A common and false perception of abseiling is that it is an adventure activity that is completely safe. But as many have discovered accidents do occur even in controlled circumstances.
The BMC’s Equipment Failure Investigations include abseil ropes cut through, failed anchors, detached karabiners, and abseil devices that ‘mysteriously’ did not control the speed of descent.
Add to this clothing and long hair tangled in the abseil device; trips, flips and swings; the end of a rope being reached unexpectedly; plus the odd jammed rope, sharp edge and falling rock or piece of a equipment, and you have a much clearer understanding of the hazards of abseiling and why it claims lives. As with all methods of descending abseiling is dangerous; but it is particularly unforgiving of any mistakes or failures.
For most experienced climbers abseiling is an activity to be avoided unless it is the only way of getting off a climb or down a mountain - for the unwary it can be a fast introduction to discover the quickest way to reach the ground.
Solid anchors cannot be over emphasised and should be totally reliable for a training abseil. If retreating or descending make sure the anchors are the best available and whenever possible use a second anchor point as a back-up. If the ropes are to be retrieved from below the anchors must be set up to allow the ropes to run through smoothly. Always carry tape or cord for constructing or extending abseils anchors.
Joining two ropes
For a long abseil where it is necessary to join two ropes a reliable knot must be used. Probable the most reliable is the double fisherman’s knot, but this can become jammed after an abseil. An alternative is an overhand knot but make sure the ends of the knot are long (you only want it to undo easily after you have completed the abseil).
Different belay plates and abseil devices provide different levels of friction, and new and thin ropes provide less resistance than thick or older ropes: make sure you know what to expect from the combination you use. In particular take care when using a figure of eight to abseil because it can accidentally mis-align itself across the karabiner gate. If it becomes even lightly loaded when mis-aligned it can lever open and detach itself from a properly screwed up karabiner with dire consequences. At least one fatality and a number of serious injuries have resulted from this.
Rockfall and edges
When setting up the abseil avoid positions with loose rock or sharp edges in the area where the rope will run. If it is unavoidable to abseil down loose rock, with care, it can be removed to help avoid in being accidentally pulled down when the rope is retrieved. A loaded rope stretched over a sharp edge can easily be cut through, so avoid doing this if at all possible and if in any doubt use some form of rope protector.
Secure yourself and the ’top’ of the abseil ropes to the anchors being used for the descent. If it will not be possible to see the ‘bottom’ ends of the abseil rope tie a knot in them before carefully throwing the rope down the cliff making sure anyone below is aware you are abseiling. Position the rope to avoid any sharp edges. If the ropes are to be retrieved from below position the knot so it will not catch in a constriction as you pull it from below. Always consider using a prussik knot or other back-up system on the abseil rope in case you need to sort out a tangle, need to rest, and to guard against losing control.
Before committing all your weight to the abseil ensure that your belay device and screw-gate are properly aligned. Abseil smoothly and directly down the ‘fall line’ and avoid bounces or pendulums that may draw the rope across an edge. Once at the next abseil position (or the base if on a sea cliff) secure yourself and the ‘bottom’ of the ropes to a new anchor point. It is helpful for the last person to abseil with a karabiner attached to whichever rope will be pulled, this will help separate the ropes prior to pulling them down. If it is a multi abseil descent the last person, having satisfied themselves that the main anchor is reliable, can remove the back-up anchor for use lower down.
Once the first climber has completed the abseil they should do a short test pull to ensure the rope will run properly. If it does not then the climber at the anchors should be able to identify the problem and rectify it. Once everyone is down carefully pull the correct rope. When pulling the ropes if possible take shelter from any rocks that might accidentally be dislodged.
Despite precautions sometimes the rope will jam. If it does then try to flick it free or change the pulling angle. If after repeated attempts to free the rope it still will not move then someone will need to go back up and sort out the problem. If you still have both ends of the rope you will be able to either prussik up both ropes or climb up (tying into the rope at intervals to protect yourself). Do not prussik on a single rope as it could pull free at any moment with fatal consequences. If the rope has only partly pulled through leaving you with just one end it is better to climb back up with the rope you have. If there is no way you can climb back up you may have to cut the rope and continue as best you can.
- Back up your anchors
- Keep the rope clear of loose rock and sharp edges
- Take precautions to avoid losing control or abseiling off the ends of the rope
- Abseil smoothly
- Do a test pull after the first climber completes the abseil
- Keep self and ropes attached to anchor points
In addition to all the above those supervising abseils have a duty to consider potential risks inherent in the abseil and to take whatever measures are practicable to control those risks. The following table indicates the risks that should be taken into account and suggests how the might be controlled:
Independently anchored safety rope (essentially a top rope for the abseiler).
|Rockfall and dropped equipment
||Careful selection of abseil site
|Loss of control by the abseiler
||Clear demonstration and instruction
Good ‘launch’ position and descent line
Separate safety rope
Use of appropriate harness and abseil device
|Avoiding long hair and loose clothing becoming tangled in the abseil device
Individual at bottom of rope to provide additional braking
Prussik knot or back up device
Helmets may prevent head injury in the event of loss of control
Children with under-developed waists and adults with certain body shapes may require a combination of chest and waist or full body harness.
|Equipment failure including rope cutting
||Care in positioning rope and aligning equipment
Use of rope protectors
Separate safety rope
|Abseiling off the end of the rope
||Care in selecting abseil position
Knots in the rope ends
Prussik knot or back up device.
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