Belfry Bulletin Number 210 by Belfry Bulletin

The Belfry Bulletin No 210

August

Monthly Journal Of The Bristol Exploration Club

19 Vol. XIX No.8

Once again the time has come for nominations for the next year’s committee to be sent in. Older members will remember that we used to print a special form for this purpose, until it was realised that only about five or six of the two hundred printed were actually used. To save paper, therefore, the form is no longer required. For newer members, the drill is this. If you have any members in mind to stand for the next year’s committee, first ASK HIS PERMISSION to nominate him. Then write on a piece of paper, “I wish to nominate ………as a candidate for the forthcoming election for the B.E.C. Committee and he has agreed to serve if elected.” Then put down your OWN name and membership number and send it to Bob Bagshaw, 699 Wells Road, Knowle, Bristol 4, or give it to him in person. You may nominate as many people as you wish. There is no need to nominate any of the present committee members since, unless they no longer wish to stand, they are nominated automatically. The first of the improvements to the B.B. has now been put into effect. This consists of a manuscript book, into which the editor sticks all manuscripts received – thus cunningly preventing their loss (a regrettable occurrence which has been known to happen from time to time in the past!). This book will also provide a check on any controversy which might arise in the future. Please help by writing ON ONE SIDE OF THE PAPER ONLY when submitting material for the B.B. Thank you. “Alfie.” _______________________________________________________________________________________ This being the season for caving abroad, we thought the following article, although rather long, would be appropriate for this month….

Showcaves

Switzerland

………by “Mo” Marriott. My first opportunity of seeing something of caves in Switzerland presented itself in the form of a trip to the famous Hollock (I can spell sometimes!- Ed) on March 14th, organised by a club in Zurich. For quite a modest fee, a whole day excursion to some of the showcaves in Northern Switzerland was offered. I accepted this offer gladly and piled into the coach waiting at Zurich at 7.00am, somewhat bleary eyed! The Hollock lies in Canton Schwyz, some 30 miles south of Zurich and about the same distance east of Lucerne. The journey from Zurich takes one over several small passes rising to about 3,000 feet and through the gentle mountains of Canton Zug – with the curiously shaped mountain Rigi dominating the south shore, and eventually through the narrow streets of Schwyz. The final stage of the journey is along the Muota Valley, a steep sided valley with some very impressive limestone cliffs and a very noticeable escarpment formation in places. After a while the bed of the valley grew steeper, swings towards the east and climbs up to the little village of Hintertal at about 2,000 feet – the Priddy of Northern Switzerland. At Hintertal, the party was met by Professor Bogli, one of the leading figures in Swiss speleological circles, who first gave us an excellent lecture – illustrated with slides – on the geology and hydrology of the Hollock and the area around the cave. He then gave us a brief account of the exploration of the Hollock System.

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The Hollock lies on the western spur of a group of mountains rising to about 9,000 feet. This spur is formed between the Bisis Valley and the Pragel Pass. In fact, at Hintertal, no less than four major valleys join the main Muota Valley, one of them draining land up to 11,000 feet. These valleys were formerly glaciated, although in recent times the glaciers have retreated, and in the area of the Hollock, only remnants of ice remain. Large amounts of glacial debris may still be seen in the valley floors. A large over thrust has occurred in the area, running S.W. – N.E., and the whole mass has been thrust over the Santis group of mountains some miles to the north. Considerable local faulting has also occurred, and evidence of this may be easily seen in the cliffs along the Muota Valley. This faulting has evidently influenced the pattern of drainage in the area to a considerable extent. The majority of the water feeding the Hollock is derived from melting snow and ice, and it is because of this that the visit was made in winter, since the major part of the system often becomes flooded with melt water in spring and summer. The Hollock was the scene of a famous rescue some years ago when several people were trapped in the cave by flood waters for quite a few days. After the lecture from Professor Bogli, the party was taken to see the major resurgence of the Hollock System. Here the water rises through a mass of boulders at the base of a highly waterworn cliff. At the time of the visit, only a mere trickle was flowing through the boulders, but during the late spring and early summer, a fast river is formed some 20 yards wide and a yard or more deep. One curious effect of this is that the cave is cooler in summer than in winter, due to the cooling effect of melt water. The party then returned to the village where we were equipped with large hand carbide lamps, and set off up the icy track to the entrance. The entrance passage descended gradually. The cross section of the passage is lens shaped with the major axis orientated along the bedding. In some places the size and symmetry of the passage section is quite remarkable. There is a noticeable absence of formations in this section of the cave, no doubt due to the effect of the seasonal floodwaters. However, this is more than made up by the abundance of all kinds of phreatic features, which makes the cave a living textbook for the student of hydrology. Everywhere the rock is smooth and polished by the action of the water. In one section, known as the “Glacier Garden” there are a whole series of perfectly formed potholes, some of them with a perfectly formed conical ‘island’ in the centre of the cavity. Many of these potholes were filled with large transparent blocks of ice – hence its name. Also in this section, Professor Bogli pointed out several very high ‘solutional spirals’ in the roof – in effect the opposite feature of the pothole. The formation of these involves the mixing of two different streams of water at different temperatures and containing different amounts of dissolved gasses. All the other phreatic features were to be seen, but in a profusion that I have never seen before. Some unusual features included one produced by water flowing over the ‘end grain’ of thinly bedded limestone, resulting in a regular saw-tooth pattern. In several places, the flow markings indicate a vertical upward flow of water through cavities of extremely large cross section. I would hesitate to even try to estimate the amount of water involved. The tour eventually halted ay the “Bose Wand” – literally “Angry Wall” in quite a large chamber about a mile from the entrance and about a hundred and fifty feet below it. At this point, we were reminded that in summer conditions, we would be fifty to sixty feet underwater! The tour had only shown us a mere fraction of the system – the principal claim to fame of the Hollock being that it is the largest single system in the world. The return to the surface, was followed by an excellent lunch at the village hostelry – with traditional Swiss music and yodelling. (At which point, in spite of our opening remarks, we are going to leave ‘Mo’ until next month, to allow room for a report on the recent rescue in Swildons, which we think members who are not in the area would like to hear about. Ed.) _______________________________________________________________________________________ Remark by Alan Thomas: “If caving receives much more adverse publicity, the B.E.C. will have to go underground!”

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RESCUE in SWILDO NS On Sunday, 22nd July, at approximately 4pm, there was a cloudburst over Mendip, and a large amount of water fell in a very short time. This followed a week of heavy rain, which had saturated the ground and the water from the cloudburst thus ran straight off the fields into the streams. After this rain, three cavers thought it would be wise to check up on the state of Swildons, where they found that the stream had risen alarmingly and that the entrance was impassable. They then checked on the barn and found evidence that at least four people were in the cave. The M.R.O. were accordingly alerted and Howard Kenny and Jim Hanwell arrived on the green and decided that the police should be informed. They in turn informed the fire brigade. By then several people had arrived on the green and Howard and Jim asked the Franklin brothers and Mike Palmer to stand by to enter the cave when possible. The Fire Brigade started pumping with three pumps at approximately 7.30pm, but by 8.15, the water was still about six inches above the grating and the pumps were only just holding this level. However, after some deliberation, the party entered the cave. It was decided to go through Kenny’s Dig to Jacob’s Ladder to see if the party were down there, then to proceed down the Short Dry Way as far as the top of the Forty. In the passage just before the turn to the Wet Way, the water was almost six feet deep, and the first man was roped on to traverse above the water. Once past this obstacle, the rescue party made very good time to the Water Rift. This was sumping, and the party had to go through the upper keyholes. The first three to be rescued were found at the end of the passage above the Forty, and they informed the rescuers that four other people were at the bottom of the pitch. Pete Franklin went to the top of the pitch and thought he saw a light shining through the water. Mike Palmer confirmed this and they decided that something would have to be done quickly if there was a person stuck on the ladder. Accordingly, Keith sat in the narrows above the pitch to block some of the water while Pete looked over the edge. He saw that one of the party had climbed the ladder, but had been unable to get over the edge and had got onto the edge just below the lip of the pitch and had tied himself on. Keith let the water go while Mike lifelined Pete over the edge. Pete tied the bloke on and the others hauled him up. He was cold and very wet, but after some glucose and chocolate, he was none the worse for his ordeal. He had been on the ledge for an hour and a half. He told the rescuers than one of his party had fallen off the ladder, but thought he was only winded. After a further twenty minutes, the water level began to drop – due to the fire brigade starting up more pumps – and it was decided to descend the Forty. Pete went down with the First Aid Box and emergency rations, and was followed by Keith with the M.R.O. goon suits. They found three others in the passage at the bottom of the pitch, out of the water and in no danger. Keith returned to the top of the pitch to tell the others that everything was all right. Mike then took the M.R.O. telephone down, and Howard came down to check up and helped tie them on a lifeline and hauling rope. Within minutes, a very efficient hauling party pulled the three up the pitch and escorted them out of the cave. Everyone had cleared up and left the cave by 12.15pm. The speed and efficiency of the rescue was greatly helped by the good work of the fire brigade, and the Waterworks, whose pumping enabled the rescuers to enter the cave when they did and kept the water low enough for the rescue to continue. The rescuers helped the fire brigade to clear up the hoses and pumps and everyone left the site at 1.15am _______________________________________________________________________________________ DON’T FORGET THE A.G.M. AND DINNER

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Notices The B.S.A. National Conference will be held this year at Leeds University, Bodington Hall, from the 10th to the 13th of September. Members who are interested should apply to Bob Bagshaw for further details. +

The printing blocks for the B.B. covers having worn out, a new set is about to be made. This gives an opportunity for a change of cover design. Several new designs will be on show at the Dinner this year, and members will be asked to state their preference. If any member wished to submit a design, it should be done on card, TWICE FULL SIZE. Suitable cards are available from the editor for ‘do it yourself’ enthusiast. +

Cave

Communications

This is not a formal report on what is being done on the subject of Cave Communications, so much as a short article to give members some idea as what is being proposed. Several meetings of those interested in the subject have been held, under the auspices of the B.E.C. and at this stage most of those taking part are agreed on some general principles. Telephones posses the great advantage of requiring very little or no power to operate them, and can be made very small and light by the use of modern components. They suffer, however, from two main drawbacks. Firstly, they need a line between each end. Experience in Cuthbert’s has show that such a line does not remain in good condition for very long, and the expense and trouble involved in taking it down the cave and installing it permanently seem only marginally worthwhile. Some new experiments with a strong line are being done, and it may alter the position as far as damage to permanently installed lines is concerned. There remains the second drawback to the use of telephones – their lack of flexibility. It is hardly possible to lay a complete telephone network throughout a complex system like Cuthbert’s the Cave Communications men have thus concentrated their attentions on other forms of communication. Radio is obviously the most attractive of these. There are however, some problems. Radio waves will only pass through rock if extremely long wavelengths are used, and this in turn makes the problem of producing the right sort of aerial very great. Most of the systems which are being designed at present make use of some form of loop aerial. This seems to be the best method. The aim of the systems being designed is to be able to communicate through a thousand feet of limestone so that cave to surface and cave to cave communications will both be possible. Telephones will then be restricted to short distances in the cave – say each side on an obstruction or flooded part of the cave, so that the small amount of line required can be easily carried and laid on the spot when required. A new idea, which may prove possible in the more distant future, is to use earth mode communication. This is a technique related to earth resistively measurement and has been used in a very limited sphere in the U.S.A. The importance of good communications to rescue work is very plain. Much other work could also benefit. We look forward to being able to report in the B.B. on the first successful system in the not too distant future.

Page 5 “Alfie.”