Climbing Ropes

Originally climbing ropes were made of hawser-laid hemp and were not very strong, resulting in the golden rule of pre-war climbing, "The leader must not fall". After WWII, much stronger hawser-laid nylon ropes became available but these still suffered from abrasion as each thread appeared on the surface of the rope at some point. They were also very stiff to handle and coil.		Right: Hawser laid hemp rope.
Modern Kernmantle (literally "Core-Sheath") ropes consist of an inner core of strands of rope and an outer protective sheath. Not that long ago such climbing ropes were either 11mm single or 9mm half (or confusingly, double) - but better technology has seen half ropes of 8mm and single ropes as thin as 8.9mm!		Right: Kernmantle rope.

Types of Climbing Rope:
Climbing Ropes are either Dynamic (stretchy) or Static (non-stretchy). For climbing we only use Dynamic ropes as a fall onto a static rope could cause serious injury due to the lack of bounce.

Static (or semi-static) ropes ropes are mainly used for abseiling in situations where you do not want any rope stretch.

Dynamic ropes are available in three major types.

Single ropes have been tested as safe to use on their own. Currently they can range in diameter from 8.9mm to 11mm. These are generally used for bolted sport climbs, at climbing walls, and for outdoor education use, where all the protection points are in a straight line. Half (or Double) ropes have been tested as safe to use in a pair where each rope is clipped alternately into the protection. They range from 8mm - 9mm in diameter. Using a pair of double ropes (Double Rope Technique) is common practice in the UK where most routes involve natural protection, but little known in many other parts of the world where bolt runners are the norm.
Double rope technique involves leading on two ropes and clipping them into separate runners. Nominally this is done alternately, but in practice several runners in a line may be clipped to one rope before the next runner (somewhere off to the side) is clipped to the other. The advantages of Double Rope Technique are many - the main ones are: there is less chance of both ropes being chopped in a fall or cut by rockfall, it is easier to protect the second and leader on traverse pitches, there is less likelyhood of rope drag or gear being lifted out by rope movement, and you can use many more protection points. You can also abseil twice as far if you have to abandon the route. There is of course no reason why a single rope can not be used as a half rope and paired up with a rope of smaller diameter though you need to be aware of the possibility of slippage when abseiling due to the differential drag caused by the different diameters of rope running through the belay/abseil device. This can easily be dealt with by making sure that the knot is positioned so that you are pulling the narrower of the two ropes when you retrieve them.
Twin ropes are those that are tested to be safe only when both ropes are clipped through every protection point. Their main advantage over half ropes is that they are lighter, and over single ropes that they are less likely to get chopped. However the disadvantage of not being able to clip into several laterally positioned gear placements means that they really aren't suitable for UK use. In reality there is no absolutely safe rope and what is offered are varying degrees of safety. Broadly speaking, the thicker the rope, the less likely it is to be cut on a sharp edge. There is no absolute reason why a climber should not lead a route on one 8mm rope but there is a greater risk of the rope being damaged or cut in a fall. In certain circumstances this risk is slight and so single 9mm ropes or less are often recommended for ski-touring, glacier travel, easy alpine routes and scrambling, but not for rock-climbing.

Rope Length:
Virtually all ropes come in standard 50m lengths these days and this is the best length for most people wanting them for trad use.

However if you are a regular vistor to bolted continental rock you will find a 60m (or even 70m) single rope a great benefit as most pitches are over 25m long, and of course you need double the length of the pitch to lower back to the ground. It is possible to climb 30m sport routes on a pair of 50m ropes but this involves considerable faffing at the lower-off.

For half ropes, 60m ropes can be a good idea for harder winter and alpine routes where good belays are scarce, but be warned you will need two as you will seldom find anyone else who has one! 99% of UK climbers will find 50m half ropes the best choice for about 90% of what they do.

All Kernmantle ropes shrink with use by as much as 10%. Good manufacturers allow for this by cutting their ropes longer than the advertised length.

Belay Devices:
Different diameter ropes work best with different belay devices. For fat ropes (10.5mm/11mm) a "slicker" (smoother running) belay device such as a Black Diamond ATC is ideal whereas for narrow ropes (8mm/8.5mm) the Black Diamond ATC XP offers a much better braking effect.

Rope Labelling:
When looking at ropes in a shop you will see that the labels contain some or all of the information listed below.

UIAA Falls		The number of Factor 2 falls that the rope will survive in a standard UIAA rope test using an 80Kg weight for single ropes or a 50Kg weight for half and twin ropes. Bear in mind that most climbing falls are less than Factor 1 (Fall Factor = Height of Fall/Length of Rope which Holds It. In normal circumstances the maximum possible is Fall Factor 2, sustained when a climber falls off with no gear in and doesn't hit anything on the way down. So a climber who falls of with 5m of rope out and a runner at 2.5m, and so falls 5m, generates a Factor 1 fall. The number of factor 2 falls is only an indication of one aspect of a rope's "strength". Abrasion resistance and the ability to pass a sharp edge test are possibly more important. Most climbers would consider retiring a rope after only one big factor 2 fall - and many would probably themselves retire after such a fall! There are also several test houses for ropes, and one in particular was extremely generous with it's test ratings a some years ago. There are still a few ropes out there with unlikely-looking test results and this can explain the large differences in fall factors between otherwise similar ropes.

Impact Force		Measured in kilo-Newtons (kN), this is the force actually transmitted to the climber, rope, and belay components. The lower this force is the better. It is may be increased with rope usage and falls sustained and then becomes a major factor to consider when deciding when to retire your rope.

Sharp Edge Test		A test designed to mimic a weighted stretched rope falling across a sharp edge of rock. The standard UIAA test involves a mass of 80kg, with a fall of factor 1.77 held over a metal edge of 5mm radius to simulate a karabiner. A newer test uses the same weight of 80Kg (55Kg for one strand of double rope), and the same fall factor, but this time over a sharp edge of just 0.75 mm radius. However the safest way of avoiding your rope being cut is to use double ropes. Neither of these tests appears to be compulsory, so figures aren't always quoted.

Static Elongation (or Elongation in Use)		Measures the amount of stretch the rope will experience with the weight as detailed above hanging on the rope. Single ropes should not stretch more than 8% and half ropes more than 10%.

Dynamic Elongation (or Elongation at First Fall)		During a fall, however, the forces on the rope will cause it to stretch some 20-30% in the UIAA drop test.

Sheath Slippage		The amount that the sheath may slip over the core when undertaking such activities as abseiling and jumaring. The UIAA test measures the amount of sheath slippage on a 2.2 metre section of rope run through plates five times under a load of 50kg. The slippage should not not exceed 40mm and on good quality ropes is usually nil.

Sheath Proportion		Normal ropes have a sheath/core ratio of 35-45%. For ropes that receive a lot of hard use such as frequent top roping, wall use, and working routes ropes are produced with at least 45% sheath giving these ropes a longer life span albeit at the expense of being marginally stiffer.

Rope Treatments:
Once upon a time ropes were either Standard (also referred to as Classic) or Dry-Treated. (also referred to as Superdry), the latter being suitable for winter and alpine climbers as the extra treatment helps stop the rope from becoming waterlogged.

Now each manufacturer offers a rather bewildering variety of treatments on their ropes.

		Coating Finish is a Mammut treatment involving coating the inner strands of the rope with Teflon to make them slide over each other in order to minimise chafing and improve friction co-efficiency. Loading, e.g. through a fall, is uniformly distributed through each individual filament, thereby optimising performance. In this way, substantially lighter ropes with the same number of falls, or ropes which can hold a substantially higher load and have the same weight can be made. Coating treated ropes also have reduced rope drag, absorb less dirt and moisture, are especially easy to handle.

		Older dry treatments just treated the rope's sheath, but now leading firms such as Mammut and Beal treat both the sheath and core. Superdry and Golden Dry treatments are similar in what they do and result in a more effective and durable dry treatment that optimises handling, abrasion resistance, dirt resistance and life span.

		Older and cheaper non-dry ropes have no treatment. However better quality non-drys from Mammut and Beal now receive a special heat treatment called Duraflex or Dry Cover. This increases water resistance and reduces abrasion from dirt, but is not a total dry treatment in itself.

Middle Marking		All Mammut and Beal ropes have the middles marked with the possible exception of occasional special offers and some of the cheapest ropes. If your rope does not have a centre marking, Beal make a marking ink which has been tested to ensure that it will not harm the rope.

Duodess/ Bicolour/ Safe Control		Duodess is Mammut's term for marking the centre of the rope by changing the weave patern of the sheath. Beal call the same thing Bicolour or Safe Control, depending on the rope.

Program		A Beal treatment for Sport Ropes that gives a harder wearing sheath over the area most likely to be abraded when working a route. Thus the two ends of the rope have a supple weave for the first 1.5 metres for ease of tying in. The following 4 metres have a stiffer weave to give better resistance to abrasion and general wear on the part of the rope which sustains the majority of work and rubbing. The middle part of the rope has a supple weave for optimum handling.

Tangles (and how to avoid them):
Once ropes were literally coiled but nowadys most climbers lap (or butterfly coil) them as it results in far fewer kinks in the rope and provides a much better method of carrying it when on steep ground. This video from Stephen Koch is one of many on You Tube and illustrates well how it is done.

When uncoiling a new rope for the first time, it is particularly important that this process is reversed and the rope is "un-lapped" without putting any twists or kinks in it. Having done this, carefully run the rope through your hands, from one end to the other, checking for any lumps or other defects (if you find any, return it straight away to the shop you bought it from). If all is OK, then lap-coil it as above.

For more information on ropes, see Mammut's Rope PDF.