By: Björn Strömberg  | Date: 2008-05-19  | Category: Tips & Tricks    | (12) Comments

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;

1.  The belaying technique: Moving inwards can prolong the fall by meters but if you instinctively sit-down you can instead reduce the fall by some -20 cm.
2.  Rope condition: A worn out rope can easily reduce the softness by a meter or so.
3.  Rope drag: A fall, especially high up, gets harder by the level of the rope drag.
4.  Belay device: The ATC may increase the softness by 20 cm.
5.  Weight: Lighter climbers will get harder and more static falls.

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 don’t 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 isn’t 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 it’s 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 rope’s 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 don’t have these answers but we encourage a debate and discussion about rope condition.

GriGri safety by 8a