To buy a new climbing rope is pretty similar to getting a mobile phone contract. There are numerous types for seemingly endless uses.
So we thought we would organise the whole thing a bit and explain to you, which rope types exist in the first place. So, what exactly is the difference between single ropes, half ropes and twin ropes? And which is most suited for which use?
The different rope types
First, one can differentiate between two “basic rope types”: static ropes and dynamic ropes.
Static ropes, or kernmantle ropes with low elasticity, are used whenever the strain is strictly static, for example in mountain rescue or as fixed ropes. A static rope only has very low elasticity (max. 5% stretch), therefore it is, strictly speaking, only a semi-static rope, but in colloquial language among climbers it is called static rope.
These ropes can under no circumstances be used for climbing (lead climbing as well as second climbing)! Due to the low elasticity, even a fall with a fall factor 1 can cause serious injury and equipment failure! If you want to know more about impact force, we recommend you this site by Petzl.
The opposite to static ropes are dynamic ropes, which can stretch due to their twisted fibers. The stretching enables the rope to absorb the energy that is created by the fall. Without these properties, strong forces would affect the climber with each fall. So, a dynamic rope can absorb forces occurring during a fall and thereby prevent or minimise injuries.
The more the rope stretches, the more force is being absorbed. Although they generally may not stretch more than 40 percent, otherwise, there is a danger of hitting ties or the ground.
Types of dynamic ropes
The uses of the different ropes have many overlaps, however, we have nevertheless tried to assign the ropes to different disciplines.
- Uses: sports climbing in the hall or on a rock, ice climbing, mountaineering
- Symbol: circle with a 1
- Approx. 8.7 to 11 mm
- 51 – 85 g/m
- UIAA falls: at least 5 with 80 kg (no worries, a real UIAA fall is practically impossible during normal use)
- Static elongation 8 – 10 %
Single ropes are mostly used for sports climbing in the hall or outdoors or for ice climbing. They are comfortable and easy to handle and their high diameter usually makes them durable. Not just the diameter, but also the sheath percentage is crucial for the durability. That is the mass ratio between rope mantle and rope core. The higher the amount, the more abrasion resistant and durable the rope will be. The sheath percentage is always included in descriptions of a rope.
For people who are doing a lot of indoor climbing and top rope climbing, a high sheath percentage is important, as the rope is under a lot of strain.
A thicker single rope will also be more tear-resistant – however, with each millimetre, the friction is increased – in the anchors as well as the belay device itself, which makes climbing more exhausting. When doing a lot of lead climbing and long routes, it is worthwhile to pick a rope with a somewhat lower diameter, to save strength with both friction and weight.
For beginners, it is a good reference point to buy a rope with a diameter of more than ten millimetres.
Many single ropes have a mark in the middle. This is to ensure that the climber wont climb higher than half the entire length of the rope when doing lead climbing. For anybody who spends a lot of time in different climbing areas, “bicolour” ropes are recommendable. Their halves are each a different colour, which makes it easy to see the middle of the rope – even after having used it for some time. Although middle marks serve the same purpose, after long usage, they are often no longer easily recognisable.
Quite often, single ropes are also used for mountaineering, for example when climbing passages on rock are present. Here, usually a relatively thin single rope is chosen, as it weighs less.
- Use: alpine climbing, ice climbing and mixed climbing, glacier and mountaineering, traditional climbing
- Symbol: Circle with 1/2 inside
- Approx. 7.5 – 9 mm
- 40 – 55 g/m
- UIAA falls: at least 5 with 55 kg
- Static elongation 12 %
Half ropes are mainly used in alpine climbing, mountaineering and traditional climbing. The usage of two different strands of rope raises the redundancy: the probability that both are severed at the same time by a rockfall or a sharp edge is extremely low.
However, the biggest advantage of half ropes is that you have the entire length for rappelling (60 m single rope = 30 m rappelling stretch. 2×60 m half rope = 60 m rappelling stretch). This can be especially helpful when retreating from or aborting a route. However, half ropes don’t always have to be used with a double strand – on a glacier for example, where a “serious” fall is unlikely, you can easily just carry one strand with you. This should, however, absolutely be waterproofed, since a wet rope is not only much heavier, but also unwieldly (especially when frozen) and loses resilience.
The alternative to the half rope technique is the twin technique – here, you always use both strands.
- Use: alpine sports climbing. Exclusively with double strand!
- Symbol: Circle with two entwined circles
- starting from 6.9 mm
- starting from 35 g/m
- UIAA falls: Double strand 12 with 80 kg
Twin ropes should only be used by specialists. They are used when every gram counts – usually in extreme rock, mixed or ice climbing routes. They are exclusively used with double strands, as the danger of the ropes tearing is otherwise to high. When seconding, you also have to exclusively secure with double strand. You should make sure that the strands are always inserted parallel into the anchors.
These are ropes that are sold in short lengths and are mostly used to support the psyche – especially with children. The rope strength (approx. 8 mm) is sufficient to support small slips or to pull yourself up – but definitely not more. Although every half or single rope is more universal in its uses, they are not sold in such short lengths.
A hiking rope may under no circumstance be used for climbing, no matter in which discipline!
Climbing ropes that are much used in nature are subject to numerous weather conditions: Humidity, UV-rays and dirt, for example. Each of those can have an adverse effect on climbing ropes, although the time it will take, varies. Humidity has a very short-term effect, while dirt and UV-rays have a long-term effect.
Although you can avoid humidity quite successfully (at least in sports climbing), this is much more difficult with dust and sun. So, if you know that you want to use the rope a lot outdoors, it is advisable to buy a waterproofed climbing rope. Such ropes have the dry treatment included in the manufacturing of their components. Those dry treatments are usually very long-lasting and, in the best case scenario, will last as long as the rope itself. If the dry treatment of a climbing rope is destroyed, it cannot be renewed. Please don’t try to treat the climbing rope with DWR treatment by yourself.
The right rope length
In general, climbing ropes are between 20 and 200 meters in length. When choosing the length of the rope, you should first be clear on what you want to use it for. Hall or alpine tour? Mountaineering or designated outdoor areas? When doing rock climbing, it’s a good idea to take a look at the map. How long is the tour? Are there rappelling spots and if yes, over what length is rappelling needed? Many climbing guides have a recommendations for rope length, however, you should stick to a 70 m long rope for outdoors to have reserves for emergencies. On short outdoor routes, 50 m are usually sufficient. In alpine multipitch route touring with long rappellings and big gaps between the stands, one should pick 80 m or even 100 m to be on the safe side. In mountaineering, the ropes are often much shorter due to their weight, however, this depends on the size of the rope team. As a backup for via ferratas or hill walking, a short rope is also practical – here, 30 m ropes are ideal.
Climbing halls keep getting bigger and the routes higher – therefore, ropes shorter than 50 m are not a great choice. If necessary, get information beforehand in the hall and ask for a recommendation – many halls already have them on their websites.