The early mountaineering rope was made of cotton, and then developed into hemp. After 1950s, it was made of polyester fiber with excellent tensile strength, durability and abrasion resistance.
Contemporary mountaineering ropes are designed and produced according to the regulations of contemporary mountaineering. Climbing ropes are all made of net woven ropes with a layer of outer net outside several twisted woven ropes, instead of ordinary plastic ropes. According to the different application regulations, there are mainly two kinds of wear resistance and friction, and the outer net of mountaineering rope is also divided into single weaving or double weaving. Generally speaking, the mountaineering rope with single woven outer net has less friction and is more wear-resistant. There are many colors of mountaineering ropes. Generally speaking, the ropes used by different members of the same mountaineering team are better to be split in color, so as to avoid losing things in technical operation.
Manufacturers divide ropes into two categories: power ropes and static ropes. Static rope can’t absorb impulse by stretching and is more durable than power rope. It is generally used as a FIXEDROPE for cave exploration, rescue and mountain climbing, and now it is also often used in high-altitude downhill. The static rope is designed to have as little ductility as possible, so it can hardly absorb large impact force and is generally not used as a landing protection rope. Power rope can stretch and absorb the impact caused by falling and protect dictatorship for landing. Power rope (main rope) is the key of all rock climbing protection systems. Compared with static ropes, customers of power ropes are more concerned about the net weight and impact frequency of power ropes. Power rope has excellent elongation, although it can absorb impact energy, but it is not known that if it is not used correctly in an unfavorable application environment, the elongation of power rope will cause chattering up and down with similar spring properties, which will also cause unnecessary inconvenience to users.
Contemporary rope consists of a rope core and a coat, which can protect the rope from abrasion. The length of rope is generally measured in meters, and today’s 55-and 60-meter ropes have already replaced the previous 50 meters. Although the long rope is heavier, it can climb the longer cliff. Manufacturers generally manufacture 50,55,60,70 meters in length. Diameter Diameter is generally indicated by mm.. Fifteen years ago, the diameter of 11mm was fashionable. Now the period of 10.5mm and 10 mm. Even the diameters of some single ropes are 9.6 and 9.6 mm. The rope with large diameter has good commercial insurance index and durability. Light ropes are generally used for mountaineering protection. The net weight is generally measured in grams/meter. Net weight is a stronger consideration index value than diameter. Choose a rope with a small diameter without pursuing perfection and lightness.
The International Association of Mountaineering Associations (UIAA) is the authoritative department for developing rope inspection standards. The specification for detecting rope strength by falling UIAA is called drop test. 80 kilograms of hanging objects were used for the single rope in the experiment. In the experiment, one end of the rope was fixed to make the 9.2-inch rope fall by 16.4 feet. That will result in a drop index value of 1.8 (the vertical height-width ratio of the drop is divided by the length of the rope). Theoretically, the most serious drop index value is 2. The higher the drop index, the more limited the rope’s absorption of impact kinetic energy. In the test, the 80 kg load had to fall over and over again until the rope broke. The environment of UIAA falling experiment is more severe than that of real climbing. If the falling frequency is 7 in the test, it doesn’t mean that you have to throw it away if you fall 7 times.
But if the falling rope is too long, you have to consider throwing it away. Impulse should also be considered in the drop experiment. UIAA’s specification for the impact force at the first fall is 985KG. Static data is stretched at one end of the rope to hang a 65KG(176 lb) load, depending on the length of the rope. There is no doubt that the power rope will stretch a little when the load is negative. The UIAA specification is within 8%. However, it is different in falling. The rope will stretch 20-30% in UIAA experiment. When the rope coat drags the rope and suffers friction. The coat will drag along the rope core. During UIAA testing, a 45KG hanging object is suspended with a rope of 2 or 2 meters and rubbed on the edge for 5 times, and the drag of the coat should not exceed 4 cm.
Post time: Oct-25-2023