- 33 -

BELFRY BULLETIN VOL.23 No.4 April 1969 Number 253 + + + + + + + + + + + + Hon. Sec: A.R. Thomas, Westhaven School, Uphill, Weston s Mare, Somerset.

CONTENTS: ‘Doodles’ 33 THEORY AVAILABLE TO CAVE SURVEYORS 34 Letter 39 Just a Sec 39 M.R.O. Report 40 Monthly Notes No.22 41 Route Severity Diagram 43 Library list No.1 45 ‘THE WATERFALL’ 46 O.F.D. III 49

EDITOR: D.J. Irwin. 23 Camden Road, Bristol 3. Non-members B.B. subscription 18/6 p.a.

Price 2/- post paid or single at about 1/6 each Have you paid you sub? If not the B.B. mailing list gets ‘slashed’ next month – so get your sub in to Bob NOW.

“He’s not been the same since he read the note in the B.B. about the club that has both a Tackle Master and Tackle Mistress.” ‘Doodles’

-----------

BELFRY WORKING WEEKEND

A working weekend has been arranged for the 10/11 May – will members prepared to help contact the Hut Engineer: John Riley.

A series of thefts have taken place from several club huts here on Mendip recently including the Belfry.

Will all members using the Belfry, help to prevent temptation, ensure that the hut is always locked when no one is left there and that all the club tackle is locked away in the store.

- 34 - A BRIEF REVIEW OF THE THEORY AVAILABLE TO THE CAVE SURVEYOR

By Mike Luckwill

INTRODUCTION The theory upon which surveying calculations are based has been fully developed over the last hundred

years and is adequately documented in a number of standard textbooks. These books also detail the method of carrying out the calculations by hand, although frequently the mass of information to be processed is more suitable to computer processing; here again the techniques are standard and the software packages readily available. However, the large amount of survey data now in existence; the complex systems to which much of it applies and the increase in the accuracy of this data which will be seen during the next few years; demands that full use of the resources be made, and so it seems relevant at this time to review the theory available. Although at times use will be made of worked examples, this article is not to be intended to be one of intrusion, nor does it contain any theoretical justification of most of the formulae used: for this, the reader must turn to standard texts. Assuming the reader has some mathematical ability the following books may be used, although any library will have at least one reference book of a suitable standard:

Clarke. “Plane and Geodetic Surveying for Engineers.” London: Constable, 1963. 2 vols. Allan, Hollway and Maynes. “Practical field surveying and computations.” London: Heinemann 1968. Rainsford. “Survey adjustment and least Squares.” London. Constable, 1957. Many surveyors worship the tin-god called “the close traverse” by means of a ritual called “closing the

traverse”. Unfortunately they seem to have forgotten the basis of this dogma, and, sadly, seem unable to apply it in the more complex cases when it is of more value. It does seem important the hours of hard, dedicated caving required to obtain survey data, the maximum amount of information is not always extracted; or, even worse, more then the maximum is magically produced from nowhere.

In order to put the procedures into some kind of context we shall imagine ourselves faced with surveying

a complex cave to a high degree of accuracy (at least C.R.G. grade 6). The resulting survey will be a complex network in three dimensions. The surveyed line between two nodes on this network will be called a traverse and is fully defined by three numbers and a datum point, such as one node. In order to simplify the rest of the paper, each of these three numbers will be loosely referred to as a distance, elevation or bearing. Also the reader should remember that any calculation using distance will in practice be triplicated. The aim of the field work is to measure all the traverses; this work is planned by means of theoretical calculations beforehand and is followed by computations based on more theory. ERRORS

Wherever a measurement is made it is accompanied by an error. Errors are of three types; gross, systematic and random. Gross errors are mistakes on the part of the surveyor and they must not occur; although this is easy to say, it is not always easy to practise, but as it really a practical matter and not theoretical one shall leave it. Systematic errors are difficult to detect in the field; every precaution should be taken to either remove them by careful calibration or turn them into random errors. Random errors cannot be avoided but are practicable and amenable to statistical analysis. We shall assume that in every case random errors are normally distributed although this is not in fact the case for indirectly found quantities. STATISTICS

If a line AB is surveyed n times, the results will be distributed about a mean, as in Fig.1. If each result has an associated error ‘e’, the error associated with the mean will be e .n hence the usefulness of making a measurement as many times as possible. The mean is called the most probable value (m.p.v.). The difference between the mean and the ‘true’ value is called the systematic error and one of the aims of the surveyor is to

- 35 - reduce this as much as possible. Since the true value can never be found (if it were it would never be recognised as such) the object of the survey is to find the m.p.v.

FIGURE 1.

From a knowledge of the mean, X , the standard deviation, V , can be obtained: n

xxfV 2)( −

=

The standard deviation is a measure of the spread of the results about the mean and so represented the precision of the set of results. It is very important to note that it is possible to have a precise set of results and a high systematic error, i.e. high precision and low accuracy.

The badly named ‘probable error’, E is related to V by E=0.6745V . Less than 1 result in 1000 will lie outside the limits +3E and -3E. any result lying outside the limits 5E and -5E can safely be rejected as being incorrect. An example is now worked. Example 1.

Calculate the mean and standard deviation of the following set of results. Should the value 101.1 be rejected?

Using an assumed mean of 100:

X f xf x - x 2)( xx − f 2)xx −(

100.2 1 0.2 -.318 .1011 .1011 100.3 6 1.8 -.218 .04752 .2851 100.4 10 4.0 -.118 .03192 .1392 100.5 13 6.5 -.018 .00324 .0421 100.6 12 7.2 .082 .00674 .0809 100.7 5 3.5 .182 .03312 .1656 100.8 2 1.6 .282 .07952 .1590 101.1 1 1.1 .582 .3387 .3382

∑50 25.9 1.0542

50

9.25 = 0.52 standard deviation = 0211.0

Xmean, = 100.52 = 0.15

E = 0.1

- 36 - In this case the 5E limits give 100.02 and 101.02. thus the result 101.1 should be rejected as containing a

systematic or gross error.

FIGURE 2.

The probable error may also be used in planning the survey: if, for example, co-ordinates are required to 1m, the survey should be designed to give a probable error of 0.3m, with the expectation that only one co-ordinated in 1000 will be outside the required precision.

The normal distribution curve also gives the probability of obtaining any result (Fig.2). The probability

that two results will differ by 3 V is approximately 0.0045. If two such results are obtained than a systematic error is suspected. The maximum systematic error that can pass undetected is therefore related to the standard error, which must be known beforehand. The standard error may either be found by analysing survey data obtained with the instruments, or may be calculated theoretically from a knowledge of the instruments. In the latter case a check should be made to ensure that these theoretical predictions are being realised in practice.

ADJUSTMENT

Having performed the pre-survey calculations, we make the survey and calculate the internode distances. We now have a three dimensional network with all the internode distances known. If we were to attempt to draw the survey at this stage we should quickly discover that the data is not self-consistent.

A reference to Fig.3 which shows the distances along 7 traverses in a hypothetical system, will show that,

for example, each possible route from A to E results in a different value for the distance A to B. The problem is to adjust each traverse distance do that we, must ensure that the new values lies within the limits of error of the old values.

FIGURE 3

In order to illustrate the process the system will now be adjusted: - First we choose A as a datum point. We then let the m.p.v.s. of B,C,D and E be w,x,y and z. If we

consider each individual traverse, there is a difference between the observed distances and those calculated from the m.p.v.s. The difference is called a residual and we can set up 7 equations:

- 37 - Line. AB BC BE CE AD DC DE

V1 = w – 30 V2 = x – w – 15 V3 = z – w – 25 V4 = z – x – 13 V5 = y – 40 V6 = x – y – 3 V7 = z – y – 18

Using the theory of least squares; the minimum amount of disturbance to each value is obtained by

making the sum of the squares of the residuals a minimum. The equation is obtained from one observation (the distance along a traverse).

There is another set of equations which we might use: if we call the m.v.p.s. of the distances AB, BC, BE,

CE, AD, DC, DE; d1, d2, d3, d4, d5, d6, d7, then by taking the three circuits P, Q and R we have:

P = d1 + d2 – d6 – d5 = 0 Q = d3 - d4 – d2 = 0 R = d6 + d4– d7 = 0

These are called condition equations, since they refer to the condition that a closed traverse the distances

add up to zero. Putting d1 = V1 + 30, etc., we now have three equations: V1 + V2 – V6 – V5 – 2 = 0 V3 – V4 – V2 + 3 = 0 V6 + V4 – V7 – 2 = 0 It is possible to choose other circuits, but there are only three which are unique. Once again the best adjustment is made by causing the sum of the squares of the residuals (v12 + v22 +

V32 + V42 + V52 + V62 + v72) a minimum. A choice must be made between using the observation equations and using the conditions. Whichever is chosen a set of simultaneous equations will arise and it is the solution of these equations which involves the labour (or preferable a computer). The number of equations to be solved will be the same as the number of independent unknowns if we use observation equations, or the same as the number of conditions if we use condition equations. Clearly in this example we shall use condition equations. When the three equations involved are set up and solved we find that the residuals are:

V1 = - 4/24, V5 = 4/24,

V2 = 3/24, V6 = -25/24,

V3 = -35/24, V7 = 29/24.

V4 = 6/24,

The adjusted distances then become: AB = 29,

2024

BC = 16,24

7 BE = 23

,2413

AD = 40 ,24

4 DC = 1

,2423

DE = 19,24

5 CE = 13

,246

The reader is left to check that the adjusted distances are self- evident. Having obtained an adjusted traverse distance, the position of the individual stations along the traverse

must now be adjusted. There is no theoretical basis for either of the methods available do it, it is usual to use the simplest. The two procedures are that of Bowditch and the Transit method. As the Transit method does not adjust the bearings as much as Bowditch’s method it is to be preferred in the case of a magnetic survey; it involves an adjustment in, the easting of each leg, equal to the mis-closure in the easting multiplied by the easting of the leg and divided by the total eastings of the traverse. The Bowditch method involves the easting, say, multiplied by the length of the leg and divided by the total length of the traverse.

- 38 - COMBINATION OF ERRORS

We have seen that we must predict the probable error of each traverse: this is obtained by combining the errors associated with each leg.

If n quantities are summed the standard error of the sum is n times the standard error of each quantity

(assuming these to be all the same). Example 11.

PQ is a traverse containing n legs of length and bearings a1. An error da1 in a1 will result in a displacement of Q at right angles to the line of the traverse of an amount sda1. If the standard error of these errors is e, then the standard error of the position n of Q will be given by:

E = ±se n Example 111

PQ is a traverse containing n legs of length s and clockwise included angles a1 with errors as above. The displacement of Q at right angles to the line of the traverse will be (n – i)sda1, caused by an error in a1. The standard error of the position of Q will be given by:

E = ±se 6/)12)(1( −− nnn A quick comparison of these two results will show why the prismatic compass was considered superior to

the astrocompass when accurate cave-surveying first started. Since the prismatic compass is now being used to the limit of its precision by one or two surveyors, it will soon be replaced by a theodolite; the latter instrument will be more precise, however, than an astrocompass.

Knowing the error, E, produced by the angular errors, we can plan the precision of the taping; which

should produce a standard error of not more than E/ n in each of n legs. If the traverse is in the form of a loop the easting and northing errors will be about 1/ 2 of the error of a

straight traverse of the same length. EXPRESSIONS OF ACCURACY

A C.R.G. grade 7 covers a multitude of sins. Only one of the many forms in which the accuracy of a survey may be expressed will be discusses: it has the advantage that it enables traverses of different lengths to be compared. The factor Q is defined by:

Q = t/L½

where t is the total misclosure (true distance) and L is the total length of the traverse. Note that the factor has units. A misclosure of 1 metre in 1000 metres gives Q = 0.03. perhaps this is a suitable target for cave-surveying during the next view years! WEIGHTING

No mention has been made so far of the ability of the surveyor to weight his data. Every computation so far discussed can be readily modified to take account of weighted results: the problem is a practical one and of utmost importance. Data of equal reliability have equal weights. Rarely will surveyed data or calculated data have equal reliability and so the surveyor has to attach a weight to each piece of data. For length measurements it is usual to assume that the weights are inversely proportional to the length of the line; however, the conditions involved in cave surveying are so different from surface work that this is no longer a satisfactory assumption. Since the purpose of this article is not only to review established procedures, we shall not speculate upon the problem. There is no doubt, however, that the problem must be solved, either by theoretical analysis of survey data, before cave-surveying can be considered an accurate metrology.

- 39 - SUMMARY

We have considered the complex case of high accuracy. The surveyor is at liberty to simplify or omit the procedures available whenever the accuracy of the survey is too low to warrant them. However, in some cases any attempt to simplify only results in confusion. For example, if a complex system has been surveyed to a low accuracy, it may be just as well to adjust the results using the principle of least squares, knowing that the result will at least appear at the end of the work, as to try to adjust the results by inspection of the drawing which may easily lead to difficult decisions having no theoretical procedures available.

Whatever procedures are used it is most important that as well as giving the results, in the form of co-

ordinates perhaps the standard error, or probable error, is given and the size of the misclosure stated. In this way the user of the survey will not only be able to interpret the data correctly, but will be assured that the surveyor is himself aware of the accuracy of the work.

----OOOOO----

LETTER TO THE EDITOR

Dear Sir, Would Mr. Taylor care to clarify his statement in the February BB (No.251) that his self

appointed Holy Trinity of the B.E.C. (Messrs Taylor, Targett and Sell) are the only real climbers in the Club? As an unreal climber I would like to attempt to defend the other followers of the faith

Basically, rock climbing is merely an integral part of mountaineering, skiing, orienteering, snow and ice

climbing and straight forward daisy picking; ramblings are also part of this great pastime. In conversation with the three concerned, never once have I heard an appreciation of the mountains

mentioned. Surely this is one of the prime reasons for climbing as many life-long participants would agree. I have been led to believe that when one is ‘real’ climbing one starts at the foot of the mountain and climbs by one’s chosen route to the top. Mike Luckwill wrote about ‘real’ climbing last year (BB No.242 May 1968 – Ed). Two routes 3,000ft. in all and a total height of gain of some 6,000ft. But I may be mistaken.

Here in Scotland we use our local crags merely as practice grounds, not ends in themselves. Maybe our ‘real’ climbing friends should try a typical Scottish winter weekend: - Drive 200 miles, pack camp gear 4 to 5 miles, camp, plough through snow – sometimes waist deep, carrying bivvy and climbing gear. The routes can be up to 2,000ft. of heavily iced rock – this means often cutting steps for long periods of time. The end of the climb at 4,000ft. and then descend to camp. Pack up next day and descend to car. This in my estimation constitutes ‘real’ climbing.

Before I close this letter I would like to point out that I am not trying to minimise Mr. Taylor’s feat; I am

trying to point out that to be a real climber one must do what one enjoys most in the hills or on the crags and not them try to belittle anyone who doesn’t particularly see any point in it. Steve Grime. Fife, Scotland.

ooOOoo JUST A SEC with Alan Thomas

Congratulations to Tony Meaden and Phil Kingston on their forthcoming nuptials. -----------

Kangy was home recently on a flying visit. He was full of admiration for the French test pilot.

----------- On a recent holiday to the skiing area of Scotland, ‘Alfie’ managed to break his right leg when a ski hit

some soft snow. He is hobbling about on one leg chasing the cat but hopes to be back in circulation shortly. ------------

Perhaps it is time to remind members that all trips by club members should be written up in the club log, according to the rules of the club. It does not matter that members, caving or climbing, do not return to the Belfry, where the log is kept, immediately after the trip; it does not matter if the dates are out of order. Try to remember after a trip to write it up in the log as soon as possible after the event.

- 40 -

Could St. Cuthbert’s leaders also ensure that every member of their party signs the St. Cuthbert’s Log before going down the cave. This, of course, is the book in which the leader should also write details of the trip.

---------- It is hoped that the Club exhibition, which is on show in Wells Museum from 14th to 25th April, may go

‘on tour’ afterwards. We should be glad to hear from anyone who can suggest a suitable venue for an exhibition of ‘Caves and Caving’ during May or June. This could take the form of either 12’ x 6’ or 6’ x 6’ show case of exhibits.

----------- Report of the Hon. Secretary of the M.R.O. -Dr. Oliver Lloyd (abridged)

Cave Rescues and Incidents

There were six of these in the twelve months, (there were in fact 7 – this being added to this report as 4A – Ed) which is again an improvement on last year. The most notable change has been an absence of Swildon’s Hole rescues, since the loss of the 40ft. pitch due to the floods of July 10th. It must, however, not be assumed that the present route taken by the stream and by cavers would be passable in the event of a real flood. The bar and pulley over the 40’ in Suicide’s Leap were carried away by the flood. Arrangements will be made to replace them.

1. Cuckoo Cleeves, 10-3-68

Axbridge C.G. found a large party of juvenile novices led by Adventure Unlimited which had got into

difficulties. They were ill-equipped and were having difficulty re-ascending the 13ft. pot by their knotted rope. A.C.G. helped them to the surface. M.R.O. was not called out. 2. Sidcot Swallet, 13-4-68

Member of 1st Kingston Hill Venture Unit got stuck at head of final drop. M.R.O. called at 1.55pm and by 2.20pm party from B.E.C. had reached the cave and brought caver to surface at 3pm. 3. Sump Rescue Turnout to Pontypool, Mon. 22-4-68

At 8.10pm Dr. Lloyd received a telephone call from Mel Davies in Pontypool to say that sump apparatus and divers were needed to explore flooded conduit, in which two children were believe to have been lost. Lloyd and Savage reached Pontypool Police Station at 10.00pm and learnt that the incident had been concluded: it was a false alarm. 4. Nine Barrows Swallet, 12-5-68

Benham, aged 34, caving with E.S.C.C. was climbing in Crystal Chamber when he fell and broke his tibia

and fibula in one leg. At 2.50pm Dr. Thompson was called out, arriving at cave 3.10pm. He splinted both legs together and put him into the carrying sheet. He was out of the cave in about one hour. 4a. Swildon’s Hole, 25-5-68

Party of three cavers became exhausted in the Double troubles. Search party got together. Returning party of divers escorted the party to the 40’ where rescue team met them. 16 people were put on standby. 5. Swildon’s Hole, 26-5-68

Martyn, a novice caver with more enterprise than resources, having had his first caving experience the previous day in Burrington, descended Swildon’s Hole in a party of three. He had no wet suit, but in spite of the delay at the 40’ he went down to end through sump 1, only to find on his return he was too cold to climb the 40’ ladder. Entered cave at 12.30pm and the incident began at about 4pm. 4.40pm M.R.O. called and advance party entered cave at 5.10pm. Meanwhile his party with the aid of the Clifton College cavers rigged

- 41 - up a double lifeline on the pulley in Suicide’s Leap and Martyn climbed without any difficulty. The subject emerged at about 5.50pm.

Webb (leader of Martyn’s party, had been a member of CSS) but this was not one of the Club’s trips. A certain amount of ill-feeling resulted from inaccurate reporting of the incident. Reference to the Warden’s log shows that inaccuracies did not stem from there. 6. Swildon’s Hole, 2-7-68

At 9.30pm Robin Main called at Belfry to say that two cavers, who had entered the cave at noon, had not

returned the keys. Turner and party, after checking local pubs went down and searched the upper series leaving the cave at 11.30pm. (The 40’ wasn’t laddered). They could not be found.

------ Practice rescues were carried out in the following caves during 1968: - St. Cuthbert’s; Longwood; Swildon’s and G.B. Cavern. Besides these, baths practices were held with the

new neoprene bag and the Sump Rescue Apparatus Mk.2. A Swildon’s practice held on the 40’ (after the flood) by S.M.C.C. brought the following comments by

Bob Craig: …for the first 10ft. three people are necessary in the chamber below the 40’. Two people on the ledge above the 10ft. drop and below the squeeze at the rift end are essential. As there is no room to pass in the rift, 4 people should then take over and be prepared to carry up the new rift. The waterfall pitch below the Water Chamber creates no problems but a person halfway up this 15ft. drop is useful to guide the “victim” and supply some pull.

On 14-8-68 a meeting of Wardens with Chief Inspector Reese of the Wells Police discussed various

subjects including Walkie Talkies – Wells Police have to hire them from the Home Office and are kept at Keynsham so make time to obtain them during rescue; relations with press – during rescue reporters should be referred to Warden in charge on surface, who will have detailed off a member of M.R.O. to act as Press relations. Afterwards refer them to the Warden in charge; NO COMFORT COULD BE OFFERED TO A RESCUER, IF HE WAS CONVICTED OF HAVING EXCESSIVE BLOOD ALCOHOL LEVEL WHILE DRIVING ON HIS WAY TO A RESCUE.

------- MONTHLY MOTES No.22 by ‘Wig’ St. CUTHBERT’S GOUR HALL AREA (caving Report No.13, Part F) will be on sale on Saturday 19th

April 1969. price 3/-. The contents include a detailed survey of the area; photographs; R.S.D.; description and survey notes. The survey includes all known passages in the area.

------ G.B. RESCUE

Many members living in the Bristol area will know already of the rescue from G.B. of a party that had been trapped in the cave overnight 23/24 march. A team of St. Albans Caving Club entered the cave on Sunday and obeying the instructions locked

the entrance gate behind them. On their return they found that the key would not turn in the lock and while forcing the lock broke the key broke. The following day one of the wives phoned Geoff Bayne of the ‘Old Vic’ at Priddy to find out what had happened. Bayne went to the entrance and found the party. Having determined the trouble, Baynes called the FIRE SERVICE, who after a little trouble managed to prize the door open

Two important questions must be raised regarding this incident that is not unknown on Mendip during the

last few years.

1. Why didn’t the party leave a note with someone to say what time they would be out of the cave? Of the St. Albans party did they not know the elementary rule of leaving a note with the farmer or at the hut where they were staying, then how many other caving parties on Mendip are doing the same thing? Have the local ‘pubs’ that ‘take-in’ cavers over the weekend any method of telling where the parties staying with them are at any time? – if they haven’t then it’s time they had.

- 42 - 2. Why was the Fire Service called at all? Why wasn’t the M.R.O. called to deal with this simple affair

instead of calling an already overworked public service? -----

St. CUTHBERT’S – Rabbit Warren. About 130ft. of new passage has been discovered in the Rabbit warren very near the Railway Tunnel. It consists of a very tight entrance passage leading to two small and very muddy chambers with fine stal. flows along one side. A passage at one end of the second chamber continues for several feet before degenerating into a very tight bedding plane, the upper end of which ends in a boulder choke. The area has been taped in order to preserve the fine crystal clusters in the basins of some small gours.

------ LONGWOOD/AUGUST KEY

Members wishing to visit Longwood/August System can obtain the key from Dave Irwin, 23 Camden Road, Bristol 3. To ensure that the key arrives in good time for the trip will you contact Dave in good time, at least 14 days notice, so that the key can be sent to you. O.F.D. III trip.

On the recent trip to O.F.D. III during the Easter weekend, the following tackle was used and should be put on record for other members who may wish to visit this fine system.

2 – 25ft. ladders 2 – 5ft. tethers 2 – 120ft. lifelines 1 – 10ft. ladder

The lifelines and 10ft. ladder are for ‘travelling’ purposes and will be found useful on the many climbs

and traverses.

APOLOGIES

The Editor would like to offer his apologies to all members who have not yet received their B.B.’s for some of the issues of this year. A number of pages have been running out of print before all of the BB’s could be assembled but the situation should be sorted out in the next few weeks when it is hoped that BB printing methods will be back onto an even footing. WHITSUN MEET in YORKSHIRE

Camping at Skirwith Farm. The programme of meets include Tatham Wife Hole; Alum Pot; Grange Rigg; in addition a private trip organised by the Dining Room Digging Team will be paying a visit to Black Shiver Pothole. Kingsdale Master Cave can be visited without prior arrangement. B.B.’s

Several members have requested that the B.B. be sent to them unfolded. If this is the case will members send addressed envelopes to Dave Smith, Flat 15, 193 Wensley Road, Coley Park, Reading. If you have not received your BB’s for any month then Dave’s the man to contact to find out whether it has been sent to you or not. SUBSCRIPTION REMINDERS

This is the last B.B. you will receive unless you have paid your 1969 subscription – remember it was due on 31st January – send it to Bob now (699 Wells Road, Knowle, Bristol 4).

- 43 - ROUTE SEVERITY DIAGRAM by S.J. Collins

PART 4. Wetness

The basic sign for wetness is a wavy line. This goes outside the passage or pitch, so that if we want to draw a passage that is both wet and constricted, the signs do not get in each other’s way. Once again, it does not matter whether we draw the wetness sign outside one or the other side of the passage, and if the passage is wet and tight, we can draw the two signs on the same side of the passage or on opposite sides just as we please.

Everybody should now be able to draw a wet pitch. It should not even be necessary to illustrate one, so we shan’t bother. PART 5. Exposure

By this, we mean exposure in the climbing sense. In case there is someone who is not familiar with the term, you are in an exposed position in a cave if it is possible to fall from where you are to some lower place in the cave.

Constriction was indicated by putting a sign (like a sharp point) INSIDE the passage or pitch. Wetness

was indicated by putting a wavy line OUTSIDE the passage or pitch. There is only one other place we can use, that is the actual side itself. Exposure is thus indicated by BREAKING THE ACTUAL LINE IN THE PASSAGE OR PITCH. Thus, a ledge is shown like this: - B

A

In the case of EXPOSURE of this sort, the actual side on which the exposure occurs is the one shown dashed. Thus, in the passage below, of you were going from A to B you would expect to cross a ledge with a drop on your right……

If anyone has been doing some thinking, I can almost hear the objection coming up at this stage. Why is

a pitch drawn with solid walls when you are in an exposed position al the time you are climbing it? The answer is that a pitch drawn with solid lines means that you would expect to use TACKLE on it (which should keep you from falling!) This is distinct from a CLIMB which is drawn like a pitch but with exposure signs like this….

DAIGRAM.. ACTUAL SECTION THROUGH PASSAGE

WET PASSAGE

…….and means that you would normally be expected to climb it without tackle.

- 44 - PART 6. Boulders

The hazard represented by rocks was not originally part of the R.S.D. but has been added at the request of many cavers. Again, we use the actual passage side and the inside. In fact, our basic passage becomes very distorted – as it does in real when passing through a boulder ruckle!

We use the basic boulder sign (◊) in other ways, which we will show later. The reader who has been doing some thinking may well have another objection at this stage. He may

think “old Collins told us that all these signs could be used together if necessary. Now he has gone and introduced a sign for a boulder ruckle with the sign for tightness. We can’t therefore show a tight boulder ruckle”.

THIS IS TRUE – and it was one of the reasons why this was not part of the original R.S.D. Later, we

shall be able to use a way round it. PART 7. Junctions and routes

We said that there were eight basic symbols. We have dealt with the signs for PASSAGE, PITCH, CONSTRICTION, WETNESS, EXPOSURE, BOULDER and now we come to the last two.

Passage junctions are shown just as you would expect. Like this…..

………..and thus basic sign is the one by which we denote that two or more routes are in the same cave space. This might be in a large chamber or along the floor and halfway up a high rift. They are shown as separate routes within a dotted area. This sign can be used to denote the route passing through a large chamber if desired. To be continued.

------ BRITISH SPELEOLOGICAL ASSOCIATION National Speleological Conference and Exhibition MANCHESTER UNIVERSITY September 12th – 15th 1969

PHOTO SALON…..open to all cave photographers. Each entrant can submit up to three colour slides and up to three black and white prints. All entries are returned after the showing at the conference.

There will be three prizes of £3, £2 and £1 in each section. All colour slides should bear the name of the photographer and should be spotted at the left hand corner (bottom) facing the viewer. Entries should be submitted to the Photo Salon Secretary, Mr. Price, 28 Cherrytree Way, Southmoor, Nr. Abingdon, Berks, not later than September 3rd, 1969.

Application forms are available from Photo Salon Secretary or Ian Standing, Grove Cottage, Watledge, Nailsworth, Glos.

- 45 - LIBRARY LIST No.1 Caving Books (a) a1 Texas, The Caves of Nat. Spelio. Soc. U.S.A. a2 Jenolan Caves – Australia B. Dunlop a3 Homes of Primeval Man – Czech J. Kinsky a4 Wookey Hole: It’s Caves and Dwellings H.E. Balch a5 Cave Men, New and Old (2 cps) N. Casteret a6 My Caves (2cps) N. Casteret a7 Ten Years Under the Earth (2cps) N. Casteret a8 The Cave Book Earth Science Inst., U.S.A. a9 Mendip – It’s Swallet Caves and Rock Shelters (2cps) H.E. Balch a10 Mendip – The Great Cave of Wookey Hole H.E. Balch a11 Mendip – Cheddar, It’s Gorge and Caves H.E. Balch a12 Mendip Caves, The H.E. Balch a13 Derbyshire, The Caves of T.D. Ford (1st Ed) a14 Cave Hunting W. Boyd Dawkins a15 Caves and Caving No.2 B.S.A. a16 Underground Adventure Gemmel & Meyers a17 Caves of Adventure (2cps) H. Taziefe a18 Rouffignac, The Cave of L.R. Nougier and R. Robert a19 Adventures Underground V.S. Wigmore & A.N.W. a20 British Caving Ed. Cullingford, C.R.G. (1st Edition) a21 Darkness Under the Earth (2cps) H.W. Franke a22 Caves and Caverns of Peakland C. Porteous a23 Pennine Underground N. Thornber (1st Edition) a24 Underground in Furness E.G. Holland a25 Copper Mines of Alderney Edge ‘Jug’ Jones a26 Cyprus, Some Caves of ‘Jug’ Jones a27 Scotland, Some Caves and Mines ‘Jug’ Jones a28 Pre History A. de Pradenne a29 Yorkshire Caves and Potholes, No.2 Under Ingleborough a30 Yorkshire Caves and Potholes, No.1 Under North Ribblesdale a31 Netherworld of Mendip H.E. Balch a32 Exploring Caves Cullingford a33 Hunters and Artists Peake & Fleure a34 Subterranean Climbers Chevalier a35 Lascaux – A Commentary Houghton Brodrick a36 Lascaux Cave Paintings, The a37 Au Fond des Gouffres N. Casteret to be continued BEWARE – B E W A R E = B E W A R E …………Beware

A scout sent his sleeping bag to a dry cleaners and took it with him to camp. He died from the cleaning fluid fumes. If you send your sleeping bag to the cleaners ensure that it is well aired before using it by turning it inside out and hang it up for several hours before use.

----OOOO---- IT’S THE THOUGHT THAT COUNTS

It was reported that four boys has left O.D.G. for Pike of Blisco and had not returned. It was misty as Sid and a few others took the land rover to the top of Wrynose and started to search the west slopes of Pike of Blisco. There was a storm but fortunately the boys were soon found and taken down to the land rover and back to Langdale. The following day the four called at the O.D.G. and asked to speak to the boss. Sid appeared and the largest of the four shyly told Sid, “We have had a whip around mister, and will you please accept the 13/4 we have collected?”

(Langdale Mountain Rescue Report)

- 46 -

THE WATERFALL by ‘Jock’ Orr.

It was Monday and the sight of Alan Thomas crouched over his camera, in the act of photographing a freak horizontal icicle hanging under Ladywell aqueduct by Plantation Swallet reminded me of the waterfall I discovered on a hot summer day many years ago. It was up in the hills away on the far side of a valley at a place called Roman Bridge.

I daresay other people knew about the waterfall before I did. It’s there if anybody takes the trouble to

look for it. There wasn’t anyone around on the day I, or rather we, found it. And since that day happened to be arranged so that everything was just right, and as it should be, and because the surprise of finding this perfect waterfall put the finishing touch to a perfect day; she named it Enchanted Waterfall.

After this, we kept in touch fairly regularly for the next few weeks and then I had to go away for some

time; there were no replies to the letters I wrote and I got to wondering about this and losing sleep over it I shrugged it off as one of those things. I never heard from her again.

Alan noticed my apparent lack of interest in the icicle and he remarked that it was a pretty good icicle and

deserved a photograph. I replied with some absent-minded comment, and still thinking about Roman Valley, which I hadn’t thought about for many years because I had forgotten all about the place long ago, delivered one of those seemingly disconnected remarks that tend to annoy people by saying that the appearance of the aqueduct would be enhanced if it was demolished and reconstructed in the form of a stone arch instead of just being a leaking pipe.

“Oh! I don’t know,” say Alan, “The pipe is quite adequate for the purpose.” – and I suppose he was right. We set off then along the path to the Mineries and inspected the ice which was giving off a sound not

unlike a deep and mellow xylophone note, which we thought was quite unusual, and listened to it attentively. We then proceeded on our way over towards Priddy Pool, where buster, the dog, who had been trailing us condescended to join the walk.

In the forest we found the peculiar shapes of ice formations on the underside of the ice lying in the track

ruts quite interesting, and then decided it was time to retire to the Hunters. It was about then that I thought that since Roman Bridge was somewhere in North Wales and I happened to be living there, then it would be a good idea to find it on the map and go and see the waterfall again some day.

We finished our beer and then set off on tour of the ruins of what Alan described as the site of the Old

Iron Masters of Mells, which felt held a fine dramatic echo, steel, and ringing hammers about it. The walk finished in fine style with a pounding march along a mile of railway track, and back again, to

see some non-existent antique railway engines which had evidently been stolen from the derelict engine shed and carted away by someone with a mania for collecting old steam locomotives.

During this perambulation my boots appeared to have spouted extensions which tripped and kicked

against the concrete railway sleepers and caused my gammy ankle to buckle and jar agonisingly at every step. I must admit I was a bit sick of watching Alan’s springy step ten yards ahead of me and by the time we reached the car I felt as if I was dragging along a bag of looses bones tied together with string inside my left boot and was glad of the chance to sit down.

In the evening Alan retired to his caravan to prepare for an appointment in Wells and I departed from

Mendip and drove home through snow covered countryside to Anglesey and went to bed, dead beat! On Tuesday I lit a fire and cooked a hefty mid-afternoon breakfast and out of curiosity had a look at the

map whilst eating and spotted Roman Bridge almost straight away. It was near enough to get there within three hours and having nothing else to do for the rest of the day I gathered outdoor clothes and rations and set off from the cottage in search of Roman Bridge.

Usually I do my driving at night to avoid the day time traffic, but there wasn’t much on the road this day.

The freezing east wind came rampaging down out of the snow-covered mountains and bellowed through the

- 47 -

Francon Pass. And Bethesda Town had put up the shutters. On the way up the pass the wind gusted under the car and lifted it on its springs and then swooped up and belaboured the sides until it felt like a speed-boat bumping across choppy waves. At the side of the road the telegraph wire snaked and whipped around on the ground where it had torn free from the leaning poles. Road grit and small rocks and lumps of frozen snow flew along above the road surface as if the law of gravity had gone mad. Overhead, the sky was grey-black, and on the other side of the pass, as if guarding the entrance to some titanic lair up in the mountains. Perfedd and Foelgoch and Y’Garn crouched and steamed in frost haze like might stone beasts covered with great black-rock scare stark against the snow on their backs. Their supper was cooking, a fine brew of boiling black cloud and writhing veils of sleet spouted around inside the Devil’s Kitchen. Except for the reassuring presence of two R.A.F. Mountain Rescue Land Rovers standing on the car park at the Mountain Rescue Post there wasn’t a sign of humanity to be seen anywhere.

The whole place brooded and skulked under the lead coloured sky. Llyn Ogwen was a solid sheet of ice and nearby Tryfan glared across the wilderness from under his black crags. I looked over my shoulder, half expecting a troop of abominable snowmen to come marching down out of the murk, and got the car away off down the road as fast as I could.

Along the road, Betws-y-Coed was still digging itself out of the snowdrifts and I noticed ice flows on the

River Conway as I drove over Waterloo Bridge. When I turned off the main road to Roman Bridge, where the headwaters of the Lledr have their source, I met the full force of the penetrating east wind blowing flat out across the wide snowbound expanse of open ground. It looked as bleak and as bitter as deserted wastes of the Artic. I shivered in the warmth of the car, and if the track had not been clear of snow I would have turned round and got myself out of the place.

Evening was drawing near and light began to fade and it was a long way back to Anglesy. Now I had

arrived I decided to stay where I was for the night and drove the car in behind a stone wall which afforded a convenient wind break. I left the engine and heater running while I settled down inside my sleeping bag for the night remembering to switch off the engine before going go sleep. Outside, in the frozen night, the wind moaned and soughed through the branches of some nearby pine trees with an eerie persistence while I thought of food, bright fireplaces and comfortable armchairs and a book.

I awakened in the dark and struggled out of my sleeping bag, cursing the freezing cold, and switched on

the interior light. The car windows were covered with snow and the air inside was stuffy. According to my wristwatch it was ten o’clock, but I wasn’t sure whether it was night or morning; whichever it was I needed some fresh air. I dressed swiftly and covered up in nylon waterproofs. There was probably a blizzard blowing and I would need protection when I got out in it. The car doors would not open and I noticed that the inside of the car was festooned with small icicles from the condensation. Eventually I succeeded in winding down one of the windows and started digging upwards thorough the snow by scooping it into the car!

It was Wednesday morning alright and I was relieved to see it was daylight and that it had stopped

snowing. My hands were frozen stiff and the gloves were wringing wet with the tunnelling but there was nothing else for it but to get down to the luggage boot for the spade and dig the car out of the drift which had accumulated in the shelter of the wall. The effort soon warmed me up, and ravenously hungry with the keen air and cold I lit the primus stove and prepared a steaming bowl of porridge and raisins. Between mouthfuls I contorted my face to produce a most satisfying reflection of glowering disgust in the driving mirror, which despite the toiling and the traumas of the morning incarceration, put me in a good mood.

After breakfast I emerged from the fuggy warmth of the sopping-wet and steamed-up interior of the car

glad to get out of it and after leaving a note stuck on the inside of the windscreen to say “gone for a walk, back soon” set off towards the hillside in the direction of where I remembered the waterfall to be, climbing the first two hundred feet or so at a steady pace.

It was all very different from the last time I had been there; the warm peaty-herby scents and the blue sky

and the blazing summer day. I stopped for a moment to ease the gasping of cold air to normal breathing and slow pounding heart to a steady beat, and then continued on upwards across the snow-covered side of the hill until the waterfall came into view.

- 48 - And there it was. I gazed in astonishment at the transformation. The waterfall had changed itself into a

surprise of cascading ice crystal; a flow of gleaming glass; an intricate candelabra of glittering icicles and the water scintillated, chattered, chuckled, tinkled, hissed, splashed and sprayed like a shower of sparkling diamonds over and through the ice and on into the frozen pool.

I made my way cautiously down the side of the gorge, which wasn’t all that deep but nevertheless a trap

with all the ice underfoot, and settled myself in a niche in the rocks at the edge of the stream and gazed at the spectacle, at the same time trying to make myself as unobtrusive as I could for fear of breaking the spell.

No doubt there were bigger frozen waterfalls than this. There was, maybe, a waterfall turned to ice and

stuck to the side of a mountain somewhere, too magnificent and lofty and wide to inspire anything except awe at the grandeur of it all; but this one was indeed a truly enchanted waterfall set in a secret place amongst the wilderness of black rock and frozen snow.

Although it was sheltered and out of the wind down in the gorge, the cold was beginning to gnaw at me

and I shifted around carefully with a wary eye on the smooth ice at the edge of the frozen pool. The last thing I wanted was a ducking in the chilled water. I changed position, all the while muttering and marvelling to myself, and then, without warning, a huge white and brown bird floated out from a recess hidden behind a cluster of icicles high in the back of the gorge. Startled for a second by its sudden appearance, I nearly lost my footing and slipped into the freezing pool, before I recognised that the bird was a large owl. It hovered for a moment and started at me intently out of its round eyes and then swooped over my head and glided away down the stream on sharp, thin wings, like a silent phantom.

I stood stock still for some minutes hoping that the owl would return but the cold began to creep in on me

again and I to leave take my leave of the waterfall, reluctantly, pausing at the top of the gorge to look back at the scene.

Up on the high ground a real eye-stinger of a wind let fly across the frozen snow, sweeping scuds of drift

snow through the air. Dark clouds wracked across the whole sky and the hills glowered and hulked in their solitude. Everything in sight was black and white with touches of grey. Black rock and black laceries of walls and boulders across the white snow. Black trees and black forests in the distance.

I took shelter from the wind in the lee of a rock and ate my rations of dry oatmeal and raisins and lit a

roll-your-own cigarette and puffed away at it with great enjoyment, calculating how long it would be safe to say up here before the light faded.

Away to the west behind nearby hills, the clouds thinned to a murky yellow glow and revealed the

triangular peak of Snowdon illuminated a lurid orange from the evening sun. To the north, rearing in the foreground, the black ramparts on the flank of Moel Siabod; and further to the right, Moel Siabod himself towered, glowered and grim, in shredded cape of flying black cloud.

I stood up out of the shelter and took a hard long look at Moel Siabod. A few moments ago the summit

had been visible, and now Siabod had his head buried in the cloud and was sniffing the blizzard. I felt an extraordinary compulsion to start climbing upward towards his slopes and into the streaming cloud, and it was an effort to look away from this remote and fearsome dominance. Away to the east, the hills had vanished from sight under the advancing snow. The first flurries of white granules swept in on the wind, hiding the valley below. It was time to get off the hills and sown to the shelter of the car. I made the descent with care, anxious to avoid any ankle trouble on the way down, but content with my walk in the hills and feeling fit and fresh from the cold clean air.

Back at the car I was in the middle of packing up when the farmer from Coed Mawr came, driving down

the track on a tractor. He stopped and I walked over to meet him. “Did you enjoy your walk?” he bellowed through the wind. “Yes thank you,” I shouted back. “Very much indeed! I’ve been up to the waterfall.” He looked at me with some concern. “Oh yes? nasty place that, very dangerous. I remember there was a bad accident there a few years ago.”

- 49 - “Can’t say it struck me as being dangerous,” I said. “In fact I’ve always thought of it as a pleasant spot.

Accident did you say?” “Aye!” he shouted above the wind. “Young lass, it was. She fell off the top of it and got drowned in the

pool.” He blew hot breath into his cupped hands. “A mighty cold day to be out walking, I reckon. Looks like more snow.” I stared up at him. Stuck for a reply, and nodded my head. He shrugged his shoulders and revved the tractor engine. “Well, I’m off. Cheerio.” I watched him lurch off up the track and then got into the car and drove away from Roman Bridge Valley, slowly, because I was thinking that it was a sad, bitter place.

That night, the weather report on the radio announced blizzards pouring into Kent, Dorset, Somerset and

North Wales. Down at the ‘Stag’ the talk was all about Anglesy being cut off from the mainland. I gazed into my beer and said nothing, there are some people you can talk to and others you can’t

I drank my beer in a silent toast to the enchanted waterfall, and I thought about what the farmer had said

up at Coed Mawr, and remembered about the letters that never got an answer, and I also thought too about the white and brown speckled owl and its staring eyes and sharp thin wings and wondered if it was sitting snug and warm in its roost amongst the icicles; then I imagined it slipping through the warm summer night air on its silent wings.

Maybe I’ll go back and look for the owl again someday. But, thinking it over, maybe it would be better

not to. ---OOO---

B.E.C. TRIP to O.F.D. III by Dave Yendle

In glorious sunshine a happy party of Roy Bennett, Dave Irwin, Dave Glover, ‘Bucket’ Tilbury, ‘Bert’ and myself wandered up the hill to the top entrance of the 15 mile long O.F.D. System – and above all things actually entered the cave!

Winding our way through the maze of entrance passages we soon reached Gnome

Passage and so on to the Chasm – a fantastic rift of huge proportions. The way lay along this enormous rift up and down interesting climbs until we reached the ‘dreaded’ rift traverse which is over 200ft. in length.

The atmosphere was tense as ‘The Wig’ edged his way across the tricky start of the traverse when, at the

critical moment, a thunderous crash resounded through the galleries. Panic followed until we realised it was only Roy dropping a boulder down a huge hole! At last we staggered across the traverse and after more climbs and a squeeze (quite out of place in such a large cave) reached the Three Streamway. On the way, very near the streamway we saw some magnificent bunches of helictites - some nearly 1ft. long.

We by-passed the initial section of the streamway, by traversing over the streamway to a high level

passage by means of a maypole placed in position by members of the SWCC and so on up to Smith’s Armoury – a pleasant end of the cave after over half-a-mile of fine streamway. Smith’s Armoury is a large chamber thought to be very near the Byfre – the sinking point of the O.F.D. stream. As a very strong draught was whistling though the chamber Roy, Bucket and myself set out to see if there was a way through the terminal boulder choke – there wasn’t! The return journey was not without incident, dangerously poised boulders, interesting climbs, but after nine and half hours underground we emerged into the cold night air feeling quite pleased with our efforts.

00000OOO00000 BELFRY KEYS can be obtained form Bob Bagshaw – 2/6 each. COMMITTEE CHANGE NEW COMMITTEE POST

Bob Cross has been co-opted onto the Committee as Assistant Hut Warden.