Tolminski Migovec Cave Exploration

SLOVENIA

Winter Reconnaissance 1995

Our original plan for this was to visit the plateau in February '95 and hire a sets of telemark skis (or mountaineering skis) as this would make movement in deep snow much easier. We were unable to obtain this type of ski in London but Andrej our friend from the local Caving Club seemed to think that we would be able to pick up some locally (although his English on the telephone is not very good) so we borrowed as much mountaineering gear as we could from IC mountaineering club, and hoped that this would be sufficient. The first day we tried unsuccessfully to hire skis from the hotels (they only had downhill skis), we therefore decided that we had to go for it in mountaineering gear- Andrej seemed to think that it would be hard but possible.

We spent a day waiting for good weather and took the opportunity to have a look in Mala Boka which is a resurgence cave currently being explored (by bolting up shafts) by members of the JSPDT and is currently 400m high and has been dye connected to Skalaria(-900m) on the Kanin plateau -- there is still a long way to go to connect them, but a connection would give a 2000m cave. We only had a short trip in to the first sump as our caving gear was limited to a helmet and zoom, it was our first chance to have a look in the cave as the entrance is completely sumped in the Summer because of the volume of snow melt coming off the mountain.

The next day we started up the mountain, starting early in the morning from Tolminske Ravne (800m), the snow depth at this altitude was barely covering the ground, the snow depth quickly increased as we got higher and by the time we got to 1200m we were struggling to move in deep snow, the only way to progress was by crawling. We reached the shepherds huts, the usual halfway point, after a six hour slog, a journey which usually takes about one hour in summer. Fortunately by this stage things had improve significantly, because of the very low temperatures the snow was much harder so movement was much easier, We waited in the shepherds huts for one day for the weather to improve and then headed up the mountain at 4.00am the next morning in order to get a full day logging holes.

The position of the holes was logged in a number of ways. Firstly we had a Global positioning System (GPS) kindly lent by Trimble Navigation which gives your location (Lat/Long) on the map by triangulation with satellites. We found that this device must be calibrated with a number of known points on the map and this will show a constant error which can be subsequently subtracted from the reading to give a theoretical accuracy of about ten metres, although this wasn't borne out in practice. It also needs to be able to see large area of sky and goes through batteries relatively quickly (especially at low temperatures).

Our other more 'bucket and spade' techniques for logging holes was by triangulation off peaks with a compass (this was very inaccurate) and by marking the rock surface in the blowhole with spray paint (this proved very effective but was only possible if you could get down the hole).

Investigating a blowing hole

We logged a large number of holes, 56 in total which were blowing through 2- 6m of snow, it was possible to climb down many of the holes and once inside the warm air coming out of the holes made them comfortable and warm spots (ideal bivi spots). On the plateau we constantly roped together because of the risk of falling down a shaft, this happened on a number of occasions but fortunately always in shallow shafts and no crevice type rescue was necessary. The trip in general was extremely cold and for one person it took a month to regain the feeling in his big toe. All in all an interesting trip and a nice introduction to winter mountaineering.