Everything You Wanted to Know About Ropes

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This is a brief set of answers to some of the FAQs about ropes that get asked on the Forums. It was initially put together by Stefan Kruger for uk.rec.climbing newsgroup and has now been adapted for use on This FAQ is meant to be added to and improved over time so please send in your Questions and Answers.

A half rope (top) and a single rope (below)

What is the difference between 'single', 'half', 'double' and 'twin' ropes?

A: Single and double are fairly obvious, half is a rope that needs to be used in a pair, twin refers to a rope designed for slightly different useage in a twin rope system.

Single rope is exactly that, a rope that you use on its own. It is most commonly used for sport climbing or short pitches on smaller crags when trad climbing. A thicker rope is used, usually 10mm up to 11mm thick. This is indicated by the manufacturer by using a '1' in a circle on the manufacturer's information.
A half rope is one which is designed only to be used in a pair when climbing using double ropes. A half rope is usually 8mm to 9mm thick and is indicated by a '1/2' in a circle on the manufacturer's information.
Double rope climbing tends to be used on traditonal routes. The main advantage of a double rope set-up is that it can reduce rope-drag, if used competently. On the other hand, having to deal with two ropes require more sophisticated belaying skills, plus that if you get it wrong when clipping ropes you can really end up in a messy tangle. Double ropes are also (for obvious reasons) intrinsically more secure in the (unlikely) event of a rope actually breaking.
Twin rope refers to a rope which is specifically designed to be used in a pair where the ropes are treated as one strand and both clipped into all the protection on the route, be it hand-placed or bolts. The benefit of a twin rope system is that it offers the lightest option when weight is of paramount importance in mountaineering and big wall environments. They also of a greater level of safety in situations where a rope may be cut in a fall. However, twin ropes aren't popular since they are awkward to use and less versatile than a 1/2 rope system. A twin rope is indicated by a circle with two overlapping smaller circles inside it.


How long a rope do I need?

A: Usually, as long as you can afford.

For double ropes 50m will probably be enough for most pitches and abseils. Find out what your regular climbing partner has though since there is nothing worse than climbing on double ropes of different lengths.
For single rope climbing, especially sport climbing where you have to lower off, then buy a long rope. Don't even consider anything less than 60m and try to get 70m if you can afford it. This will enable you to safely lower from all but the very longest sport routes. Anything shorter can leave you dangling and has also frequently been the cause of lowering accidents. The added bonus of long ropes is you can trim the ends off as they get older in order to prolong the life.


Someone offered to sell me a second-hand rope. Should I buy?

A: In general, probably not.

Two reasons: firstly, unless you know the seller well, it can be difficult to assess what sort of action the gear has seen. The rope you're considering might have held several factor 2 falls. Don't skimp on safety. Secondly, can you be sure that the kit wasn't stolen from someone's car at the bottom of Stanage?


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When should a rope be retired?

A: Tough call.

A rope should be retired if it is damaged, if it has held a big fall, or if it has seen active duty for a prolonged time. Consult the rope manufacturer's technical documentation to find out what the expected life-span is. If the core is visible anywhere along the length then retire immediately. Also retire if it's been subjected to aggressive chemicals, e.g car battery acid or chlorine.
If you are unsure then inspect your rope; how does it feel when unweighted and weighted? Feel for lumps and kinks, 'mushy' soft spots of the core. If it seems to be losing its elasticity and becoming 'wire-like' then it will probably still be strong enough but it will become more and more dificult to climb with. Another sign of an old rope is 'ovaling' where the rope becomes oval-shaped when weighted. On the other hand a slightly furry sheath is probably nothing to worry about.
If your rope becomes damaged near one end then you can always salvage the rest of the rope and use it for the climbing wall or routes on shorter crags.


What is a 'fall factor?

A: A (crude) measure of the stress a given fall puts on the rope (or on the climber, if you like).

See full article here.


My rope is dirty. How do I go about washing it?

A: Read Graham Gedge's full article here

How do I mark the middle of my rope?

A: Probably safest using specialist marker pens.

The middle mark is essential when sport climbing and lowering-off a pitch. It is also a useful indicator when for coiling the rope, and to serve as a remider for the belayer when half the rope is fed out. Most ropes come with a middle marker in place; some flash ropes even change colour or sheath braiding pattern. However, some ropes at the budget end sometimes come without a middle marker, and the middle mark also tends to disappear over time on many ropes.

It's tempting to just take a marker pen and ink in the centre, but chemicals found in normal marker pens can potentially damage the kernel nylon fibres. Beal sell a rope-friendly marker pen specifically designed for this purpose.

Many people simply wrap some finger tape around the centre. This is a somewhat temporary solution - belay devices tend to strip off or move this after a while, but is perfectly adequate, especially if you mainly climb pitches shorter than half the rope.


How do I cut a rope?

A: Use any old knife

Get hold of any old knife, it doesn't need to be a sharp one. Heat it up on your gas cooker until it is glowing red then quickly slice through the rope over a block of wood. Use the hot knife to seal the end to avoid any further fraying.


Q: What is impact force?
A: Rope manufacturers often quote an "impact force" for their ropes. This is the force transmitted to the system when taking a UIAA standard fall. Thus in general, a lower value is better as it will result in less force being placed upon the piece of gear taking the fall, increasing the likelihood of that gear holding.

Q: What does the rated number of falls mean?
A: Rope manufacturers often quote an maximum number of falls for their ropes. This is the minimum number of standard UIAA falls a rope survived during laboratory test conditions. For twin ropes, both ropes are tested together and the number of falls quoted is how many both ropes survived.

Q: What is a UIAA standard fall?
A: A 4.6m fall with 2.6m of rope paid out (fall factor of 1.77) and an 80Kg load. When testing twin ropes, both ropes are tested together. However for half-ropes, only one half-rope is tested.

Further Reading

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30 Mar, 2007
Something is a bit odd here: "Double rope climbing tends to be used on traditonal routes. Certain routes requireThe main advantage of a double rope set-up is that it can reduce rope-drag, if used competently." Other advantages of double ropes include not having to pull a load of slack out of the rope that is clipped into your last piece of gear, in order to clip the next piece of gear, and also, being easily able to bring up two seconds. Advantage of a single rope is that it is usually lighter than two half ropes to carry.
2 Apr, 2007
Something further: As I understand it, your definition of twin ropes would not appear to be entirely accurate and requires clarification. Strictly speaking, a twin rope system is not simply an alternative use of 1/2 ropes, as suggested. Climbing ropes are produced in 3 categories, single, half and twin (all differently annotated on the rope end markings). In the UK, we commonly only see single and 1/2 ropes in the shops. Twin ropes are more commonly seen on the continent. A twin rope is used as described (ie both strands clipped into the runners). However, this differs from the use of 1/2 ropes in that the 2 strands should never be separated. Effectively it is always used as you would a single rope, except when abseiling, when you abseil on both strands, allowing you to abseil double the distance allowed by a single rope. Used correctly, this system should not lead to increased impact force, as the twin rope is designed for such use. However, if 2 1/2 ropes are used to emulate such a system, you can expect an increased impact force on your runners. As with any rope system used, the impact force on your crucial last runner can be minimised with use of extended runners further down to reduce drag. The Beal website illustrates the differences here:
Thanks, I have amended the article slightly. The other aspect of twin ropes that still does compromise the safety is that two ropes load karabiners badly hence they tend to be more likely to fail in a 'krab gate open' situation. For normal rock climbing I can't see any situation where I would recommend some uses a twin rope. Alan
2 Apr, 2007
Marking the middle of a rope using any form of pen is, according to this article, not recommended And while we are at it can we have a relevant search link included at the bottom of the FAQ, so people can look for more information themselves. eg. for marking the middle of a rope :-
Well if Beal stop producing their pen then perhaps we need to get a bit worried. I suspect they will be on the ball on this one. Sorry, but I don't really like doing that. I think people themselves are aware enough to search Google and we probably also have our own different ways of using Google. Your link brings up loads on non-relevant links as well. Alan
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