Note that this is a re-print of the original publication, based on a scanned copy. During the process of converting the original paper copy to this electronic version, the original formatting, page layout and page numbers have been lost. All diagrams and surveys have been scanned from the original and are consequently of poor quality.
Diving in the Predjama System by JM Boon
Blue Pencil Aven by R Biddle
Published by the Shepton Mallet Caving Club
The Mineries, Wells Road, Priddy, Wells, Somerset, BA5 3AU
I am at something at a loss for a suitable topic of this editorial. Perhaps you will look upon what follows as space filling burble, but I might draw your attention to the fact that this issue marks the beginning of our fifth year of publication.
These nine issues have contained twenty-nine articles and eighteen surveys. A study of the authors responsible for these articles shows clearly the club's indebtedness to Mike Boon, no fewer than ten articles have come from him, and that is more than twice as many as his nearest competitor in the Journal Stakes. Many thanks Mike for making this job possible.
Now what about someone else challenging his position?
An account of a dive in the Grapajama, a tributary of the great Predjama, Slovenia, is to be found in the SMCC Jnl Series 3 No 4 (Nov 1962)
Steve Wynne-Roberts and I returned to the area in the summer of 1964. Our objectives were twofold, first to attempt the through passage from the Grapajama to Predjama, diving whatever sumps may block the route, second, to explore the Lokva stream, which is thought to have formed the dry passages of Predjama, downstream of the point where it sumps 500 foot from daylight.
We were a party of six, John Blunt, Pete Smith, and Bobbie Toogood in one car, Dorothy Clegg, Steve and I in another but owing to several minor mishaps only a week together remained when the party assembled in Jugoslavia.
Minor illnesses (squitter?) then made Steve and I unfit for diving so we cut our losses and made for the Adriatic to convalesce. The others, having explored Scocjanske Jama at the lower end of the Rakov Scocjan basin for 500 feet to a sump, and boated on Zadna Jama at the upper end, joined us by the sea.
Having seen the Derbyshire lads off on their journey to England we continued to roast in the sun until there was no reasonable excuse for not going caving. Our first target was the main stream sump of the Lokva river, and this we attempted on the 4th August, a Tuesday. This section is active only in flood, normally the stream sinks among the rocks by the entrance. With the "tadpole" cylinders and three Scubair demand valves we crawled along the 500 feet of low passage leading to the sump, a pool about 20 foot long and 20 across with a gently descending flat roof.
I dived first, wearing one cylinder on my side and towing another behind. After a roomy underwater passage about 80 feet long I entered a large chamber with knee-deep water. A further short dive of ten feet at the far end of the chamber led into a long chamber with a steeply rising bank of shingle. Still kitted up I followed it to a small drop into a basin of limpid water hollowed out of milk-white rock, beyond a drop of 12 feet led into a large descending passage. I returned to Steve on the upstream side of the sump, he was only wearing a lightweight suit and so was not keen upon diving the sump.
Alone I retraced my steps through the sump and descended the 12 feet into the passage which proved of magnificent dimensions, twenty by thirty feet. This did not last, the roof dipped towards the surface of a pool, but it was only a thin leaf of rock, and it left me a couple of inches air-space. Beyond the cave continued in a series of majestic meanders for about 700 feet, the way was predominately downhill, but banks of flood borne stones necessitated some up and down progress. Among the boulders were many items of household rubbish, saucepans and the like, out of place and slightly sinister in this wild and awe inspiring cavern.
I noticed three ox-bow passages in the roof. Evidently bored out by the great spring and autumn floods. Towards the end of this section I heard the low growl I had been hoping for, the active Lokva stream entering the cave. It burst from a tight packed mass of stones on the left to lose itself in a shallow pool where the roof dipped to within two or three feet of the water; then shaking itself free the stream ran helter-skelter for 40 yards down a steep stoney passage to slide into a constricted sump. But this was not the end for a steep bank led upward over the sump and I began to wonder how much further I could go before I met the inevitable sump. It was 300 feet on, a great black pool 30 feet across. I stepped in and was out of my depth almost immediately.
Back with Steve again, we decided to leave the equipment in the cave until the Thursday when we would return to make a survey and dive the end sump.
On Thursday we took three cylinders and demand valves to the final sump. Diving hard against the right wall I found myself descending an underwater slope of silt and flood debris at an angle of about 60° to the horizontal. The visibility was about 2 to 3 feet, at an estimated depth of twenty feet the sump seemed to level and I crawled under a rib of rock to find a steep slope of more compacted material which I followed upward feeling certain that I had cracked the sump. I passed two small air surfaces, four or five feet overhead, which I did not attempt to investigate, and having found my way past an immense log I entered an air-space 20 feet by 10 feet, but, unfortunately bounded by rock on all sides. I followed the wall to the left, and started to descend, I assumed I was starting another down and up leg, again I seemed to go down interminably. Suddenly I found a courlene guide line. The one I had laid on the way in. I had moved through 360° and the line was looped around some obstruction. After some careful thought I decided which section of line must lead to base, and fortunately for my nerves made the correct choice. After retrieving the line we decided against further diving and started on the survey, reading a good compass of Jugoslav origin to the nearest five degrees, and pacing distances. When plotted our survey showed the passage to total 596 metres and that the cave headed slightly west of north, that is towards the resurgence and in line with the major dry passages of Predjama.
In Postojna that evening we discussed our find with our friends Dr Rado Gospodaric and Prof Frances Habe of the Institute of Karst. Predjama is Habe's pride and joy and he produced innumerable maps which moved Steve to a rare pitch of enthusiasm. We decided to attack the sump terminating the West branch of Predjama on Saturday and Sump 2 in Grapajama on the Sunday.
On Saturday the thunder muttered over the cliffs of Predjama and Rado decided that it would not be safe to attempt the sump at the end of the West Branch, the approach to which is through deep pools and narrow rifts. Instead we tackled that terminating the East Branch, this is a resurgence sump discharging the waters of the Grapajama swallet. After following the enormous passages of Predjama for about one mile we reached a small rift carrying the Grapa stream. This led upstream to the sump but by a series of moves in boulder chambers and through ox-bow passages we avoided the irksome crawl up it. The final passage just before the sump is quite roomy, 10 feet high and 15 wide, and floored with a hard bright sand which led us to expect good visibility in the sump. In this we were disappointed, the visibility being again no more than two to three feet, but after only 50 feet under water we emerged into open cave.
From the beach of the sump we could see an ominously sump like pool so Steve made a 'recce' whilst I remained kitted up. In a few seconds I heard his shout "It goes".
Together we explored a sharp edged rift passage which obviously takes a severe battering from floods. After 90 feet of rift we followed a canal, with steadily decreasing air-space, for 100 feet to a sump. The sump looked as though it would be hundreds of feet long and we did not feel like attempting it.
Just before the start of the canal we found a mud slope on the south side of the passage that led to a tight squeeze into a muddy tributary passage. This we followed upstream for 80 feet to where a further squeeze gave access to a small unstable extension. Prospects here seemed poor and we returned, exploring two ox-bows to the rift passage as we went.
Figure 1 – Sketch survey of the Predjama System
Safely back with the others we chewed Jugoslav biscuits as we made our way out of this beautiful cave. This proved to be our last dive as that night torrential rain began and prevented further caving before we left for home on the Monday.
To summarise the prospects of the Predjama system, it would seem that the 200 metres or so of unknown cave separating the downstream sump (sump 2) of the Grapajama and the upstream termination of Predjama East Branch is mainly flooded and probably not worth attempting. Of the sump terminating the West Branch I have no first hand information, but it is quite certain that there are further large sections of open cave beyond the second sump of the Lokva River Cave. The scale of this system is so great that the length of carry alone will make any further attacks specialised and dangerous operations.
Our sincere thanks must go to Rado Gospodaric and Frances Habe who plied us with liquor and surveys whenever we appeared and helped us in every possible way. This was one of the most pleasant aspects of the trip and we very much appreciated it.
Monograph by Dr. OC Lloyd
Published by the U.B.S.S. at 10/– 30 pp, 8 plates, and survey
This report brings up to date, and under one cover, information published earlier in the UBSS Proceedings.
The report opens with a historical sketch, follows with a detailed description of the cave, and ends with a comment on the geology. As the cave is unknown to your reviewer comment cannot be made on the accuracy of the report but is clear and very readable. The same cannot be said of the survey. In order to keep the price low far too much information has been crammed onto one sheet making it very difficult to understand.
On the whole it is fair value for money and will prove very helpful to anyone caving in Clare.
It was Mike Thompson that first put into my head the idea of trying to climb Blue Pencil Aven in the Paradise Regained Series of Swildons Hole. To reach the aven one traverses across the head of Blue Pencil Passage then turns right to follow the Blue Pencil stream upwards through a squeeze to the foot of high aven, the stream falling down from high above.
On Sunday 22 November 1964 a party comprising Martin Mills, and Phil Romford, Barry Lane (of BEC), Bob Craig (of MNRC), and myself set off to make the attempt.
Our plan was to split into two parties at Tratmans Temple, one party carrying all the tackle through St. Pauls while the other went via Sump One, collecting some maypole from Sump Two and joining the first party by way of the Trouble Series, the "Troubles" having been bailed by the St. Pauls party. The maypole was incomplete and so remained at Sump 2 and when the parties were reunited we decided to attempt a free climb of the aven.
I crawled through the squeeze to the aven and climbed easily up for about 40 feet to a ledge. The rock was rotten and the stream falling on ones head made it an unpleasant business. On the ledge I found a sling and "crab", presumably left by some previous climber when making his descent by abseil. Martin quickly joined me and together we examined the next section. At the ledge the aven had a cross-section of about 15 feet by 6 feet but our lights did not reach the top of the aven.
We were both cold and wet, in spite of wetsuits, so we hauled a ladder up to the ledge and descended to join the rest of the party for food & fags.
Back on the ledge I belayed to a convenient flake of rock while Martin, slings, pitons, and hammer hanging from all parts of his anatomy, climbed above me. Martin found this section to be fairly easy, it being possible to back-up, or straddle, most of the way to the top.
"Below", shouted Martin as a boulder of no mean dimensions whizzed past my ear and crashed within feet of those at the bottom of the aven. I have never seen an aven cleared of cavers so rapidly, but I had to remain. After a few more boulders fanning my face, (I was no longer cold) a worried voice came from above "I'm holding up a very large boulder, but can only support it for about five minutes whilst you get clear". My feet did not touch a rung as I descended and then shot through the squeeze to safety. The boulder whistled down slicing twice through a nylon rope and coming to rest with a resounding crash at the bottom.
Hearing the "All Clear" from Martin we returned to the foot of the aven. He hauled up our remaining ladders, belayed them to a piton and I was able to make the 70 foot climb to join him.
Together we explored about 70 or 80 feet of tight passage crawling over pink flowstone and gour pools. The stream enters by an impenetrable fissure just below the top of the aven and the newly explored passage (which shall be called Milche Passage, as he did the necessary gardening to enter it) is probably an older passage that the stream has now abandoned. The passage is principally a narrow sloping rift, up to 15 feet high, its walls well decorated with Dog Tooth Spar crystals. At one point some perfect crystals can be seen through a circular hole, 4 inches in diameter, in a false calcite roof about one inch thick.
Milche Passage terminates in a cross rift which is the largest part of the new extension, one can actually stand and walk.
We returned to the surface after ten hours underground, our support party feeling very cold after their long wait whilst we explored.
Figure 2 – Plan survey of Blue Pencil Aven
Figure 3 – Elevation survey of Blue Pencil Aven
Published by D & C Pub Co Ltd, Exeter
Price 4/– per copy (21/6 for six issues, post free.) 40 pp.
A glossy bi-monthly magazine for cavers is one publicity description of this publication, and it fits the goods offered. It is aimed to cover all aspects of the science and sport of caving a difficult object, but it has been reasonably well attained in those first two issues. It was probably a good sign that some Mendip cavers felt it might not succeed because of a heavy bias to Mendip, but a careful count of the contents showed that this supposed bias did not exist. Yorkshire is covered by articles on Mossdale and Low Douk, there is an article on Cil-yr-Ychen, and reports on new discoveries in Mendip. Other articles are on caves in Germany, a new Yorkshire show cave, the Mendip Cave Registry, ropes for caving, cave photography, water analysis, and the Dead Sea Scrolls, a creditably varied collection.
The second issue continues this high standard. A serious criticism can be raised however that a writer has been allowed to review his own works in glowing terms, hardly ethical journalism, better editing should eliminate this. As with any new publication that cannot call on members of a single organisation for support there must be difficulty in obtaining articles (this may be the cause of the action criticised above) but if the publishers can demonstrate that this is a sensible Journal of a high standard then after a few issues this should sort itself out and the standard climb yet higher. Personally I hope that this magazine will be a success.