The 2017 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 Caves Project.
As per previous years the majority of work was concentrated on the resurgence cave of Cueva del Nacimiento, a 12km+ 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 2017 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.
The 2017 expedition has continued to build on the successes of previous trips advancing exploration in line with objectives and discovering over 2km of new cave and a number of new leads.
Cueva del Nacimiento
Over 770m of new passage was discovered and surveyed in Cueva del Nacimiento with a number of new leads identified. Exploration in the far reaches was hugely eased by the set-up of a permanent camp in Death Race 2000, during a May recce trip. Thanks to the May trip, this camp remains relatively well stocked. Complex route finding throughout the cave remains an issue.
This aven was climbed for over 40m and is now the highest point in the cave at +535m above the entrance. A number of leads still remain and this area continues to be the most promising for further discoveries leading into the mountain toward the deeper vertical caves. Terror Firma is only 40m vertically and 200m horizontally from some parts of the surface in the Sierra del a Corta region, so renewed effort on the surface here may provide a middle entrance into the system.
60m of new passage was discovered but unfortunately loops back down with no further leads.
189m of passage was found in the area above the Teeth of Satan. A number of promising leads remain and its vicinity, close to the Wet Aven, mean further exploration would be worthwhile.
Over 100m of passage was found beneath the Death Race 2000 chamber and an undescended pitch still remains.
The following provides a list of the main leads in Cueva del Nacimiento:
- Jurassic World – The sandy dig – long term digging project,
- Jurassic World – Terror Firma – main aven,
- Jurassic World – Terror Firma – the ‘muddy way’,
- Jurassic World – a high window near the large stal boss passage,
- Jurassic World – Dinosaur Aven – from the final rebelay is a possible continuation of the main aven,
- Die Hard – 1 unclimbed aven (possibly a bypass to Dinosaur Aven, although may connect)
- Death Race – Pina Colada Sump – A sizable rift ongoing beyond sump and a very remote dive site,
- Death Race 2000 – main aven climb remains unfinished,
- Death Race 2000 – Joe’s Crack –undescended 20m pitch,
- Death Race 2000 – Aven before P Chamber – rift continues,
- Teeth of Satan – Satan’s Chode – Three passages remain unexplored,
- Teeth of Satan – Wet Aven – small hole (with echo beyond) at top of avens,
- Dan’s Big Room – maze of unexplored passages above,
- Parting Friends sump – second sump remains unfinished,
- Far Upstream sump – major long term deep diving project,
- Road to Certain Death sump – major deep diving project.
The expedition concentrated mainly on seeking a route past the blockage in Pozo Castillo. This still remains elusive but over 600m of previously unsurveyed cave was added to the survey.
Pozo del Castillo
Pozo del Castillo remains a cave with huge potential but the main way remains impassable since the 1980’s. FT16, FT17 and Segura 1 have been relocated, explored and surveyed in an attempt to piece together the wider picture of the system. This will continue to be an ongoing objective of future expeditions.
The following provides a list of the main leads outstanding in and around Sistema Castillo:
- Pozo Castillo – undocumented mine workings above second pitch,
- Pozo Castillo – flooded mine passage at bottom of second pitch,
- Pozo Castillo – half flooded main passage, not explored,
- Pozo Castillo – route beyond stacked deads in main passage,
- Pozo Castillo – boulder choke at end of upper crawl (surface connection),
- Pozo Castillo – continuation over the top of the 30m pitch,
- Pozo Castillo – Thatcher’s Squeeze. Sound of a large volume of water from beyond
- Pozo Natacha – upper series not fully surveyed and documented,
- Pozo Natacha – tight constriction at limit of exploration, above end of undescended
- 20m pitch.
- T143 – on surface, just past Pozo del Castillo entrance, undescended 50m pitch,
- T147 – undescended pitches close to Pozo del Castillo, old descriptions suggest this
- may be original way into Pozo Natacha upper series.
- Blenda, Blenda II – draughting mine, north of Segura 2,
- T303 – undescended pitch, requires hammering, but may lead direct into T302 Torca del Reloj.
Cueva de la Marniosa
The passing of Sump 2 was a major achievement of the expedition. The difficulty of the cave beyond Sump 1 had always been a daunting challenge, but with the small size of Sump 2 now revealed, the ease of getting more ‘dry’ cavers in to support divers beyond Sump 2 becomes a possibility.
Torca de Branaredonda (3.2 Fallen Bear)
Fallen Bear was revisited late in the expedition, following new information, about the current limit of exploration, from the Spanish. A number of new leads were identified. With the cave holding potential for further discovery this will also form a new objective for future expeditions. To this end, only the entrance series was derigged, with ropes remaining in situ to the limit of the 2017 ‘exploration’.
|Arwel Roberts||South Bristol Speleological Society||UK||2017||Tresviso 2017|
|Bob Clay||South Bristol Speleological Society||UK||2017||Tresviso 2017|
|Derek Cousins||Lancaster University Speleological Society||UK||2017||Tresviso 2017|
|Alex Hannam||Cardiff Hill Divers||UK||2017||Tresviso 2017|
|Chris Jones||Cardiff Hill Divers||UK||2017||Tresviso 2017|
|Dave Powlesland||Cardiff Hill Divers||UK||2017||Tresviso 2017|
|Gareth Davies||Cardiff Hill Divers||UK||2017||Tresviso 2017|
|Josh Bratchley||Bristol Exploration Club||UK||2017||Tresviso 2017|
|Dan Workman||Bradford Pothole Club||UK||2017||Tresviso 2017|
|Emma Battensby||Bradford Pothole Club||UK||2017||Tresviso 2017|
|Hannah Moulton||Bradford Pothole Club||UK||2017||Tresviso 2017|
|Michael Young||Bradford Pothole Club||UK||2017||Tresviso 2017|
|Phil Walker||Bradford Pothole Club||UK||2017||Tresviso 2017|
|Sam Deeley||Bradford Pothole Club||UK||2017||Tresviso 2017|
|Thomas Lia||Bradford Pothole Club||UK||2017||Tresviso 2017|
|Fernando de la Fuente Moreno||Asociación Deportiva KAMI||ESP||2017||Tresviso 2017|
Thanks also due to Colin Boothroyd, Dave Checkley, Howard Jones, Mark Sefton, Steve Foster, Ken Daykin, John Boardman, Carolyn Ginnever, Toby Dryden and the people of Tresviso.
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