Kernmantle rope
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This article needs additional citations for verification. (February 2013) |
Kernmantle rope is rope constructed with its interior core (the kern) protected with a woven exterior sheath (mantle) that is designed to optimize strength, durability, and flexibility. The core fibers provide the tensile strength of the rope, while the sheath protects the core from abrasion during use. The name is derived from German Kernmantel which means core jacket.
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Use as climbing rope [edit]
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This section may require copy-editing. (May 2013) |
The nylon ropes that were used in yachts for hauling were tested and found useful in climbing and caving and are now the modern standard. The German company Edelrid introduced the first Kernmantel rope in 1953 which revolutionized fall prevention. Hemp climbing ropes and rope breakage soon became a thing of the past. In 1964, Edelrid developed the dynamic rope, the first rope capable of withstanding multiple falls. It became the forerunner of the modern dynamic climbing rope. Although there were occasional innovations, the rope used today is similar in construction, strength, and durability across manufacturers. There are several major manufacturers, including Pigeon Mountain Industries (PMI) which is popular with cavers,[1] Mammut, Sterling, Beal, Edelweiss, Blue Water, Roca, Tendon and Maxim. Overall there is a huge variety of climbing ropes available for different kinds of uses; for instance there are well over hundred different dynamic single ropes (the most popular rope system in climbing).[2] Kernmantle ropes are still used in sailing and other sports, but the technical requirements are usually not as rigorous as in climbing since those applications are not as critical to safety. Smaller kernmantle ropes are commonly called accessory cords; they are often used to make prusik knots and loops or to attach accessories such as chalk bags.
One or more of the rope characteristics (strength, durability, and flexibility) is often altered, depending upon the ultimate use of the rope, at the expense of the other properties. For example, rope used in caving is generally exposed to increased abrasion, so the mantle is woven more tightly than rope used in climbing or rappelling. However, the resulting rope is cumbersome and difficult to tie knots in.
Kernmantle construction may be used with both static and dynamic ropes. Static ropes are designed to allow relatively little stretch, which is most useful for applications such as hauling and rappelling. Dynamic rope is used to belay climbers, and is designed to stretch under a heavy load to absorb the shock of a fallen climber. Dynamic ropes manufactured for climbing are tested by the UIAA. A test of "single"-standard involves tying an 80 kg (176 pound) weight to the end of a length of rope. This weight is then dropped 5 meters (16½ feet) on 2.7 meters (9 feet) of rope, with the rope running over a rounded surface simulating that of a standard carabiner. This process is repeated until the rope breaks. For "double"-ropes the weight is 55 kg and for twin ropes two strands are used. In addition to number of drops, the impact force is also measured. It is a common misunderstanding to think that the number of drop test falls (as conducted by the UIAA) is the number of real-life climbing falls a rope can sustain before it becomes unsafe. The drop test falls are of extreme severity and a real-life climbing fall will not often generate a comparable force. This adds a margin of safety for the climbers who use such ropes.
Rope care [edit]
Kernmantle rope should be inspected before and after every use for any form of damage. "Boogers," which indicate internal damage to the kern, will appear as tufts of white threads poking out from the mantle. Ropes that have been severely stressed will have tapered sections to the rope, where it is visibly or palpably thinner. Rope that has been abraded or cut on sharp edges should be examined closely by an experienced user who may choose to cut the rope at that point, rather than risk it parting at that area.
Rope may be cleaned by forming it into a chain sinnet, to prevent excessive tangling, and washing it in a front-loading clothes washing machine with soap flakes. Strong cleansers, including bleach and detergent should not be used with life-critical Nylon components. Commercial rope cleaning devices are available from the climbing and rescue companies CMI and PMI.
Typical specifications [edit]
| Dynamic ropes | ||
|---|---|---|
| Diameter | Typical impact force* | Typical weight |
| 8.1mm (~5/16") | 6 kN (1350 lb) | 42g/m (0.45oz/ft) |
| 9.8mm (~3/8") | 8 kN (1800 lb) | 63g/m (0.67oz/ft) |
| 11mm (~7/16") | 9 kN (2000 lb) | 78g/m (0.84oz/ft) |
*Dynamic ropes are rated for a certain number of falls (usually 5-10) at a given impact force.
| Static ropes | ||
|---|---|---|
| Diameter | Typical breaking strength | Typical weight |
| 9mm (~11/32") | 21 kN (4700 lb) | 51g/m (0.55oz/ft) |
| 10mm (~3/8") | 27 kN (6000 lb) | 66g/m (0.71oz/ft) |
| 10.5mm (~13/32") | 30 kN (6750 lb) | 69g/m (0.74oz/ft) |
| 11mm (~7/16") | 34 kN (7650 lb) | 75g/m (0.81oz/ft) |
See also [edit]
References [edit]
- ^ Smith, Bruce; Allen Padgett (1996). On Rope; North American Vertical Rope Techniques (New Revised ed.). Huntsville, Ala.: National Speleological Society. p. 21. ISBN 1-879961-05-9.
- ^ Tribevine.com. "Search results for: Climbing > Ropes > Single". Retrieved 2011-10-29. Text "Ropes" ignored (help); Text "Single " ignored (help)
