BB86/1
BB JOURNAL OF THE BRISTOL EXPLORATION CLUB Vol. 8 No.86
October & November 1954
Notes on Cave Surveying by S.J. (Alfie) Collins. Cave surveying is not difficult. Almost any caver, with a bit of patience can turn out a reasonable survey of a cave. These notes, I hope, may be a help to cavers who are interested in doing some surveying underground and for general caver who may like to know what is going on when a survey is in progress. A survey can be very useful to a caver. Besides showing the general layout of the cave, where the main pitches, and places needing tackle are, and many other details of the cave structure, it can also used to point the way to further work, such as the joining up of two passages or the possibility of finding another entrance to the cave system. The exact location of any interesting finds or specimens can be marked on a survey. This may be important as a guide to further work in the same place. A passage not previously noticed can be checked against the survey to find out whether it has been previously explored. Finally, the surveying of a new cave is a means of showing other cavers what sort of cave has been discovered and what they are likely to expect on visiting it. A survey need not necessarily be a very elaborate affair using complicated equipment. The Cave Research Group divide surveys into seven classes according to their accuracy as follows: GRADE 1. A rough sketch of a cave drawn entirely from memory after leaving the cave. This is the type of plan that is drawn usually by a caver to show others roughly what the cave is like. No scale is used and all distances and directions are guessed. A lot depends on a good memory and an ability to visualise the cave after you have left it. GRADE 2. A rough sketch of a cave drawn in the cave. All distances and directions guessed at. No equipment is used. Two useful tips here. The first applies to all surveys. Have as much light as you possible can, it’s much easier to estimate the size and shape of a cave if you can really see it. Secondly, for guessing at angles stand up and point your arms in the two directions and then look at the angle between your arms. Of course, you can always stand up! GRADE 3. This and all the higher grades are made by using instruments. Grade 3 by using the simplest possible instruments – a small cheap magnetic compass for directions and a knotted string for distances and the Grades 4, 5, 6 and 7 by using more elaborate equipment which will be described later in these notes.