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<title>CUCC Expo Surveying Handbook: Underground</title>
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<h2 id="tophead">CUCC Expo Surveying Handbook</h2>
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<h1>Surveying methods: underground</h1>
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<p>The idea of the survey is to produce a map of the cave that is accurate,
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useful for route finding and possible connections (and look pretty). In most
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caves (and particularly in Kaninchenhöhle), enough information has to be
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collected for the full survey to be drawn by people who haven't visited all
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of it. The work involved in redrawing a huge survey each year is enormous, so
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it is becoming increasingly important to record enough so that a computer can
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draw it later.</p>
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<p>This being expedition caving, time is limited, but don't forget that
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no-one else may ever come here again, so the idea is to efficiently record as
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much info as possible. It is best to record all your passage to high
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accuracy, but if constrained by time and manpower (eg. this is the last
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chance to survey, on the derigging trip of a cave which is now "finished"),
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it is better to record all the passage, rather than part of it to a very high
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standard. Particularly to be avoided is a survey that doesn't connect to the
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rest of the cave.</p>
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<p>You are collecting data to fulfill a number of needs: the actual position
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of the passage for finding where it goes and possible connections; the shape
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of it for drawing pretty surveys; the location of possible leads for future
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exploration; geological info for working out how it got there.</p>
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<p>For small caves the survey should be drawn up for publication by those who
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surveyed it. However, it is important to realise that for big caves (eg.
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Kaninchenhöhle) the survey will be drawn up by a small number of people,
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usually in Cambridge. They may not have visited the bit of cave which you
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survey, and they have no chance to go back to check anything which is
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unclear. The same applies to the passage description, which is a complex
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evolving document. Ambiguities in your description may not become a
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problem for several years, by which time you may no longer be in contact
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with expo or may not remember anything about the passage.</p>
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<p><b>Surveying ethics</b>. Remember: <em>survey what you find - don't leave
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it for someone else</em>. Your ability to find new passage without wasting time
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reexploring stuff seen before depends on those who came last year leaving good
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documentation. Likewise, future expeditions will be more rewarding if you have
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finished the job of exploring with a good survey.</p>
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<h4>Survey Standards</h4>
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<p>Both on the surface and underground, CUCC tries to achieve a grade 5c
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survey and the information below is the minimum that can be collected <b>in
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the cave</b> (or on the ground) to achieve this.</p>
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<ul>
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<li>Compass and clino read to the closest degree (but if it is in the middle
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there is no time wasted in recording the half).</li>
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<li>Tape to the closest centimetre.</li>
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<li>A cross-section with dimensions at least every station or leg (however,
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every time the passage changes significantly is deemed more suitable).</li>
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<li>A detailed plan and <em>elevation</em> sketch. This is actually easier to
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draw if it is done accurately to scale and direction (some surveyors carry a
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ruler and protractor to put the centre-line accurately in the book to sketch
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round). The sketch should contain as much detail as you would expect to find
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on the finished survey. As well as the obvious walls, floor and roof, pitches
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and traverses, detail should include direction of slopes, nature of floor
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deposits, direction of airflow, static and moving water, avens, boulders,
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climbs and the best route to take to avoid damage to the cave. When noting
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airflow and water, it is as well to record the weather on the surface, or
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make notes on any sudden changes. Boulders big enough to be significant
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should be sketched to scale, while general rubble can be noted and drawn in
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later. Make sure you know the conventional symbols for various floor
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deposits, though for large areas you can just (for example) write "sand".
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Geological detail is often obscured by rocks or mud, but it is useful, where
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visible, to record the location of shelly bands, faults, dip and strike of
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any prominent bedding or other cleavage planes, and any old flow markings
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(direction and approx diameter). Anything unusual which would make a good
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landmark is also useful, and of course, man-made things like pitch rigging,
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traverse lines or cairns.</li>
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<li>We use Therion protractors undergound for estimating directions when we are sketching passage shape and direction. We have templates in <a href="../templates/therion1_250.pdf">1:250</a> and <a href="../../templates/therion1_500.pdf">1:500</a> scales. (Thanks to Martin Budaj for these.)
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<li>The left, right, up, down (LRUD) from the survey station to the general
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passage wall, not the closest piece of rock. These should be <b>measured</b>
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whenever the relevant point can be physically reached (ie. not for the roof
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20m above), and estimated otherwise. Although the information should be
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derivable from the sketch, this is not reliable and LRUD provide a very
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useful cross-check. The meaning of "Left" and "Right" should be consistent
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along the survey and not swap over when leapfrogging. If there is a
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significant bend in the survey, the sketch should make clear exactly which
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directions were taken.</li>
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<li>On pitches, LRUD is not very meaningful. Instead, take four directions
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in a horizontal plane to the shaft walls. Most often this will be NSEW, but
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in a rift pitch both ways along and both ways across the rift is more
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useful - record approx compass points of the directions taken.
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<p>LRUD is becoming increasingly important so we can use some of the
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fancy cave visualisation software which is now becoming available. For
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a discussion of how to record this data, see Andy Atkinson's article in
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<a href="lrudcp10a3.html">"Enhanced LRUD Recording"</a> (originally published in the
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<a href="http://www.chaos.org.uk/survex/cp/CP10/CPoint10.htm#Art_3">Compass
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Points archive</a>. </p></li>
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<li>Station location. Some stations will never be used again, and the location
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is only needed when drawing up, as an additional helpful datum. Stations at
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junctions, or in long passages where junctions may have gone unnoticed, should
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be recorded in enough detail to be found again quite unambiguously by someone
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who hasn't been there before. If you say "bolt" make it clear which bolt.
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Remember that next year the anchor will have to be found, not just the obvious
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hanger. And someone may add a new bolt - is your description adequate to ensure
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that the old one is found ? A sketch to find the point may be useful - in more
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detail than will be used to draw up the survey. The Easegill resurvey folk are
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using special coloured plastic markers for permanent survey stations, which
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some may like to try in Austria. They make station identification much more
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certain, which is important when the next person to carry on the survey may
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never have been here before.</li>
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<li>Names. If you know passage and/or pitch names, record them on the survey,
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preferably with both the numbers and the sketch. If a name covers a long
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passage, record "station 13, start of passage X" ... "station 47, end of
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passage X". This helps prevent the meaning of names changing over time, which
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can make connecting new passages to old surveys very hard, as
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people look in entirely the wrong place for your stations...</li>
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<li>Question Marks. These should also be recorded both with the numbers
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and on the sketch. Make it clear where the nearest survey station is, and
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choose such stations to ease the job of future explorers, so they can be
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found again.</li>
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<li>Info for the whole survey. This means date, personnel, which instruments
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were used, state of the tape (eg. was the first 20cm missing ?). Also
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include calibration. Compass should be calibrated (ie. a reading taken
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between two known points) by each person who reads instruments on the
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survey, using the same technique as used in the cave. Clino should have
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readings taken from both ends between any two points (ie. A to B and B to A)
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at least once, and ideally each time the clino is bumped (compromise is
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before and after the trip).</li>
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</ul>
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<p>There are a whole load of <a href="hints.htm">hints and tips</a> on how to
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do the above, written from experience in Austria.</p>
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