BEC digs

Search Our Site

Situation.

St. Cuthbert’s Swallet is situated in Priddy, Somerset the National Grid Reference being 343505. The entrance is at the base of a low cliff face at the southern end of the depression to the west of the ruins of St. Cuthbert’s lead works. From the Belfry, take the well worn path which leads to the Mineries pool for 100 yards. Turning right, a track crosses Lady Well stream and descends into the large depression already mentioned. The cave entrance is locked.

Discovered.

The cave system was discovered in October 1953 by the Bristol Exploration Club.

Principal features of the System.

The cave entrance is at 800 feet above sea level, and aneroid measurements have given the depth of the cave at approximately 400 feet. The total length of passages so far explored is estimated to be in the region of 1 mile.

The cave can be conveniently divided into two sections as follows: -

  1. THE ENTRANCE SERIES. This extends from the entrance to the first choke, consists mainly of active stream passages, and includes most of the pitches normally encountered on a trip down the cave. The gradient is at first almost vertical, but gradually decreases.
  2. THE FAR SERIES. Comprises the rest of the cave and consists of gently graded stream passage occupying the lowest portion of a large and complicated system of interconnecting passages and chambers at various levels. The largest chambers and most stalactite formations occur in this part of the cave. Tributary streams are met with, although much of the series is inactive.

Description of the System.

A 15 foot timbered shaft through clay leads to a small horizontal passage into the rock face. A narrow bedding plane leads off to the right, a 10' vertical drop follows and a small chamber is entered. The floor of this chamber falls away in a ladder pitch. This is the ENTRANCE PITCH, a narrow rift which was only 6½" wide at one point, but which has been enlarged to 10". A certain amount of water is met a few feet down the pitch, and under very wet conditions water also enters at the top. The pitch is then impassable.

At the bottom of the pitch, a rift goes off down a scree slope and through a large pile of boulders, where a large amount of chert may be seen projecting from the rock. The character of the cave at this point resembles the boulder ruckle in Eastwater. Another notable feature is the presence of many ochre deposits. Stalactites having ochre centres and calcite on the surface are also found. This section of the cave is also subject to heavy drip. A high or low level route lead to the 'chamber at the top of the ARETE PITCH. The floor of this chamber is made up of jammed boulders which may be studied on descending the pitch. The pitch is 20' and the landing is on the edge of a large rectangular block - the arête. From this pitch a choice of two ways is available

THE OLD ROUTE.

The OLD ROUTE is reached by dropping through the floor of the ARETE CHAMBER. A low passage is followed for a few feet, ending in the UPPER LEDGE PITCH, a 10' drop onto a ledge overlooking a high rift. From this ledge, the LOWER LEDGE PITCH gives access to the bottom of the rift via a further 15' drop. At this point a stream enters 15' up the right hand wall, so that it is best to pass on quickly as a partial wetting is inevitable. The stream way here is of large dimensions, about 60' high for some 20'. Two right angle bends follow and the passage alters character, A rift is entered - the WIRE RIFT - between one and two feet wide and descending steeply with the dip. The stream is active at this point, cutting deeply into shale beds. All holds slope steeply down dip and are covered in clay. The roof rises, and some stalactites can be seen high up on the left hand wall. The passage continues for 30' and then dips steeply into the WATERFALL PITCH. A traverse over the top of this pitch loads to a platform. WATERFALL PITCH, which is 20' deep, may be descended from this point. At the base of this pitch, 20' of passage leads to WET PITCH - a 15' drop in the stream. The stream is left and straight ahead a short climb loads to MUD HALL, whilst on the left a mud covered bedding plane leads to STREAM PASSAGE on the NEW ROUTE.

Before describing the NEW ROUTE, a further passage has to be described. Beyond the traverse over WATERFALL PITCH the WIRE RIFT continues, but becomes very narrow. A squeeze over or under a chocked boulder leads to a dividing of the ways: to the left a very narrow bedding plane leads downwards but soon becomes too tight to follow, and to the right a meandering stream passage continues. After a further 30' the passage opens out into a large chamber - UPPER MUD HALL. The UPPER MUD HALL PITCH, a 13' drop, gives access to the floor of this chamber.

THE NEW ROUTE.

At the northern end of the ARETE CHAMBER, a small drop leads to PULPIT PASSAGE. Water from a small passage in the roof is the start of the new route stream. It is interesting to note the distribution of water between the old and new route streams. Removal of one rock would lead to a diversion of the old route water into PULPIT PASSAGE. During the excessively wet summer of 1954, the new route stream was deepened by 2' in this passage.

The head of PULPIT PITCH is reached after 100' of passage. This is a large rift at right angles to the passage just mentioned. Vertically above this pitch is a stalactite curtain with the corresponding conical stalagmite a few feet down the pitch, which is 60' deep. The pitch is laddered from a convenient ledge on the right, care being needed when placing the ladder. The ladder lies against rock for a few feet then hangs between the wall and a rock flake, this is an awkward spot when ascending the pitch as the ladder has to be left and the flake negotiated from the outside. 34' down the pitch a ledge is reached then a traverse along this to the left and a drop of a few feet gives access to the PULPIT, a long stride round the wall, a scramble down and the bottom is reached. The rift narrows to a few feet and the stream flows over one small drop after another to the top of GOUR PASSAGE PITCH. At the bottom of this pitch, another drop of 15' leads to GOUR PASSAGE. Brown stalagmite gours bridge the stream and are up to 2' wide and 3' high, the pools being silted up with mud and gravel. They are coated with a brown deposit containing a large amount of manganese, the deposit is probably pyrolusite. Some eight to ten gours occur in the next 100' of passage. Halfway down this section, two tributary passages enter opposite one another. To the left, a steeply ascending passage can be followed for about 200'' and cuts deeply into shale beds. It is interesting to note that, as soon as this passage reaches solid limestone, it rises vertically in a well shaped pot hole which has not yet been ascended.

On the other side of the main stream passage, the other tributary passage enters a narrow bedding plane extending as far as the bottom of WET PITCH. The passage is a very tight crawl over eroded stalagmite flow. A little further on down the main stream way another tributary enters via the left hand wall. This is the DRINKING FOUNTAIN. This tributary, like the one just mentioned, can be followed for about 200'.

Proceeding downstream, an awkward 6' drop has to be negotiated, and at this point severe folding of the rock has occurred, the strata at one point being vertical. On the right, a short climb leads to a bedding plans and MUD HALL. Soon after this, the top of the WATER SHUTE is reached. Here the water flows down a 43° slope. This slope fellows the strata and only poor hand and foot holds occur. An alternative route to the right is mud covered and not to be recommended. Looking upwards from below the WATER SHUTE presents an impressive picture with a second higher arch contributing to the scene. From this point, the general gradient of the stream passage is nearly horizontal except in a few isolated places. There are several passages entering the roof in this section of the cave which have not yet been fully explored.

A few yards downstream from the WATER SHUTE the old route stream cascades down the right hand wall, and a little further on, a passage from MUD HALL enters on the right. By following the stream across several small pools and a deep mud patch, TRAVERSE CHAMBER is reached. This is almost circular, up to 50' high, with a small waterfall falling 25' on to a gravel floor from a passage high up in the left hand wall. In this chamber, an altimeter gave a depth of 300' below the entrance. A few yards down the stream the FIRST CHOKE is reached. The passage roof drops rapidly until there is only sufficient room for the water to escape above the gravel and mud.
To return to the TRAVERSE CHAMBER, a false bedding plane on the right .can be entered via an awkward ledge, the traverse, an easier way into this, bedding plane is to climb out of the stream just before TRAVERSE CHAMBER is reached. About 70! Up the bedding plane, on the left, a small hole leads to a squeeze through unstable boulders and a short drop into BYPASS PASSAGE. Just beyond a 6' drop, the roof lifts and SENTRY PASSAGE can be seen 13' up the wall to the left. This leads to UPPER TRAVERSE CHAMBER and can be entered by a climb just above the 6' drop. Continuing down the passage for a little way, a short drop leads back to the stream.

Progress upstream is only possible for a short distance as the roof drops rapidly to meet the level mud floor and meandering stream at the lower side of the first choke. A few yards downstream the cause of the first choke is seen to be stream blockage of boulders behind which gravel and mud has silted up.

The very high rift now continues down dip for several hundred feet. The floor is nearly horizontal and rises through the rock beds which lie at about 30°. In one place chert projects into the passage and at several places stalagmite flew, generally covered in red mud, covers the walls. At the end of this Section, a 6' climb onto a ledge by some white stalagmite flow gives access to EVEREST PASSAGE.

The whole character of the stream passage now alters abruptly. The system shows well rounded passages containing remnants of a fill mainly composed of sand, carboniferous limestone .and red sandstone pebbles. For a short distance the stream is lost, the way lying past a 6' long slab of rock above a small pit where the stream is visible, then down a 4' drop back to the stream. Various openings on the left hand side up dip lead to the RABBIT WARREN. At one point it is necessary to crawl under the remnants of the gravel fill. This may be avoided by a 4' climb to the right into a well developed meander passage.

The STREAM PASSAGE continues along a horizontal floor, round several bends with the stream meandering from side to side. On the left, a climb over a steep slope with a liberal coating of mud, gives the easiest access to the RABBIT WARREN and 20' further downstream, a low opening on the right under a brown stalagmite flew leads to the DINNING ROOM. Fifty feet further down, the stream drops down a narrow slot between the right hand wall and a flow of stalagmite. The slot is impassable, but can be bypassed either by a tight squeeze ahead or by climbing over the top of the stalagmite bank to the right to the to the top of STALAGMITE PITCH. This pitch leads into a well formed pot, new covered in brown stalagmite. The stream continues over some silted gours, a squeeze then gives rise to a sharp left turn in the passage. The STREAM PASSAGE now continues for 130' in a straight line and consists of an enlarged bedding plane inclined at 30°. The whole of the passage is mud covered and is named the SEWER PASSAGE. This bedding plane continues up dip for 80' before widening out and joining the lower end of the RABBIT WARREN.

At the end of SEWER PASSAGE, a sharp right turn occurs and a tributary stream enters en the left. This is almost certainly the water that sinks at PLANTATION SWALLET, some hundred yards north of the St. Cuthbert’s entrance. This stream brings down more water than the main stream. Temperature measurements in November 1953 showed this water to be 1°C colder than the main stream, supporting the view that this is surface water travelling to this point by a fairly direct route. The water from PLANTATION SWALLET is the only large enough source of water in the vicinity. PLANTATION WATER can be followed up for a matter of 50'' when it can be seen to issue from a stalagmite bank through a number of small holes. It is thought that PLANTATION STREAM has also been entered further upstream in the RABBIT WARREN.

Returning to the main stream, after PLANTATION JUNCTION the stream way assumes a more rift like nature and continues over a gravel bed for fifty feet. The stream way then becomes partially blocked by a stalagmite flow on the left. A climb over this by the side of a fine stalactite pillar and a small crystal pool leads to a drop and back to the stream bed. The roof of the stream passage at this, point is of gravel cemented, with calcite. A low crawl in the stream bed or alternatively a climb to the right over a stalactite bank leads to BEEHIVE CHAMBER. A large orange coloured beehive formation gives the chamber its mane. High in the wall, behind the BEEHIVE, an awkward climb leads to a narrow system of passages known as the PIROLUSITE SERIES which contain large amounts of this deposit. A small stream runs through the system, entering high in the roof of a rift passage and unable to be followed. Downstream it disappears through a small hole. It is believed to be the stream that runs into the gours in GOUR HALL.

From BEEHIVE CHAMBER, a tricky climb over a stalactite flow leads into GOUR HALL. The most noticeable feature is the size, since it is the largest Chamber on the active stream route. At the point of entry the roof is 60' high and the width of the chamber is about 20'. On the right, a stalactite flow descends vertically for 20' and then flows over a 10' vertical face into the GREAT GOUR. This measures 18’ by 12’ and is filled with water to a depth of 6-9'', below which it is filled with mud. Standing on the GREAT GOUR and looking downstream, the stream can be seen to emerge from under a Series of subsidiary gours altogether some 25' high. The stream can be followed from BEEHIVE CHAMBER, along a low wet crawl to this point, the crawl containing a surprisingly large amount of stalactite.

Access to the stream is gained by climbing down the side of the GREAT GOUR. The Stream passage remains high for the next 150' but gradually becomes narrower, finally sinking in a formidable looking sump on the right of the passage. The sump at first sight appears to be stagnant, but on closer inspection it is seen that the stream runs off slightly to the right with a high velocity.

There is a short continuation of the main stream passage but this soon becomes too tight for further exploration. A vertical wall of shale can be seen 6' ahead of the furthest point reached. The rift above the sump can be ascended for some way and a passage has been entered some 30' up and followed for 60', when it becomes too narrow.

THE UPPER SERIES.

The upper series consists of a number of high level interconnecting chambers. These are all situated at a higher level than the stream passage. The upper series may be entered from numerous points in the cave. Those in common use are as follows: -

  1. Via the old route to the UPPER MUD HALL,
  2. Via the new route to EVEREST PASSAGE. . '
  3. From the DINING ROOM via the CERBERUS SERIES.

A climb from the stream bed below the WET PITCH on the old route leads into MUD HALL. This is a large chamber with a high roof and is 60' in length and a boulder covered floor. Various routes lead from this chamber. From the entrance, straight ahead, a rocky passage leads to a 20' pitch, The MUD HALL PITCH, which drops into the main stream passage below the WATER SHUTE. There are also two openings in the floor. One leads to the old route stream, which eventually disappears into a narrow bedding plane to re-emerge in the stream passage. The other opening leads into the ROCKY BOULDER SERIES. This as yet has not been fully explored. Yet another route from MUD HALL leads into UPPER MUD HALL. This is via the piled boulders at the top of the chamber.

The floor of UPPER MUD HALL consists of piled boulders It is roughly the same size and shape as MUD HALL. Ascending the chamber, PILLAR CHAMBER is reached. This chamber is ‘L’ shaped and is about 10' high. There is evidence of considerable rock movement. Broken formations lie everywhere and some have been cemented to the floor by further deposit. This section has been called as a result the STALACTITE GRAVEYARD. Fractured pillars that have since re-joined may also be seen. PILLAR CHAMBER is so named because of the pillar which may be seen on the right of the chamber. This is a substantial column 1' in diameter which has also been fractured. Unfortunately it is a dirty brown colour. Behind this pillar is a set of finer pillars. By squeezing past these, an extension may be reached. This region is a boulder ruckle and gives the impression of being fairly near the surface. A molar of Elephas has been found here. ( see appendix 4.).

An awkward 10" drop in the corner of PILLAR CHAMBER leads into another chamber containing some good floor deposits. A steeply descending boulder slope from this chamber leads to a right angle turn in the passage. The passage now has a sandy floor and is about 30' in height. A narrow squeeze, between a suspended boulder and the rock face on the right, leads to the top of BOULDER CHAMBER. This chamber varies in height from 8 to 20 feet, is irregular in outline, and slopes down dip for 100 to 200 feet. The floor is boulder covered and to the right of the entrance is a prominent cracked corner of rock. This is known as QUARRY CORNER and is dangerous. There are a number of routes from BOULDER CHAMBER, but before describing these, the ROCKY BOULDER SERIES mentioned earlier will be described.


ROCKY BOULDER SERIES

A hole in the floor behind the pillar in PILLAR CHAMBER leads to a large aven which is 60' high and 20’ across, with some stalactite flow down the far wall. A descending passage leads off, and after 100', a 13' pitch is reached. ROCKY BOULDER PITCH. This drops into a small chamber and continues past an unstable rock spur. At this point a harrow bedding plane on the left leads into MUD HALL. The passage continues through a narrow tube where a small window opens into OUBLIETTE PITCH. This is a narrow bottle shaped drop which is choked at the bottom. The way on is through a narrow vertical crack, to a boulder strewn chamber. At the far side a 23' pitch, ROCKY BOULDER LOWER PITCH, drops down a narrow crack into a high rift which soon enters a succession of small mud coated chambers, ending in a mud choke. This whole system appears to be flooded in times of heavy rain the water then seeping away through numerous small cracks. The system has not yet been fully explored, and it is believed that it can be entered from QUARRY CORNER.


THE UPPER SERIES (CONTINUED)

To the left of the BOULDER CHAMBER, a traverse past a large boulder leads after 100' to UPPER TRAVERSE CHAMBER. This has a fine stalactite flow, with a very good crystal pool on its lower slopes. A further 13' drop from this point leads to an active stream bed which if followed downstream leads to a 25' drop inro TRAVERSE CHAMBER (See new route). The upper reaches of this stream have not yet been explored. A scaling pole will be necessary for this, as a 20' vertical pot is reached. 50' up the stream way.

A climb round, the UPPER TRAVERSE CHAMBER gives rise to a steep boulder slope. There are some fine formations to the right at this point. If the boulder slope ahead is climbed, HIGH CHAMBER is reached. This is a large rift chamber 60' high and 20' wide, the floor consisting of boulders heavily encrusted with calcite. On the left of the chamber is a high boulder pile which has not yet been climbed. There is a short continuation passage in the far wall of the chamber, which soon closes down to a narrow but extensive bedding plane. On the left there appears to be another continuation 40' above the floor. Scaling poles will be necessary for this.

In the floor, near the traverse round UPPER TRAVERSE CHAMBER, it is possible to enter SENTRY PASSAGE. A 6' drop below some orange curtains leads to a 15' climb down through boulders. The passage descends rapidly with squeezes and potholes. A projecting flake of rock - the sentry - is reached and a 15' drop then leads to the BYPASS PASSAGE.

Returning to the top of the BOULDER CHAMBER, a route goes down dip to CASCADE CHAMBER. The route is rather indefinite, but keeping to the left and descending, the roof becomes lower and some erratics may be seen. The roof rises after a few feet and the floor forms a ledge before dropping away more steeply. Prom this point the main feature of the chamber may be seen. To the right a beautiful white stalagmite cascade something like 70 feet in length, descends at an angle of 55O. The cascade is split up by a series of small drops. These are decorated with stalactite organ pipes. The floor of the CASCADE CHAMBER IS 25 feet below, and although it would be possible to descend, it would be most inadvisable to do so as this would undoubtedly spoil the cascade. An alternative route is given at the end of this section. A little below and slightly to the left is a remarkable curtain hanging from the steeply sloping roof. It is 5 feet long and18 inches deep. A light behind this formation shows it up to its best advantage.

Returning once more to the BOULDER CHAMBER and descending to the right past QUARRY CORNER, EVEREST CHAMBER may he¬re ached, before entering EVEREST CHAMBER, a small passage to the left can be seen. This gives a view of the each of the organ pipes in CASCADE CHAMBER. EVEREST CHAMER consists of a series of interconnecting sloping chambers all containing stalactite formations. In the lowest chamber a remarkable tusk like stalactite 7 feet long hangs from a rift in the roof. On the right of this chamber' a stalactite flow has formed on gravel which has since subsided, and drip pockets can be seen projecting below the flow. A small climb to the left of this flow leads to a high rift chamber beautifully decorated. A guide tape has been laid here as some of the floor deposits are especially fine. On the left is a nest of cave pearls, behind which the floor is carved, into a series of intricate mud pillars, following the tape under a low arch, CURTAIN CHAMBER is reached. This is a very high rift, the left hand wall overhanging a little. On the right is a boulder slope well cemented with calcite. At the far end the rift rises, and 20' up a passage can be seen. This has not yet been entered but it is thought that it may join up with the lake in the CERBERUS SERIES. By climbing the boulder pile to the right, the main feature of CURTAIN CHAMBER may be seen. A large number of curtains, something like twenty in number, descend from a flow in the right hand wall. They are so close together and so intertwined that the exact number is hard to determine. They are all a foot or more in depth with a dark brown banding, on the outer edges, showing the creamy white stalactite into greater contrast. Great care is required in entering this chamber to avoid these curtains which reach to within 4 feet of the floor. As with CASCADE CHAMBER, no description can do them justice. In the floor of CURTAIN CHAMBER, a hole in the stalagmite leads to a small passage which descends steeply through pebble infill to EVEREST PASSAGE.

A short drop in the floor of EVEREST CHAMBER also leads to EVEREST PASSAGE. This is 10' wide and descends steeply for fifty feet when a large boulder - Everest -is reached. The way down is an easy slide but the return journey is a more strenuous affair, a scramble over a pit leads to a hands and knees crawl under a cluster of straws. To the right a 4' drop leads to one end of the RAT RUN. The height of the passage increases and after a short drop into a muddy passage, the main STREAM PASSAGE is reached. The stream flows so quietly at thia point that it is not noticed until one is standing beside it.

Immediately after passing the crawl in EVEREST PASSAGE, an opening on the left gives access to a bedding plane. Traversing to the left it is possible to look down into the STREAM PASSAGE. A bridge of jammed rocks can be reached and by crossing this, a continuation of the bedding plane can be followed. An ascending passage gives rise to a dividing of the ways. To the right HAREM ROUTE leads to the CASCADE CHAMBER whilst on the left, an alternative continuation of the bedding plane leads into CASCADE CHAMBER at the bottom of the cascade. Turning to the right at this point is a large passage which is quickly choked with boulders, but a small opening on the right leads to the RABBIT WARREN.

THE RABBIT WARREN

The RABBIT WARREN is far too complex a system for any detailed description. In the main it consists of a network of passages interspaced with steeply sloping bedding planes and chambers. It extends from CASCADE CHAMBER along the east side of the STREAM PASSAGE to PLANTATION JUNCTION, thus tending to keep up dip from the stream. There are extensive stalagmite deposits in the system. In the main they are of a dirty brown colour, but in places they are especially beautiful. The easiest entrance to the RABBIT WARREN is by climbing the mud slope from STREAM PASSAGE, just before the DINING ROOM is reached. This provides an alternative route to the lower reaches of the cave as STALAGMITE PITCH is thus bypassed.

One passage in the RABBIT WARREN deserves special mention. It contains some fine dry gours, very small but unlike usual gours. They have built up vertical lower edge about one inch high and are orange brown in colour. They are protected by a tape. Further on, an ascending passage contains hundreds of very fine hair erractics, all growing from one bedding joint. This passage ends in a shallow pool, which is covered in soap flake calcite.

Proceeding up dip from this point, over an awkward six foot stalactite bulge, a passage on the right enters a tight vertical squeeze. This gives rise to a more comfortable passage which opens out into a wide bedding plane. This contains a large stream and a smaller tributary. 'After 50' the stream is seen to flow under a low roof into gravel and boulders. This stream is thought to emerge at PLANTATION JUNCTION. These streams cannot be followed far in the upstream direction since the water emerges from, several small holes in the same stratum. This is a characteristic of a pressure fed system and hence there would appear to be no possibility of ever forcing a connection between this point and the swallet from whence the water flows (Presumably PLANTATION SWALLET.).

THE CERBERUS SERIES

The CERBERUS SERIES is best entered from the DINING ROOM. As mentioned earlier this is reached from the STREAM PASSAGE just before STALAGMITE PITCH. The entrance is marked with a strip of red reflector tape to facilitate easy finding by a stranded party. Part of the DINING ROOM has a gravel and stalagmite false floor as a roof, which snows incipient roof pendants.

The DINING ROOM is roughly twenty feet square and is used as a base for exploration and survey trips in the cave. At the far end of the chamber a climb over a. muddy bank leads to CERBERUS HALL. On the left a small trickle of water descends in wet weather and below a false floor a small hole leads to an inner chamber. This chamber is 6' wide by 20' long. It has been flooded at one time, and the roof at one point bears some unusual stalactites which have the appearance of rounded cylinders with the ends stuck together. There is a way out of the chamber at the far end but this soon closes down.

Turning from the right from the DINING ROOM, CERBERUS HALL is entered which is a 20' wide high passage. It has a sandy containing some deep pockets formed by strong drip action. At the end of this chamber a 15' drop leads by a solutional passage to a further chamber – MUD BALL CHASMBER. At the far end of this chamber a high level passage 15' from the floor continues over the top of LAKE CHAMBER. At the lowest point of MUD BALL CHAMBER a squeeze on the right leads to the RAT RUN. This is a small tube, and by keeping to the right throughout, EVEREST PASSAGE is reached. Just before the climb into EVEREST PASSAGE is a well formed pot hole now containing a symmetrically cracked mud deposit.

By keeping to the left through the RAT RUN, a descending passage leads into LAKE CHAMBER. This is 30' wide and slopes downwards to the lake, the level of which fluctuated with rainfall. Since first entering this chamber in march 1954, the water level has sunk from 15' until in October 1955, the pool was dry. A little way above the lake at the far end is a high level passage which is thought to join up with CURTAIN CHAMBER.

Compiled from notes by: - R. Bennett; A. Coase; C. P. Falshaw; J. Waddon; 11 July 1956.

APPENDIX 1

Access to ST. CUTHBERT’S SWALLET is limited, as the BRISTOL EXPLORATION CLUB has signed an agreement with the landowners to the effect that entry into the system will be strictly supervised. Water entering ST.CUIHBERT!S is used in the paper mills at Wookey Hole and also for domestic purposes. Therefore no risk of contamination can be allowed.

The B.E.C. is willing to provide the necessary guides for organised visitors to the cave.

NO NOVICES will be allowed into the cave system under any circumstances.

The DINING ROOM is equipped with Primus, paraffin, carbide candles and food. These are kept in airtight containers. Leaders are responsible for ensuring that these stores are replaced as used since they are intended primarily for use by a stranded party.

A telephone has been installed from the DINING ROOM to the club headquarters. This may be used by all parties.

Nature has provided a rubbish pit in the DINING ROOM in the form of a 10' blind drop to the left near the entrance/ All are asked to use this.

APPENDIX 2

Notes on animal remains found to date in St. Cuthbert's Swallet.

The remains so far discovered in the cave floor have been very few and consist entirely of teeth. About three teeth of Bos have been found in the sandy floor deposit of EVEREST PASSAGE. The age of these is indeterminate, but they are of fairly recent origin.

The most interesting relic is a tooth of Elephas which was found on 16.1.54 lying amongst pebbles of Old Red Sandstone in am abandoned stream way at the top of ROCKY BOULDER PASSAGE and brought out of the cave on a later trip. The tooth is in such a fragmentary state that the only definite thing which can be said is that it is an upper molar, probably of Elephas rrimigenius.

It is thought that the tooth is a "derived fossil" having been washed out of a gravel deposit, and subsequently redeposited where it was found.


APPENDIX 3

LIST OF TACKLE REQUIRED IN THE CAVE.

The main pitches in the system have now been equipped with permanent steel ladders. A traverse wire has been fixed in the wire rift on the old route.

Pitch Total Drop Ladder Required Lifeline & Tether Required
1.Entrance Pitch 25' 25' 5' tether.  No Lifeline.
2. Arête Pitch 35' Permanent Ladder Not used.
3. Ledge Pitches 30' Permanent Ladders Not used.
4.Waterfall Pitch 25' 20' 40' Lifeline.
5. Wet Pitch 15' 15' 20' Lifeline.
6.Pulpit Pitch 60' 40 ' 5' Tether.  100' Lifeline.
7. Gour Passage Pitch 20' 15' 20' Tether.
8.  Mud Hall Pitch 20' 20' 30' Lifeline.
9. Stalagmite Pitch. 20' 15' 5' Tether.
10.Upper Traverse Chamber Pitch 15' 10' 20' tether.
11.Traverse Chamber Pitch 25' 25' 40 Lifeline.  40' Tether.
12. Rocky Boulders Pitch 15' 15' 20' Tether.
13.Oubliette Pitch 15' 15' 10' Tether.
14. Pocky Boulders Lower Pitch 25' 25' 50' Lifeline, 50' Tether.
15.Upper Mud Hall Pitch 15' Permanent Ladder Not used.

The above list refers to B.E.C. Tackle. A lifeline is not required on the Entrance pitch as it is too narrow to fall far. A lifeline is essential for passing tackle however. An additional 10' tether is required for belaying life line man on pulpit pitch. A pulley block and a further 5' tether enables last man to be lifelined from the bottom. A 15' hand climbing line and 20' tether is required for beehive chamber and gour hall.

APPENDIX 4

The formation of the system.

As is often the case on Mendip, the cave appears to have had a long and involved history, inheriting its basic features from an earlier topography.

Its formation is best understood by first studying this basic system without the later modifications such as the formation of stalactite or silt deposits. The system is then seen to consist of a compact network of interconnecting passages and chambers in three dimensions. The passages show no evidence of control by gravity and current markings are absent. They are commonly rounded, in section and very rarely show open joints in the roof. This typo of cave formation is typified by the RABBIT BARREN where large sections may be studied free from secondary effects.

Where fossiliferous rock beds occur, the less soluble fossils project, often in perfect detail, and oven calcite veins are outlined as slight projections. An example of this may be found in the upper parts of the CORAL SERIES. In other parts of the cave extensive shale bands occur and the regular contours described above are not met with. Instead, projecting beds of this insoluble material are met with, often with a crumbly residue covering rock surfaces. The strike passage leading to PULPIT PITCH is an example of this, and shows fragile fossil shells in the shale where calcareous material has been leached out. In general, cave development is restricted in such shale and limestone beds.

The features described above are not consistent with formation by free surface streams. They record a long period of solution below the water table without measurable current flow, and represent a typical phreatic cave system. Many of the downward, continuing passages in this system are blocked by a clay or gravel fill, for example, the bottom of the ROCKY BOULDER SERIES. Passages running towards the surface tend to be choked by rock falls. This suggests that the system was originally much more extensive, though it would seem unlikely that it could have extended much above the present land surface which is duo to Triassic Plantation.
Not all the passages in this system grew to man sized dimensions. Smaller passages are occasionally revealed by roof collapse as meandering inverted half-tubes such as may be seen in the roof of the CASCADE CHAMBER.

In many places extensive gravel fills occur. They are often cemented by stalagmite deposits and may be revealed as vertical deposits by subsequent stream action. An example of this may be seen at the far end of CASCADE PASSAGE where the fill consists of over 10' of pebbles of old red sandstone, carboniferous limestone and trias.

Large masses of unconsolidated gravel are to be found in one part of ROCKY BOULDER SERIES arid passages completely gravel filled are met with. A notable example of another type of fill is found in the small passage above the entrance to the dining room. It consists of sand of a purity quite rare in cave deposits.

Clay and mud fills are quite common. In the upper part of the system and in the main streamways the deposits of red clay found are identical with those occurring near the mouth of the cave. Some of the deposits found in the original phreatic network are probably the insoluble residue of the limestone. The main streamway and adjacent passages are, for the most part, coated with a thin layer of mud often bounded vertically with a 'tide mark'. In some places the mud is drying out and peeling from the wet walls. This may possibly be the result of the sudden disappearance of the small lake which used to occupy the depression above the cave.

The removal of fills from under stalagmite coatings often gives rise to false floors. At the rear of the DINING ROOM a section of flooring projects from the wall while collapsed portions lie near by. The coating on these latter pieces appears to have been eroded by drip and shows a naadle like surface presumably due to the resolving of crystalline material. Further along CERBERUS PASSAGE a slump pit occurs in the clay floor where material is being removed from below.

The deposition and removal of fill may leave a clear record on cave roofs in places where no fill now exists. When a clay deposit reaches a cave roof, solution will still occur unless current flow ceases, and isolated portions of the surface will be masked by the rising fill. Continued solution will leave a series of isolated pendants such as occur in several places, e.g. the RABBIT WARREN. This probably represents a true phreatic episode. The pendants in the crawl leading to the DINING ROOM are of special interest as they are in stalactite. This same roof also exhibits a meandering groove a few inches wide and passing between the pendants apparently independent of gravity. It exhibits current markings and represents the first stage in the removal of the fill by a vadose stream.

Free surface streams are also responsible for modifying the system in other ways, near the surface, water has entered by percolation down joints and bedding planes, enlarging them and causing collapse or leaving a network of constricted rifts. The main mode of development under these conditions is by solution by thin films and trickles of water. This gives rise to clean scalloped rock surfaces with grooves due to water trickles. Fossils and chert project almost intact due to the low abrasive powers of the films. Shale beds also tend to project, though not restricting development as much as in phreatic systems. The undersides of limestone projections are usually uneroded due to the inability of the films to cling to pronounced overhangs.
Development by free-surface streams appears to be small even where large gradients occur. This is because streams in much of the- system are still engaged in removing fill, often without contact with cave walls, as in the stream way beyond the LEDGE PITCHES. Even WATERFALL PITCH, which appears to be a major vadose feature, has been formed from a solutional rift visible under the lip of the waterfall. The constricted rift leading to the pitch is vadose only for the bottom few feet and potholes occurring have resulted in only limited enlargement above the stream bed.

It should be noted that the actual formation of the gravel fills represents an extensive episode of vadose activity probably dating from glacial times. If this occurred comparatively rapidly, the streams transporting the fill would leave little evidence on cave walls.

As has already been stated, the formation of the cave is best explained by means of the concept of deep seated phreatic flow as postulated by W. M. Davies. This leaves the basic problem of the conditions responsible for forming the cave largely unanswered. A comparison of the system with nearby Eastwater would be helpful on this point.

CR2-1

 

CR2-2

 

CR2-3

 

CR2-4

 

CR2-5

SURVEYING IN REDCLIFFE CAVES. BRISTOL.,. 1953 - 4. Description of the cave system.

The system known as REDCLIFFE CAVES is a man made system excavated in the sandstone ridge which is approximately bounded by Redcliffe Way, The Floating Harbour, Bathurst Basin and the New Cut.

The cutting of the caves probably commenced during the Middle Ages.  This report, however, is not concerned with the historical side of the cave system, although it is worth noting that the caves appear to have been connected with the Slave Trade and also with the quartering of prisoners from the Napoleonic Wars, who constructed the diversion of the Avon into its present course through the New Cut.

The caves appear to have been formed by driving a series of entrances from the north side of the ridge and linking these by excavating all the sandstone between them to form a system having an almost constant roof height and level floor supported by a series of irregularly shaped and positioned pillars of the original sandstone.

No attempt was made by the excavators to introduce any form of order or symmetry to the system, the position and size of the pillars bearing little relation to the function which they have to perform, in supporting the roof.

In course of time it was found, not surprisingly, necessary to supplement the original system of pillars by walls arches and fillings.   These were of stone, brick and more recently of concrete.   The process is still being continued as more support becomes necessary.

During the War, bombs penetrated the cave system, the roof of which is only about 15-feet below ground level.   The ash filling which was subsequently introduced has, according to old accounts, cut off portions of the system completely.

In places wells have been sunk from the surface which go right through the cave system and on through the cave floor.

A circular wall of stone has been built for each well from floor to ceiling of the cave, thus giving the effect of a continuous shaft when viewed from the surface.

In many places, where the original excavation has not been modified, the marks of the tools used can still be seen on the walls.

The walls have, in some instances, almost closed off large portions of the caves and thus it is often necessary to make long detours to reach the far side of a particular wall.   However, holes existing in some of the walls proved . useful and sights were often taken through such holes.

Objects of the Survey.

As originally planned, the surveying of the Redcliffe system was undertaken with two objects in mind.   The first to obtain a plan of the cave system and the second to give members of the B.E.C. an opportunity to undertake surveying work in Bristol during the week, under conditions reasonably similar to those obtaining in a natural cave.

The permission of the City Engineer's Department, under whose management the caves come, was applied for and obtained in November,  1952 and the first trip took place in January, 1953.

Survey work in 1953.

The first few trips were spent in exploring the system.  It was found to be difficult to obtain a mental picture of the shape and direction of the cave owing to the maze like nature of the system.   It was finally decided to run a series of closed polygon traverses through the cave, using modified Astro compasses mounted on tripods, and tapes.   The error involved by ignoring elevations was agreed to be very small owing to the extremely level nature of the floor.   By the end of February, a large portion of the system had been covered in this manner and the results plotted and checked.

It was decided, at this stage, that the system would provide an interesting testing ground for an experiment in the use of a Plane Table for underground work and a suitable table was constructed by one of the surveying party.   This was used to obtain the position of walls and pillars until a halt was called in the work at Easter, when it was felt that the coming of the summer would interfere with the survey.

Survey work in 1954

The survey was restarted in April, 1954.  It was now felt that, by this time, the second of the original objects of the survey had been carried out, and so the work in 1954 was done by a small team of surveyors, the object being solely to complete the survey.    During the intervening time work on the 1953 results had brought slight discrepancies to light and so work started with a check on some of the earlier polygon traverses.   As a result, an earlier misinterpretation of the position of one of the station marks was discovered, and after resurveying this traverse work on the rest of the system was resumed.

The methods described previously, were used up until June, when a new method was adopted.  It had been found that, providing care was taken in setting up the Plane Table, it could be used to plot line traverses to the same order of accuracy as the Astro compasses and hence the line survey and detailing could proceed simultaneously.  Permanent stations were still used, so that the work could be checked if it became necessary.

By October, 1954, the survey covered a large part of the system.  Further Work would entail entry into portions of the caves which had been the scene of much rock fall.  Special permission would have to be obtained before a survey was concluded.   A few small passages were, however, investigated.  A lower grading has been claimed for these portions of the survey.

Surveying Methods.  Polygon Traverses.

The methods adopted for the polygon traverses conformed to the usual practice for cave surveys of this type.  Survey stations were selected at suitable points and their position recorded on the roof by means of carbon markings from acetylene lamps.  The caves, although damp, are not as wet as normally encountered and the markings thus made appear to be permanent.  The roof, being level, afforded an excellent place for marking since accidental obliterations were avoided by this method.

A plumb line was then dropped from the station mark, and the Astro compass on its tripod positioned underneath.  A light was similarly placed under the next station mark, and a bearing and distance taken.  A bearing of the last station was then taken in a similar manner and the Astro compass moved to the next station.

A 100ft. steel tape and a 66ft. cloth tape were used, the cloth tape being checked against the steel tape before use and a correction made.

Surveying Methods.  Plane Table Operation.

As a result of the experience gained in the use of a plane table for such work, the following method was evolved and is recommended to any cave surveyors who may be considering the us: of a plane table.

A team of three surveyors was used although four can be employed.  No.1 operates the plane table and commences the work by setting up the table under a survey station, or at some other convenient point.  At this stage, the others assist by erecting the plumb line and setting up lights from other stations which are visible from the operating point.   No.1 then takes sights onto all these stations draws the appropriate lines on the record card and labels the card with the position and any other details.  The table is now set up and orientated.

No.2 now proceeds to the first portion of wall to be detailed and places a light level with the sighting arm of the table.   No.1 then takes a bearing onto this light No.2,who has also the free end of the tape, then places this at the same point and No.3 pulls the tape taut (standing over the plane table) and calls out the distance to No.1, who then records it.  When this has been done, No.1 l gives a signal and the process is repeated.

From the description given, the method may appear slow, but in practice, with an experienced team, detail work may be done rapidly.  In the case of this survey, the team became so used to working together, that each member was able to anticipate the requirements of the others so that very few requests were necessary and work proceeded almost in silence.

The remainder of No.3’s job consists of illuminating the plane table, so that No.1 can concentrate on recording. Whenever a No.4 is available, he takes over this part of No.3’s work.  This results in a crowd round the plane table however, and is best avoided by built in illumination.  In any case, No.3 has to take great care to avoid jogging the table or obstructing No.l1who has to move right round the table as the work progresses.   On the other hand, No.3 must keep close to the table as the tape must be read from its centre.

No.2, in addition to providing the stations along the walls, must decide on the best places from which readings should be taken and illuminate the stretch of wall so that No.1 can see to draw the connecting lines between the points.

Nearly a hundred plane table records were produced by this method during the course of the survey.

Surveying Methods        ....Plotting.

The polygon traverses were first laid out to a scale of 1:100 on a drawing board.   In the case of those portions of the survey where the entire work was carried out by plane tabling, the required lines were taken off the records and tabulated with those from the Astro compasses.   Errors were then distributed and the final line survey produced.

When all the stations had been thus positioned, the station positions were transferred onto tracing paper and each plane table record traced through.  Since the records were produced to the same scale, direct tracing was possible.  After correction of the plane table records, the entire survey was reduced to a scale of 1.200 and finally drawn on a stable paper in drawing ink.  The plans were duplicated from this master copy and hand coloured in "Pelican" waterproof drawing inks.

Suitable location marks were incorporated on the master copy so that the overlying streets could be added to the copies in a contrasting colour.

Accuracy.

An accuracy equivalent to the Cave Research Group No.6 grading has been claimed for the main portion of the survey.   The degree of closure of the polygon traverses was consistent, the angular readings closing better than the distances on both methods.   No closed traverse was accepted with a discrepancy of more than a foot in station position.

The plane table results were found to vary by an amount depending on the radial distance from the recording point.  The maximum distance used in the records was 30 feet, and the variation on pillar or wall position at this distance amounted to nearly one foot.  However, since features at this distance from the recording point were usually common to at least two and often three adjacent tablings, a mean position could be established.   This variation of  a 3% in radial distance was felt to be mainly due to the visual "filling in" between recorded points on the plane table records.

Another advantage which was used to reduce some cumulative inaccuracies consisted of making use of the straight sections of wall.  An open traverse, including both sides of such a wall, should not show any tapering and over a long stretch of wall, a slight angular discrepancy will produce such a taper which may then be distributed over the traverse.

The Survey.

Owing to difficulties mentioned on page 3, it was found not possible to survey the entire system, hence the dotted line on sketch does not represent the complete cave system.

Sketches of the system are appended to this report. The first shows the division of the system, for the purposes of the survey, into series having a relatively closed periphery in accordance with normal cave practice, the second shows the system complete with all pillars and walls.   The maze like nature of the system will be appreciated from the second sketch.  The shapes shown for pillars are those approximately midway between roof and floor, i.e. the "waists" of the pillars.   Since most of the natural pillars are vaulted into the roof and floor to a considerable extent, the effect is to constrict the cave from the point of view of visibility and in some cases ease of movement.

Possible Extent of the Gave System.

In common with nearly all underground places, exaggerated accounts of the extent of the system are to be found.    In the case of Redcliffe, however, we have a good guide to the probable extent, since this must be in any case limited by the shape of the sandstone ridge under which it lies. The western end of the present system consists of natural rock over its entire length so that extensions to the west are ruled out.   A few cuttings exist in the cliff face to the west, but these are separate from the main system.

To the South West, a tunnel definitely joints the railway tunnel and possibly crossed it.  This appears to be an isolated tunnel, however, and on the most optimistic estimate, may have once been a "back door" coming out by the New Cut.

The area between the South Eastern Series and the Shaky Series is undoubtedly full of workings, which extend right round the entire eastern face of the surveyed system.

It is very probably that the workings go under Redcliffe Hill and that an entrance exists or existed in the church. This would probably represent the most Easterly point, as the gradient begins to fall from here onward.

Thus, it would appear likely that the area surveyed is at least half the total system at its greatest extent and may well amount to two thirds.

Conclusions.

A survey of the accessible portions of Redcliffe Caves, has contributed to the surveying experience of those taking part and afforded an excellent opportunity for the use of the Plane Table as an aid in underground work to be studied.

As a result of the experience gained, the Author has since used a Plane Table under natural Cave conditions.  In conclusion, the author would like to acknowledge the help given by many Club Members on this project and in particular the regular plane table team without whose continued support, the survey would not have been possible.

S.J. Collins,

January 1956

The first image shows the plan to scale 1:200

CR1-1

 

The second image shows an outline plan showing the surface features and the names of the series/extensions.

CR1-2

Caving Report No 3

The Manufacture of Lightweight Caving Ladders

 

by B.M. Ellis - May 1958

Introduction.

During March 1956, one hundred feet of lightweight caving ladder were made; first a ten foot length which was tested under severe conditions to ascertain the suitability of the method used, then one twenty and two thirty five foot lengths these lengths being regarded as the most suitable for use in Mendip caves. This report deals, in detail with the method used in the construction of these ladders.

Detailed specifications will be found in later sections of the report, but the main specification of the ladders is:

Overall width of rungs     6"
Distance between wires  5 ¼"
Distance between rungs 10"
Method of rung fixing      Taper Joints
Method of ladder joining  "C" rings

The author's reasons for deciding on this method of ladder construction will be found at the end of the report. The method of rung fixing by the use of taper pins is not claimed to be original; the author copied the idea from the Westminster Speleological Group ladders that he had used for many years and found to be very satisfactory. On checking these W.S.G. ladders after several years of service no case of rung slip was found to have occurred, nor had any damage been caused to the wires by the method of rung fixing employed.

The report is divided into seven sections under the headings given below:-

  1. Materials required, their suppliers, specifications and cost.
  2. Preparation of materials carried out prior to assembly.
  3. Method of assembly of the prepared parts.
  4. Details of the jigs used.
  5. Approximate times involved in the different stages of manufacture.
  6. Tensile strengths, weights and bulk of the ladders
  7. Conclusions.

The March, 1956 prices of materials are quoted as a guide some of these prices fluctuate, especially that of aluminium alloy tubing. Names and addresses of suppliers are also given for reference. All these suppliers are recommended as being quick and helpful.

Let it be said, though probably unnecessarily, that the author is not an engineer but he did have the advice of one.


 

SECTION A - Materials.

TUBING for rungs

The tubing used was BL 6 quality Dural tubing obtainable from:-

Blackburns ( London) Ltd.,
Drayton House,
Gordon Street,
London, W.C.1.

The dimensions of the tubing were 3/8" O/D x 16 s.w.g., sold in thirteen feet lengths @ 9d. per foot. It can either be sent, when packing and carriage are extra, or collected from the firm's warehouse in Stephen Street, London.

WIRE ROPE.

Flexible round strand rope of best plough steel with galvanized finish and plain ends. The construction of the rope is 6/19, i.e. six strands of nineteen wires each, with a fibre main core. The 1/8" diameter rope used has an actual breaking strain (manufacturer's figures) of 0.61 tons. The cost was £1/8/6 per hundred feet (which weighs approx. 2 1/4 lbs.), carriage extra. It is obtainable from:-

Bridgwater Wire Rope Works Ltd.,
Bristol Road,
Bridgwater,
Somerset.

THIMBLES.

Figure 1Cadmium plated thimbles to take 1/8" diameter rope of the dimensions shown in figure 1 are obtainable at 3d each, plus postage, from:-

William Good and Sons Ltd.,
46, Fish Street Hill,
London, E.C.3

Dimensions C=7/8"  B=1/2"   D=1/8"

Figure 1

ROD for taper pins.

The pins were cut from 5/32" diameter mild steel rod obtained through a friend @ 1d. per foot.

TUBING for sleeves.

Copper tubing of 1/4" I/D found lying scrap was used.

CHAIN for "C" rings.

Figure 2Chain links having the dimensions shown in figure 2 were used. It was found lying scrap.

Figure 2

The quantities of these materials required for the manufacture of one hundred feet of ladder are:-

        Alloy Tubing                                                    65 feet.
        Wire Rope                                                       220 feet.
        Mild steel rod                                                  25 feet.
        Sleeves, thimbles and Chain Links          4 each per length of ladder



SECTION B - Preparation.

RUNGS.

The jig used for the cutting and drilling of the alloy tubing is described on page 5 and shown in figure 4. The rungs are cut six inches long and drilled 5/16" from either end using a number 29 drill. The cutting is done by holding the tubing in the angle of the jig in a bench vise and cutting off square against the jig; the drilling by holding the tubing in the same position in the jig in a flat bed vise and using a vertical bench drill. Finally the ends of each rung and the drilled holes are cleaned using a fine file. The dimensions of the rungs are shown in figure 4.

 

WIRE ROPE.

The best method for cutting the wire rope was found to be as follows. Bind the rope with Wire of about 22 s.w.g. either side of the point to be cut, leaving about 1/8" between the two bindings, and then cut with a hacksaw. The lengths of wire required are as follows:-

For Ten feet ladders                     11 feet.
For Twenty feet ladders               21 feet.
For Thirty five feet ladders           37 feet.

One end of each cut length is left bound and the other is prepared for threading. The method finally adopted to prepare the end for threading is first to tin it with solder for a length of three inches with the original binding in place, then place a second binding above the first and cut between the two. The second binding is then removed and the end carefully cleaned using a very fine file; no loose strands of wire must remain. To tin the end of the wire, it should be immersed in a tube of molten solder for several seconds, removed, and the excess solder melted off using a micro-bunsen burner. Care should be taken to remove all the grease present on the wire when sold before soldering.

THIMBLES.

These are purchased ready for use.

TAPER PINS.

All attempts to purchase something suitable were of no avail and the pins have to be manufactured from mild steel rod. The rod is ground to a flat taper on an ordinary bench grinding wheel using the jig described on page 5 and shown in figure 7. After grinding, the taper is filed smooth and the pin out to an approximate length of one inch. (See note in Section G.) The taper pins are of 5/32" diameter, having a flat taper at an angle of 15 - 20 degrees to the length of the pin. The overall length of the pin is not critical as long as there is at least 7/16" at the full diameter beyond the end of the taper.

SLEEVES

These are cut ¾" long from the copper tubing, cleaned with a file and slightly flattened by a light blow.

"C" RINGS.

Two cuts are made at an angle of 43 degrees to the length of the link, at the centre of on one side of each link. The cuts are cleaned using a large square file.


 

SECTION C - Assembly.

HEADERS.

The parts comprising each header are shown in figure 5. A thimble is forced open, a "C" ring threaded on, and the thimble closed; the wire is threaded through a sleeve, around the thimble and back into the sleeve until the bound end is almost at the bottom of the sleeve. The complete assembly is pulled tight, and in this position the sleeve is squashed fairly tight. Either end of the sleeve is then soldered, using a micro-bunsen burner and soft solder (60% lead, 40% tin.)

Figure 5

RUNG FIXING.

The rungs are threaded on two wires which have had headers assembled at one end of each. The first rung is placed in the slot of the rung spacing and fixing jig (described on page 3) having the rung stop, and the rung is spaced exactly five inches from the top inside curve of the "C" ring by using the header distance attachment described on page 5. This distance of exactly five inches ensures that, on joining two ladders together, there is no difference in distance between rungs at the join. The first rung is fixed in position by hammering a taper pin between the inside of the rung and the wire, care being taken not to damage the wire with the pin. (The effect of the pin is shown in figure 6.). Having fixed one side, the ladder is reversed in the jig so that the other end of the same rung is then against the rung stop, and the rung is then fixed to the other wire in a similar manner. The pins must be placed on the same side of the wire for each rung, with reversal of the side for succeeding rungs - this is done to prevent any curling and spiralling of the ladder due to the slight bend in the wire imparted by the taper pin. Having fixed the first rang, the ladder is moved up in the jig and the position of the second rung taken from the one already fixed. One rung is placed in each pair of slots, the wires pulled taut, and a pin driven in. For this operation it is advantageous to have two people working on the construction. Due to the rung stop fitted to the jig, it is necessary to reverse the ladder before hammering in the second pin, but this operation also cancels out any errors that may be present in the construction of the jig.

BOTTOM HEADERS.

Having fixed the last rung of the ladder, it is left in the jig and the bottom header assembled in the same manner as the top one. The correct position in relation to the bottom rung is obtained by using the header distance attachment. When the header is assembled in the correct position, it is pulled tight, the point where the cable left the sleeve being marked. The header is then disassembled and the wire cut at the mark made. It is then reassembled without using the jigs, pulled tight and squashed as mentioned in (1) above, and soldered, thus completing the ladder.


 

SECTION D - Jigs used.

RUNG CUTTING AND DRILLING JIG.

(see Figure 4.) This jig consisted of a length of one inch angle iron cut square at each end and exactly six inches long.  5/16" from each end was drilled a hole using a number 27 drill, the distance of the centre of the hole from the angle being such that it lay vertically over the centre of a piece of 3/8" diameter tubing held in the angle.

TAPER PIN GRINDING JIG.

(Figure 7.) A piece of 2"x 4" x 1¼" brass was cut so that one side was at an angle of 15 - 20 degrees to the others. A hole of 11/64" diameter was drilled perpendicular to this face and 1 1/4" from one end. The width of the brass was then reduced by ½" to 1½" by sawing to cause the drilled hole to appear along the cut face. This operation was considered necessary because the decreased resistance on striking the face would have caused the hole not to be straight if the hole had been drilled directly to the face. Along the opposite face was soldered a two inch strip of 16 s.w.g. brass. A hole was drilled vertically across the original hole and tapped to take a ¼" Whitworth bolt to which had been brazed a butterfly nut. The width of the jig was such that a piece of 5/32" rod placed through the hole and clamped by the bolt would just be ground by the grinding wheel used, the plate running along the edge of the platform of the wheel and thus preventing the jig itself from touching the grinding wheel.

RUNG SPACING & FIXING JIG.

(Figure 8.) Two pieces of ¾" angle Dural, twelve inches long, were bolted parallel, 5¼" apart, on a sheet of 12"x 8"x ½" Tufnol. In each length of Dural were cut two slots, 7/l6"' wide and exactly ten inches apart; these slots were ½" deep and were to take the rungs. Opposite one of these slots was bolted a short length of 1" angle iron parallel to, and 7/8" away from the Dural, to act as a stop for the rung when hammering in taper pins.

HEADER DISTANCE ATTACHMENT.

This consisted of a piece of 1¼" angle iron approximately 5" long and drilled to take an O.B.A. bolt. The position of this bolt was such that when the angle iron was placed at the top of the rung spacing jig the bolt was exactly five inches from the centre of a rung placed in the top slot of the jig.


 

SECTION E - Approximate times involved.

These times must be taken as being very approximate, as times per job decrease rapidly with the number done. These times are the average of those taken by the author. Further more, extra time must be added for experimentation with methods available, manufacture of jigs, and miscellaneous hold-ups such as replacement of broken hacksaw blades and treatment of burnt fingers obtained when grinding taper pins.

Preparation.

RUNGS:

Cutting................................................. 15 seconds each.

Drilling................................................. 20 seconds each.

Filing.................................................... 60 seconds each.

WIRE ROPE:

Measuring, Binding and cutting...... 4 minutes per length.

Tinning ends for threading............... 3 minutes per length.

TRIMBLES:

No preparation necessary.

TAPER PINS:

Grinding............................................... 30 seconds each.

Filing and cutting................................ 30 seconds each.

SLEEVES:

Cutting.................................................. 15 seconds each.

Filing..................................................... 30 seconds each.

"C" RINGS:

Cutting.................................................. 90 seconds each.

Filing..................................................... 60 seconds each.

Assembly.

HEADERS

Assembly............................................. 4 minutes each.

Soldering.............................................. 1 minute each.

RUNG FIXING:

Threading............................................. 15 seconds per rung.

Fixing..................................................... 90 seconds per rung.

BOTTOM HEADERS:

Assembly............................................... 8 minutes each.

Soldering.............................................. 1 minute each.

These times apply to one person working except in the case of rung fixing (Two people) and drilling rungs (Two people, two vises and one drill). The times include putting into, and taking out of, appropriate jigs.


 

SECTION F - Tensile strengths, weights and bulk.

TENSILE STRENGTHS.

Before use underground, each ladder was subjected to a general test by hanging each end in turn from a tree, and making the ladder take the weight of two people, their weights totalling 340 lb.

Tensile strengths were applied to the following, "C" rings, end loops and rung fixing. In each case the load was applied as fast as was possible on the machine, approx. 1,000 lbs per minute. Although this rate in no way represents shock loading, it is felt that the figures obtained are still relevant as only in very exceptional circumstances would a caving ladder be subjected to shock loading.

"C" Rings. Eight chain links of the type used were cut through one side of the link and tested in pairs. In each case, the links started to open at the same load.

End Loops. Four loops were made in exactly the same manner as those used on the ladders, one loop on either side of a short length of cable. The weaker loop of each pair is thus the one whose strength is recorded. Both these loops slipped at the weight given below.

Rung Fixing. A short length of cable was centrally fixed on a rung by means of a taper pin as used in the construction of the ladders, and pulled. The rung was found to slip at the figure quoted below but serious failure of the materials did not occur. Two samples were tested in this manner, both slipping at the same load; in one, the hole drilled to take the wire was slightly enlarged on one side and there were two broken wires ( out of 114 ), in the other no damage was visible.

Results.

"C" rings started to open at         675 lb.  (0.3 tons)
End loops slipped at                 1,010 lb. (0.45tcns)
Rungs slipped at                           560 lb.  (0.25tons)

For interest and comparison purposes, tensile strengths were determined of an eye splice made in the cable and also of a loop in the cable secured by means of a shackle. With the former, the cable broke at the bottom of the splice at a load of 1,120 lb. (0.5 tons), while at this loading there was no sign of slip in the shackle. It was considered that the bulk and weight of a shackle was not justified by the increase in strength of 110 lb. over the soldered loops, especially as the soldered loop was not the weakest part of the ladder. Similarly for the extra work involved in making an eye-splice in the cable

WEIGHTS AND BULK

Weights and bulk of the finished ladders.

Length

Weight

Diameter when rolled

35 feet

4¼ lb.

6 inches

20 feet

2½ lb.

4 inches

10 feet

1½ lb.

3 inches


 

SECTION G - Conclusions.

The time taken for the design, assembly and construction of the four ladders was longer than that expected at the outset as they took about thirty man hours to complete. This time includes the manufacture of all the jigs and experiments to find the best method of accomplishing various tasks. The time taken for the construction itself was about twenty man hours. Perhaps if more cavers helped with the construction of caving ladders they would then realize the work involved and therefore take more care of the tackle they use.

When making a further ladder at a later date only one item was changed from the method described in this report. This was to do away with the taper pin grinding jig and to make the taper by holding the rod in a vise and using a very coarse file. This method was found to be quicker, easier and also prevented the serious overheating of the metal.

The overall cost for the construction of one hundred feet of ladder was approximately £6 - 5 - 0. The cost may be divided very roughly as:-

Wire Rope                 £3 - 4 – 0
Rungs                       £2 - 9 – 0
Taper pins                        2 – 0
Thimbles                           4 – 0
Carriage on goods           6 – 0

Sufficient materials remained after the construction of the ladders to make a ten feet length of "knobbly Dog." This consists of a single wire rope on which are mounted centrally three inch lengths of alloy tubing at one foot intervals. It is used as a hand line on near vertical slopes. The tubing for this was fixed in a similar manner, that is by use of taper pins.  To ensure that the pins were driven in to the correct position, a small diameter punch, marked at the correct depth, was used.

For considerations of cost and bulk it was decided to make the ladders as narrow as practical. Having cut the rungs to give a width of 5¼ inches between wires, some doubt was felt in practice but no difficulty has been experienced, by people using size 10 boots. (The author does not know of anyone with bigger feet having used the ladders). The ladders have been extensively used since manufacture, and everyone who has climbed on them has pronounced them entirely satisfactory.

The choice of a rung distance of 10 inches was made with ease of climbing the longer pitches in mind. For pitches of over eighty feet, a rung distance of twelve inches had been found uncomfortable, especially by the shorter caver.

The choice of ladder length's will always be a matter for discussion; just let it be said that this choice has been found satisfactory.

Originally, the ladders were carried by rolling as shown figure 56a of British Caving (Page 327) but this method was found to impart a kink in the cable at the start of the roll. More recently, the ladders have been carried by folding them backwards and forwards at every other rung, and tying. (see figure 56c in British Caving) This method has been found convenient and is definitely quicker than rolling.

In conclusion, the author would like to thank all the people who helped in the construction of these ladders, many with advice and some with practical help.

B.M.Ellis, January 1957.

Editor's Notes

This Report is based on a rough draft found amongst the effects of the late Don Coase, one of the 'leading lights' of the B.E.C. in its earlier years and who was responsible for the construction of most of the club tackle at that time.  That he did not live to complete this Report is yet another reason, amongst so many, for regretting his untimely death.  However, Norman Petty - with assistance from Alan Sandall - undertook the not easy task of completing another person's manuscript. Caving Report No. 10 is the result.

The date of the original draft is not known but it must have been before the publication of Caving Report No.3, "The Manufacture of Lightweight Caving Ladders", because this did not appear until four months after Coase's death.  It is possible that he had seen the manuscript of Report No. 3 and this seems probable from some of the points made.  In this case the draft must have been written during 1957, this in any case being the most probable date.

As already stated, only a very rough draft was available and this, in places, has had to be altered slightly.  However, the aim throughout has been to keep it in the style and intention that it is thought Don would have desired.  The draft covered Sections 1, 2, 3, 7 & 9, and part of Section 5, and luckily a list of the intended contents.  Norman Petty has written the remaining Sections and some of the drawings were prepared by Alan Sandall.

The points where Caving Reports Nos. 3 and 10 overlap are very few as they cover different methods of caving ladder construction.  In fact it is felt that this Report and the revised edition of No. 3 are complementary end between them give a good insight to the construction of caving tackle.


 

1.  INTRODUCTION

The need for a lighter and more compact ladder for caving has always been obvious to anyone who had to carry a soaking wet wood and rope ladder in and out of any but the easiest of caves.  Probably the earliest of lightweight ladders were made by dÙJoly in France during the 1930's where the need was more urgent than in this country.   Ladders often had to be transported up several thousand feet of mountain side on rough tracks and the amount of ladder repaired for some of the bigger French potholes would probably be enough to ladder every pitch on Mendip.

The use of lightweight tackle did not cone into general use in Britain until after the Second World War, probably due to the increased availability, and technique of using, aluminium alloys developed in the aircraft industry.  The Bristol Exploration Club had previously produced some lightweight ladder which was not entirely satisfactory, but with the opening of St. Cuthbert's Swallet late in 1953 with its large number of pitches the need was pressing for a considerable amount of new tackle.  The decision was made to concentrate on lightweight ladders, not only from the ease of transport but also in view of the higher factor of safety, ease of inspection and increased life when left underground for long periods. In actual fact during the earlier stages of exploring St. CuthbertÙs ladders were left in the cave for up to three months without any signs of corrosion or other deterioration.

This Report is intended to put on record the experience of the B.E.C. in designing such tackle and it is felt that if it prevents anyone else committing some of the mistakes the B.E.C. made, it will have served a useful purpose.  Also included is a description of a piece of equipment designed for a specific purpose in St. Cuthbert's, the Hand Climbing Line, or as it is more popularly known by club members, the 'Knobbly Dog'.  This is a new idea as far as the writer knows and may prove useful in other caves.  In conclusion are some remarks dealing with the use of tackle.


 

2.  ORIGINAL B.E.C. LIGHTWEIGHT LADDER

 

Figure 1

This was made in about 1942 or 1943 when the only transport available from Bristol to Mendip was bicycles.  It consisted, of aluminium alloy tubes 1/4" diameter for rungs and the wires were 1/16" diameter Bowden cable.  The attachment of the rungs to the wire was simple if nothing else.  The rungs were drilled right through at either and, the wire pulled out through the open end and tied in a clove hitch round a 2 B.A. brass bolt.  The nut was tightened up and the whole lot, knot, nut and bolt soft soldered tug-ether.  In practice it worked reasonably well with the small amount of use to which it was put but the wire was too small and started rusting.  Also, with the kinking of the wire around the bolt, the pull did not come in a straight line and the wire started cutting through the thin wall of the rungs.  The writer suggests that the factor of safety was about zero!  Another failing was that having been left rolled up for a considerable period, on the only occasion that the writer used it, after having stopped off at the bottom of the 40 Foot Pot in Swildons Hole, the lower section rolled itself up and hung eight feet up the pitch.  However, it was light and small enough to go in a bicycle saddle bag.  The method of rung fixing is shown in figure 1.


 

3.  B.E.C. STANDARD LIGHTWEIGHT LADDER- Materials & Preparation

The first ladders built to this pattern were constructed in 1949-50.  There were a number of faults in these early ladders but it is believed that these have been overcome.  The descriptions given are amplified by the drawings of the component parts.

End Plugs.  These are-made from 1/2" diameter Duralumin rod and are cut 1" long. They are drilled and tapped-along their length to take the 1/4" Whitworth grub-screws that are used. Duralumin is preferable to aluminium as it is considerably easier to drill and, in particular, to tap the holes.

One of the major defects of the earlier ladders was the design of the end plugs.  They were made as shown in figure 2(a) and due to the tapped hole stopping as shown the grub-screw, when tightened, forced the wire into the aluminium.  Under load this deformed and let the rung slip, down the wire.  One remedy that was tried was to insert a plug of aluminium between the grub-screw and the wire as it was thought that the tapping was not deep enough but this was not successful, the rung still slipping.  The ladder was eventually dismantled and the grub screw holes drilled and tapped right through, as the present design, then reassembled using new wire.  After the initial bedding-in, no more trouble was experienced.  With this method the wire is forced into the hole and given a kink when the screw is tightened.   This kink is not severe enough to weaken the wire appreciably but does positively prevent slipping of the rungs.  The present method is shown in figure 2(b).


Figure 2

Rungs.   These were originally constructed of 3/4"o.d. x 1/16" wall aluminium alloy tubing but a cheaper substitute was found by using 3/8"o.d. commercial aluminium electrical conduit.  This suffered from the drawback that the wall thickness is greater than 16 gauge and a press of some sort is needed to insert the end plugs.  All later ladders were constructed from 5/8"o.d. x 16 gauge wall alloy, tube and in this case, the end plugs are made from 1/8" rod. All other dimensions of rungs are as stated on figure 3.         To facilitate the construction of the large number of rungs required, a cutting and drilling jig has been constructed for 5/8"o.d. rungs.  This is shown, in figure 4 and is case hardened all over and is surface ground on both sides.  The rungs are cut to length by sliding in a length of tubing flush with one end and then cutting down close to the other end with a hacksaw, finally filing the end square against the jig.  The burr on the outside of the rung can either be removed by filing or by rotating the rung against a sanding disc of a 3/4" electric drill.  At the same time the rung end should be chamfered. The burr inside the rung is best cleaned by rotating a round nosed parallel rotary file exactly 1/2" diameter in a 1/4" electric drill fitted in a bench stand, then feeding the rung end on to the rotary file for not more than 1/8".  This provides a starting guide when pressing the plugs in.


Figure 3

The next operation is to insert the end plugs.  The plugs for the earlier ladders were a sliding fit in the tube and this was found to be a serious drawback as after the wire holes were drilled the plugs slid out of line.  For this reason the practice has since been adopted of using 16 gauge (0.064") wall thickness.  With 5/8” o.d. tube the inside diameter is 0.497" and this gives an interference fit of 0.003" when using 1/2" diameter plugs.  The plugs are pressed into position, one at a time, by using a carpenterÙs cramp as shown in figure 5.


Figure 4


Figure 5

After inserting the plugs the rung is placed in the cutting and drilling jig and the holes for the wire drilled using a 1/8" drill.  If the rungs are made of Dural or a similar hard alloy the holes are slightly countersunk to remove the sharp edges.  It has been found that some of the individual strands of wire in contact with the hole broke after a few months use if this was not done.

Grub Screws.  These are 1/4" Whitworth x 1/4" long hexagon socket grub screws, preferably of "Allan" or "Unbrake" manufacture.  The type of end of these screws varies, figure 6, but the only one readily available is the half or reversed cup point (a).  Although this is not ideal it seems to serve well in practice.  There is one variation of this that must not be used and this is where the cup point is serrated.  This, when tightened, cuts into the individual wires of the rope.  The preferred type is the cone point of 60° (b), if this can be obtained, as this causes no damage to the wire.


Figure 6

Wire Rope.  Originally this was 10cwt aircraft cable of 7/19 construction but now 15cwt cable of similar construction is used as the cost is the same.  This type of cable is extremely flexible and is made of seven strands, arranged as (a) in figure 7, each strand being made from nine teen wires (b), and each individual wire, approximately 0.01" diameter is galvanised.  On no account should a wire rope be used with a fibre core as this acts as a sponge holding water in the centre of the rope and thus accelerates corrosion. (Editor's Note: Fibre cored wire ropes have been used satisfactorily for caving ladders without corrosion - see Caving Report No. 3A.)


Figure 7

End Fittings (C-Links).  Considerable variations exist in the type of end fittings but the most popular is the C-Link and this has been standardised for all B.E.C. ladders and ancillary equipment.  The simplest is undoubtedly a link cut from a piece of chain.  Various chains were cut and tested on a tensile testing machine and the low figure at which most links failed was rather surprising.   Loads in the order of four or five hundredweight resulted in the links opening right out as shown in figure 8.  Tests were continued until a section of 3/8" close pitch chain was found to stand 520 pounds before any opening of the gap occurred. The loading was slowly increased with the gap gradually widening until at a load of just over nine hundredweight the link opened fully with no increase of load.  The link showed no sign of fracturing.  This chain, which was manufactured from E.N. 8 steel, was considered to be more than adequate for the purpose and a length was obtained - sufficient for several hundred links.  As the facilities were available these links were cadmium plated and this does in fact give a finished look to the completed ladders.


Figure 8

Thimbles.  The wire end is passed round a tinned iron or stainless steel thimble which contains the C-Link.  The readily available thimbles are designed for 1/2" circumference rope which is slightly larger than 10 or 15cwt. aircraft cable.  The correct thimble for the aircraft cable seems to the writer to be rather small and flimsy and so the 1/2" circumference thimble has been used, being flattened to the diameter of the rope used.

Wire End Fixing.  Two methods have been used for finishing off the ends of the wire.  The earlier ladders using 10cwt cable were clamped and soldered in a ferrule.  All the later ladders using 15cwt cable have been spliced.


Figure 9

With the ferrule method a one inch long piece of 1/4"o.d. copper pipe is carefully cleaned and flattened in a vice to the shape shown in figure 9, just sufficiently to slide two sections of the wire through it.  The ferrule is then thoroughly tinned inside and out.  This is important as otherwise corrosion could be rapidly set up between the copper and zinc coating of the wire.  The wire has then to be tinned either side of the thimble for an inch only, and the free end cut so that it stops just at the end of the ferrule.  To assemble, slide the ferrule on to the wire, then pass the wire round the thimble containing a C-Link and finally slip the end of the wire into the ferrule again. After pulling the wire tight round the thimble, the ferrule is squeezed as flat as possible in a vice and then the wire-ferrule assembly is soldered up.  When soldering care must be taken not to apply any more heat than necessary and under no account must a naked flame be used as otherwise the temper of the wire is lost.  For the same reason a tin-lead solder is also preferred.  It will be obvious that a non-corrosive flux is essential and for this purpose "Alkaray" flux, which is approved by the Aeronautical Inspection Department as being non-corrosive, has been used on all the later ladders.  It is also necessary to clean the wire well before soldering and methylated spirits, carbon tetrachloride or a similar solvent are required to remove the oil incorporated in the rope during manufacture.  The "Alkaray" flux has none of the penetration of, say, ''killed spirits" and in practice has been found difficult to solder rope which has been kept in stock for a period when the zinc coating has tarnished.  (Editor's note: This method of forming end loops is not to be recommended as the long term effects of the solder on the rope are not known, see the revised edition of Caving Report No. 3.)

Eye splicing the cable end seems to be the safest method as it is possible to inspect the splice periodically by removing the binding, whereas with the ferrule method it is possible for the wire to corrode in the ferrule and the first warning is when the ladder breaks in service.  The difficulty of splicing the cable is not great and anyone can splice a hemp rope can, after a little practice, make a fair splice in wire rope.  However, it is a tedious job and painful on the fingers. The writer, who is by no means an expert at the job, finds it takes approximately an hour to make one splice. The writer's technique is first to bind the cable five inches from the free end and then open out the strands back to the binding and solder the cut ends of each strand for 1/8" to prevent the individual wires coming apart.  Baker's Fluid or "Fluxite" can be used for this as the ends will be cut off later.  Then assemble the cable round the thimble containing the C-Link.  The cable should be bound to the thimble, or the method the writer finds easier, using the oversize thimbles, is to close over slightly the outside of the thimble so that-the wire is held securely.  Then remove the binding from the free end of the cable.  Various ways are possible for making the first round of tucks and the method adopted by the author is that given by the British Standard Institute for splicing wire ropes.   Details are given in the Appendix.

The British Standards Institute specify a five round splice three rounds of full strands and the last two with approximately half of the wires cut out, thus causing the finished splice to taper.  The writer, however, prefers to make four full rounds and then two with halved strands just to be on the safe side.  These additional rounds of tucks are made in exactly the same way as the second round, being pulled tight and beaten after each round.  Finally the surplus wire is cut off sand the whole splice served (or bound) with either waxed twine or small diameter (20 gauge maximum) galvanised wire.  The purpose of the binding is to hold the whole splice tight and to cover the short projecting cut ends of wire.  The waxed twine is preferable as it leaves the splice relatively flexible but it is liable to chafe or rot through under cave conditions unless frequently inspected and renewed.

One point that is worth taking some trouble over is getting the distance of the ends, from the rungs, correct.  This should be 5 1/2" from the centre of the end rung to the inside of the far end of the C-Link so that when the ladders are joined the rung spacing remains at an 11" pitch.  If care is not taken it will be found that one side will hang lower than the other, which makes it disconcerting when climbing the finished ladder.

Another method of finishing the ends is the "Talurit" splicing process. This is similar to the ferrule method except that the ferrule is a thick aluminium sleeve which is swaged on to the rope .by means of a hydraulic press.  This process is usually done commercially and tends to be expensive, costing 2/11d per splice although a reduction in price is made when more than six are done at one time.  In comparison, the charge for a hand splice, made commercially, is 1/9d irrespective of the number.


 

4.  B.E.C. STANDARD LIGHTWEIGHT LADDER - Assembly

Having prepared all the component parts of the ladder as described in Section 3 the wire rope sides are cut to length allowing several inches spare.  One end is soldered solid for approximately two inches and then filed down so that it slides easily through the holes drilled in the rungs. As this end of the rope is cut off after threading, "Baker's Fluid" may be used as the flux for soldering.

C-Links are spliced on the unsoldered ends of the two wire ropes and the first rung threaded on and positioned 5 1/2 inches from the centre of the rung to the inside of the far end of the C-link.  The grub screws are then tightened to clamp the rung.  The remaining rungs are clamped three or four at a time using either the jig shown in figure 10 or else a wooden spacer 10 3/8" long.  When the last rung has been fixed the soldered ends are cut off and the C-links spliced in position.


Figure 10

At this stage the wires and splices are treated with a good rust preventative such as "Tokall". This is obtainable from Croda Ltd, Cowick Hall, Snaith, GOOLE, Yorks at 17/6 per gallon, including carriage and can be applied by brush, oil-can or dipping.  The author finds an oil can very effective, dipping being messy and requiring a large volume of liquid.  The ladder is left to dry for two or three days before the splices are served.

All the grub screws are checked to ensure, that they are really tight and then to protect them against rust and mud the screw sockets, exposed threads and ends of the rungs are filled with hot candle wax.  The surplus wax is removed by lightly countersinking with a 5/16" drill. When in use the ladders should be treated with "Tekall" or a similar solution not less than twice a year - this being applied when the ladders are clean and dry.

Rung and Wire Spacing.   The rung spacing has been standardised at 11"; this being about the practical maximum.  Climbing a ladder with a 12" pitch is quite an effort, whilst some ladders of another club with rungs at 15" or 16" pitch proved impossible to a novice who had to be pulled up and a very strenuous gymnastic feat for an experienced caver.

The spacing between the wires has been fixed at 6".  This gives plenty of room for the normal climbing boot complete with nails.

Ladder Lengths.  The ladders are made in lengths of twenty and forty feet, these being considered convenient lengths.  It is felt that standardised, lengths should be made to avoid confusion, it being annoying to reach a pitch and find that the ladder is too short because two ladders used were each five feet shorter than it was thought.


 

5. WOOD AND WIRE LADDERS

When lightweight metal ladders were first put into service a few club members complained that when climbing these after a strenuous wet cave, the aluminium rungs caused cramp in their hands.  This was no doubt due to the high thermal conductivity of the metal, so several lengths of ladder were made using wire rope and wooden rungs.  An experimental ten feet length was first built and when this proved satisfactory, a further fifty feet were made.  These were not replaced when they wore worn out as the original complaints had ceased, probably due to the fact that in St. Cuthbert's Swallet, the scene of much of the club's activities for the last few years, the pitches had been fitted with rigid metal ladders.

The general design can be seen from figure 11.  The main consideration was to make them as simple as possible using only simple hand tools.  The rungs are made of ash, 7" x 1" x 7/8" having all the corners removed, and drilled at six inch centres to take 10cwt wire rope.  They are supported on aluminium sections made by cutting 5/8" x 5/8" diameter plugs in half to form semi-cylindrical pieces, and drilled to make a sliding fit on the cable.  A short length of tinned 18swg wire was passed through the centre of the wire rope, bent parallel to the rope and soft soldered to take the weight.  A similar solder globule above the rung enabled the rung to be slid up the wire for inspection of the rope but at the same time preventing the rung from getting too far out of position. Obviously this type of ladder could only be hung from one end.


Figure 11


 

6. SPECIAL PURPOSE ULTRA-LIGHTWEIGHT LADDER

(Editor's note: This section had not been written by Coase, and Petty does not know the method of construction.  Very clear diagrams had been drawn, however, and these are reproduced as figures 12 - 14. As the reproduced diagrams are not as clear as the originals the following interpretation of them is given.)

The ladder was constructed using 10cwt, 7/14 construction cable and had rungs of 6" overall length with a rung pitch of 11", the distance between the wire centres being 5 1/4".  The rungs were oval in cross-section, 3/8" x approximately 11/16" (the latter figure is not given on the drawing and has been obtained by measurement of the rung as drawn) but whether this cross-section was purchased or formed from circular tubing is not known.  Similarly the wall thickness of the tubing is not shown but appears to be approximately 14 gauge.  (Don Coase was a draughtsman and it is assumed that his original diagram was drawn at least approximately to scale.)

Each rung was prepared by drilling, through one side only, two holes at 5 1/4" centres with a No. 32 drill.  On the opposite side of the rung was cut an 1/8" wide slot, 7/32" deep and at an angle of 45° to the length of the rung.  This is shown in figure 12.

The method of rung fixing appears to have been as follows.  Rungs and 1/4" diameter copper ferrules were threaded alternately on to the wire rope, then at 11" centres the ferrules were squashed flat and soldered.  A rung was centred over each ferrule by threading the flattened ferrule through the slot in the bottom of the rung and finally the rung was clamped by flattening the end tightly over the ferrule.  This method of fixing would necessitate the ladder being hung


Figure 12

from the correct end so that the rung was forcing the ferrule against the drilled hole and not against the slot.  The fixing of the rungs is shown in figure 13.


Figure 13

The third diagram, figure 14, shows the jig used for slotting and drilling the rungs.  It was manufactured from 3/4" x 1/8" angle iron and made to fix on a bench vice in place of the hardened jaws.  The inside measurements of the angle iron were cut to 13/16" x 11/32" from the 3/4" x 3/4" and they are so arranged in the vice that they form, in cross-section, a hollow rectangle into which the rung fits.  Appropriate guide slots and drilling hole were than made.

 

Figure 14

Note:  A ladder of very similar dimensions is used by the Shepton Mallet Caving Club for normal use but these use the 'taper pin' method of rung fixing. 'The method of manufacture has been fully described in Caving Report No. 3A.


 

7.   TETHERS AND SPREADERS.

Tethers.  (See figure 15.)  These are simply a length of 15 cwt aircraft cable with the ends finished off by any of the methods suggested for ladders, each end being fitted with a C-link. Standard lengths are five, ten and twenty feet long.  Although it has not been done to date, it is strongly recommended that a loose C-link should be incorporated in each tether, free to slide up and down the wire, to enable the tether to be fixed round a rock or other suitable belay and leaving the end free to carry a spreader and then a ladder.  (See remarks under 'Use of Tackle', below.)


Figure 15


Figure 16

Spreaders.  (See figure 16.)   These are similar in construction to tethers except that they are made with a fixed C-link in the centre.  Even if splicing of the ends is adopted, this centre link requires the wire to be fixed by a tinned copper sleeve or, as an alternative, seized for at least one inch with galvanised soft iron wire, or tinned copper wire, and then run over with solder.


 

8.   THE USE OF TACKLE.

Due to the short ends of the ladder, if the sides are joined together to a tether, a considerable bending stress is imposed on the wire where it enters the first rung - see figure 17(a).  This is extremely detrimental and leads, to early failure of the wire at the bend point. Another bad practice is to shackle the two sides of the ladder together and fix them over a "Rawlbolt" or stalagmite boss, figure 17(b).  This was done by one club member on the Forty Foot in Swildons and led to one wire breaking whilst the ladder was being climbed.  (Examination of the broken portions of the wire gave increased faith in the soldered ferrule type end fixing as the ferrule had been bent into almost a semi-circle round the "Rawlbolt" without any sign of the wire pulling out.)

 

Figure 17

For these reasons, it is essential to use either a spreader or to connect either side independently to the ends of a tether, figures 17(c) and (d).  When using a tether and shackling back to the loose C-link it is essential to avoid bending the wire more than absolutely necessary; see figure 18. A further point when shackling two lengths of ladder together is to make sure that there are no twists in the wire before joining the C-links.  It should be obvious that neither the ladder wires nor the tethers must be bent over sharp edges of rock.  Any permanent kink in the wire will reduce the life very considerably and the rock will probably rub through the zinc coating of the wire when the wire is repeatedly stressed with people climbing the ladder.


Figure 18


 

APPENDIX I

The Splicing of Six Stranded Ropes.

Reference:       British Standards Institution Handbook No. 4, Part 1, pages 178 - 182 (1958 edition).

Place the thimble in a vice with the rope vertical.  The main part of the rope should be on the right hand and the tail strands on the left. Seize the thimble at the crown and on both flanks.

The length of the tails for a five tuck splice should be four inches for each 1/8" diameter of the rope.

First series of tucks.  (See figures 19 and 20.)

The tail strands are numbered 1-6 anti-clockwise and the spaces between the strands of the main part of the rope are lettered A - F, also anti-clockwise.

A fibre main core should be tucked with tail No. 1 and then cut off.  A wire mean core must be split up, distributed amongst the tails and tucked with then for at least three series.


Figure 19

 

 

Tail No.

In at:

Out at:

 

 

 

1

B

A

 

 

 

6

C

B

 

 

 

2

B

C

 

 

 

3

C

D

 

 

 

4

D

F

 

 

 

5

D

E

 

 

 

 

 

 

 

 

 

Second Series

 

 

Third Series

 

Tail No.

In at:

Out at:

Tail No.

In at:

Out at:

1

B

C

1

D

E

6

C

D

6

E

F

2

D

E

2

F

A

3

E

F

3

A

B

4

F

A

4

B

C

5

A

B

5

C

D

 

After the third series of tucks, the wires of a wire main core may be broken off and the number of wires in each of the main tails reduced to half the original number, preferably by 'breaking out'.  To 'break out' wires take each wire separately, snatch back to the point where it emerges from the rope and then twist the wire - handle fashion - reversing direction if necessary and the wire should part in the gusset.  The remaining wires should be twisted up to a rough strand formation and at the same time this should enclose the cut ends in the centre. After reducing the number of wires in the strands the fourth and fifth series of tucks are made.

 

Fourth Series

 

 

Fifth Series

 

Tail No.

In at:

Out at:

Tail No.

In at:

Out at:

1

F

A

1

B

C

6

A

B

6

C

D

2

B

C

2

D

E

3

C

D

3

E

F

4

D

E

4

F

A

5

E

F

5

A

B

 


Figure 20

 

Been down St Cuthberts? Buy the report and get a free survey!

Less well-known than many of Mendip's other major cave systems, St. Cuthbert's Swallet offers much to those whose interest extends beyond mere sporting activity. Not only does it contain fine pitches and streamways but it has numerous large chambers, some beautifully decorated, intricate phreatic mazes and up to seven distinct levels. It is without doubt Mendip's most complex cave system and, not generally realised, it contains perhaps the finest and greatest variety of formations in the area. Among its displays are found magnificent calcite groups such as the 'Curtains', 'Cascade', Gour Hall with its 20ft high gour, 'The Beehive', Canyon Series and the 'Balcony' formations in September Chamber, all of which are without peer in the country. There are also superb mini-formations including floating calcite crystals, over twenty nests of cave pearls, and delicate fern-like crystals less than four millimetres long; a variety that few other caves can boast.

Access is strictly controlled by the Bristol Exploration Club. Conservation was the prime reason for wishing to control access to the cave. To achieve this aim it was decided by the BEC at their 1955 Annual General Meeting to introduce a warden system. St. Cuthbert's Swallet was one of the first caves in the country to be so protected. This action has often been the centre of controversy. However, the fact remains that, after thirty years, the cave is essentially still in pristine condition and proven justification for the warden system.

The St Cuthberts report was written and compiled by D.J. “Wig”  Irwin with additional material by Dr. D.C. Ford, P.J. Romford, C.M. Smart and Dr. J.M. Wilson. Running to 82 pages and containing a vast array of photos and a wealth of information this doesn’t just deserve to be on every cavers bookshelf, you should get one for all your friends too (well maybe).

Copies can be purchased from the Belfry for a very reasonable sum.

 

 

Subcategories

The BEC's series of caving reports cover a wealth of knowledge and experience.Most of these were written many years ago but still contain very pertinent information covering many aspects of the clubs activities.

 

Been down St Cuthberts? Buy the report and get a free survey!

Less well-known than many of Mendip's other major cave systems, St. Cuthbert's Swallet offers much to those whose interest extends beyond mere sporting activity. Not only does it contain fine pitches and streamways but it has numerous large chambers, some beautifully decorated, intricate phreatic mazes and up to seven distinct levels. It is without doubt Mendip's most complex cave system and, not generally realised, it contains perhaps the finest and greatest variety of formations in the area. Among its displays are found magnificent calcite groups such as the 'Curtains', 'Cascade', Gour Hall with its 20ft high gour, 'The Beehive', Canyon Series and the 'Balcony' formations in September Chamber, all of which are without peer in the country. There are also superb mini-formations including floating calcite crystals, over twenty nests of cave pearls, and delicate fern-like crystals less than four millimetres long; a variety that few other caves can boast.

Access is strictly controlled by the Bristol Exploration Club. Conservation was the prime reason for wishing to control access to the cave. To achieve this aim it was decided by the BEC at their 1955 Annual General Meeting to introduce a leader system. St. Cuthbert's Swallet was one of the first caves in the country to be so protected. This action has often been the centre of controversy. However, the fact remains that, after thirty years, the cave is essentially still in pristine condition and proven justification for the leader system.

The St Cuthberts report was written and compiled by D.J. “Wig”  Irwin with additional material by Dr. D.C. Ford, P.J. Romford, C.M. Smart and Dr. J.M. Wilson. Running to 82 pages and containing a vast array of photos and a wealth of information this doesn’t just deserve to be on every cavers bookshelf, you should get one for all your friends too (well maybe).

Copies can be purchased from the Belfry or Bat Products for a very reasonable sum.


Also Available as a PDF download from the downloads section from the publications menu

The monthly newsletter will remove ‘internal’ members items from the regular Belfry Bulletin and hopefully be able to update our members more frequently on news, BEC events, local caving related events, any internal stuff members may like to know, dig updates, gossip, etc. etc. It will also contain a rolling calendar which will list both BEC and member events and any other cavers related events on Mendip and the wider community where appropriate.

The newsletter is totally internal to BEC membership and will not be distributed outside of the club, unlike the BB which is exchanged with other clubs and  eventually published publicly on the website.

{loadmodule GoogleCalendar}

{module [570]}

The Belfry Bulletin is the journal of the Bristol Exploration Club.

The current editor, always welcomes articles and pictures as this journal is what the members make it by sending in contributions. As well as his postal address published in the Belfry Bulletin, he can also now receive articles by e-mail to This email address is being protected from spambots. You need JavaScript enabled to view it.

 

The entire archive of back issues is available here entirely due to Andy Mac-Gregor. Over a period of four years Andy has scanned and converted to text via OCR every single issue. When you consider that most of these were printed on a Gestetner duplicator you'll appreciate the scale of this achievement.