The main focus of the Votla Gora 2008 Expedition to the Tolminski Migovec plateau, Western Slovenia, was the connection of Sistem Migovec (11493m - 5th longest in Slovenia) with Vrtnarija (5229m - 11th longest) to make the second longest cave in Slovenia (16722+m). Separation was 28m on the centre line with many going leads. This was not achieved, but 1.2km of cave passage was found and explored.
The part of Sistem Migovec that we were attempting to connect to was the bottom of M2, the original deep cave on Migovec pushed back in the early 1970s by the Slovenian JSPDT. Below the epic Tolminski Silos pitch (120m), the cave shut down into a series of small pitches with extremely tight rift, which had to be exploded open for passage. Exploration finished in the 1970s at yet another such rift.
During the first two weeks of expedition, the UK team rebolted and rerigged M2 via the original, more direct, entrance to the original pushing point. Once there the UK team attacked the rift with hammers and chisels, but the progress was slow. In the middle of the expedition an experienced Slovenian caver with access to explosives came on a trip at the same time as another team explored some of the near passage in Vrtnarija. This trip obliterated a large rock that was blocking the rift, but also collapsed the wall of the rift. Net distance gained - minus 50 cm! However, with another session of manual work the choss was cleared. Perhaps worryingly, the extremely loud explosion was not heard by the other party in Vrtnarija, though one must add that they were extensively 'gardening' large rocks down the 52m Dangermouse pitch!
Early exploration in Vrtnarija was concerned with extending the 'bottom' end of Captain Kangaroo. The first recee trip was over 12hrs in spite of no new rigging taking place, and concluded that significant work was required just to improve the rigging and expand some of the more arduous squeezes. In particular there were three tight sections of rift in the 'Mudslump' extensions from 2007. As such, the first few trips down to this area of the cave consisted of two parties - an advanced one pushing the bottom end while the other progressed slowly 'improving' (in many cases instigating...) the SRT rigging. For one notable pitch, "Kill 'em All" which had been rigged for no apparent reason without a traverse line, the advanced party beckoned the clean-up group down to rig the pitch safely before they would ascend!
This after a section of acrobatic rift below Kill'Em All (p22), Dark Tranquility (p44) was discovered. The leads were very much ongoing - another pitch, and many windows. There were also entering avens. However, on inputing the survey data (we have a solar-powered laptop running Survex in our mountain top bivy), we discovered that we had dropped well below the bottom of M2 and therefore our current connection possibilities.
As such, attention shifted to higher leads to try and secure a connection in 2008. From the "Something Fishy" chamber a series of pitches were explored which included the impressive Dangermouse (p52). The leads at the bottom are rather dubious, but it makes an extremely pleasant 72m shaft series (Penfold, Dangermouse, Green Back, Giblet Breakfast) which has a very valuable commodity on it indeed - a seemingly faithful stream enters halfway down Dangermouse and collects in a secluded 2m diameter plunge pool.
The Captain Kangaroo series is extraordinarily dry after Bonus Chamber (it is actual dust, not water vapour, that ruins flash photos in this part of the cave), and the water on Dangermouse is likely to be an important part of future underground camping plans for 2009.
From Kill'em All, a number of avens are noted. One of these was gained by a rather gung ho climb with uncertain belay to reach rift that led away from the pitch. On a future trip, the rigging was improved to an acceptable level and the rift was pushed to a squeeze. This soon gave in to hammer attack, and led on to a initially upsetting pitch head. There was clearly something big and echoing below, but the pitch head was initially a fair squeeze for an anorexic cat! Disturbingly, considering it was also our floor, the rock around the pitch head shattered easily and with a few hours of work produced something probably passable. The rotten nature of the rock was a concern when placing the belays, and gained this section of cave the name 'Cheesecake'. A short 10 meter pitch dropped onto an epic rock bridge in a large chamber, with shafts disappearing down (perhaps combining below) on either side with multiple second free falls. A notable rift led off South (towards M2) from the far side of the chamber, but required a bolt traverse out to it. By survey, this rock bridge is 21 meters directly above Dark Tranquility (p44), so it is likely that at least one of the pitches connects.
Due to a shortage of gear, a trip was made down the 'Olympic Rift' arm of Captain Kangaroo to recover equipment and scavenge rope from the (left rigged since 2007) pitches. The exploration end was a tight rift leading to a very large space, most likely a reconnection to the Space Odyssey / Concorde pitch in the main Vrtnarija shaft series. An unsuccessful attempt was made on the squeeze - it required expanding. The pitches were derigged and the rope removed to the bone dry Traverse Chamber for immediate use in 2009.
In this region a surface dig started and quickly broke into considerable passage with a large draft. This was pushed very actively for a number of trips, before an unfortunate connection being found into Jelly Chamber of Vrtnarija. As the explorers at the time commented "Well, at least its 800m deep now!". This Vilinska Jama entrance demonstrates the worth of spending time and effort on surface excavations, as well as pointing to the plausibility of checking all the small side passages in established systems.
Above the Vrtnarija/Vilinska valley is a limestone pavement that extends from beyond the entrance to M2. Here a surface cave, E1, was discovered in 2007 with a \~20m entrance pitch. During 2008 some stones were excavated to an extremely tight (sub human) sized pitch head blowing strongly. This will require chemical persuasion to pass, but due to the (now surface surveyed) location, is a cave of some interest for 2009. Strangely for a surface cave it has some well defined cave formation (large meander), which appears to have been saved from infill by an overhanging entrance and position next to the edge of the plateau.
On the mountain we were joined for a couple of weeks by the younger generation of the Slovenian JSPDT. The majority of their efforts were directed to a cave on the Western edge of the plateau, gained by a rather jaw-dropping abseil of 100m into the mile-deep Tolminka valley! This cave "Monatip", whose entranced was noted in 2006 and exploration begun in summer 2007, is very different in nature to the other mountain caves, being mostly horizontal with the entrance at 1730m appearing to be a dried stream way. Monatip was extended to a total surveyed length of 710m, before connecting into the Primadona / U-Bend system at -151m. The exit via the easy Primadona shaft system was welcome!
It is unclear whether Monatip will be revisited in the future. Some of the original enthusiasm for its exploration was it heading South-East into 'blank mountain', but unfortunately it quickly developed back towards the South-West and Primadona. However, it certainly indicates that Primadona itself is a very fertile area for further exploration.
Also on the Western Plateau is Planika Jama, discovered simultaneously with Monatip. Far more vertical in nature and partially choked with snow, this was pushed to an ice filled chamber with 'phreatic like' blow holes through the ice. Unfortunately this original chamber was not reached due to the shifting ice levels - lots of snow fell in the Winter before the expedition, but also a lot of rain in the spring. In Planika this appeared to have drilled a 1m diameter hole through the initial snow plug which gained an icy vadose development which dropped via a short pitch to a tight blowing rift. Armed with only hammer and chisels, three cavers spent a full day smashing this rift to reach a tight squeeze into a further chamber. Exploration was left at this extremity. On another occasion, a window noticed near a rebelay ledge was pushed (again necessitating the expansion of tight rift) to gain a large chamber which actually went higher than the original entrance to the cave.
In Sistem Mig, a return was made to the pitch explored in 2007 named Plopzilla (P105). The objectives were to photograph the large pitch, investigate the extension boulder choke on one side of the pitch, and to derig the rope to NCB for use in future years looking at other possible shafts coming off this neglected area of the system. The boulder choke was climbed down through for tens of meters, halting when reaching a committing climb down through the ever unstable boulders. Once everyone present had confirmed that "it goes, but I'm not going there" they derigged. Unfortunately the long exposure film photographs taken with the aid of manually fired flashes on abseiling into the shaft were badly fogged, probably due to the camera not being so light tight after its many caving trips! A great pity, as the shaft had a beautiful fluted triangular-prism cross section.
NCB still holds interest for us, for though it was discovered in 1995 and provided the key for the discoveries of 1996 it has since been visited rarely (due to its long distance in time from the surface). A fair amount of surface prospecting has been concerned with investigating the clear valley located on the mountain top above which contains the small M15 and M17 caves. M17 was re-entered but found to be choked with ice. Small caves were found nearby initial digging has been started.
The weekend after the expedition van headed home, a small Slovene / English team went back down M2 armed with an enormous drill & battery. With 6 shot holes they blew their way through the rift, to the head of a short pitch.
This was returned to in October 2008, and dropped - all the new finds in M2 being surveyed at the same time. The new pushing front is another, almost impenetrable rift, and a climb up into a series of tight phreatic passage. The survey data indicates that M2 itself is trending away from Captain Kangaroo. During the expedition a major error was discovered in our survey data - namely that the wrong M2 entrance (there are two, separated by 25m horizontal) was connected into the surface survey. This caused a jump in the position of the bottom of M2, taking it further from Vrtnarija.
With the corrected data, our closest approach is now 23m between the large chamber found below Cheesecake and the confluence at the end of M2.
In summary, Migovec now has three major systems and over a dozen smaller caves in active exploration. The exploration in Vrtnarija was at the very end of our endurance limits - the minimal trip length to achieve anything was 15hrs. Our plans are to camp down there in 2009 in order to have far more man hours at the 'coal face' and to offer the psychological and physiological refuge of a camp in a location that, in spite of its relatively shallow depth, is truly a long way from a safe place.
The mountain is unique in having such complicated Alpine cave formation at various depths, and now constitutes 21.988km of passage beneath just a square kilometre of surface.
Everything newly explored was surveyed to BCRA Grade 4b, underground photography as part of documentation took place in Vrtnarija, E1, Plopzilla (Sistem Mig) and Planika. We were limited by there being only one underground photographer on the expedition.
A new survey on an East-West projection has been drawn of M2 and Vrtnarija.
By Jarvist Frost
This work is licensed under a Creative Commons Attribution 4.0 International License.