Septrin
The 2010 and 2014 ‘too tight’ leads were explored and found to be still too tight for further exploration. There is the potential for the constriction at the bottom of the Backshot pitch to be capped for a way on, but it is likely to close down quickly.
There remain two higher level leads, one at the bottom of the 3rd true pitch where the known way on leads down to the left. The passage also appears to lead to the right and down which does not lead into known cave. This would require a constricted traverse and potentially capping to widen the pitch head.
there is a lead into a small active streamway at the bottom of the furthest of
two unclimbed avens accessed from
the small chamber above Pussy Attack. This was hammered for a time to widen
the opening with no success. The stream
drops 1m and then disappears around a corner, which could close down
|Adam Spillane||Bradford Pothole Club||UK||2018||Tresviso 2018|
|Alastair Gott||Technical Speleological Group||UK||2018||Tresviso 2018|
|Alberto Ortega||Grupo de Espeleologia Geologicas||ESP||2018||Tresviso 2018|
|Antonia Headlam-Morley||Sheffield University Speleological Society||UK||2018||Tresviso 2018|
|Arwel Roberts||South Bristol Speleological Society||UK||2018||Tresviso 2018|
|Ben Thompson||Sheffield University Speleological Society||UK||2018||Tresviso 2018|
|Bob Clay||South Bristol Speleological Society||UK||2018||Tresviso 2018|
|Brendan Hall||University of Leeds Speleological Assocation||UK||2018||Tresviso 2018|
|Chris Jones||Cardiff Hill Divers||UK||2018||Tresviso 2018|
|Conor McGurk||Sheffield University Speleological Society||UK||2018||Tresviso 2018|
|Corin Donne||Sheffield University Speleological Society||UK||2018||Tresviso 2018|
|Craig Hamer||Sheffield University Speleological Society||UK||2018||Tresviso 2018|
|Dan Workman||Bradford Pothole Club||UK||2018||Tresviso 2018|
|Dave Collins||Cardiff Hill Divers||UK||2018||Tresviso 2018|
|Dave Powlesland||Cardiff Hill Divers||UK||2018||Tresviso 2018|
|David Botcherby||Sheffield University Speleological Society||UK||2018||Tresviso 2018|
|Derek Cousins||Lancaster University Speleological Society||UK||2018||Tresviso 2018|
|Emily Mackinven||Cardiff Hill Divers||UK||2018||Tresviso 2018|
|Emma Battensby||Bradford Pothole Club||UK||2018||Tresviso 2018|
|Fernando de la Fuente Moreno||Asociación Deportiva KAMI||ESP||2018||Tresviso 2018|
|George Breley||Sheffield University Speleological Society||UK||2018||Tresviso 2018|
|Glen Sankey||Sheffield University Speleological Society||UK||2018||Tresviso 2018|
|Hannah Moulton||Bradford Pothole Club||UK||2018||Tresviso 2018|
|Helen Fairclough||Sheffield University Speleological Society||UK||2018||Tresviso 2018|
|Imogen Furlong||None||UK||2018||Tresviso 2018|
|Jake Sturgeon||Sheffield University Speleological Society||UK||2018||Tresviso 2018|
|Jason Gotel||Cardiff Hill Divers||UK||2018||Tresviso 2018|
|Joe Daniels||None||UK||2018||Tresviso 2018|
|Joe Sharp||Bradford Pothole Club||UK||2018||Tresviso 2018|
|John Dewison||Sheffield University Speleological Society||UK||2018||Tresviso 2018|
|Jolene Pollard||Sheffield University Speleological Society||UK||2018||Tresviso 2018|
|Josh Bratchley||Bristol Exploration Club||UK||2018||Tresviso 2018|
|Kelda Jones||South Wales Caving Club||UK||2018||Tresviso 2018|
|Leo Bradley||Sheffield University Speleological Society||UK||2018||Tresviso 2018|
|Lisa Boore||Chelsea Spelaeological Society||UK||2018||Tresviso 2018|
|Louise Baddeley||Sheffield University Speleological Society||UK||2018||Tresviso 2018|
|Lydia Clare-Leather||Sheffield University Speleological Society||UK||2018||Tresviso 2018|
|Lydia Clare-Leather||Sheffield University Speleological Society||UK||2018||Tresviso 2018|
|Mark Holdcroft||Sheffield University Speleological Society||UK||2018||Tresviso 2018|
|Max Kenworthy||Sheffield University Speleological Society||UK||2018||Tresviso 2018|
|Michael Holliday||Sheffield University Speleological Society||UK||2018||Tresviso 2018|
|Michael Mlyniec||Sheffield University Speleological Society||UK||2018||Tresviso 2018|
|Michael Woodward||Sheffield University Speleological Society||UK||2018||Tresviso 2018|
|Molly Smith||Sheffield University Speleological Society||UK||2018||Tresviso 2018|
|Oliver Hall||Sheffield University Speleological Society||UK||2018||Tresviso 2018|
|Phil Walker||Bradford Pothole Club||UK||2018||Tresviso 2018|
|Rachael Rix||Sheffield University Speleological Society||UK||2018||Tresviso 2018|
|Rob Middleton||Bradford Pothole Club||UK||2018||Tresviso 2018|
|Sam Deeley||Bradford Pothole Club||UK||2018||Tresviso 2018|
|Stuart Coxon||Bradford Pothole Club||UK||2018||Tresviso 2018|
|Toby Dryden||South Wales Caving Club||UK||2018||Tresviso 2018|
|Tom Chapman||South Wales Caving Club||UK||2018||Tresviso 2018|
|Tommy Moore||Sheffield University Speleological Society||UK||2018||Tresviso 2018|
|Will Burn||Sheffield University Speleological Society||UK||2018||Tresviso 2018|
Thanks also due to Alan Braybrooke, Howard Jones, Colin Boothroyd, Mark Sefton, Carolyn Ginnever, Ken Daykin and the people of Tresviso.
Documents & Links