Journal Series 3 Number 10

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.

 

Contents

A Mounting for Cave Survey Instruments by BM Ellis

The Great Flood at Eastwater 1910 by Barton

Survey of an Extension to the East Series of Holwell Cave, Quantock by BM Ellis

Review: Mendip Cave Bibliography and Survey Catalogue

 

 

Published by the Shepton Mallet Caving Club

The Mineries, Wells Road, Priddy, Wells, Somerset, BA5 3AU

http://www.shepton.org.uk

 

Editorial

Once again someone has removed a fixed aid from Swildons Hole. The bars of Mendip now echo to arguments for or against the return of the drainpipe to the 40.

Whilst I have some sympathies with the view that the place for the use of fixed aids is at the furthest point of exploration, and forcing some people to think twice about a descent of the 40 may in fact lead to a decrease in the number of incidents, no one can have any liking for the manner of its removal.

If those responsible feel that they are following in the steps of some members of the SMCC might I point out that there was on that occasion no question of creeping in during mid-week and the 'aids' were returned to their owner.

People with a yen for the anonymous removal of objects from caves might restrict their activities to the piles of rotting clothing, rusting tins, and decaying food to be found in so many places.

 

A Mounting for Cave Survey Instruments

A frequently used combination of instruments for cave survey is an ex-WD liquid damped prismatic compass and an Abney level. These are hand held for a CRG Grade Five survey, or tripod mounted for Grade Six. The main disadvantages of this combination are the time taken to sight two separate instruments, the one not being sighted having to be packed away safe from mud, and the difficulty of sighting and reading this type of compass when the line of sight is far removed from the horizontal. Accurate readings are, in the authors opinion, almost impossible if the line of sight is elevated by more than 30°, or depressed by more than 10°.

Thought was given to this problem and it was thought that there would be an improvement in the case of use, time taken, and accuracy, if the two instruments were mounted together such that it was only necessary to sight one, and then take readings from both instruments. The requirements of such a mounting are:

  1. a levelling device at the top of the tripod (ball & socket joint)
  2. facility to traverse the instruments in a horizontal plane
  3. the sighting lines of compass and level should be parallel
  4. the axis about which the instruments traverse, that about which the level is elevated, and the sighting line of the level should all meet at a point.

These conditions are fulfilled by the mounting shown in the sketch below. The lower bearing (A) is demountable and the lower part fixes onto a ball and socket head of the tripod. The device can be rotated at joint A and locked in any position by the thumbscrew (B).

Two small spirit levels (C) arc fitted to the platform, at right angles to each other, to indicate that levelling is correct. The Abney Level can be rotated about a horizontal axis at the bearing E. This bearing is also provided with a locking screw but it is omitted from the diagram. The compass (F) is mounted on the platform at the side of the level and has a simple traversing mechanism used in adjustment only.

In use the bottom of bearing A remains on the ball and socket head of the tripod and target lamps have been made which also mount on the lower part of bearing. These have the lamp at the same height above bearing A as is bearing E. Target lamps and instruments are thus interchangeable.

Before being put to use in the cave compass and level must be aligned by sighting both instruments on a distant object (the compass being traversed by a system provided on the platform) and the compass securely locked onto the platform. If the magnetic deviation were known, and the adjustment could accommodate it, the compass could be set to read True North bearings.

Figure 1 – Sketch of the Survey Instrument Mounting

Figure 1 – Sketch of the Survey Instrument Mounting

In the cave two tripods fitted with ball and socket heads and lower sections of bearing A are set up at the first two stations. The survey instruments are placed on one and a target lamp on the other. The instrument platform is levelled, then traversed to sight the Abney Level on the target. The platform is re-levelled, if necessary, the target re-sighted, and bearings A and E locked. The instruments can then be read at leisure. The station position is the intersection of the axis of bearing A, the sight line of the level, and the axis of bearing E.

This instrument mounting was first put to use in one of the caves at Cannington but the real test came at Easter 1965 whom a survey of Cefn Cave (Denbighshire) was made; this survey is to be published separately. The mounting was to be quick and easy to use and the closure errors obtained compare very favourably with another Grade Six survey made by the author in a part of Holwell Cave (Quantock). In Cefn Cave the "leap frog" method was used, instruments only being placed at alternate stations, thus only one bearing taken for each leg. In a survey at Holwell individually mounted instruments were read for forward and back bearings on each leg. Closure errors on the Cefn Survey ranged from 0.6% to 1.1% while at Holwell it was 0.5%. It seems reasonable to assume that if two bearings had been taken on each leg of the Cefn survey that it would have been as good as the Holwell survey.

Thus our expectation of improved accuracy has not been fulfilled but it appears that the same degree of accuracy is obtained while this mounting of the instruments made the surveyor's task easier and quicker. The only disadvantage is that the instruments are far from being balanced about bearing A, thus placing considerable strain on the ball and socket joint. Neither does this mounting assist in solving the problem of illuminating the instruments, though it should be noted that lighting is only needed for reading after the instruments have been sighted and locked into position. Experiments are being carried out on the possible use of Perspex light guides from a sufficiently distant source.

If required the instruments can still be used hand held, the mounting forms an excellent grip, but the instruments must be sighted and read individually.

BM Ellis

October 1955

 

The Great Flood at Eastwater 1910

The account which follows was written in August 1910 by a young subaltern of the Northamptonshire regiment. The story of the soldiers trapped by flood waters in Eastwater is a part of Mendip history only previously known from the writings of Balch and Baker. This account, by the young officer who later became Col. Barton shows, if nothing else, that cavers were the same then as now.

Priddy Camp, Wells, Somerset. Sunday, August 28, 1910.

As some of the 58th had met in Wookey Hole Cavern certain local cave experts the latter very kindly invited a party of ours to go down Eastwater Hole Cavern, about 3/4 of a mile from our camp.

It being a long time since I had any holiday away from mess accounts and correspondence I took the opportunity of a day off and after early morning service joined the party at 11 am.

Our hosts were Dr. Baker, from Kent, who has done some climbing in Switzerland and writes books on the Mendip Hills, Mr. Troup who lives in Wells and has been at the game for some ten years, two young farmers who live near, and a Mr. Donner, from London, who studies archaeology, but who was new to cave exploration. Russell, Capell, and Elston, with myself, made up four from the 58th, all novices.

Soon after 11 we started down a small shaft about 15 feet deep, an easy climb down projecting rocks, then worked through a small tunnel to the boulder basin which is like a sugar basin some 80 foot deep filled with large boulders instead of sugar and one winds ones way, sliding and crawling between the chinks. We were armed with candles for after leaving the entrance there was no light below, three acetylene lamps were carried, and I had an electric lamp as a reserve with a spare battery.

We now came to a point where surface water poured from above in a fine cascade, clear of which we clambered along a ledge, a rough wet slope on one side, a solid rock on the other, then we came to a very small tunnel through which one could just wriggle head first, bent like an S in one place. We now came to more open passages and clambered along the sharp shelving rocks, a very small stream of water trickling along a V-shape gulley 4 to 8 feet below. There were no stalactites in this subterranean waterway save here and there a small one of a few inches. The waterway deepened to some ten feet and one worked along by half lying against one side on a sloping ledge and pushing ones feet against the opposite wall. After a few yards of this we got good sitting room on wet rocks and had lunch, about 2 pm. We then commenced the second part of the exploration.

Taking a side gallery we worked down to a large chamber and stood on the edge of a natural shaft some 100 feet deep, a vertical drop into a black abyss. Ropes had been brought and Dr. Baker and Mr. Troup were down below, just a faint gleam of their lights could be seen in the inky blackness over the edge. The guests were asked to go on. Now in broad daylight I feel extraordinary uncomfortable looking over the staircase of a hotel, but moral courage was not enough to make me honest and say I preferred to stay on top and in a few moments, with a life line under my arms, I was sliding down the second rope and dangling in the dark. Down, down, down for 50 feet then one was just above the men waiting below on a ledge, but some feet away from it horizontally. "Now swing into the ledge", so kicking the rocks at the side one swung onto the ledge and had a firm footing again.

We then crawled head first down another small tunnel and came to a crack in the rocks through which one could only squeeze oneself with difficulty and then we came to another vertical shaft some 100 feet deep. There were no more ropes so we terminated our trip some 400 feet deep below ground. The experts had been down this shaft also on previous occasions. Magnesium wire only lighted up the upper part of this well but we heard stones bounding down against the sides for a long time before the final splash come. A heavy cascade was falling into this well from a point in the roof some way off us, and roared like a huge water pump.

It was now about 5 pm and we turned back.

At the ledge on the first shaft one put on the life line, took hold of the climbing rope, and gave the signal to those above to haul away, then out one swung to the centre of the shaft. Before I got to the top I had very good reason to regret that past months have been given to handling a pen instead of doing gymnastics & there was not much wind left or strength in the arms, although the men at the top practically hauled me up the whole way.

An electric light strapped to my belt was certainly better than carrying a candle in ones mouth.

The experts scaled up the sides without the men above taking their weight and one has been known to go down and up the 60 feet in the dark without any rope or lifeline. We moved back the way we came. The music of the water had now increased & on reaching the first cascade it was found that heavy rain had swelled the torrent & our retreat was cut off. The deluge splashing over the narrow footway which would have instantly extinguished candles and lamps.

Now the cave experts are made of stuff rather better than average men and holding a council they started to economise the lights for once lights are expended the game is over. They decided to try and work up through another passage to one side of the water.

Dr. Baker squeezed himself up through narrow slits some 15 feet high, so narrow that neither Russell nor I could force our way, two others followed and worked their way to a chamber above us, then let down a rope through a natural chimney some 25 feet high and using feet, knees, elbows and hands one struggled through to another narrow gallery. A sandwich was issued to all and the remains of about two more kept for the possible contingency of a 24 hours stay below ground.

We started again down a sharp rift & then turned off and had 50 yards sidling in spread eagle fashion along a steep slippery slope of rock which shelved to the unknown regions above as the rock came down to within a few inches so that we were like the ham in a sandwich. So narrow was the slit that at times one had to take out the things in ones breast pocket to squeeze along.

Figure 2 – Sketch from Barton's Original Notes

Figure 2 – Sketch from Barton's Original Notes

With practically nothing to grip with ones hands one had to keep from slipping by pushing ones backs and heels against the upper part of the sandwich.

Occasionally one dislodged a small stone which went rattling away to the depths beneath. Rounding a corner we got to a natural water worn staircase and climbing became easier. At the top we got into a small shower bath but passing through the leaders reported that the cascade had lessened in volume so working through another crack in the rocks we turned in the main water channel. The leaders took on my electric light and acetylene lamps and pushing up through the showers of dripping water turned round and gave us light for our candles were soon extinguished. Only a few yards of this and we were again in the boulder basin, clear of the water rush and very shortly at about 11.30 at night we reached the surface to find some half dozen of the 58th awaiting anxiously our return. The heavy rain all day had swelled the small stream, they were much concerned to see the water pouring down the entrance to the cavern.

It was a curious experience. I certainly admired the skill resource of our cave experts to whom this water difficulty was also a novelty.

Of an old suit of service dress uniform I had not much left all the prominent parts of the garment having disappeared.

A hot bath and blankets were very acceptable after the prospect of a 24 hour stay below ground in drenched clothes with the likelihood of a lighting failure.

So ended a Mendip holiday.

Editor's Note

This tale came to me as ten sheets of writing paper, slightly faded, clipped together at one corner. The original is in a longhand that I found some difficulty in deciphering, I have tried to reproduce it as exactly as possible, and appears to be a carbon copy. It could well be that it was written for regimental records and Barton decided to keep a carbon for himself.

The original remains in my possession but photocopies are held by the SMCC library and the Bristol Central Reference Library.

 

Holwell Cave, Quantock

Survey of an Extension to the East Series

A description of the East Series of Holwell Cave, together with a grade V survey appeared in SMCC Journal No. 8 (Nov. 1964). Shortly after this a note appeared in the "Speleologist'', Vol.1, No.1, (Jan 1965) and "British Caver" Vol. 41 (1965) that three local cavers had managed to force two squeezes and make a connection from the chamber just beside the Main Entrance to the East Series.

In July 1965 Bill Tolfree and I visited this extension and made a grade V survey. This survey used the same instruments as the earlier survey and this extension made a closed traverse of 312 feet. The surveys, when superimposed, failed to close by three feet, an error of just under 1%.

A copy of the survey of the extension will be found overleaf, all errors have been distributed in this new survey and so this part can be added directly to that already published.

Figure 3 – Survey of Extension to the East Series, Holwell Cave

Figure 3 – Survey of Extension to the East Series, Holwell Cave

BM Ellis

October 1965

 

Review: Mendip Cave Bibliography and Survey Catalogue 1901 – 1963

RW Mansfield, TE Reynolds, & IJ Standing

Cave Research Group Publication Number 13 144 pp. offset litho 16" x 8"

It is with some pride that members of SMCC may dwell upon the fact that one co-author of this valuable publication is a fellow member. The authors are to be highly congratulated upon this work which will enable one to find the relevant article from the vaguest information. The cross-referencing is so detailed that from such information as "something about strange shaped stalactites in Goatchurch" the exact reference, and access to the relevant publication, can be quickly found.

The work is divided into Introduction Definition, and six Divisions - Catalogue of Publications - Author Index - Survey Catalogue - Subject Index - Cave Index.

The Definitions, which are vital to the understanding of what follows, I found most confusing. One must realise that the numbers heading various paragraphs refer to the Divisions, hence the apparently missing No. 1. Further some information appears to be misplaced, statements referring to the publications searched and abbreviations to be used should surely appear under the notes on Division 3 and not Division 4. Also notes on the access to publication publications are split, one would expect to find all this with the notes on Division 2.

The author index, Division 3, is the heart of the bibliography, there are over 780 entries in alphabetical order of authors. Division 4, the survey catalogue could almost stand alone, but its inclusion is logical and greatly extends the value of the work.

Division 5, the subject index, is a useful section. There are sixteen subject divisions ranging from Accident and Rescue, through Biology, Chemistry & Physics, Diving, Mining, Historical, Sentimental, and Practical, to Societies. Divisions 5 & 6 are both cross-referenced back to Divisions 3 & 4.

It will require careful search to find errors and omissions. I think I can claim to have spotted two, an incorrect reference to Swildons Hole under the Accident & Rescue section, and surely the WI Stanton 1951 plan of Swildons was available as a separate sheet? It is to be hoped that a list of corrections will soon appear.

The offset litho reproduction is clear and easy to read, the plastic comb binding and board covers may not stand up to hard use but at 30/- (25/- to members of member clubs of CRG) it is good value for money.

 

Attachment

 Journal Series 03 Number 10