Canyoning techniques

This page contains some thoughts on the advantages and disadvantages of some different canyoning techniques that you may see used by people in the club. It is not meant as an instructional.

Rigging Techniques

There are many ways of rigging abseil anchors in canyons. What technique is best will depend on your experience, equipment and the conditions in the canyon you are doing. Some things to consider when setting anchors are: amount of friction (single or double ropes), contingency options (what can you do if something goes wrong), time to set up, ease of pulling the rope, belaying options, and how easy is it to get off the abseil at the bottom.

However you decide to rig the anchor, the first point is to check the quality of what you are connecting your ropes to. Check slings and rope all the way around for damage and replace them if necessary. Try to determine the line the rope will take. Are there any sharp edges the rope may get dragged over? Is there a potential for a big swing if someone slips? Is the rope likely to get jammed on pulldown? Check around the line of the rope and the top of the abseil for loose rocks that might be dislodged. Also check out the situation at the bottom of the abseil. Can you see the bottom? Are you going to be able communicate easily or do you need to arrange signals. Are you likely to end up in the water? Can you bottom belay?

Throw and go

Throw and go refers to a rigging style where the rope is threaded through the anchor and both ends are thrown down. Each person to abseil clips their descender into both ropes. This approach is probably the most commonly used by canyoners in Australia. It is however not ideal when abseiling into water, especially if the water is moving. Care should be taken to ensure that both ends of the rope reach the bottom.

Advantages

  • Quick to set up
  • Simple
  • Everyone abseils on double ropes so there is plenty of friction.

Disadvantages

  • Does not give you many contingency options. If someone gets stuck on the abseil and can't free themselves then you either need a second rope, have to pull them up or prussick down.
  • Requires unclipping at the bottom of the abseil, which can be problematic in water.
  • Can result in tangled ropes at the bottom, which would be dangerous in fast flowing water. Fast flowing water is rare in normal conditions in Australian canyons, but is definitely a consideration for New Zealand.

Isolated strands

Set as for throw and go but the strands are isolated (with alpine butterfly or slip knot method) so that people can abseil on either strand. Everyone but the last person abseils single strand.

Advantages

  • Can speed up progress of a larger group since one person can be clipping on whilst another is abseiling.
  • Provided the anchor is strong enough, the second strand of rope can be used as a 'rescue' rope if someone gets stuck on the abseil

Disadvantages

  • Not great if there is substantial water since people must unclip at the bottom. Also sending a second person down to assist if someone gets stuck is not a suitable contingency plan if the abseil is in a waterfall!
  • Most people are abseiling single strand so there is less friction.

Single strand tied off with a munter hitch

The rope is connected to the anchor via a munter hitch on a locking crab. The munter hitch is locked off and everybody but the last person abseils single strand. If something goes wrong the munter hitch can be released under load and the abseil line can be lowered. There are several variations of this basic technique.

Basic Technique (for dry or slow flowing water)

Throw down enough rope that you are sure its at the bottom (if you can see the bottom you can set the rope so that it just reaches). Tie off and lock off munter hitch. After the first person you can optionally adjust the length of the rope so that it exactly reaches the length of the abseil. In deciding whether to adjust the length of the rope you can take into account whether how much water is at the bottom of the abseil and if you want to bottom belay. Everyone but the last person abseils single strand on the locked off munter hitch. This technique is good if you are abseiling in a waterfall with substantial flow since it provides a usable contingency option.
Advantages

  • If someone gets stuck on the abseil they can be lowered from the top
  • If the rope is rigged exactly to the bottom, everyone but the last (and possibly first) person can just slide of the end of the rope without unclipping their descender

Disadvantages

  • Most people abseil single strand - less friction
  • The last (and possibly first) person has to unclip to get off the abseil which might be dangerous in fast flowing water.

Single strand set to exact length of abseil (AKA the 'French System')

As for the previous technique except that the rope is set deliberately too short for the abseil if you can't see to set it exactly right from the top. The first person abseils till they can see the bottom and then gets lowered from the munter hitch until the rope reaches the bottom exactly. It is very important that the first person can still clearly communicate with the top until the rope has reached the bottom. Everyone but the last person abseils on the single strand. If there is a maion at the top, the last person can set a bina or knot block and also abseil single strand. Alternatively a person at the bottom can act as a counter weight on the non-abseil strand. This technique is recommended if there is fast flowing or white water at the bottom of the abseil, making unclipping or getting tangled at the bottom a severe risk. Fast flowing water at the bottom of an abseil is rare under normal conditions in Australia but may be real consideration in New Zealand.

Advantages

  • If someone gets stuck on the abseil they can be lowered from the top
  • everyone (including the last person if block or counter-weight is used) can just slide of the end of the rope without unclipping their descender
    • Disadvantages

    • Most people abseil single strand - less friction
    • Bottom belay generally not possible
    • Requires a rope twice the length of the abseil
    • Requires that clear communication is possible between the top and the person setting the abseil
    • Slower to set up

    Munter hitch anchor with top belay

    Set a rope to the length of the abseil and lock of with a munter hitch. People abseil on this line and are belayed from the top with the other line. If something goes wrong, the person's weight can be taken off the abseil line from the top by locking off the top belay and releasing the munter hitch. A system to consider if you have a short canyon and beginners.

    Advantages

    • Many contingency options. You can lower someone from the top on either the abseil line or top belay
    • Top belay provides reassurance and security for beginners
    • Redundancy in that if the abseil line is cut or damaged due to a slip dragging to rope over a sharp edge, the person is seperately secured by the top belay line
    • Everyone but the last person can slide of the abseil line at the bottom and thus doesn't risk losing their belay device

    Disadvantages

    • Slow
    • Top belay and abseil line could twist and tangle in water at the bottom. Not recommended for fast flowing water.