Ropes used for rock climbing are dynamic ropes, designed to stretch on impact to absorb the energy generated by a fall. For most cragging and single pitch climbing, a single rope with a diameter of 9–10mm is ideal. For longer routes, alpine climbs and winter conditions, you might opt for a dual rope system with thinner ropes used in pairs.
Dynamic ropes are very durable. Despite what you might see in action movies, they don’t break under normal use. They are constructed with a tightly braided sheath (the coloured part) that protects the load-bearing core, and manufacturers must test them rigorously and systematically. Note that MEC also carries static ropes. These have very little stretch and are not used for climbing, only for hauling gear or in rescue situations where there is no chance that a fall will shockload them.
Sixty-meter ropes are kind of standard for most climbers. A longer 70-meter rope allows you to extend pitches, but it also weighs more and takes up more room in your pack. You should always be aware of the length of your rope and the length of the pitch you’re on to ensure that you have enough rope (twice as much rope length as the length of the pitch) to rappel back down safely.
Ropes used exclusively for gyms or for crossing short sections of glaciers can be shorter. At most indoor climbing gyms, 40-meter ropes are the norm.
Climbing ropes are categorized into three types based on their diameter and intended use. You can identify the category of a rope by looking at the symbol marked on the tape at either end.
With most diameters around 9 to 10.5mm (even as thin as 8.6mm), these ropes are intended to be used individually for all around climbing and top-roping. Their relatively fat diameter makes them durable to stand up to abrasion and withstand more test falls. The thicker ropes in this category (above 10mm) are good for high-abrasion situations (top-roping) and are the best choice for your first rope. Thinner ropes (9.5mm and under) suit alpine climbs, hard redpoints and long pitches. They weigh less and are less bulky, but are rated to withstand fewer successive test falls.
Found in diameters from 7.1 to 9.2mm, half ropes (sometimes called double ropes) are always used in pairs. They are clipped into protection alternately, one line at a time, to keep the ropes running straight to limit rope drag over bulges, overhangs and traverses, and to minimize impact force. Another advantage is that you can descend with a full rope length when you rappel. Two ropes are also less likely to be cut by falling rock, ice or sharp edges, and when used properly, half ropes deliver significantly less impact force than a single rope. Purchase pairs in two distinct colours for efficient use and ease of organization. Although a pair of thin ropes weighs more than a single rope, the weight can be shared among partners, and in some situations (glacier travel) a single half rope can be used as an ultra-light option.
Twin ropes are designed for alpine routes. The essential feature is that their thin diameter (7.1 to 9.2mm) makes them almost as light as a single line, but offers full-rope-length rappels and high safety margins. The twin rope system uses two identical ropes, but unlike half ropes, they are both clipped into the same piece of protection. They require stellar management and organization to prevent twisting and tangling, and record much higher impact forces than single or half ropes.
Dry and non-dry finishes
Dry ropes are impregnated with a fluoropolymer-based solution to make them as water-resistant as possible. Absorbed water increases the weight of the climbing rope and reduces its strength considerably. Use of dry ropes is essential for alpine and ice climbers, or for glacier travel. Non-dry ropes will suffice in other conditions, although a dry treatment is also useful for reducing wear from abrasion.
A measure of a rope’s elasticity and ability to absorb energy in a fall. The higher the impact force number, the more energy the climbing rope will transmit to the belay system and the protection. Low impact forces create a soft catch and are a benefit with uncertain protection or falls on short lengths, but they usually mean the rope will have a greater stretch, which can be a nuisance when top roping.
The International Union of Alpine Associates (UIAA) tests and certifies dynamic climbing ropes using standardized tests. CE certified ropes use virtually the same testing standards.
Single ropes are tested by dropping an 80kg mass attached to a measured section of rope repeatedly until it snaps. The rating indicates the number of falls the rope withstood. Ropes that cannot withstand at least five falls are not approved. Half-ropes are tested with a 55kg mass. The fall rating indicates the number of falls withstood by a single rope strand. Twin ropes are tested with 80kg dropped on two strands. This test generates an unusually high amount of force that is very unlikely to be generated in a real-world climbing situation.
Tests measure the dynamic elongation (stretch), of a climbing rope under a dynamic load. Currently, the maximum allowable stretch on the first drop of the test, using a single rope is 40% with an 80kg load. Information about the elastic property of a rope is important in its relation to impact forces. A rope with greater dynamic elongation will have lower impact forces. But, keep in mind that a climbing rope with lots of stretch can be difficult, if not potentially dangerous to use on a top-roped climb.
Care, cleaning and retirement
Store your rope in a dry place at room temperature. Keep it away from dirt, chemicals, acids and alkali compounds, oxidizing agents found in concrete, and sunlight – these all degrade nylon.
- Use a rope bag. Dirt contains tiny, sharp microcrystals that can cause internal damage to a rope.
- Don’t step on it. This can work the sharp dirt particles through the sheath and into the core.
Washing a climbing rope
Be nice to your climbing rope, and wash it by hand in cool water with a mild chemical-free soap. Rinse it well, and spread it out to air-dry, but avoid putting it in direct sunlight. You can also use special cleaning products and dedicated rope-cleaning brushes. Some substances, such as salt and tree pitch, can be removed with a mild soap, but will probably require several washings.
- Don’t wash your rope in a machine with an agitator, as it can easily be stretched and damaged.
- Don’t dry it in a dryer, in direct sunlight, or above a heat source.
When to retire a climbing rope
The life expectancy of a rope depends on amount of use, number of falls, climbing technique, type of rock, and handling. Top-roping is hard on a rope and can abrade it quickly.
Manufacturer’s recommended rope retirement schedule:
- 5 to 7 years if used for a couple of pitches every few months
- 2 years for normal weekend use
- 3 months of near daily use
- Up to 1 year of part-time use including multiple falls
- If a rope is damaged by rock fall, crampons or sharp rock edges. If you are certain the damage is limited to an end, you can shorten your rope by cutting off the damaged piece.
- Retire your rope if it suffers a fall that approaches factor 2. That’s a fall that’s twice the distance as the amount of rope run out from the belay. In a factor 2 fall, you fall past your belayer and end up hanging below them.