Abseiling

Rappelling is another name for this sport that involves backing down vertical cliff faces on a rope and harness. The rugged, beautiful Blue Mountains near Sydney are Australia\'s abseiling capital. In the Margaret River region in Western Australia, you can do it as mighty breakers crash on the cliffs below. You can even do it in the heart of Brisbane on riverside cliffs. Abseiling is one of those activities that appears to be enjoyed by those who do not know of its risks. Consequently, most non-climbers like it whereas most climbers do not. The reason for this is probably because most non-climbers have never done an abseil under anything but tightly controlled conditions. One abseil under normal conditions would convince them otherwise! So why do most climbers have a dislike for abseiling? Basically it is down to two things: single system with no backup. Easy to get wrong. However with a little thought many of the risks may be reduced, though not entirely removed. What is the best rope to use for abseiling? If you are just going to be abseiling less than half a rope length then any rope will do as you simply take the middle of the rope and attach to the belay point then lower or drop the two ends. If the abseil is longer (up to a rope length) then you will need two ropes. The only restriction here is that both ropes should be the same diameter. Using an 11mm rope with an 8.5mm rope will lead to problems as the two ropes will interact with the abseil device differently with the thicker rope having more friction and passing through the device more slowly. A slight difference in diameter (9mm & 8.5mm) is nothing to worry about. What Knot should I use to tie the ropes with? There is much discussion as to which knot is best to use to join the two ropes together and over the years thoughts have changed. The table below summarises the various knots that are in common use for tying two ropes together for abseiling. One point to note is that for all the knots, the “tails” should be at least 30cm in length to allow for slippage and tightening of the knot. Knot Difficulty Notes Double Fishermans Easy to get wrong. This is the knot by which to judge all others. If tied correctly, it is the strongest knot available for this purpose. If your ropes are of different diameters then it is the only knot to consider. It does have some major drawbacks though: it is very difficult to undo after being loaded; it is also symmetrical meaning that it is likely to snag easily. Figure of Eight Not as easy as is imagined. To tie the figure of eight correctly requires that both ropes travel a particular path through the knot. This is very difficult to ensure in a stressful situation. In addition to this, the knot has an alarming tendency to roll along the rope when stressed at right angles to its main axis. Not recommended Overhand Fairly easy. At first the overhand knot looks as if it would be weaker than the figure of eight but in fact it is both stronger and more resilient to pulls across its axis Reef Simple and easy The reef knot (square knot) is very simple to tie but, like the double fishermans, is a symmetrical knot so suffers from the same problems of being prone to catch. It is a very poor knot to use for ropes of different diameters. Perhaps its best use is in the centre of a double fishermans knot, using the latter as a safety backup.