Weight factor (climbing)

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The weight factor is measured at a climbing procedure the diversity of the weights of the climber and his belayer . The climber is secured by the belayer with a dynamic climbing rope . The weight factor is specified here, which is calculated from the following quotient :

If the climber is heavier than the belayer, the weight factor is greater than 1; for a heavier belayer less than 1. Current recommendations also take into account the absolute weight difference in kilograms:

When climbing in top rope , the weight factor should not exceed 1.5.

Climbing in the lead climbing an absolute weight difference of ± 5 kg is considered optimal. From a difference of 10 kg, additional measures are recommended. The weight factor previously given here has been dispensed with.

Types of weight differences and their risks

Weight of climber <weight of belayer

A lower weight of the climber compared to the belayer (weight factor <1) can lead to hard falls in which the climber hits the wall hard. During the fall, the climber is usually not braked suddenly, but rather dampened by the rope stretching of the dynamic climbing rope and the body weight of the belayer, as he is pulled upwards and the energy is dissipated through the friction between the rope and the carabiners. If the belayer is heavier than the climber, the fall energy is less attenuated, as this occurs almost exclusively through rope stretching and the belayer is hardly pulled upwards. This makes the fall feel hard for the climber. The smaller the weight factor, the harder the fall will be.

Weight climber> Weight belayer

If the weight of the climber is greater than that of the belayer (weight factor> 1), a very dynamic braking behavior occurs in the event of a fall. The fall is dampened by the rope stretching in the dynamic climbing rope and the body weight of the belayer being pulled upwards. The larger the factor, the stronger and more dynamic the belayer is drawn upwards. Inexperienced climbers are usually not aware of this risk potential. If, in the event of a fall, the belayer hits the wall with a strong pull on the rope or is pulled on the first intermediate belay and loses control, with the possible consequence of letting go of the brake rope, the climber falls as a result. Even when lowering after a successful ascent, a lighter belayer has difficulties in lowering his climbing partner in a controlled manner, as he always experiences a strong rope pull.

Measures if there is a significant difference in weight in the lead climb

In the meantime, safety research by the DAV has refrained from recommending weight factors that can still be found in the older literature, since the absolute differences in the higher weight classes diverge greatly. Today, an absolute weight difference of ± 5 kg is therefore considered optimal. From a difference of 10 kg, additional measures are recommended.

In the case of a much lighter climber, the belayer needs to be very soft and secure so that the fall is not too hard for the climber and he is not injured by the impact. This is done - in the case of belay devices with blocking support exclusively - by means of body-dynamic belaying. The belayer must actively jump off or walk with the onset of a fall at the right time so that he does not remain rigid like a concrete pillar. With dynamic belay devices, dynamic belaying is also possible, in which the rope is let through in a controlled manner, which requires a lot of experience. The alpine clubs offer safety courses for this.

The following methods can be used for a heavier climber.

Attaching an additional weight

In order to absorb the energy generated by the climber's fall, the weight of the lighter belaying partner can be increased by adding an additional weight, for example a sandbag. To do this, it is attached to the rope loop on the belayer's climbing harness . However, this method restricts the freedom of movement that is necessary for dynamic securing. A particularly bad combination is the use of a sandbag when using a tube . A light person may not have the necessary holding power if they are also pulled down by the sandbag.

Attach the rope to the neighboring route

Another way of securing with a difference in weight is to attach the rope to a securing point on the neighboring route, also known as a friction clip. This greatly increases the friction due to the additional friction angle of the deflection. The friction created in the deflection dissipates energy that no longer has to be absorbed by the belayer. The disadvantage of this method is that on the one hand the neighboring route is occupied. On the other hand, the generally increased friction helps the belayer to catch a fall of the heavier climber, but makes it more difficult for the climber to pull the rope. In addition, if the rope is also attached in the neighboring route, the strong deflection can lead to increased kinking of the rope. Kangles are spiral twists in the rope. A rope that is very tangled is uncomfortable to use and when abseiling there is a risk that the strands will wrap around each other in such a way that you can no longer pull them off.

Use of a braking resistor

The braking resistor is a mechanical device that is also hooked into the first bolt of the intermediate safety device along the safety line , in order to intentionally increase the rope friction - as with the friction clip. In this way, in the event of a fall, a further part of the impact force is absorbed by friction, and the fall tensile force arriving at the belaying partner is reduced. The secondary route does not have to be used here. Well-known devices are the Bauer rope brake with static friction and the Ohm, in which the additional friction sets in dynamically after being triggered.

Attachment of the belayer to a fixed point

The belayer can attach himself to a fixed point behind him on the ground with the help of a sling or the like. This prevents the belayer from being pulled up to the first express set (intermediate securing on the wall) or even losing control of the securing after a strong push, which is increased by the weight difference. In individual climbing halls, eyelets are attached to the floor, which in turn are tripping hazards for the belayer. When climbing on the rock, a tree trunk or a root is suitable. Dynamic belaying through active belaying, i.e. active jump by the belayer in the event of a fall, reduces the impact on the body of the climber. With an attachment to a fixed point, dynamic securing is limited.

literature

Web links

Individual evidence

  1. ↑ a b Chris Semmel: Alpine curriculum - climbing: safety, equipment . Ed .: German Alpine Association [DAV], Association of German Mountain and Ski Guides [VDBS] in cooperation with the Alpine Association South Tyrol [AVS]. 2nd Edition. tape 2 , A. BLV Buchverlag GmbH & Co. KG, Munich 2011, ISBN 978-3-8354-0255-3 , p. 85 .
  2. ↑ a b c German Alpine Club: Sport climbing: belaying with weight difference. 2017, accessed February 7, 2018 (eng).
  3. ↑ Chris Semmel: Stop falling - safely and gently . In: German Alpine Association (Ed.): DAV Panorama . No. 3/2012 , 2013, p. 74, 75 ( alpenverein.de [PDF]).
  4. ↑ Jörg Helfrich, Julia Janotte and Florian Hellberg: Weight differences when belaying - heavier? And if so, how much? . - DAV Panorama, year 2016 issue 6, pp. 52–55