CUCC Expo Surveying Handbook

Wookey's hints and tips

... to save you going back to do it again.

"hmm - not going to finish this even slightly, so some points to bear in mind:"

• The compass must be held level to get a meaningful reading. A left/right tilt will cause a systematic over or under reading, whilst sighting up or down a steep leg may cause the compass to stick. It is easier to sight from the lower station by keeping the tape in position and sighting along it.
• Take care with lights, batteries, helmets and anything else which could be magnetic - check your gear on the surface, or your work could be seriously impaired. If your light affects the compass, then hold it away from the instrument when lighting it. Keep the compass well away from steel objects like bolts, steel karabiners or maillons, tripods or ammo cans when sighting.
• Practice using the compass above ground to avoid classic errors like reading 56 as 64 (ie. counting the wrong way from the 60 marker).
• Degrees are on the left hand scale on clinos. The other scale is percent gradient - this is better than nothing if you can't read the degree scale (make it abundantly clear in the notes), but reading the wrong one without realising gives useless results.
• Pick survey points so you can get your head in, and so you can see both ways as easily as possible. Note that Bolts are good things to use as stations (because we can find them again), but don't put the compass within 30cm as it will give joke readings. Sight from the other end of the leg, or put the compass behind it and look past the bolt.
• Write decimal points as slashes to stop them getting lost in the mud. Make sure they don't look like "1"s. It is helpful to always write compass readings as three digits before the decimal point, and clino as two digits with a sign. Add leading zeroes if needed (eg. 031/5 +02/5).
• "Notes" should call back readings to "Instruments" to check. Make sure you call out what you have written, not what you heard. It helps to ensure both of you have brains in gear if you change the format. Eg. "Instruments" calls out "Compass thirty seven point five", and "Notes" calls back "Oh, three, seven point five, compass".
• Instead of writing all the data on one sheet, and the sketches on another, you may like to write all the info for a few legs on the same sheet so that mud does not accumulate on one important data sheet in grubby areas.
• Have a separate front sheet without anything important on otherwise it might get rubbed off.
• Take at least one spare pencil!
• Return instuments to the carbide dessicator before you fall asleep otherwise they are likely to fog up the next time. Don't leave them in the cave, both for the above reason and because the next survey may need them somewhere else entirely.
• Leapfrogging is a good idea in general but you don't have to be religious about it. It is almost impossible in tiny passage, and sometimes a point for a survey station is so obvious that you have to use it, but can't actually take readings from it.
• Draw plans and extended elevations in horizontal bits of cave, with cross sections for each typical section of passage. Orientate your cross sections (ie. show which direction they are looking) on the plans. It helps always to do the cross sections looking in a consistent direction.
• Draw extended sections in two directions for vertical cave, with plans where required. Mark directions on plans and sections otherwise they are impossible to orientate later. A plan with only one station and no direction indicator cannot be orientated. It is easiest if the drawer takes a spare compass for this (doesn't have to be a good one) in vertical work.
• Think ahead when surveying pitches, especially long ones. Take two tape measures for stuff over 30m, or three well-organised people and some handy big croc-clips!
• Record the serial numbers of instruments (comp/clino/tape). Also write down dates, endpoints, surveyors, cave, any conventions used for symbols, passage widths etc.
• Find out where you are going to join your survey to before you go, otherwise your surveys will be left hanging in space. From 1996, the QM list is supposed to tell you the nearest existing survey station - make sure that you can identify this (look at the relevant year's survey book).
• Calibration is useful at 161a: ie. compass from lower to upper cairn, and from lower cairn to Bräuning Zinken (if you know where it is - highest point near right-hand edge of Bräuning Wall (just over the bush!)). See the "Taking bearings" doc for photos. Clino from lower to upper cairn and back down. Several readings for each calibration is best.
• Take care when holding your survey notes when using a carbide - they catch fire very easily (a friend of mine lost over 300m of survey notes in Mulu once like that - Andy F)

that'll do for now – wook