The Belfry Bulletin Number 203 January 1965
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Monthly Journal Of The Bristol Exploration Club
Vol. XIX No.1
January Edition. The December B.B. having come out (at last) in January, it would only seem natural for the January B.B. to come out in February. We promised last month to make a resolution not to make rash predictions about the future, so we must hold that, as 1965 goes on, it may be possible for us to catch up. Caving News. Apart from meets (which were published in last edition of the B.B.) There are some additional Caving items as follows: S. Cuthbert’s Spring Clean.
This will take place on Saturday, March 13th.
Are you interested in taking part in (or initiating!) a serious project in Cuthbert’s? Apart from surveying, A meeting on the above will be held at the Belfry at there are many problems such as the determination of water flows, which could benefit from a serious 7.30pm on Saturday 13th. study. Why not come to the meeting and air YOUR views.
Work in Cuthbert’s
Why not make March 13th your lucky day The Hon. Treasurer wishes to remind members that their Annual Subscriptions fall due on the 31st of January. We know that it’s a bind having to pay but, apart from keeping Bagshaw’s records up to date and replenishing the Bagshaw Boozing Fund, it does help if subs are paid promptly. In many cases, it is not known whether the member concerned intends to continue his or her membership and it will help all those who organise club affairs if you pay as soon as possible! _______________________________________________________________________________________ THE LOGISTICS OF CAVE SURVEYING The topic of cave surveying can always be relied on to produce intense discussion and serious articles. Over the last few years, we have had “Thoughts on Survey Grades” (B. Ellis, B.B. 169, 2.) an article on the uses of surveys (S.J. Collins, B.B. 170, 6.) and a Colloquium (31.8.63) which forwarded recommendations to the Cave Research Group. The most important property of a survey is its accuracy and it seems to me, as a result of several factors, as soon as accuracy is mentioned, one thinks of the instruments used and the corresponding C.R.G. grades. This point of view, which is prevalent on Mendip, is rather limited and results in rather haphazard surveys. The reasons for it are that firstly, the cave is always available – this enables the survey to be made leisurely and at the caver’s fancy – and secondly, the reasons for making the survey are usually obscure or subconscious. (One of the points made in the second article referred to above). Let us suppose that a cave survey has to be made in a limited number of trips, as for instance on an expedition to an unexplored area, and examine how the method of surveying would change. Once again, accuracy is all important, but I would suggest that the concept of accuracy must change from that of suitable instruments to that of reproducibility. In order to check a normal survey, a second survey has to be compared with it, and if theses do not agree, a third survey must be made and so on until two agree. The
Page 2 final product will still be only as accurate as the grades claimed for initial surveys; surely an extra expenditure of time should warrant an increase in accuracy.
The following programme for a hypothetical surveying expedition is therefore based on the concept of reproducibility. When examined in this way, several other advantages arise and these will be commented on later. The basic requirement of the programme is reproducibility and the practical requisite is the setting up, along the main survey routes, survey stations which will remain in place for the duration of the expedition. These stations could be made quite simply from a tin lid and three wooden legs, and their sole purpose is to provide a reference point on which a compass and a clinometer can be placed. The programme, which is very elementary and merely intended as an illustration, assumes that three survey teams are available. The result of the programme should be a main line survey which is to Grade VI and has been completely checked, and cave detail of this main line to Grade V which has been checked in places of interest. The flowing advantages arise from the programme: The main line can be checked, to the required accuracy at any point. The most difficult parts of the cave, or the furthest reaches, can be surveyed when the team is fresh and enthusiastic, leaving the earlier parts towards the end of the expedition. The cave detail can be surveyed to any degree of accuracy, enabling an inexperienced team to contribute valuable work without lowering the accuracy of the completed survey. Once again, the most inaccessible parts of the cave can still be surveyed when the team is fresh. The Grade III main line survey enables a rough plan of the cave to be made and any points of interest which arise from exploration can be surveyed before the more routine work. From the point of view of an expedition, the plan enabled a number of teams to work in the cave at once and not all of these need be survey teams. For example, the Grade III survey would enable a geologist to start work without waiting for the accurate survey. Mike Luckwill. Hypothetical Survey Programme. Trip Team I Team II 1. Place survey stations throughout Grade VI survey of stations the cave. 2. Independent Grade VI survey of “ stations 3. “ “ 4. 5. 6. 7.
Team III Grade III survey stations Finish
of
Grade Va survey of cave from stations. “ Finish “ Finish Help team 3 “ Check errors in Grade VI survey. Check errors in Grade VI “ survey Combined teams check any necessary points and finish Grade Va survey of cave detail.
Editor’s Note. As the author points out, the subject of cave surveying continued to exercise club members, and this is the latest of a number of articles that we have printed on this subject from time to time. We hope to be able to find space next month for any comments. _______________________________________________________________________________________ The Hut Engineer would like to remind members that gifts of tools would still be welcome, and would enable the improvements which are being made to the Belfry to go ahead even faster!
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Letter to the Editor. Dear Sir, Now that Dave Irwin has specified in detail how he would like his yearbook and diary, may I review the 1956 Speleological Yearbook and Diary? It is a pleasure to see the year’s caving summarised so knowledgeably and concisely (7 lines per inch as against 6 lines per inch for 1964) and I appreciate the size which makes it a decorative part of my bookshelf. The diary section might make up its mind whether its purpose is to record or inform and thus will influence its future size. The Cave Physics is, of course, useless. Empirical data would be of more value, together with suitable references. A word of warning is necessary about the knot information provided. The Tarbuck is a slip knot and to use it as a waist loop invites strangulation – better round the neck – quicker! However, one can only express admiration for the glossary with its 388 entries against British Caving’s 221. Is this a record? In conclusion, a worthwhile and thoroughly enjoyable effort which fits into my anorak pocket. Yours, etc. Kangy. _______________________________________________________________________________________ Editor’s Note. We now have two rather opposed views on this book, from which we feel, the average club member should be able to form his own opinions and we feel that further correspondence on this subject is not likely to add significantly. There is, however, one small comment on a point on which both of the reviewers agree – the ‘Caving Formula’ which have been included in this years edition. It is reproduced below.
Caving
F o r m u l ae
I must confess (with tongue in cheek!”) My Caving Maths were rather weak. I’d gaze on curtains and erratics Without a thought for mathematics. No wonder – as I’ve learned to say – I often went B over A And hit the bottom hard, I guess (For v2 = 2gs!) Now my belaying’s so much neater, (log T by Tφ is uθ) And when on traverse, I would grope To find some hanging chain more rope Their whereabouts no longer vex Now I know y is Acoshx. So now I cave most perfectly With help from ‘Caving Formula’ And if you think this isn’t true 4/3 of p r cubed to you!
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Mathematical Puzzles : by Sett This Month’s Problem. Two club members arranged to spend their summer holidays at the Belfry. Amongst other things, they each reckoned to eat 1 pound of potatoes a day for 14 days so they arranged for a 28lb bag to be delivered. At the last minute, they were prevented from taking their holiday as arranged and had to postpone it for a week. They agreed with a third member that he could use some of the potatoes provided that he took an exact number of pounds and paid for them later. When they eventually got to the Belfry they found that the third member had already returned home leaving an opened bag and a crude but efficient balance made from a plank and a knife edged boulder. There was no record of how many potatoes had been taken. A quick walk to Priddy Stores and they found that Harry had a complete set of weights going up in single units from 1lb to 28lbs. “But”, said Mr. Glover, “You don’t need to take all of them. These will be sufficient to determine how many pounds you have left.” What would be the values of the minimum number of weights borrowed? The 20 hour trip round Cuthbert’s can be made with the consumption of 23 containers of Carbide per caver, provided that there is an even number in the party. Obviously some of the early dumping trips must be made at the previous weekends and the final assault will be quite a marathon. Pairing off, the party make 4 trips to the 18 hour point and return to base. One of each pair then makes a fifth trip. On each trip, a container is used and a further one dumped. Each pair now sets out to the 17 hour point, dump their containers and return to 18. Each member now takes one container to 16 and returns to 18. Take another container to 16, return to 17, pick up container dumped there, and back to 16. Take one container to 14, return to 16 and hence back to the entrance. This completes all the preliminary laying out for the return part of the trip, leaving one container per caver at the 14 hour point and half a container per caver at the 18 hour point. Total consumption, 9½ containers per caver. The caver of each pair which did not make the extra trip previously now makes two trips to the 1 hour point, dumps two containers and returns to the entrance. All the members of the party now take four containers to 2 and return, then take 1 container to 2, return to 1 to pick up the container at 1, and back to 2. Take 2 containers from 4 back to 2. Take 1 container to 5 and return to 4. Take 1 container to 6, return to 5 and back to 6. Proceed to 14, proceed to 18, half fill each lamp and back to the entrance. Total consumption 23 containers. I’m reasonably sure that there is a more economical method if all the laying out is done by each pair instead of sharing the job. An extra pint is offered for the solution to this problem. “Sett” _______________________________________________________________________________________ If you are thinking of moving in the near future, don’t forget to let Bob Bagshaw know of your new address. Unless you do this, you will quite likely stop receiving the B.B. _______________________________________________________________________________________ Once again, we must point out that, although we still have a two or there long articles in the ‘stockpile’, we have nothing of the size to fill half to three quarters of a page. As a result, it is necessary to attempt to fill up a page of the B.B. with dam silly notices like this one. _______________________________________________________________________________________ The Mendip Cave Registry could do with VOLUNTEERS to act as REGISTRARS for some of the caving areas into which the registry is divided. The duties of such registrars are to collect and keep up to date all information on caves, digs, etc. in the area and all published information of them. For any further information on the working of the Mendip Cave Registry contact Bryan Ellis or Alfie. _______________________________________________________________________________________ Copies of nearly all the B.E.C. Caving Reports and a large number of other publications, including many SURVEYS are available from Bryan Ellis. Write to him or call at the Shepton Hut for an up to date catalogue and price list. His address is: - B.M. Ellis, Knockauns, Comwich, Nr. Bridgwater, Somerset.