Journal Series 3 Number 5

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.



The Avens in Swildons Four by MM Thompson and JM Boon

Bacteriological Tests of Some Cave Waters by D Brooks, E Casey and J Bacon

Discoveries in Ogof Daren Cilau by JM Boon

Agen Allwedd, A Cave Dive by FJ Davies

Review: Report on the Investigations of Pen Park Hole

Review: Some Technical Aids for Cave Exploration

Swildons Streamway 1962 by FJ Davies


Published by the Shepton Mallet Caving Club

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



This issue has grown and grown. Articles describing last year's work in Swildon's Hole, added to reports on a successful venture at Easter have produced a real king-size journal. I hope we will be able to maintain this standard.

We have also, in this issue, an article by some guest writers. Over the past three or four years SMCC members have often acted as hosts to students of Seale Hayne Agricultural College caving on Mendip. Now three of these students have cooperated to give us an interesting account of bacteriological tests on cave water. Boil before drinking may be sound advice.

Caving activities in Mendip have, already this year, been marred by another fatality, that of a young girl at Longwood on the 17th March. The multiple causes which led to this tragic result are too numerous, and almost certainly not fully known, but it is our feeling that at least one factor was the presence of a party containing inexperienced people in such a difficult cave under conditions of unsettled weather. Might we appeal to all introducing novices to our sport and pastime that the first two or three trips should be in caves with a very easy exit. The fact that 99% of novices could be safely taken to Sump I in Swildons on a first trip does not justify the risk of such another occurrence.


The Avens in Swildons IV

Chapter One

Swildons IV was entered by the WSG in June 1957 after two years hard work in Blue Pencil Passage. On the initial exploration the aven close to Sump 4 was noticed and marked down for further exploration. It later became known as Cowsh Aven. In February 1958 the WSG got wind of an attempt by RMA Sandhurst CC to climb the Aven using pitons. Club competition was more marked in those days with the result that the WSG was galvanised into action. Ralph Lewis produced a maypole which could be transported through Blue Pencil Passage. It consisted of 18 sections of 2 feet each, the whole thing constructed in mild steel. The total weight was alarming and a very large party was organised to take it into the cave. Club members present included Ken Dawe, Jerry Wright and myself, the party being led by Len Dawes. The journey through Paradise and Blue Pencil is one of those trips which I prefer to forget but eventually all the sections were laid out and the pole bolted together. After a struggle we got the head of the pole to the point where the stream seemed to emerge. Len Dawes climbed up followed by Frank Darbon and myself. Above the head of the pitch a rift continued upwards but the stream emerged from an awkward looking passage leading off the "landing". We started to explore the passage but missed an obvious turning. We continued along a tight passage to the foot of a short climb and an aven, the distance covered was about 75 feet. The rest of the party had meanwhile taken the other turning and emerged at the foot of a big and wet shaft. This was obviously the main route so the maypole was dismantled and hoisted into this second aven. Len tried to climb up but was defeated by the amount of water falling on him. Several others had a go but with the same result.

On the 23rd February, Len, Ken, Jerry, Frank and myself returned. This time we managed to get to the head of the pole but no further. Immediately above the wall bulged out and beyond that there seemed to be a ledge. We next turned our attention to the second aven where we had noticed a ledge 15 feet up. We transported enough maypole to get there but were disappointed to find that this was only a recess, not a passage.

Subsequent to these first trips Jerry Wright scaled the second aven to a height of about 50 feet finding that it closed to on impassable crack. Ken Dawe and I climbed the rift above Cowsh Aven entering an ascending passage above the streamway. It terminated in a pitch which I descended. After 20 feet the walls belled out and I found myself spread-eagled 40 feet above the streamway. If asked, Ken, will no doubt provide a fair imitation of the anguished cry which floated up to him "....... tight rope Ken, tight rope!". But, by far the most important, an individual climbed the Great Aven to the ledge previously noticed. This proved to be 40 feet up. I believe that the climber was Noel Cleeve. The shaft still continued upwards with no sign of the source of the stream.

Shortly afterwards a good tug on the ladders in Cowsh Aven brought the whole thing down, and our only link with the upper storey had gone.

In November 1958 during the course of the diving operations it was found that the water sinking on Priddy Green fed the Main Aven. As a result we started digging on the Green. The total depth attained was 100 feet which added to the 100 feet climbed from Swildons IV still left 250 feet to go. The link up seemed as far away as ever. (See SMCC Journal Series 2 No. 1, May 1959, and Series 2 No. 4, November 1960).

MM Thompson

December 1962

Chapter Two

In the face of the formidable barrier at 100 feet in Priddy Green (a low arch giving access to the underside of an area of unstable boulders) enthusiasm had petered out by the end of 1960. Early in 1962 Mike Thompson suggested re-starting work, as the continuance of the Swildons streamway in VI and VII suggested that the Priddy Green route could still be an important factor in basing the transport of diving gear to Swildons IV. Out of this attempted revival of the dig arose the obvious idea of tackling the problem from the bottom as well as the top, i.e., resuming the exploration of the Great Aven in Swildons IV. In addition to being an interesting exploration in itself, spectacular discoveries from this direction would obviously spur diggers at Priddy Green to face the worms and green slime with some degree of hope.

Some doubters thought it unwise to prejudice the success of the summer diving operations in Swildons by carrying out involved climbing trips concurrently, but the venture got off the ground as a joint in MNRC/SMCC project, with MNRC providing the maypole and most of the men. Several other clubs joined in the actual climbing and gave invaluable assistance in preliminary carrying trips, notably BEC, SWETC, WCC and Leeds University Union SS. the opening up of the direct route from Swildons II to IV through Sumps 2 and 3 on May 5th gave us a distinct advantage over Len Davies and his men of 1958 for as we could take the maypole sections straight through the sumps their length was not limited by the bends of Blue Pencil Passage. (Our maypole consisted of 9 x 6 feet lengths, 3 of iron, 6 of alloy total 54 feet). This route also saved much energy in the transport of the formidable amounts of ironmongery, ropes etc. involved.

On May 20th the last of the maypole sections was towed through the sump and a party comprising Bob Pike, Bob Craig, Dave Tanner, Ron Teagle, Pat Mellor, Shirley Drakes and others of SWETC and myself could begin maypoling. David St. Pierre is one of the few well-organised cavers I know, and had meticulously packed away all the wherewithal for a nice hot cup of coffee in IV. Milk, sugar, coffee, Billy, cups, spoons, cooker were all produced from a little canvas bag, and neatly arranged on a limestone ledge, but alas he had forgotten to bring any fuel. Secretly very pleased I returned to the rusting shambles of our maypoling equipment. The first aven up from Swildons IV streamway (Cowsh Aven 27 feet) we maypoled quite easily, and Pat Mellor climbed up to fix a piton for a ladder. The rest of the party were lined up and we broke the maypole into sections and moved up through the few feet of tight passage to the foot of the Great Aven, which Len Dawes and his fellow WSG members had tried to scale in 1958.

The base of the Great Aven is shaped like a boat in plan, with the stream falling straight down the sharp end. We raised five of our maypole sections without much trouble, but by the time we had fixed on a sixth it had become very hard to raise and was under considerable tension. The most likely explanation seemed that the weight of the pole was causing the top to sag against the walls and snag beneath undercut ledges. We countered by working the base of the pole until it was lurching backwards and forwards rhythmically, and then pushing the pole violently upwards in the hope that the top had whipped out of its ledge. In this way we sometimes gained six inches at once, but by the time we had forced on the seventh section the pole was like a strung bow. It was impossible to see the top in the gloom and spray of the shaft, however Pat Mellor felt equal to the act of faith required and climbed up. He called down that he had reached a ledge and three of us went up to join him. We found that the maypole was some 8 feet short of the ledge which was semi circular in shape and cut into the side of the upward continuation of the Aven. (The distance from the ledge to the foot of the Great Aven was later measured as 43 feet).

After inspecting a blackened nylon sling and rusty karabiner (left by Noel Cleeve in 1958) we took a look at our next scaling problem. This was a smooth semi-cylinder rising sheer from the ledge; it appeared to grow narrower overhead and the stream sprayed gently down from it. Free climbing was out of the question, so we decided to plant the foot of the pole on a projection on the far side of the Aven opposite the ledge. Without further ado we freed the top of the pole and hauled it up. However with its bottom 20 feet clear of the ground it started to shed its lower sections on the assembled populace below. It was amusing to watch the little yellow lights 40 feet below, darting hither and thither as they scrambled frantically for cover, but when the cheerful din of metal on rock ceased it became apparent that no one had been brained. We took what was left of the pole to bits and re-erected it as it came past the ledge. Here our earlier difficulties with the top catching under ledges were intensified by having to work in restricted conditions astride a 40 foot drop, and only by whipping the pole like a fly rod and suddenly jerking it upwards could we make any headway. We managed to get four sections of the pole i.e. 24 feet up the pitch but greedily tried for a fifth; struggle as we would we could not shift it and pausing for a moment the pole once again disintegrated, however by leaping athletically about we managed to catch the poles before they descended on those below a second time. The topmost section was suspended out of our reach by the ladder having caught on some projection. We pulled the other end of the ladder to no effect and it is indicative of the state of mind that maypoling seems to induce that we even considered simply climbing up it.

Eventually we decided the only way to get the first maypole and ladder down was to construct a second, rather after Tom Sawyers method of finding lost marbles by flicking more in the same direction. The second maypole (4 sections 24 feet) was cast into the wake of the first, and one of us climbed up and succeeded in dislodging the ladder and the Mark 1 maypole section. At about this time a torrent suddenly discharged itself from the aven so we left the maypole in position and retreated from the ledge, with Mellor muttering ‘wetter than the wet pitch in Lost John's" (We worked out later that the downpour corresponded to a thunderstorm on the surface, the time interval being about half an hour). By the time everyone had reached the surface it had been a 15 hour trip.

Three weeks later, on June 10th, a party comprising Ron Teagle, Dave Turner, Ken Dawe, Mike Thompson and I returned, with Bob Craig, John Letterson and Fred Davies coming in later to survey. The Dawe and Thompson axis was in sparkling form and things were cheerful throughout. A hole was drilled just off the top of the maypole (i.e. 20 feet above the ledge of the Great Aven); we inserted the rawlbolt, clipped in the ladder (half the strands of the left side wire were severed) and, with great relief dismantled the maypole. Ken climbed the ladder and pronounced that the aven above was climbable but he was a married man. Oh for the days when women slept in the tackle shed.

Unable to face the prospect of another trip into these regions I climbed up for 8 feet or so beyond the rawlbolt on slimy rock, and cast round for a crack to take a second running belay (the first being the rawlbolt). The most obvious chance was a large upturned spur of chert like an oversize coat-hook on the left hand wall. I tapped this gingerly with a piton hammer whereupon it promptly cracked across the base, but stayed in position. The only other cracks about were too wide and came to a definite rounded closure. (Underground limestone, in Swildons at least, seems rarely to offer the excellent cracks for pitons which sometimes occur in limestone rock climbs, presumably because of lack of frost action). By now I found that staying on my greasy perch was becoming an effort, and I asked for one of the "expansion stemples" (a bolt fitting into a sleeve of pipe with a nut to adjust its position), to be sent up on the second line. In an unguarded moment I leaned my hand on the coat-hook whereupon it broke off and fell uninterruptedly for 27 feet until it struck the middle of Mike Thompson's back, as he hunted for a stemple. He was knocked to floor (of the ledge, not the Great Aven) but sustained nothing worse than a bruise and left the cave with Ken Dawe. Considerable pressure (moral) was brought on me to abandon my attempt, but although torn with remorse at having clobbered Thompson I could see a feasible route up the aven and in any case couldn't climb back. There was now only Ron Teagle on the ledge, still steadfastly holding the line, but the enforced wait bore some fruit in that I found a minute lip of chert on which I could drape a sling and a crack of about ¾ inch across which I wedged two pitons (i.e. at 90° to the usual way). Fred had by now arrived and I climbed up from the deadly little cluster of running belays on sloping ledges for a further 10 feet to the top of the aven (later measured as 55 feet from the ledge). The aven narrowed considerably in this section and a tight passage carrying the stream entered on the line of the main axis. The squeeze into this was exceptionally tight, but as the passage ahead seemed dead straight, I decided to force it, and after a few feet emerged into a good chamber. Ron, Fred, Dave and John came up and the removal of some stones in the stream bed on the lip of the aven made the squeeze much easier. We explored an almost vertically ascending stream passage in solid grey rock to the foot of yet another big aven discharging the stream. This we called Maine's Aven in honour of Mr. Maine of Manor Farm. Fred climbed up a wall of fractured rock and rotten stal on the left for 10-15 feet, but there was clearly no free-climbable route to the top. We estimated the height at about 50 feet. The maypoles were far too long to pass the squeeze so we decided to evacuate the whole series of gear, all in fact we left behind were two or three abseil slings. One point we did finally clear up the nature of the rift in the floor of the passage leading to the second (Wright's) aven, and taking the stream that falls down it. This proved to be a 15 foot drop in clean rock narrowing down to a tiny arch. We returned to the streamway and Fred dived through to St. John's Bell. He dragged through the six alloy poles on a rope, being met in II by Ron Teagle and Dave Turner. Dave got the alloy poles out of the cave later in the week, but in the best tradition two iron poles are still rusting in IV.

Figure 1 – Plan Survey of Cowsh Avens, Swildons Hole

Figure 1 – Plan Survey of Cowsh Avens, Swildons Hole

Figure 2 – Elevation Survey of Cowsh Avens, Swildons Hole

Figure 2 – Elevation Survey of Cowsh Avens, Swildons Hole

Fred's survey showed that the first aven (Cowsh) was 27 feet high with a further rise of about 15 feet to the foot of the Great Aven (43 feet to the ledge, 35 feet from ledge to top), from here the passage rises about 30 feet to the foot of the third aven (Maine's Aven) which is 30 feet plus. Thus the total height gain from the streamway was of the order of 190 feet. The vertical distance from the entrance to Priddy Green dig to Swildons IV is 430 feet and the depth of the dig is 100 feet; the remaining vertical distance is therefore only about 140 feet. From this viewpoint the maypoling operation was a success, however Maine's Aven is no nearer Priddy Green dig than Cowsh Aven, the horizontal distance to be covered has not been decreased. The discoveries had the desired effect on digging at Priddy Green, and much enthusiastic work was put in by Noel MacSharry and his Basset Hounds (RAF Compton Basset Expeditionary Society) and others. This resulted in the discovery of an interesting side-chamber and passage, but the main choke remains unbeaten, despite bang and slave labour.

A Technical Note on Maypoles

Probably the best way of joining maypole sections is by securing them by brackets with a 2 inch overlap, and recommended by Railton and other authorities. However, when, as in this case, the nature of the cave restricts the length of the pole to about six feet, this method is uneconomic, and a system of male and female ferrules may have to be used. The MNRC (Hensler, with the addition of three iron sections) maypole, was of this type and was subject to several weaknesses:

  1. The joints were too tight. When smeared with grit or mud it was hard to assemble.
  2. Each section should have a grub screw to attach the female ferrule securely to the male. (The minds of the double-entendre experts are ticking over audibly). This would prevent the converse trouble of self-dismantling maypoles.
  3. Every section should have a large hole drilled transversely at top and bottom to take a foot long 3/8 inch iron bar with ease to aid pushing the maypole up the rock face, and guying with a double rope at a suitable height. (The Hensler maypole had some holes, but they were infrequent and too small to insert a bar pushed by blows from a hammer).

My own feelings are that where possible steel rather than alloy sections should be used owing to greater rigidity, and that the first man up a maypole should not be double-lined from the bottom; the main danger is of the pole falling or collapsing in which case he will be better off unhindered. I also feel that maypoling shafts of more than 30 feet in height is probably unjustifiably dangerous owing to the unmanageable behaviour of poles longer than this.

ЈM Bоon

April 1963


Bacteriological Tests of Some Mendip Cave Waters


The purpose of bacteriological testing of water supplies is primarily to determine the degree of safety with which it can be used for drinking.

Water can be expected to contain bacteria from any of three groups:

  1. Natural water bacteria.
  2. Soil bacteria, the intermediate Aerogenes and Cloacae groups. (These are coliforms).
  3. Intestinal bacteria, caused by faecal contamination by animal or man. Can be subdivided into pathogenic (such as Salmonella Typhi or Shigella Dysenterine) or non-pathogenic (such as faecal Streptococci or faecal coliforms). Bacteria lying in the pathogenic intestinal sub-group are the only ones which make water actually unsafe to drink.

When dealing with drinking water supplies it is important to have a simple test easily repeated at regular intervals. Thus the usual water tests are not concerned with the precise identification of bacteria present. The coliforms are easily detected. If the water is contaminated by coliforms (non-pathogenic) then there is a strong possibility that pathogenic bacteria could also be present and the water is regarded as unfit to drink.

The Tests

The non-pathogenic coliforms are gram-negative rods capable of fermenting lactose and producing organic acids and gas, but the coliforms may arise from two sources, the soil, or recent faecal contamination. The first are the Intermediate Aerogenes and Cloacae, the second Escherichia Coli. The Presumptive Coliform Test detects the presence of any coliform contamination whilst the Differential Coliform Test positively detects Escherichia Coli (faecal).

Presumptive Coliform Test

50ml, 10ml, 1ml and 0.1ml samples of water are inoculated into Bile Salt Broth and incubated at 37°C for 48 hours. The production of acid and gas is an indication of the presence of coliform organisms. The quantities of water used in the samples has a statistical significance and probability tables can be used to obtain a rough value of the total number of coliform per 100ml of water from the number of tubes showing positive results.

Differential Coliform Test

Only Escherichia Coli (faecal origin) can produce acid and gas when incubated at 44°C. Inoculations from all positives in the presumptive test are made into fresh Bile Salt Broth and incubated at 44°C.

Agar Plate Colony

The above are the tests normally used to determine suitability of water supplies for drinking. Should more information be required then a sample is placed on agar jelly and incubated. The individual bacteria grow into colonies visible to the eye (under the microscope) and can be counted. (This number is far more precise than that from the Presumptive Coliform Test which has probable errors which may make figures quoted too high by 26% or too low by 70%). Various bacteria may also be specifically recognised by the shape of the colony.

Ministry of Heath Standards

Presumptive Coliform Test

Chlorinated supplies: Coliforms absent from 100ml quantities.

Non-Chlorinated supplies:

  • Class 1 Excellent: 0 Coliforms per 100ml quantity.
  • Class 2 Satisfactory: 1-3 Coliforms per 100ml quantity.
  • Class 3 Suspicious: 4-10 Coliforms per 100ml quantity.
  • Class 4 Unsatisfactory: over 10 Coliforms per 100ml quantity.

Differential Coliform Test

Escherichia Coli (the faecal origin bacteria) should be absent from 100ml sample of the supply. With small isolated rural supplies a minimal number (less than 5 per ml) of Escherichia Coli sometimes tolerated if it can be proved that human faecal pollution is impossible.

Swildons Hole – 22nd April 1961

Samples of water from the main stream were taken at the entrance, at the top of the 40 foot pot and just prior to sump one.

Test Results

Presumptive Coliform Test: 50ml, 1ml, and 0.1ml quantities were used. All samples in all quantities showed presence of Coliforms.

Differential Coliform Test: As all had proved strongly positive only sample III (sump one) was tested for Escherichia Coli. 50ml, and 1ml tubes gave positive, 0.1ml did not. Insufficient tubes were used to make the use of probability tables valid.

Agar Plate Test: Colony count from plates inoculated with 0.1ml of the samples gave the total bacteria present as:

  • Sample I (entrance) – 3110 per ml
  • Sample II (40 foot pot) – 1990 per ml
  • Sample III (sump one) – 5580 per ml

Also on the agar plates were recognisable colonies of Bacillus Mycoides and Pseudomonas Fluoroscenes.

Chemical Tests: A simple qualitative chemical analysis of sample III gave the results

  • Nitrate, Sulphate, Phosphate and Iron – trace
  • Chloride, Calcium and Magnesium – positive
  • Potassium and Ammonium – negative

Eastwater Cavern – 10th March 1963

Samples were taken from a small fall of water in the boulder ruckle just above the descent to Balch's Dining Room, and the water falling down Main Chamber from Harris' Passage.

Test Results

Presumptive Test: Sample A (Boulder Choke) from probability tables this water contained about 550 coliform organisms per 100ml. Sample B (Main Chamber). This was assumed to be a heavy roof drip and so we did not expect this to be heavily contaminated (our knowledge of the cave is not good). The 0.1ml test was therefore not performed but all the tubes showed positive giving at least a figure of 180 coliforms per 100 ml for this sample. This figure is probably much higher.

Differential Test: All positives from the Presumptive Test were then treated for the differential test. The only tube to show positive was the 50ml sample A (Boulder Choke). This would indicate a low level of faecal contamination (despite a large pile of horse dung close to the stream sink).


These tests show quite clearly that these waters would never be accepted as a drinking water supply. However, most cavers are the proud possessors of fairly robust constitutions and the regular visitors to Mendip should come to little harm from drinking cave water especially as they will tend to develop a resistance to the minor infections arising from such causes. This may not be the case with visitors from other areas who may develop symptoms of mild abdominal upsets.

Can we draw any other conclusions from these facts?

Water may enter a cave by various means. It may percolate the soil and subsoil and then pass by small crevices in the bedrock into the cave passages. In such a case most of the organic matter would have been filtered out of it – just as is done in a waterworks filter-bed.

It would be interesting to obtain a bacteriological test of the resurgence water at Wookey Hole. The slow passage through the phreatic zone should give an opportunity for sedimentation and the exhaustion of organic matter through bacterial action. During fresher periods one would expect the organic content of the water at Wookey to rise sharply.

As an example of such well filtered cave water one may take the lake at the extremity of Pridhamsleigh Cavern in South Devon. This showed negative to all coliform tests and an agar count showed only 500 organisms per ml.

Thus it may be reasonably safe to assume that water not deep in a cave and found to be heavily contaminated with coliforms (faecal or soil in origin) has a fairly rapid connection with the surface via open cave passage.

David Brooks, Eddie Casey and Jerry Bacon

Scale Hayne

March 1963


Discoveries In Ogof Daren Cilau

Ogof Daren Cilau is situated at the base of a cliff in the actively worked quarry reached by going up the steep rough track leading south from the cross roads by the old Daren Sunday School on the Llangattock escarpment. The NGR of its entrance is, so far as I can make out from the 1 inch OS map, SO/205155. The entrance was discovered by British Nylon Spinners Speleological Society in 1957 and it was explored by them in conjunction with Brian Price's Scouts and the South Wales Caving Club for about 1500 feet to a choke of stalagmited boulders. The cave was narrow and arduous and as there were more obvious prospects in the area no further work was done.

In late 1962 I chanced on the entrance and was intrigued by the powerful draught blowing out. Mel Davies of BNSS was kind enough to supply full details of the work done in the cave and I came back, with Noel MacSharry, after Christmas of the same year. After an unpleasant time chopping our way through ice and frozen mud in the early section of the cave we reached the choke, but three hours work with hammer and chisel had little effect upon it.

On April 12th 1963 (Good Friday), Fred Davies and I tried again with some "bang", and this time got through, a 6 oz. charge of Polar Ammon Gelignite, electrically detonated, destroyed the choke, and we made our way over fallen blocks in a passage similar to that prior to the choke for about 100 feet when it suddenly broke into a 10 feet high, 12 feet wide tunnel.

To the right it rapidly narrowed and choked with boulders after only 50 feet. To the left the passage continued to a mud choke, easily bypassed by an obvious passage five feet up in the left wall, and, in a few feet more opened up into a wide chamber with an ascending boulder slope at the other end. Clambering up this slope, to its left side, we entered a high rift passage.

To the right we followed this rift for several hundred feet, often finding it necessary to traverse high in the rift, or scramble through boulder blockages but the passage finally opened into one of inspiring dimensions reminiscent of Agen Allwedd's Main Passage. Soon after the boulder floor ascended to the smooth unbroken roof and we could see no obvious way past this obstruction.

Retracing our steps we followed the rift in the opposite direction but after only a 100 feet we were faced by a magnificent white stalagmite cascade with a pool of crystals, 15 feet in diameter at its feet. After some discussion Fred removed his boiler suit and boots and climbed up this flow to a height of 25 feet. He found no way on so future parties should have no need to climb the cascade or cross the crystal pool. There are some fine stalagmite bosses in other parts of the new extension.

This trip, during which we made an initial exploration of about 1800 feet of new cave, lasted only six hours, but it was an exhausting six hours caving. In several parts of both the new and old sections there is danger from unstable boulders. Coupled with the extremely arduous nature of the approach passages, and the difficulty of removing an injured person, this does not make the cave a suitable spot for inexperienced or ill-equipped parties.

Figure 3 – Sketch Survey of Ogof Daren Cilau

Figure 3 – Sketch Survey of Ogof Daren Cilau

JM Boon

April 1963


Journal of the Mendip Caving Group No. 3 (1962)

Price 7/6 post free from the Editor, 127 Cleveland Road, London W13 or from BM Ellis

The Mendip Caving Group follows a practice that is more common amongst the northern than the southern clubs in that it publishes a larger, more expensive journal at irregular intervals. This latest number covers the work during the last two or three years and includes the work at Pine Tree Pot (with grade 4-6 survey), Ubley Hill Pot, Stock's Hole and in Eire. As with previous issues, this is well produced, containing eleven surveys, pages of photographs and several diagrams. The photographs are rather over done however, thirty-eight on twelve pages, of which only eleven pictures have any particular merit.


Agen Allwedd a Cave Dive

The SMCC were at Llangattock for Easter 1965 and the programme included an investigation of the most downstream sump in the Agen Allwedd main stream. This sump is reached, as the very rough sketch of Agen Allwedd shows, by traversing Southern Stream Passage, 1¼ miles of difficult caving.

Mike Boon made contact with Chelsea Speleological Society and, well in advance they, with the Wessex, carried supplies of lead and a line reel with 300 feet of line on it into the cave.

On Sunday 14th April, Mike Boon and Bill Maxwell of CSS went into the cave, via Ogof Gam entrance, about 11.30 am. Some packs were given to a party of BSA on their way to attack the Boulder Choke at the upstream termination and the remainder of the gear was carried by Jerry Hill and John Lomas (CSS), Steve Wynne-Roberts and Fred Davies.

Southern Stream Passage lived up to its reputation, but Jerry Hill kept up an encouraging commentary upon just how much further we had to go, whilst a strip-tease by an overheated Steve provided some entertainment.

Arrived at the base, a low shingle bank about 150 feet upstream of the sump, we were fed bread, sausage, cheese and hot coffee at Mike Boon's Snack Bar. The service was good.

With breathing apparatus assembled and tested we waded downstream to the sump. Jeff Morgen (BSA) had decided to stay and watch operations so he was pressed into service as a belay point. One end of 120 feet nylon rope was tied to his waist and Steve went into the water. He first reappeared behind the base party, having followed the rock wall around to the right. On his next dive he went well out of sight and returned after about five minutes to report that he had reached the limit of the rope, i.e. say 100 feet into the sump, in a passage at least six feet wide and six feet high gently sloping downwards. Visibility zero.

Fred Davies then dived taking the line reel, the end of the line having been belayed to Jeff. At the 100 feet mark the line had been tied up with cotton, this was quickly reached, the cotton broken and a further 30 feet or so travelled. The stream route was easily recognisable as a patch of rough gravel, soft mud lay to either side of this. The route appeared to meander slightly but he was forced to halt as, despite regularly blowing against the nose clip, his ears failed to clear. Tying a half hitch around the handle of the line reel he dropped it and returned to base following the line.

Steve Wynne-Roberts dived again and at base we were startled by a sudden jerk on the line. When he returned Steve reported that after picking up the line reel the gradient increased considerably and after another 20 feet he reached the edge of a pot. The sharp tug felt by base party was Steve grabbing hard at the line to prevent himself falling down into this pot. He found this pot to be completely blocking the passage so he returned to base leaving the line reel behind.

Consultation between the divers gave an agreed estimate that the probe had been at least 150 feet, possibly closer to 200 feet, into the sump and to a point at least 15 feet below water level, but this is only an estimation as Steve found it impossible to see his depth gauge. No more could reasonably be attempted with the kits in use so we decided to withdraw from the cave.

The line reel was drawn back by pulling on the line but then snagged so Fred Davies dived in again to clear it. More food from the vast kitchen set up by Boon and we slowly made our way out of the cave, emerging into a screaming gale and rain at 12.30 am on Monday

Notes on Equipment

Both divers were using expanded neoprene wet suits. Fred Davies double suit of 1/8 inch material, Steve Wynne-Roberts a single suit of 1/4 inch material. The thicker suit used by Steve proved too restricting for awkward caving and caused him to remove the upper portion in the struggle with Southern Stream Passage.

The respirators used were both oxygen rebreathers of the SEBA/ATEA modification. It is felt to be quite a tribute to these sets that after a cave journey, which an unloaded caver expects to take 3½ hours, they arrived at the site of the dive in good order and ready for use.

Figure 4 – Sketch Survey of Agen Allwedd

Figure 4 – Sketch Survey of Agen Allwedd

Future Prospects

We were heavily weighted for bottom walking and the pot hole which Steve almost fell down a hazard that we were not really prepared for. Visibility was zero, but no attempt had been made to prevent contamination from further upstream. Any attempt to actually pass this sump would almost certainly be safer, if the diver is finning (there is plenty of space) and if a time is chosen when numbers in the cave are a minimum so that divers are given maximum visibility in the water. With these considerations compressed air would almost certainly be preferable to oxygen rebreathing but whether any party will succeed in carrying such equipment to the site is doubtful. Any who follow in our footsteps are welcome to the use of our lead weights, 12 x 6½ lbs, which are to be found at the junction of Southern Stream Passage and the Main Stream.

FJ Davies

April 1963


Reports on the Investigations of Pen Park Hole, Bristol

(CRG Publication No. 12)

Price 15/- post free from the Secretary, Cuilcagh, Stanyeld Rd, Church Stretton, Salop

This volume is the dearest yet published dealing with a Mendip cave and at least belies rumours that the Cave Research Group has, of recent years, become an associate member of the South Wales Caving Club. After an historical introduction it describes the work carried out by members of the BEC, UBSS and WCC to re-open the cave in 1956 and which commenced with a geo-electrical survey by the late Prof LS Palmer to determine its location and extent. Further chapters describe the geology, the fauna and miscellaneous finds – the last unfortunately being of no great historical importance. There is also a description of the cave and very scant notes to accompany a not too clear survey. The information contained in this publication is useful for record purposes but at 15/- for 54 pages it is expensive and with more stringent editing of unessential material could probably have been produced more cheaply. Except for those particularly interested in this cave the cost may be prohibitive for other would-have-been purchasers.


Some Technical Aids For Cave Exploration

by members of the South Wales Caving Club

(CRG Publication No.11)

Price 12/6 from the Secretary, Cuilcagh, Stanyeld Rd, Church Stretton, Salop; or from BM Ellis

This is a large volume (126 pages) with six sections covering the following topics: self lifelining devices; an electro-magnetic surveying apparatus; wet and dry suits for caving; a comparison of ropes made from different fibres; a method of making caving ladders using "Talurit" splices on either side of each rung; and scaling equipment. These last two sections give the impression that the SWCC has deliberately chosen complicated ways of making things but this does not detract from the useful information given.

As is expected of Cave Research Group publications this volume is very well produced and is well worth what at first seems to be a high price. Technical information of this nature is of interest and of use, but is published all too seldom.


Swildons Streamway 1962

At the close of 1961 we knew that Sump 6 could be passed, but no exploration had been made of the passages beyond, i.e. Swildons VII. Boon had also demonstrated that Sump 5 could be passed and had postulated that the streamway may thus be an easier route for divers and equipment to reach the site of operations in VI.

Work on pushing downstream started in 1962 when Ken Dawe and Fred Davies visited Swildons VI via Blue Pencil Passage. They found that Sump 5 was still well open and no work would be required to allow people to reach Sump 6.

On 5th May Mike Boon and Fred Davies dived to St. John's Bell and inserted a raw-bolt in the wall to belay a guide line. Boon then dived through to Swildons IV and so the stream route was now wide open for divers to follow. A guide line of ¼ inch diameter courlene being securely belayed at each end of the journey. St. John's Bell, Great Bell and Little Bell were all found as in the descriptions given by earlier divers (Balcombe, Davis). Little Bell is rarely noticed on the downstream journey, Great Bell being the first air space encountered.

Thus on the 2nd June four divers, Mike Thompson, Mike Boon, Steve Wynne-Roberts and Fred Davies were prepared for the journey to VII. All the equipment needed was taken to Sump 2 and packed into 4 huge army kit bags. The divers passed into IV, towing a kit bag each, without difficulty. In IV they were met by the support party who, without tackle to carry, had made light work of the journey through Paradise Regained.

Through Sump 4 and we had a kitchen set up in VI with Bob Pyke supervising. Boon and Thompson using open circuit air sets successfully passed Sump 6, then Fred Davies tried but the bulk of his DSEA oxygen kit, being on the chest, prevented him from getting through the tight constriction in the sump. Steve, with a new SEBA/ATEA oxygen kit however joined the others in VII and they made a quick exploration.

Immediately in front of the sump pool rises an impressive pile of boulders, the stream disappears into a small opening to the right of this pile, the roof rises to a height of at least 100 feet, it is difficult to see, even with a good electric head lamp. A small tributary passage enters 10 feet above stream level on the left but can only be traversed for some 20 feet when it gets much too small to permit further progress.

The climb up the boulders is steep, and far from easy, and one finishes at a height of at least 40-50 feet above the stream. Moving forward over the boulders the chamber narrows into a rift and it is possible to chimney down into the stream again.

Following the stream through a 4 feet high tunnel one is almost immediately faced by a second pile of boulders and the cave roof soars high above a muddy heap of limestone blocks once again. The climb is easier this time, the chamber narrows, the roof closes down and a nasty little squeeze between the boulders leads to a muddy, steeply sloping rift which drops into an old vadose trench. Moving south, the passage becomes smaller, the stream enters from the right, and Sump 7 is reached.

Returning to the first of the boulder chambers some small side passages, bearing south east were entered, but were not pushed for any great distance.

The withdrawal from the cave went without incident, but all were a little weary.

The next visit to these lower regions of Swildons was on Saturday 23rd June. Again we were given good loyal assistance by men from many clubs and four divers were in the cave. Mike Thompson however, so badly damaged his exposure suit on the journey into the cave that he withdrew from the assault. Mike Boon, Steve Wynne-Roberts and Fred Davies all successfully reached VII with the intention of forcing further down the streamway.

Mike Boon's open circuit air breathing apparatus was carried down to Sump 7, the rock here is very thinly bedded, with a steep northerly dip, and vast quantities of chert protruding from all the beds. The passage narrows and the approach to the sump is only 3 feet wide.

Mike successfully passed a short tight sump but then found he could communicate with Steve and Fred through a hole over the top. The passage seems to be a narrow rift, only wide enough to allow the passage of the human body below water level, but permitting sound and light to pass through its upper portions. He then went from their sight and sound for at least half an hour. When he returned it was to report that he had passed a second section of sump, longer than the first, to reach a high, wide and handsome stream passage, Swildons VIII

In his struggles with the underwater squeeze Mike had lost his face mask and so exhausted himself that he made an immediate withdrawal from the cave, diving Sump 6 without a face mask.

Steve and Fred now decided to make an attempt on Sump 7. They carried their SEBA/ATEA oxygen rebreathing kits, and lead weights to the sump and although they deflated the breathing bag when in the squeeze, did not succeed in passing through the first very tight section. Mike Boon, using an open circuit set was able to feed the equipment through ahead of him, this is not a feasible technique with rebreathing kits.

Again everyone withdrew from the cave.

Some of the well laid plans now started to go astray. Fred Davies was lost to the diving team when he had to enter hospital for some minor surgery, but on 21st July Mike Thompson and Mike Boon did visit Swildons VI and recover some of the equipment left in the cave.

The year advanced and it looked as though another push would not be held, despite all the planning, and still Swildons VII was unsurveyed. In an attempt to rectify this Steve and Fred visited the cave on Saturday 15th October. Steve was planning to use a Normalair open circuit demand valve fed from a SEBA cylinder. In diving Sump 2 he lost the spare cylinder of gas and, since this now meant he did not have enough gas to safely make the journey to VII and back the trip was altered to being simply a quick run as far as Sump 6 and back.

So the position rests in Swildons. One day we hope to be pushing on yet further, though the difficulties are now enormous, but it may well be that the discoveries at Stoke Lane will keep us occupied for a few years. Perhaps then we can return to Swildons with fresh enthusiasm and improved techniques, but before closing this article I must place on record our grateful thanks to those loyal hardworking supporters from every club that made this possible. The only name I can honestly pick out is that of Bob Pyke who spent many hours crouched over a stove in the cold depths of the cave. To all others, Wessex, BEC, MNRC, SWETC, or any I have omitted, Thank you.

Figure 5 – Sketch Survey of Swildons Seven

Figure 5 – Sketch Survey of Swildons Seven

FJ Davies

February 1963



 Journal Series 03 Number 5