Kernmantle rope () is rope constructed with its interior core protected by a woven exterior sheath 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. This is the only construction of rope that is considered to be life safety rope by most fire and rescue services.
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 rope became a thing of the past and rope breakage was greatly reduced. In 1964, Edelrid and Mammut both developed capable of withstanding multiple falls. These 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. Overall there is a huge variety of climbing ropes available for different purposes; for instance, there are well over one hundred different dynamic single ropes (the most popular rope system in climbing). Kernmantle ropes are still used in sailing and other sports, but the technical requirements are usually not as rigorous for such purposes as for climbing. Small kernmantle ropes are commonly called accessory cords; they are often used to make and loops or to attach accessories such as .
Depending upon the ultimate use of the rope, one or more of its many characteristics (material, structure, finish, color, strength, durability, elasticity, flexibility, price, etc.) are altered, sometimes at the expense of 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 in.
Kernmantle construction may be used for both static rope 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 Belaying 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 rope 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, and the requirements are the same as for a single rope --and twin ropes typically endure more drops. In addition to the 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 climbers who use such ropes as the ropes age.
A rope can 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 on life-critical nylon components. Commercial rope cleaning devices are also available, but must be used carefully to avoid kinking (& weakening) the core strands.
42 g/m (0.45 oz/ft) |
63 g/m (0.67 oz/ft) |
78 g/m (0.84 oz/ft) |
51 g/m (0.55 oz/ft) |
66 g/m (0.71 oz/ft) |
69 g/m (0.74 oz/ft) |
75 g/m (0.81 oz/ft) |
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