19 May 2008
Belaying technique and soft falls
Belaying technique and soft falls
Most climbing incidents are a result of a fall that has been broken too hard. A static fall increases the risk that the climber hits the wall and gets injured. Are you a good belayer? What is the weight difference between you and your partner? Do you have a fresh and dynamic rope or has it turned into a static trap? With some advice and training you and your climbing partner can get softer falls, loose your fear of falling/heights and as a result, become better climbers.
The five most important, ranked parameters that decide the softness of the fall are;
Based on the five parameters and a 5 m fall from a height of 10 m, i.e. the last clip was made at 7,5 m, we have put together a worst case scenario and a best case scenario. The worst case scenario results in a very dangerous totally static fall for our 50kg stuntwoman. The table below shows that her fall could have been soft if either a dynamic belaying technique or a new rope was used. The other parameters dont normally have as great impact in this case. However, as it is the first few centimeters that are the most important for the softness of the fall, even the least important parameter, the belay device, could in such a case save a broken ankle. |
Bending knees makes it impossible to sit down and helps the heavier belayer to jump upwards |
Comparison of different scenarios for a 5 m fall on 10 m of rope - Dynamic impact in centimeters |
DECIDING PARAMETERS | Worst case: 50 kg climber | Best case: 80 kg climber |
1. Belaying technique | -20 cm (Sit-down) | 200 cm (Dynamic) |
2. Rope condition | 40 cm (Worn out) | 140 cm (New) |
3. Rope drag | -20 cm (A lot) | 0 cm (None) |
4. Belay device | 0 cm (GriGri) | 20 cm (ATC etc.) |
TOTAL FALL BRAKING | 0 cm Very Dangerous | Very soft |
Note that the numbers are estimations, given to facilitate comparison of different conditions and that the five factors affect each other making it impossible to summarize the best case scenario. It should also be mentioned that an 80 kg climber would never risk a 0 cm totally static fall if the belayer isnt a real elephant. |
1. The belaying technique is the most important factor. This means that the belayer moves towards the wall upon breaking. When a light climber belays a heavy climber this is often done automatically since the weight difference lifts the belayer off the ground. The opposite case is more dangerous. In worst case the heavier belayer gets scared and moves backwards, sits down (-20 cm) and thus makes the fall of the lighter climber harder.
Heavy weight climbers should train (in a controlled environment e.g. an indoor gym) to lean forward and bend their knees when catching a fall and be prepared to jump. By standing further away from the wall belayers also improve the chances of giving a nice soft fall, it might however be necessary to initially stand to the side since the climber might risk falling on the rope causing him/her to get burned on the rope. With a dynamic belaying technique climbers will improve the safety when belaying their light weighted climbers or kids. If the belayer is standing on a shelf or for some other reason is being prevented from stepping out from the wall, it is essential to bend the knees and to be prepared for jumping when a fall comes.
A light-weighted may clip the first bolt in a neighboring route |
Leaning forward helps a heavy belayer to move inwards in the fall |
Bending knees makes it impossible to sit down and helps the heavier belayer to jump upwards |
2. The second most important parameter is the rope condition. Different ropes vary a lot in elasticity. Based on a load of 80 kg rope manufacturers declare a stretch of 6-10%, see impact force etc. After a fall the rope needs some rest to get back into an unstretched condition. If you fall/hang a lot while climbing its good to alternate which rope end you tie into as each fall causes some loss in elasticity. The ends of the rope loose the elasticity more quickly and by cutting off a couple of meters of a worn out rope you may improve the stretching ability. If a dynamic belaying technique is used, the rope will not be worn out as quickly due to a lower impact force. The rope manufactures report on scientific test-results regarding UIAA falls etc but nobody is talking about the reduction in elasticity of a worn out rope. 8a have measured that the declared stretch of 6-10 percents can get as low as 2 percents for a worn out rope. Using such a rope represents a static trap when falling! 3. The rope drag is another important parameter. Rope drag is caused by friction against the wall and/or when the quickdraws are not placed in line. This has a negative effect on the ropes ability to stretch. The diameter and general condition of the rope may also affect negatively. If there is a lot of rope drag a soft belaying technique is more difficult and the rope will not stretch as much. The reason is that the load of the fall is taken by the rope drag. On long routes the rope drag might be the main reason for hard falls. In such a case and if a dynamic belaying is not possible, you could give some extra slack to soften the fall. |
Impact force from Beal |
4. The belay device plays a minor role. Some people argue that the GriGri is the main reason for a hard fall but considering all parameters mentioned above, this is not the case. The difference by an ATC or similar compared to a GriGri, is only the few centimeters gained due to your hand could move closer to the ATC. It is important to underline that a normal use of the ATC does not mean that the rope slides through it.
Sometimes the belay may be too dynamic with fatal consequences mainly for the belayer. A light girl belaying her heavy boyfriend may collide with him, hit herself against the wall or against the first quick draw. In these cases it might be very dangerous not to use a GriGri. By clipping the first bolt at the neighboring route you increase the rope drag and reduce the risk of having an accident. If this is not possible, light climbers should be anchored to the ground. The purpose of this article is to improve the safety for climbers. The belaying technique is an important factor quite easy to adapt to and thus improve the safety. The rope condition on the other hand is a trickier question. To physically describe the forces etc. applied to the rope upon breaking a fall is extremely complex and impossible to calculate. Big falls affects the rope but so does the normal use with many smaller falls and hanging while working on cruxes. So when is the rope too worn out to be used? To give a time related answer would be useless since it depends on how often you go climbing and the number of falls etc. Is it possible to give an answer based upon the elasticity of the rope and if so, what test method and numbers should be used? 8a dont have these answers but we encourage a debate and discussion about rope condition. |
GriGri safety by 8a |
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