Marylebone Mountaineering Club Equipment Life

Climbing and mountaineering are hazardous activities with risk of serious injury or death. The MMC takes no responsibility for the accuracy or safety of the offered information Reading these notes is no substitute for instruction by a qualified person The BMC has advice on equipment life here With the increasing popularity of climbing, manufacturers are taking every advantage of the lastest advances in materials and technology to make exciting new gear available every year. But one thing never changes, climbing has been and remains a high risk sport. All the latest equipment in the world will only increase the margin of safety at which you operate. Risk can never be eliminated, so it's absolutely vital to understand the the limitations of equipment and recoginise the situations that may cause it to become damaged or even fail.
Textile Equipment Even if unused the performance of textile items such as ropes, tape, harnesses and helmets reduces overtime. Heavy use, strong sunlight and exposure to chemicals causes more rapid degradation. Items should be kept clean, thoroughly rinsed in fresh water after exposure to salt water, and regularly inspected for damage. Ropes Each time a rope is abseiled on, loaded, or fallen on the internal fibres become disorientated or damaged. When in use great care should be taken to avoid abrasion damage particularly when top roping. The performance of a rope will be reduced if subjected to repeated falls. In practice ropes only break when shock loaded over sharp or high friction edges. As a general rule for the average user, the safe life for a leading rope is around three years. Ropes should be discarded if they show obvious damage or have taken a very severe fall (not the same as a long fall). Slings Stitching on sewn slings should be checked for wear. Slings will reduce in strength if subjected to repeated falls. Strong sunlight causes degradation of the material: in situ slings, especially in hot countries, should never be trusted. Helmets Some light plastic models have a life span of only four to five years. A helmet that has received a severe blow or has been damaged some other way should be discarded. Check for cracks in the shell and at strap attachment points. Helmets are completely ineffective when not worn on your head. Harnesses Normal harnesses can retain sufficient strength to meet the UIAA Harness standard after many years of use. However, careful attention should be paid to any stitching that has worn. The harness should be discarded if the tie-in or belay points have been damaged or weakened. No reputable gear manufacturer will repair harnesses so if it gets worn you must bin it.	How do you measure the severity of a fall? The severity of a fall, from the ropes point of view, is measured by the Fall Factor. This is the distance fallen divided by the length of rope between the belayer and the falling climber. A fall factor greater than one is serious (and will result in hitting the ground on the first pitch of a route which should definetly be avoided). The maximum fall factor is 2. This happens if the climber falls off above the belayer without placing any gear (or if all the gear comes out), and can only happen on multi-pitch routes (or from the King's Walkway in El Choro).
Metal Equipment Seawater Corrosion Seawater and airborne sea spray present a number of corrosion problems of varying severity. In terms of metals used for climbing equipment, only titanium is resistant to seawater corrosion. Aluminium and steel (even stainless steel) are not. In all cases the corrosive agent is aqueous chloride ions from the salt in the water, and this generally attacks moving parts such as the karabiner gates, springs and latches, or areas of equipment where two different alloys are in contact with each other (e.g. pivots of karabiners, axles of camming devices). After every use of climbing gear on sea cliffs, and anywhere within the region of sea spray (which may extend well over and around the actual sea cliff in rough weather), it is recommended that procedures described on the right are carried out. Otherwise your gear will be useless, except as an addition to the MMC's annual Cliffhanger Award trophy. Apart from your personal gear, in situ gear on sea cliffs is particularly prone to corrosion. Pitons and jammed nuts or camming devices should be treated with the upmost caution and NEVER relied upon as a primary belay. It has been demonstrated that pitons which look OK on the surface have in fact rusted away almost completely below the surface. Fatigue Fatigue is the gradual weakening of materials due to cyclic loading. It is caused by the growth of microscopic cracks within the material until they weaken the structure sufficiently for the material to fail at loads well below the original maximum design. Each load application is known as a cycle, and the lower the load, the more cycles are required to cause a failure. If the loads are low enough then fatigue does not occur. The design of climbing equipment should take fatigue in to account in the following way: The usual loads expected should be such that many thousands of cycles are required before fatigue failure, and this should be beyond the expected usable lifetime of the equipment. However, if through exceptionally heavy or abnormal use, too many cycles have been accumulated and failure is near, then cracks in the highest stressed areas will be forming and growing. A close examinination with a magnifying glass on well used equipment will be very worthwhile - a common example is cracking at the base of the front points of well used crampons. In climbing terms, this means that reasonable use should avoid any chance of fatigue failure by limiting the number and/or severity of the load cycles. Ice axes and crampons are the most likely items of equipment to suffer from fatigue. Repeated torquing of ice axes in cracks, hitting rocks below the ice and walking/climbing on rocks whilst wearing crampons represent high load cyclical loading and will shorted the lifetimes of the equipment. Crampons should be inspected regularly for cracks, paying particular attention to sharp bends, corners, holes and the front points. Crampons should fit securely and be suitable for the intended use. Wear This is the erosion of material by friction and contact with other surfaces. It results in a physical reduction in volume of material and hence the ultimate strength of the item. For climbing equipment, any contacting surfaces are liable to wear since most alloys in common use (normally aluminium alloys) are relatively soft. The most usual high wear situation is rope passing over karabines, abseiling and belay devices. Grooves can appear in these items and since a noticable groove represents a significant reduction in cross sectional area (and therefore strength) a safe course of action is to retire the piece of equipment once such a groove as become noticeable. Cams Cams can last a very long time but the trigger mechanisms can break. This is not in itself dangerous because the triggers and wires do not play a part in their jamming ability howver if the wires break you can lose the cam. Cams can be rewired either with a kit or by sending them for repair. Planet Fear can repair cams of certain types, check here if your cams are repairable. Cracking The presence of crask in any structure that is designed to carry load is potentially dangerous, but obviously so where metallic equipment is involved. Cracks can arise for several reasons. During manufacture or heat-treatment of the equipment, commonly during welding processes. These are invariable detected at an early stage, or not critical to the intended operation of the equipment. During a sudde overload when the failure laod is exceeded nd the item breaks. This is effectivly the sudden initiation and catastrophic growth of a crack through the weakest part of the equipment. Corrosion Fatigue If cracks are visible to the naked eye, the equipment is no longer safe to use and must be retired immediatly.	Care of Equipment After Exposure to Sea Spray After finishing climbing for the day - keep the dry gear separate from the wet, and make sure it is kept away from any damp ropes, slings, clothing etc. - even to the point of carrying a drybag to store dry equipment. Any wet equipment should be washed thoroughly in tap water or a fresh water stream to remove all traces of salt, then after removal of surface water it should be hung out to dry. This should be done even if the plan is to climb the next day. If you are travelling home - do not leave any metal equipment that may be contaminated with salt in a rucksack or other carry bag where it may come into contact with slings or ropes - especially in a warm environment - as this will induce corrosion. If carabiners or camming devices are left like this for say a week, they will at the very least become discoloured and suffer surface corrosion. Within a few weeks they could be completely ruined. As soon as possible after returning home - all equipment that has benn contained with salt water should be thoroughly washed with tap water, preferable with a little mild detergent. Then remove all surface water and put in a warm dry airy place (such as a rack in an airing cupboard) to dry off the remaining moisture. With chocks and camming devices, take special care that the wire cables have been properly washed and dried. When dry - any hinges, movable joints, wires and cables etc. should be treated with a suitable aerosol lubricant, and surplus wiped away and the movement checked before storage. How long is a lifetime? Because of all the variables that affect an item of equipment when it is used, it is almost never possible to give a definitive lifetime. In all cases, the owner needs to take into account everything they know regarding: The history of the equipment - has it been involved in any long falls etc. ? The way in which it has been used - e.g. top-rope or lead rope? The BMC general advice provided in the BMC Care and Maintenance booklet. The manufacturer's advice. Most importantly, the results of visual and physical checks - which you should allways carry out every time the equipment is used. IF YOU THINK IT MAY BE TIME TO REPLACE AN ITEM OF EQUIPMENT THEN IT PROBABLY IS!
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