Note that this is a re-print of the original publication, based on a scanned copy. During the process of converting the original paper copy to this electronic version, the original formatting, page layout and page numbers have been lost. All diagrams and surveys have been scanned from the original and are consequently of poor quality.
The Dining Room Dig, St. Cuthberts Swallet by RD Craig
Bunkers Hole, Devon by WN Tolfree
The Suunto Compass and Clinometer by BM Ellis
Hawthorn Hole by BM Ellis
Shatter Cave by AJ Butcher
Cave Dam Construction by AJ Butcher
Published by the Shepton Mallet Caving Club
The Mineries, Wells Road, Priddy, Wells, Somerset, BA5 3AU
Apologies must be made for the delay in the production of the June issue of the Journal. You should receive this number some four and a half months late. This delay has been due mainly to lack of communication between all those involved in the Journal's production. Apologies must also be made for the differences in type face. This Journal has been produced in a very short time and the services of several typists have been employed.
The bulk of the articles in this issue is concerned with, or prompted by, work being carried out in St. Cuthbert's Swallet. Bob Craig describes the work being done in connection with passing the sump, both by direct attack and by digging a possible by-pass. Alan Butcher's article on cave dam construction, although prompted by this work, is a technical description of dam construction based on civil engineering design and practice. The discovery of Shatter Cave in Fairy Cave quarry has prompted a report and preliminary survey. Alan Butcher and Martin Mills are at present engaged on the survey and this should be published in the near future. The discovery of the possible 'Lost Cave of Dean' has prompted an article from Bill Tolfree. The floods of July 1968 caused a small collapse near Wurt Pit, West Harptree and this was investigated and noted for the record.
Finally there are two items where publication has only been possible in this number because of its late publication. Bryan Ellis reports the results of some tests made on some new compasses for cave surveying, and Martin Mills has reviewed the new Cave Research Group book, 'The Manual of Caving Techniques', edited by Cecil Cullingford.
A report on the progress achieved by regular midweek working on the site.
The Dining Room Dig, as the name implies, connects directly to the chamber named the Dining Room in St. Cuthberts Swallet. Access is gained from the Main Stream by climbing the steep gravel slope (digging spoil) in the Dining Room and entering an obvious passage on the left where the chamber meets Cerberus Hall.
Geologically, the dig is very interesting in that it is the only known passage worthy of note, apart from the Sump Passage, which appears on the south side of the Cerberus Hall – Gour Rift Fault. It is thought likely that, during the early development of the cave, the waters of the main stream entered the Dining Room Dig passage, which also appears to be controlled by a fault, on its journey to Wookey Hole. Subsequently, the stream abandoned this route for its present course leaving the passage silted almost to the roof with gravel and pebbles. It is thought that this deserted high level route will rejoin the main stream on the far side of the sump, and if recent water tracing campaigns are indicative, the rewards could be very high.
The dig was started by the BEC during the 1962-63 winter. The members of the first digging team were Mo' Marriott, the Franklin brothers, Dave Irwin and Barry Lane. Using a "burrowing" technique a 'T' junction was reached after 40 feet and since no obvious way on was visible, the dig was abandoned. During 1965 MacGregor visited the known end of the dig and noticed a rock roof just below the floor of the gravel. Dave Irwin and Phil Kingston with two MNRC members forced a way into a short open passage but the dig was then shelved until May 1967 due to other interests in the cave (1). During 1967 the dig was still rarely visited and it became obvious that a new approach had to be made before substantial progress in a long term dig of this nature could be realised.
During May of 1968 a group from the BEC and SMCC who were caving regularly on weekday evenings examined the Dining Room Dig with a view to digging the passage every Tuesday until the choke was passed. The burrowed passage (less than one foot high in places) was useless for passing spoil out so it was decided to restart the dig from scratch and excavate the passage to 4-5 feet high. To start the ball rolling digging was commenced on Saturday 8th June 1968 and over half a ton of gravel and rocks was removed in a 5 hour digging session. Tuesday evenings were planned so that about 2 hours could be spent at the dig, leaving for the surface at about 8.45 pm. This enabled everyone to meet socially in the local inn and also to release nervous tension after a couple of hours of very hard work. The author considers this quite an important factor in recruiting and maintaining the working force.
It took a couple of months to enlarge the passage to the known end of the dig, removing on average, about half a ton spoil each Tuesday. At the 'T' junction there was some doubt as to which direction to dig, and for a while the floor was excavated in this area, as well as straight ahead under the archway found by MacGregor The floor of the 'T' junction ceased to be dug when 30 feet of passage was entered beyond the archway, the end of which was again choked with gravel and pebbles. This brought the total passage length to about 100 feet and it was now necessary to use two sledges to remove the spoil to the Dining Room. However, the presence of many willing helpers made the distance not too severe a problem. The passage has now been pushed another 60 feet through gravel which is solid to the roof in most places, and extends 20 feet further than shown on the accompanying surveys.
The survey indicates that approximately 300 feet more passage is to be forced before the sump is passed and it is quite possible that we may have to dig all the way if the present trend continues. This would take about 2 more years at the present rate of progress but the lengthening passage must make removal of spoil more difficult. It is hoped to overcome the problem by erecting an overhead ropeway when the need arises. Since the dig was surveyed the passage has been bearing steadily to the right so the fears that it may emerge the wrong side of the Sump now seem unjustified.
The efforts of the last year have proved that mid-week digging is the only way to tackle a dig of this nature and it is most unlikely that much progress would ever be made by working at weekends only.
Figure 1 – Plan of Dining Room Dig
Figure 2 – Dining Room Dig relative to the adjoining parts of the cave
(based on MSC Accurate Outline Plan CRG Grade 6D by DJ Irwin)
- (1) St. Cuthberts Report No. 13, Part A, Page 32. Published by the BEC.
A comparison between this cave and the Lost Cave of Dean.
The cave is situated in a quarry ¼ mile south of the main Exeter to Plymouth road opposite the village of Dean near Buckfastleigh. The cave was opened by quarrying operations and consisted only of a low passage going into a chamber with a stream entering from the left and sinking in the floor of the main chamber. Subsequently a small dig was made into an extension of about 40 feet in length.
There is a possible historical reference to this cave made by the Rev. McEnery in Cavern Researches (1859). However, the cave that he described bore no relation to any of the known caves in the area and subsequently became known as the Lost Cave of Dean.
Throughout the summer of 1967 various attempts were made to locate this cave which eventually narrowed down to Bunkers Hole. Various digs were made in and around the cave itself throughout the summer and into the autumn. At the end of October a breakthrough was made into Fin Chamber by the removal of a small boulder choke and the way on was then open.
Fin Chamber is a low chamber about 30 feet x 20 feet containing a splendid curtain formation in the middle from which it got its name. This leads on to a passage which connects with a further chamber called Dry Chamber from which a further passage leads to a choke.
In typical Devon fashion the system contains one or two of the typical duplicate passages which abound there (ie. the harder way).
In April 1968 a further entrance was made to the cave to the west of the main entrance. From this entrance making certain allowances for the reusing of the floor in this section of the cave by quarry rubble, the cave ties in with McEnery's description pretty well. Although conclusive evidence has not yet been obtained it appears a probable solution has been found to the Lost Cave of Dean plus a quite sizeable extension thrown in.
The results are given of a comparison made between the Suunto compass and clinometer, a prismatic compass and Abney level, and the Survey Unit.
Some glowing reports of the Suunto compasses and clinometers have been filtering down to Mendip from the cave surveyors of the North and it was realised that these instruments should be tried and tested. Accordingly, a Suunto compass model KB-14/360R and clinometer model PM-5/360PCT were obtained and a comparison made with the instruments most commonly used on Mendip, namely the Survey Unit described a few years ago in this Journal (1). This preliminary report has been published to complement another field test report on these Suunto instruments recently published in the Wessex Cave Club Journal (2).
The objects of the test described here were to compare the accuracy, ease and speed of use of the Suunto instruments with the Survey Unit and with a prismatic compass and Abney level used as separate instruments. Five persons each surveyed a closed traverse with each of the three combinations of compass and clinometer, and concurrently the time required to make the necessary angular measurements was recorded. It is admitted that the traverse surveyed was ill-designed as it was too near to being horizontal to be truly representative of a typical cave survey traverse, but it was the same for each combination of instruments. Other bad features of the test also came to light and it is hoped to carry out a better designed series of tests in the near future.
The reason for publishing these qualified results is to emphasise a recommendation that anyone contemplating buying a Suunto compass and/or clinometer should look very closely into the matter before doing so. This is especially so in view of the costs of the instruments: Suunto compass KB-14/360R costs £6, and clinometer PM-5/360PCT costs £8 10s. Both of these instruments are available with a built-in tritium light source, when the cost of each is £10 10s. (why the lighting on the compass should cost £2 10s more than on the clinometer is not known.)
With the reservation outlined above being kept in mind, the results of the tests can be summarised as shown in the table overleaf. It will be seen that the best closure results were obtained using the Survey Unit, and this result is emphasised by the fact that although the other two combinations of instruments are hand-held, each station position was tripod marked and this will have minimised "station position error". (A tripod must be used, of course, with a Survey Unit.) The fact that the closure errors are worse is almost certainly due to the larger number of "rogue results" that were obtained with the hand held instruments and it should be pointed out that one of the 'mistakes' in the design of the test was that it included no survey legs that sloped by more than 11°. Both the prismatic and the Suunto compasses are very difficult, or impossible, to read with accuracy if the objective is far removed from the horizontal. Later tests showed, surprisingly enough, that the Suunto was even worse in this respect than the prismatic.
Note: The poor closures obtained are indicative of some aspects of the bad traverse surveyed, particularly the long survey legs included in it.
At the same time it will be seen that the Suunto instrument readings were quicker to make than with either of the other combinations, but closer analysis of the figures (not reproduced here) shows that those persons used to reading the Survey Unit obtained times as quick with this instrument as with the Suunto. The high average is due to a fifth of the readings taking considerably longer than the others; the range of times taken shows the much wider variation. (A side result of these tests has been to improve appreciably the optics on the Survey Unit used to remove the difficulty of reading the compass experienced by some people on some occasions.)
From these results it is my opinion at the present time (though it may be necessary to amend these views slightly when better tests have been made) that taking all cave surveying situations into account the Survey Unit is easier to use, and gives more accurate results than the Suunto compass and clinometer, though it takes slightly longer to use. A greater time is required because the setting up of a tripod is necessary, but the use of this tripod is not the only reason for the greater accuracy. Furthermore, the Suunto compass is not suitable for use if sloping cave passages are to be surveyed. The built-in lighting of those instruments was not found to be of any assistance when cave surveying; the human eye accommodates to the ambient lighting at the survey station and therefore cannot read the scale with the low powered lighting from the tritium source. As with the Survey Unit, external lighting of the scales was not found to be any problem, unlike both the prismatic compass and the Abney level. Finally, the components of a Survey Unit can be purchased more cheaply than the combined cost of the two Suunto instruments, though some time and effort is required to construct the Unit.
A closed traverse more typical of cave surveying has already been arranged and a better planned comparison has been devised. It is intended to start tests in the near future and the results will be published in a later number of this Journal. The part played in the preliminary test described here by club members Bob Craig, Martin Mills and Terry Prior, and also by Dave Irwin and Martin Webster (both of the BEC) is appreciated and acknowledged.
- (1) Ellis, BM – A Mounting for Cave Survey Instruments. Shepton Mallet Caving Club Journal, 3, (10), pp3-8 (Nov 1965).
- (2) Wigley, TML – Field Test Report: Suunto Compass and Inclinometer. Wessex Cave Club Journal, 10, (125), pp382-4 (October 1969).
Note: Reference (1) only describes the basic principles of the Survey Unit. Details of later improvements, such as the fitting of a larger prism, are in the course of publication.
[note: unfortunately accompanying survey unreadable from scanned copy]
Another collapse caused by the Flood in July 1968 is described.
Shortly after the very heavy floods of July 1968, Dave Roberts talked to a Mendip farmer who mentioned that a hole some thirty feet deep had appeared on his land. This was investigated the following weekend (August 10th) by Dave, Bob Craig and Terry Prior who spent several hours probing at the bottom. It was thought to have negligible chances of breaking into a cave system and therefore no further work was carried out. The hole was visited by Martin Mills and the author in October, who measured it up in order that these notes could be published just for the record.
The hole appeared in the centre of the hawthorn hedge bounding the south-west side of the field in which Wurt Pit is situated, this is on the northern edge of the Mendips, two miles south of West Harptree. The hole, six feet by seven feet wide at ground level, was sixty feet along the hedge from the gate in the southern corner of the field. The hole dropped ten feet to a platform, on which rested the roots of a hawthorn bush that originally stood in the hedge, and from the platform the floor sloped down at approximately 40° for a further six feet. Just above the platform shaft plan dimensions were twelve feet by eight. The walls appeared to be of clay and the bottom consisted of boulders in a clay fill. The sections published below were surveyed to CRG grade 5.
A preliminary report of the discovery of this cave, together with a survey.
The cave was first entered by members of the Cerberus Speleological Society on Tuesday 8th April 1969 after a short dig. They explored about 750 feet of well decorated passage with some large chambers. The first 200 feet which ran along the line of the quarry face were heavily shattered with unstable boulders in the roof. After this the passage continued for about 550 feet almost due south. There were large numbers of formations including a very fine group of helictites. The passage terminated in a very finely decorated chamber with a superb crystal floor. A passage on was visible through a squeeze blocked by stalagmite.
On 22nd April the choke was passed after several blows with a hammer and access was gained to a further 200 feet of passage ending in a chamber with a finely decorated grotto leading off. This grotto was only given a cursory glance because of the formations which abounded.
On 23rd April members of the SMCC and the BEC entered a further 200 feet of passage by forcing a squeeze just at the beginning of this grotto. The passage had a finely decorated floor with crystal pools very much in evidence. This passage ended in a stalagmite choke which required a lot of clearing and this was temporarily left for a passage which went off into a very unstable boulder choke. No draught was evident and the looseness of the boulders precluded any further exploration. The draught in fact comes from the stalagmite choke in the main passage. This marked the end of the cave passage which could be easily entered. Attempts to force the far choke are about to commence (May 1969).
The prospects for further passage are good as it is reckoned that the cave must link with the valley at Frog Lane (where members of the club were digging Hyatts Hill).
Access to the cave must be obtained through the Cerberus Speleological Society who hold the key. Permits are required for entry on to quarry property. Acknowledgements to the CSS for information regarding dates and access.
Figure 3 – Survey of Shatter Cave
Although this article was prompted by the sump operations taking place in St. Cuthberts Swallet, it is not intended to be an account of the operations but a general guide to dam building as a whole.
A well built dam constructed from natural cave debris will retain the same amount of water as a dam of complex and artificial construction. Any dam or retaining wall which has to be built underground for any purpose needs to be simple and not requiring a large quantity of material to be transported through the cave to the site. In this article I propose to outline some ways of dam and retaining wall construction which can be applied underground.
Although there are several types of construction, the mass variety of dams acting by weight alone is perhaps the simplest and most practical where applied to caving. As I have said, the mass dam acts by weight. If its weight is not great enough, the whole dam will tend to "overturn" or collapse (see Figure 4). To explain the above statement it is necessary for me to go into a little theory and I trust that the reader will bear with me.
Figure 4 – Diagram showing the theory of mass dams
It is a known fact that water pressure (hereafter P) acts equally on all surfaces it contacts, and at right angles to these surfaces. Therefore P acts horizontally on the dam. P is also proportional to depth (or head) and not, repeat not, surface area. Therefore the minimum pressure is at the top of the dam (nothing) and the maximum at the base. The pressure can therefore be represented by a triangle (see Figure 5). As the centre of gravity of a triangle is on a line that is one third of the total height above the base then the mean pressure acts on a line D/3.
Figure 5 – Diagram showing pressure in a mass dam
The weight of the dam (weight of material x area of cross section x length) acts vertically downwards from the centre of gravity. The resultant of these two forces can be represented in magnitude and direction graphically, as shown in Figure 6. When dams are designed this resultant must be proved to pass through the middle third of the base to be safe. The calculations to arrive at the above result are long and tedious and I do not intend to go into them. However, by calculation a dam to retain 6 feet head of water should be at least 4 feet wide at the base and 1 foot wide at the top if constructed to a trapezoidal shape with boulders and other natural cave material.
Figure 6 – Diagram showing resultant force of the mass dam
So much for the theory, now to ways and means. Assume a dam 6 feet high is required. There are two methods that could be used (see Figures 7 & 8).
Figure 7 – Diagram showing construction of dam with waterproof face
Figure 7 shows a trapezoidal dam of boulders. These should be of reasonable size and of regular shape. Boulders of irregular shape will cause trouble when they are built in as they do not "sit" properly on the others. The front of the dam should be reasonably smooth and the joints between the boulders packed with mud. The face should then be rendered with a mixture of mud and cement to provide a hard waterproof surface. Special care should be taken at the sides where jointing to bedrock. A pipe should be built in about 6 inches above the floor and should be of sufficient diameter to allow for normal and heavy flows of the stream. Pitchfibre or plastic pipes are the best for this as they can be obtained in continuous lengths and are not liable to breakage during transportation to the site.
Figure 8 – Diagram showing construction of dam with waterproof core
Figure 8 shows a dam which is pervious on its face but which has a waterproof core. The core may be of boulders with mortar joints or of puddled clay. The former core may be constructed first before the rest of the dam is constructed. The latter requires the mass part of the dam to be built first, or in stages, the clay core being puddled in at each stage. Either method is equally good. The outer casing of the dam may be either boulders and gravel or polythene sacks filled with gravel. Either will do depending on availability of materials. The polythene sack method is not really suitable to Figure 7 as some difficulty could be experienced in scaling the dam.
The base of the dam is very important. It should be ideally founded on bedrock. If this is not practicable then a hole should be dug to receive the foundation. This should be about 3 inches deep. Care should be taken to avoid areas where the sides of the passage have undercut walls at floor level. The mud and cement facing should be carried down to the base or alternatively a clay puddle could be used below floor level as shown in Figure 9. Perhaps the largest part of the time of the whole operation should be spent on the base so as to provide a good watertight construction.
Figure 9 – Diagram showing construction of base of dam
Siting of the dam is always important. A site should be chosen where the walls of the passage are not too far apart and the passage or catchment area behind the dam is reasonably flat. The siting of the dam at the bottom of a pitch will require a huge dam to retain any large amount of water.
A well built dam of solid water-tight construction can be quite simply constructed and will retain water during cave excavations and similar work without numerous stops to bale out.
A progress report on attempts to pass the terminal sump in St Cuthberts Swallet.
Since the beginning of this year work has been progressing on the preparations for a direct attack on the terminal sump in St. Cuthberts Swallet by members of the BEC and SMCC. The project is possibly one of the most ambitious ever undertaken by Mendip cavers and involves holding back all the water in the cave whilst the sump is baled dry and excavated.
To hold back the water for, say, a weekend it is necessary to build several dams inside the cave and one outside to block the plantation stream. The building of each dam, and the problems encountered, with the estimated capacities is discussed of follows:
Mineries Dam – Outside the cave
This particular dam was built to seal off the Plantation Stream and is sited 6 feet downstream from the track passing by the Mineries. Concrete blocks sunk into the bank at each end form the basis of construction and boulders and concrete buttress the rear of the dam. A 6 inch diameter pipe was considered adequate for taking the stream. Nevertheless, provision was made for unusual water conditions with two flood holes at the top of the dam. With a height of 5 inches above Mineries the capacity should easily exceed one million gallons - enough to hold back the water for 2 weeks at an average flow of one gallon per second. No problems were encountered although seven cwt. of cement and over a ton of sand was used during construction.
Lower Traverse Chamber Dam
This dam is sited just upstream of Lower Traverse Chamber and is designed to collect water which flows through the Wire Rift, and the stream from the New Route. One or two small inlets also feed the area. Unfortunately, to obtain a reasonable collecting area it was necessary to build the dam where the stream passed over a deep gravel bed. The foundations were laid about a foot below the gravel, but leaks developed when the water found its way underneath the dam. The problem was overcome by sealing the floor of the gravel with mud and cement. Materials used were large boulders, gravel, and mud for waterproofing. Concrete was used for facing and reinforcing the structure. The dam is 5 feet thick at the base and is built to an overall height of 7 feet. A 6 inch diameter pipe was inserted to take the stream. The capacity is estimated at 20,000 gallons, which should be adequate to stop the stream for over two days at a flow rate of five gallons per minute.
Everest Junction Dam
A significant quantity of water enters the cave via the Maypole Series, from the roof of Lower Traverse Chamber. A survey of the Main Stream Passage revealed that the most convenient area to collect the water was just upstream of Everest Passage junction. As with the Lower Traverse Chamber dam the floor is of gravel many feet deep Before laying rock foundations a 3 feet deep trench was excavated to prevent seepage underneath the dam. Large boulders were used to fill the trench and several hundredweights of mud were poured in to give an effective seal. Concrete was used for strengthening the foundations. A 4 inch diameter pipe was set in position to take the stream. Above stream level the dam was constructed mainly of boulders, pebbles (hard core), and concrete, to a height of 6 feet. Little mud was used due to the inaccessibility of the nearest deposits (nearest being the upstream choke, where most had been removed for the foundations). The dam is now complete, and no leaks have developed although it is not yet fully tested. The capacity is estimated at 40,000 gallons which should block the stream for at least two days even if the Lower Traverse Chamber dam fails.
Stalagmite Pitch Dam
This dam is not yet complete and is situated immediately upstream of the Stalagmite Pitch in the Main Stream Passage. Its purpose is that of 'second line of defence' in the eventuality of either or both upstream dams failing. The capacity will be in excess of 50,000 gallons.
Plantation Junction Dam
Work has not yet commenced but the dam will be sited below Plantation Junction and just upstream of the Gours. The dam is intended to collect the Plantation Stream which should be much diminished by the Mineries dam. The capacity could be as high as 60,000 gallons.
Gour Hall Dam
Again, construction has not yet commenced, but the dam is to be built in Gour Hall a few feet upstream of the Duck. Very little water should reach this dam and its main purpose will be storing water pumped from the sump. In case of failure of all the other dams it will be very strongly built as it is the last line of defence. Its capacity should be about 50,000 gallons.
Sump Passage Dam
This dam is intended only to collect small trickles of water and will not have a great capacity. If necessary, the water could be pumped to Gour Hall if a dangerous level is reached.
The problem of pumping the water out of the sump was given much thought but, due to the high cost of installing an electrical pump, and the danger of poisonous gasses from a petrol pump, it was decided to use a hand operated diaphragm sludge pump. It is envisaged that four such pumps will be required to give a pumping rate of 15 gallons per minute from each pump. At present only one pump has been acquired and is set up at the sump with the delivery tube (firemen's hose) to Gour Hall connected. Tests indicate the pump to be operating satisfactorily.
Once the sump is drained, conventional digging techniques will be used to remove the silt. In case of emergency the sump passage will be connected by telephone to most dams, each of which will be watched closely.
To carry through such an operation it is hoped to encourage the support of many Mendip cavers. Probably the most efficient means of digging is by operating a continuous shift system over a weekend. In this way it may be possible to break through during the two days or at least to make considerable progress.
by the Cave Research Group, edited by C Cullingford
published by Routledge & Kegan Paul (London 1969), at 84/-
This is the long awaited comprehensive work due to have been published earlier this year, and runs to 414 pages with numerous line drawings. The only photograph forms the frontispiece and shows sleeping conditions at Camp 1 1600 feet down the Gouffre Berger – appropriately illustrating what has been achieved through improved techniques. Twenty-one contributors, each an expert in his own field have provided chapters on: route finding; personal equipment and clothing; ropes, knots and splices; ladders; use of ladders and ropes; moving in a cave; scrambling and rock climbing; water in caves; underground bivouacs; miscellaneous mechanical aids; communications; digging; exploring new caves and old mines; cave diving; medical aspects; leadership and party management; teaching caving; cave rescue; planning and management of expeditions; and, conservation and access.
That the work of the contributors has been co-ordinated is creditable in itself, but there are unfortunately errors and inconsistencies in the text that editing should have removed. For example, snaplink is perhaps a preferable term to "plain karabiner". Alloy karabiners are condemned as compared with steel ones, when only two pages previously the extra weight of steel toe caps in boots was stated as tiring. Why does a compass for use underground have to be luminous? The taper pin method of ladder construction cannot be used for any size of rope and rung as both the internal diameter and interference fit of 1/32" are both critical and not just the latter as stated. Again, "pitons with elliptical eyes or round shoulders should not be used" – with the former it is the position in the hole in which the karabiner hangs in relation to the rock face that is critical; not the shape of the hole.
The style of, and approach to, the various chapters is not unnaturally very different. Compare the obvious practical experience of the author and the concise text of the chapter on bivouacs, with the 51 page treatise (copiously referenced) on the numerous methods of ladder construction, in which the best methods and materials are eventually summarised in less than a page. Chapter IX was written over two years ago and is revised with footnotes, whereas similar revisions have been incorporated in the text of other chapters. In a couple of places contributors have indicated possible future work for persons interested, more suggestions of this type would no doubt lead to advanced techniques. In contrast there are unsubstantiated statements such as "pitons are not advised for use underground" which with "too detailed to describe here" are out of place in a work of authority.
In the introduction it is stated that this Manual is to supplement the second part of 'British Caving' which contains the practice, not the science, of caving. To my mind there are two serious omissions in this respect, nothing relating to either cave surveying or cave photography – unless it is considered that there have been no developments or improved techniques in these aspects during the past seven years or so. A further improvement would have been details of suppliers of materials and equipment mentioned in the text, though this information quickly becomes dated. The eight page chapter on moving in a cave could readily have been incorporated in that on scrambling and rock climbing.
Despite those criticisms the Manual brings together in a convenient form, revised and with new work, much that has been published before albeit in numerous journals, publications etc. Undoubtedly an invaluable reference book and for this reason should be in every club library. There can hardly be any serious caver who will not find something new of note and merit in this book.