Hon. Sec: A.R. Thomas, Westhaven School, Uphill, Weston s Mare, Somerset.
EDITOR:  D.J. Irwin. 23 Camden Road, Bristol 3.

Address change

Garth Dell, 5 Millground, Withywood, Bristol 3.


Thanks to Bob Bagshaw and John Churchward for gifts of caving and climbing publications to the Club Library.

Working Weekend

September 6/7, 1969.

The last weekend that was set aside for work on the Belfry had just about nil support from the Belfry regulars.  Another weekend has been booked and will be closed to all except those actually working on the building.  Please come along and give John Riley some support.  There is plenty for members to do – repairs to the roof (some though are being done at the moment) and ceilings; water traps need assembling into the sink units; new door needed on the toilet main entrance and many smaller jobs inside the Belfry.  DON’T FORGET THE DATE AND COME ALONG AND LEND A HAND.

Burrington Atlas

Work is proceeding at a reasonable rate on the Caving Report – The Burrington Atlas.  To illustrate the publication we are looking for early photographs of caving parties and the caves.  If any member has any prints or negatives I wonder if they would let Dave Irwin know as soon as possible?

G.B. Cavern

It is reported that there has been a sizable boulder movement between the ladder Dig and Bat Passage.  This area of the cave is being closed to all parties until the U.B.S.S. have completed their inspection of the area.  Reports of boulder movement have been made from time to time since its discovery in 1965.


Cavers Bookshelf

By Roger Stenner

The Sheffield University Speleological Society Journal, Volume 1. No.4, May 1969.  No price stated.  (In B.E.C. Library).

This edition of the Journal is unlike so many other club publications in that only one of its 46 pages consists of club news unlikely to interest anyone outside the club.  The Journal contains a review of mines in the Coniston area of the Lake District, and the second part of an article on the Mines of Long Rake which is not of much value without part 1 (No.3 in B.E.C. Library).  A mine survey is included which uses the misleading practice of representing a passage by a single line, presumable because of a poor choice of scale. The script contains no details of the survey.  Reviews, letters to the editor (Biospeleological notes; Tratman on the Doolin Cave System, Eire), article ‘Pioneer  Speleologists in Derbyshire’ (largely a biography of J.W. Puttrell) and an article on University Speleological Societies (discussing problems peculiar to University Caving Clubs) make up the Journal together with an article by S.J. Thompson, ‘Karst Water Analysis’, which merits further discussion.

The article refers to more than 50 chemical (and physical) Qualitative and Quantitative analyses for major constituents and trace constituents of Karst Water.  Indicating the sort of determinations that chemists can carry out, it may provoke non-chemists into prodding any chemist in the club into action, but the limitations must be born in mind by all readers of the procedure for a particular determination their article will not and cannot take the place of a spell of a time in a library with Chem. Abstracts and Anal. Abstracts.

It is strange that a review of modern techniques should fail to mention X-ray fluorescence spectrometry for detection and determination of trace elements, and no procedure is given for routine measurement of sodium and potassium (present in more than ‘trace’ concentrations).  Procedures which turn paper chromatography into a quantitative techniques were not mentioned, and although procedures for determinations of minute concentrations of chloride and sulphate were referred to, there was nothing suitable for the larger concentrations usually encountered on Mendip.

The key question of interpretation and uses of trace element analysis was raised.  However, most techniques mentioned are also suitable for analysis of stream-bed deposits, investigations which (since streams are made to flow upstream only with some difficulty) may be of value in spite of flooding re-deposition.

Recent Additions to the Club Library

By ‘Wig’

To attempt to review every publication that reaches the club library would fill the B.B. for many years. Instead I’m taking the publications as they were handed to me by Dave Searle (Hon, Librarian) and hope that I pick out articles of interest to members.

SWETCCC ‘Speleo’, vol.7 No.2 contains an interesting article entitled ‘Swildons 5–1’ followed by ‘Free Diving’ and discusses what can be done, if anything, if a companion gets into trouble when free diving sumps.    The Royal Forest of Dean Caving Group have published an eleven page report on their trip to Ireland in 1968.    Interesting accounts of several trips.  W.S.G. Bulletin Vo.6 No.3 (May/June 1969) odd notes from South Wales; Caving and the Unconscious (see June B.B.) and an unnecessary Caving Glossary.  C.R.G. Newsletter. No.115 (Mar. ’69) has more information on the Norwegian Caves of Kjopsvik (with surveys) and Foreign Language contents (a-c).  C.S.S. Newsletter Vol.11 No.5 – The Western Taurus Mountains (includes surveys of area and Pingargözü Cave).  MSG Newsletter No.73 and 74 – club news only.  Axbridge Caving Group – Newsletter’s Ap. ’69; Mat’69 –Dangers of Hyperventilation by O.C. Lloyd (article in Spelio mentioned above in Spelio). June – reply to Oliver Lloyd’s letter in May issue.  B.S.A. list of members (Jan. ’69).  W.S.G. Vol.6 No.2 Pronunciation of Welsh words and reports of the Pengelly Lectures held at Imperial College, London.  N.P.C. Newsletter contains a report of the A.G.M. of C.N.C.C. Spelio (SWETCCC) Vol.7 No.1 contains notes on the survey of Swildon’s North West Stream Passage (incl. survey to same scale as Willie Stanton’s).  For the Spanish speaking members of the club the Bologna Speleos publication ‘Sottoterra’ contains many surveys and useful lists of publications received by their club.  (Nos 19 and 20 April and August 1968), also No.21.  Speleon (university of Oviedo (Vol.16 Nos 1-4) contains a mathematical treatise on resistivity method of locating caves and a long article by Jimenez of Cuba.  July issue of Climber; the June/July ‘Rocksport’ contains an article of interest not only to climbers but to cavers – ‘Advances in Safety Techniques; June ‘Climber’;.  Northern Caving (Northern Cave Club) Vol. No.1; Care of Lamps and Padirac.  Also interesting account of Meregill by E.E. Roberts (1908).  D.S.S. Monthly Journal illustrates how active the club is at the present time and their Journal includes many snippets of useful information regarding both caves and mines of the Devon area as does the monthly bulletin of the G.S.S.

Without any doubt the most outstanding publication received this year is from the U.B.S.S. with the jubilee issue of their Proceedings, Vol.12 No.1 contents include History of the Society in Ireland; Geomorphology and Hydrology of the Central  Mendips; The Society in Ireland; County Sligo, Ireland and revised survey of G.B. Cave at Charterhouse.  Running parallel with the caving material is of course the Archaeological reports.


Drawing Of Accurate Cave Surveys (part 2)

By D.J. Irwin

All passage detail has to be related to all the survey stations in the area being detailed. Using the data collected in the cave the outline of the passages can now be drawn into position.  But here we find another problem – how much of the information is included and what is omitted; further what is collected in the cave? 

Up to the moment the survey lines have been drawn onto the master drawing but before notes are given on how to add the information it might be as well to transfer ourselves between the cave and the drawing board and examine the detail that is required and how it should be shown on the plan, elevation etc.

Surrounding the survey line is the passage outline.  This should, as near as possible, be surveyed to similar standard of accuracy as the survey line.  Normally a closed traverse should be better than 2% (though this will naturally depend upon the traverse length).

The amount of detail to be collected will depend at the scale at which the draughtsman will draw the survey.  Two points determine the scale (to remind ourselves for a moment) -1) the maximum size of paper available to the draughtsman and 2) the minimum passage width that can draw accurately without specialised drawing equipment.

We should also consider the point of making the survey – is our finished drawing going to be published for the general caver or the specialist or both?  Let’s assume that the finished print is to be for the specialist; as we go along the survey for the general caver will also be considered.

It is obvious that the larger the scale the more detailed the survey – in terms of the passage outline etc.  This will mean that the surveyor will need to collect much floor and wall details including solution pockets, climbs, pools and any other special features.

As an example let’s assume that the cave survey is being drawn at 1” = 20ft.  What information is to be collected?  The smallest width that the surveyor/draughtsman can draw at this scale is a true dimension of 1ft. (0.05”); thus all detail collected in the cave must be greater than this.  As the cave passage is a three dimensional object it has to be shown in the three plans: - from above (plan), from the side (elevation) and through the cave showing passage relationship with their respective height values.  Similarly at any on point along the passage length there is also another group on two planes that must be taken into consideration a) passage height and b) passage width.

Passage Width

The width of a cave passage is something that proves difficult to define and I’ve met no-one that can state this so that it covers all types of passages met with in caves. When drawing the passage section the width can be shown without any difficulty but the drawing of the plan often produces problems that are not easily overcome.  Take for example a narrow sloping rift as found in the Catgut Series in St. Cuthbert’s Swallet.  It is barely more than 2ft. wide over most of its length but the horizontal distance from top to bottom is some 8ft.  Does the draughtsman draw the passage as being 8ft. wide or 2ft. wide? Another type of passage met with quite often is the ‘T’ shape.  If the passage is say 10ft. high, 10ft. across the horizontal bar of the ‘T’ and 4ft. wide in the trench what is shown on the plan?  Swildons streamway below Barnes Loop displays another common shape of cave passage.  A vertical rift narrow at the bottom but very wide at the top.  Is the full width of the passage at the top shown or the width at the bottom?

Among the many other problems associated with passage width is the minor variations near the floor level. How are these to be taken into account? A good example of this type of streamway is found below Plantation Junction and the Beehive Chamber in St. Cuthbert’s.  Here the passage commences as shown in figure 8 and gradually forms into a high, narrow rift. The shelving at the start is well marked; near the stream level on the right (facing downstream) are several ledges 1’ - 1¼’ wide while on the left a high level ledge tapers down to the streamway. Are all these variations to be shown on the plan?


As can be seen there are many variations of the same problem.  How is this to be tackled by cave surveyors ensuring that they collect sufficient information for the draughtsman to lay in the survey and also to ensure some form of standardisation in survey presentation? What is to be shown on the plan, elevation and section?

One of the requirements for a cave survey (1) is to enable a caver to get sufficient information to get him around the cave.  As this is an accepted fact agreed by all cave surveyors then it is not an idea to show on the survey what is seen by the caver when he is travelling through the passage?  In other words the draughtsman shows the passage width along the caver’s path.  In the case of the sloping rift in the Catgut Series – which in this cave is normally traversed along the floor level – the plan will show the width at a point used by the cave i.e. 2ft. ignoring what happens above or below this point; these variations can be easily shown on the elevation or passage section.

If we accept the cavers path for the passage width on the plan the passage profile at the point becomes very important.  Depending on the scale of the drawing and the ability of the draughtsman to draw accurate within the tolerances suggested above then the information gathered in the cave must be sufficient for him to show all the various changes at the caver’s level.  Where the wide section of the passage (figure 8) drops to the caver’s eyeline then this can be shown as a break in the wall outline as suggested in figure 9 illustrating a ledge entering the caver’s eyeline above.  There are not many variations that break away from the basic rule suggested above but there will be occasions when the upper parts of the passage will have to be shown on the plan – when a high level has to be shown when the cavers route to it is by a climb along ledges or ‘up the wall’.



Figure 10 illustrates the ‘ray’ method of detailing large and complicated passages and crawls etc. It will be noted from the figure how the detail is related to the survey station with no difficulty.  The author favours this method where the passage outline and prominent features are surveyed in a similar manner to the main lines. All value read on the clino above 10o are then calculated with a slide rule and are then plotted onto the drawing using a protractor to plot all the points.  The points are then joined together rather like children’s ‘follow the dots’ puzzles.  The calculation of the clino values become necessary when drawing at a scale of 1” = 20ft. or larger.  Estimated distances can involve enormous errors – some as large as 30%.  In a passage of say 15ft. wide or more, errors of 5ft. or so cannot be tolerated in an accurate outline survey.  It is even more ludicrous when plotting to the nearest foot and there are errors in the passage width of maybe 5ft. and over. For the 1” = 20ft. (1/240) scale surveys all distances should, for detailing purposes be measured to better than ±6”.


∆ Principal survey stations

       Sub - lines

___ Main survey lines

FIGURE 10    Detailing chambers and very wide passages.

No view can be expected to show any changes in passage heights, the existing avens etc.  This gives the reasons for the need for elevations and passage sections.  When the passages are all drawn in position and the outline completed a quick glance will show the complicated portions that will need clarifying (figure 11).


FIGURE 12      1 - 9

Passage Sections

Related to the plan and elevations are passage sections.  The passage section plays an important role when presenting a cave survey equal in importance to either of the other views.  What cannot be shown on either plan or elevation must be shown on the passage section.

There are two extreme methods of showing changes of passage section; they are: 1. to draw the sections at regular intervals along the survey line or 2. to draw passage sections at all survey stations.

The second suggestion omits changes of passage shape between stations and consequently does not give sufficient information.  On the other hand the first suggestion shows all the changes of passage shape will involve a tremendous amount of repetition where passages are constant over their length. A compromise must be struck and a general rule observed.  Passage sections are required at all points where there is a marked change in passage section.  This might well occur every few feet along the survey line or it might be sufficient to show the section only at the survey stations.

There are two ways in the section can be presented on a survey – 1. Draw all passage sections alongside the survey line on either plan or elevation or 2. Draw all the passage sections in a separate part of the sheet.  It is recommended that all sections be drawn as in 2.  This is because the plan and elevation may well be complicated or maybe drawn at a small scale that will prevent the draughtsman placing the sections along the passage line.  By working to 2 the draughtsman prevents cluttering the views bearing in mind that names and notes will have to be added to the various views.

As stated under ‘Passage Outline’ the plan will show the cavers path – what happens at a higher level in the passage will be shown in the passage section.  Definite solutions have not been stated in any previous notes on the subject and an attempt is made in figure 12.

Sections 1, 2 and 3 (fig.12) are straight forward and need no comment. The basic rule being that the plan shows the passage width where the caver passes and the section lines are taken through this point on the passage section.

Passage sections 4 & 5 illustrate a stream passage with an upper meander forming part of the passage (e.g. Easegill and Tunnel Systems).  Where this occurs and both are used by the caver then the survey lines should be taken through both levels and detailed as separate passages. The fact that both may be joined by a rift is shown in the section of the passage; an attempt to show the rift feature on a plan would confuse the user of the survey because the additional lines that would be required to show the rift.  The elevation, if scale permits, can be shown with a dotted line representing the upper traverse line of passage.  As the section line on the plan should be annotated as shown in fig.12, so it is important to remember that the passage section must be complete with the section line at the point at which the passage is cut.  In the past it has been a regular practice to number or letter the sections.  Letters tend to become clumsy where a large number of sections are involved – so use numbers.  For example 1-1’, 2-2’, 3-3’ OR 1-1A, 2-2A etc.  A final point – indicate the direction along the passage that the section is being viewed – upstream or downstream (figure 13).  Do not draw the section line through the plan or elevation as this will trend to confuse the user if the passage detail is complicated (figure 14).

Hidden Detail

Quite a number of instances occur when one passage crosses another – the vast majority are simple but occasions arise when a cave has several levels one on top of another. The numbers of combinations of ‘dotted’ lines need to be kept to a minimum.  Figure 15 will help solve some of the problems.  If however one is preparing a detailed map for the cavers and the draughtsman intends to show floor deposits and generally presenting a ‘pretty’ picture of the cave then displacements should be contemplated.

Detail Required On An Accurate Outline Survey

A summary is listed below: -

1.                  All vertical changes in floor level grater than 5ft.

2.                  Permanent survey stations.  The height is given in feet above Ordnance Datum.  This value is obtained by determining the O.D. level of the cave entrance and subtracting the depth of the station in question below the cave entrance e.g. cave entrance height 780ft., depth of station below entrance = 140ft. then O.D. of station

= 780 – 140 = 640ft. O.D.  (See figure 16)


3.                  Names of passages and chambers.  Print all names outside the cave passage outline.  To place names and notes inside the chamber or passage will clutter the survey. Names of individual formations and other prominent features should be added in a different print and arrow drawn indicating their position (figure 17).

4.                  Other features are shown in figure 18.

If the scale of the survey is large say 1” = 10ft., then all of the above notes may be added whenever required.  O.D. levels can be marked at every survey station.  On the other hand should the scale be 1” = 100ft. then passage widths will not allow much to be added within the passage outline.  Hence it will only be possible to mark O.D. levels at every principle junction or at selected permanent survey stations. 


FIGURE 13                                            FIGURE 14


Having decided the layout and detail to be included on the survey the final negative or original can now be traced.  On what ever material is decided (detail paper, permatrace, linen etc.) trace the grid lightly in pencil; this will ensure that the grid lines to not detract the eye from the bold outline of the passage walls or become mistaken as part of the cave outline in the various views.  When finally inking the grid lines it is preferable not to take the grid lines through the views but leave them outside the cave outline.

The thickness of the passage outline for the various scales cannot be rigidly fixed.  The complexity will not often allow thick outlines to show clearly.  To assess the best ‘thickness’ of outline produce several tests trips of the most complicated section of the cave and choose from these.  If the result gives a clean neat appearance and above all, is easy to understand all is well; if on the other hand the appearance is cluttered then try a thinner pen.  A good reason for not making the outline too thick is that when they are drawn close together an optical illusion will make them appear closer together than they really are.  When tracing the pencil original, ensure that the inside of the pen follows the line thus ensuring that the passage width remains true.

Whatever scale the survey is being drawn the following line thicknesses will help keep the outline ‘bold’ and still identify the passage detail.

Passage outlines = 1 (e.g. No.4 U.N.O.)

Pitches, ledges etc = ½ (e.g. No.2 U.N.O.)

Streams, slopes lines, arrows etc = ¼ (No.1 U.N.O. or mapping pen)

The most convenient method of lettering that is neat and easy to apply is ‘Lettraset’ – a form of rub-on stencil; failing this UNO stencils give a neat finished appearance. The advantage of ‘Lettraset’ is that it can be obtained in many types of characters giving the draughtsman plenty of scope for variety of distinctive lettering (passage names in capitals, names of features in lower case etc).  Remember it, there is nothing more unsightly than bad printing however well the survey has been drawn.  A good example of bad presentation and lettering is the newly published survey of Lamb Leer included in the Lamb Leer Report; the outline has been drawn with a nibbed pen, the lettering uneven, appearance looks cluttered (e.g. O.D. value by main pitch) sections displaced down and away from their correct position without and notes and so on.

Title Block

Many a survey up to the present time have not collected the various bits of information together on the sheet to a focal point where all of it is gathered together.  A title block will do this and also help maintain a uniform method of presentation.

Scale Bar

It is recommended that all scale bars be given in metric and feet equivalents.  It is certain that sooner or later the metric system will be fully with us in this country and so it is desirable that a metric bar scale be incorporated now to prevent change to the scale bar later.


Final Note

I’ve deliberately left out of this article details of the various types of drawing instruments that can be obtained on the market and full details of the special surveys (geological etc) that may be produced from the cave survey, nor have I mentioned details of the survey report – all of this can be found elsewhere in caving literature.  A full reference list is to be found below for further reading and nearly all are to be found in the B.E.C. Library.

D.J. Irwin
4 – Feb. 1969


(1)                BEC Caving Report no.12 – Presentation of Cave Survey Data by S.J. Collins, page 9 section2.

(2)                M.S.C. Publication (yet to be published)

(3)                As Ref.1

Other publications on various topics of surveying: -

Wessex Cave Club Journal No.89 Accuracy of a Cave Survey by D. Warburton.

Shepton Mallet Caving Club No.2 Series 4, Traverse closures.

Surveying in Redcliffe Caves, B.E.C. Caving report No.1 by S.C. Collins.

U.B.S.S. Proc.  Vol.6 No.2 Survey of G.B. Cavern.

C.R.G. Transaction – Cave Surveying.


Monthly Notes No.27

By ‘Wig’

East Twin

Members have been over to the cave and inspected the washed out rift mentioned in the August B.B. and confirmed the reports that the passage leading off at the bottom is some 35’ – 40’ deep.  This is particularly interesting as it now represents the lowest part of East Twin. The first 20’ is vertical and the general section is elliptical, about 6ft. long by 2½ft. wide.  Two small passages lead off to the left but become impassable.  Beyond the 20ft. rift, the slope of the passage eases to about a 45o slope and becomes extremely tight.  Both John Riley and ‘Wig’ could not penetrate more than a body length into this passage. Roy Bennett and Martin Hauan then ‘had a go’, Martin reaching the end reported that the passage was diggable but very light.  ‘Banger’ Bennett hopes to improve this by opening a bypass around the back of a fallen boulder.  The result has not yet been seen to enable to decide whether to proceed with the site or not. The foreman at the sight was our Tacklemaster who viewed the entire show from the top of the rift at first and towards the end from a very safe distance – outside the cave!


Sketch elevation of the opened passage.  See BB No. 250 for further details of the East Twin survey.

St. Cuthbert’s – Cerberus Series.

The extension off Cerberus Rift has been attacked with chisels to no avail; stronger measures are being planned.  On a recent visit to the site a cool friendly draught was striking one in the face.


BALLOT PAPERS will be in the post shortly to enable members to elect next years Committee.  Make you choice and return the paper to Alan Thomas as soon as possible – if not before!

As is usual during this time of the year one starts thinking about next years Club Committee.  The position at the moment is not very clear but as the closing date for the nominations draws near perhaps I might copy ‘Alfie’, who a few years ago published a potted background of all members standing for the Committee.  Andy MacGregor (1968-69) Caving Sec) and Malcolm Holt have both resigned their posts on the Committee and so will not be re-nominated with other seven.  So, for the benefit of members who are not around Mendip often, or those that have a poor memory for names, here’s the list or runners: -

Bob Bagshaw – 168-69 Hon. Treasurer.
Alfie Collins - past B.B. Editor and Committee Chairman; LTP bod.
Garth Dell – past Hut Engineer.
Chris Harvey – Belfry regular; active caver.
Dave Irwin – B.B. & Caving Report Editor; Committee Chairman 1968-659; active caver.
Jock Orr – Belfry regular; interested in Belfry site.
Norman Petty – Tacklemaster 1968-69 (hasn’t reached his 1,000ft, of ladder yet!).
John Riley – Hut Engineer 1968-69; active caver.
Alan Thomas – 1968-69 Hon. Sec; organiser of Ahnenschacht expedition 1969.
Gordon Tilly – Minutes Sec. 1968-69; handles production of Caving Reports.
Phil Townsend – Hut Warden 1968-69.
? what about a representative from the climbing section?


‘Alfies’ Spelaeodes Part 1 – to be published on the 4th October 1969.  Members 4/- post paid if order in before September.  Limited Edition.  Price 5/- after October 31st 1969.  ORDER YOUR COPY NOW.  All profits from the sale of the Spelaeodes is given to the Hut Fund.  Part 1 includes the tales of Sammy Smayle; Freddy Fry and Kenneth Lyle and his Caving Machine…..the whole work is liberally illustrated with cartoons by Jock Orr….order your copy now with Dave Irwin, 23 Camden Road, Bristol 3.  (after September add 6d for P&P).  Get your orders in now….remember

‘Once down below our Fred got going and soon,
a mass of jets a-glowing,
Quite rapidly, around our Fred
A mist of water vapour, spread,
“Oh, good!”, said Fred, “It’s hot enough
To vapourise the ruddy stuff.
It won’t belong before I’ve got
This cave all cosy, dry and hot.”
And, with a smug and gleeful smirk,
He gave the valve an extra jerk…….ORDER NOW