Avoiding Rope Damage
Each usage reduces the life span of your rope. At some time even the best rope will reach a point when its safety reserve is too low. Before this, it will usually already have lost so much practical comfort that you will have discarded it. Extreme loading can make a rope either completely, or partially useless. Naturally, if the damage is only limited to a section near the end of the rope, it can be cut off – in this case you should remember, in future, that the center marking is no longer accurate. In order to decide by how much the safety reserves of the rope have been reduced, you should be able to evaluate the danger of various factors.
The few well known rope breakages today, are – apart from sharp edge falls – the result of chemical damage by acid. Sulphuric acid from car batteries, in particular, attacks the rope’s plastic filaments and can dissolve them. The fact that this damage cannot be detected from the outside is especially dangerous. Sheath discolouration may be barely perceptible, although the basic core can be destroyed. Therefore, ropes should be never stored near chemicals.
It is difficult to estimate the potential damage of solvents; therefore the middle of a rope should never be marked with felttip pen or similar. Although a danger may be improbable, it should never be ignored
Short, sport climbing falls only minimally damage a rope; it can withstand hundreds of them. If the rope end becomes stiff or rough you can cut off the damaged section. Also, bigger falls of ten or fifteen meters don’t have to mean the end for the rope, assuming a dynamic belay technique has been used. fall factor and impact force are critical for the well being of a rope. A longer fall with fall factor over 1, which is not gently braked, can clearly reduce a rope’s safety reserve. Even then it may still hold simple sport climbing falls, but can, however, break with edge loading, even over a less sharp edge, when compared with a new rope. Under no circumstance should it be used in alpine terrain or in climbing areas with rough edges. Safety oriented climbers will replace a rope after such a «heavy» fall.
Sharp rock edges, falling rock, or a blow from an ice axe can fatally damage a rope. If the sheath is damaged so that the core is visible, or if the core filaments are also cut, you should discard the rope. Take particular care with single ropes, where there is no second strand to give redundancy.
Practical tip: When top-rope practicing on steep ice it occasionally happens that the ice axe hits the rope, with a semi-tube pick the rope can be severed. For safety, the end of the rope can be double tied in when climbing on a single rope: attach a two meter long overhand loop, with a second overhand knot and screw gate carabiner to the harness.
The old rule «don’t step on the rope» still applies, although it is only likely to be damaged in an abnormal situation. However, dirt can still be forced into the rope core and affect it.
Friction against rock, and carabiners, wear the rope’s sheath along the whole length of the rope. The greater the load and the sharper the rock - the greater the wear on the rope. The load from the weight of a body when rappelling, or lowering, damages the rope more than leading and seconding without loading the rope. For reference: rappelling reduces the life span of a rope by a factor of two to three compared with normal climbing. Lowering and top roping accelerates aging by a factor of five to ten. Friction causes the small fibers in the sheath to break causing it to become rougher and fuzzy. This can make handling more difficult and increase water absorption by the rope. If the sheath is so thin that it tears in places, or allows the core to appear, the rope should be replaced.
Practical tip: The wear from abrasion in a slingshot top rope can be reduced by using two carabiners. If the anchor is set back from the edge, it should be extended by using long lengths of static rope or webbing so that the rope doesn’t run over the edge of the rock.
An extreme form of damage caused by friction is the friction burn. This is likely to happen when one rope rubs on another, a belay device holds an extreme fall, or if two ropes are both routed through the same anchor point, by mistake. Melting is recognisable by glassy, transparent charred, or dark colored changes to the sheath. In these places the rope is somewhat stiffer, more difficult to handle and suffers from reduced performance. With more serious friction damage, the rope should be replaced.
Unnecessarily fast rappelling can cause the figure eight to become so hot that the rope melts at some points, thereby reducing its strength just at this point. Therefore, when rappelling, moderate speed makes sense.
Take care in popular areas: If two teams are forced to use the same anchor then under no circumstances should the ropes use the same carabiner, so one rope cannot burn through the other. At the main anchor each team must make its own belay. You should make sure that the ropes don’t cross.
Dirt in ropes is mostly a handling problem. It makes them stiffer and stickier. If the rope is extremely dirty, e.g. from oil, grease or tar, and cannot be cleaned by washing, for aesthetic reasons alone, it may be worth considering replacing it. Particularly dangerous contamination is caused by granite dust and sand because the quartz crystals can erode- the core fibers inside the rope – reducing the strength of the rope, especially if the rope is used for rappelling or lowering. Irregular sheath thickness and soft spots can indicate this type of damage.
When a rope is wet it is heavier and more difficult to use. If it freezes, its performance decreases. Frozen ropes may only hold half as many standard falls as dry rope, and a stiff frozen «cable» is torture to force through a descending device. Dangerous situations for freezing moisture are: glaciers softened by the sun, sudden changes in weather and wet spots on ice falls.
UV radiation from the sun causes colors to fade and accelerates aging. However, the radiation to which a climbing rope is subjected in use has a negligible effect on strength, though the fibers do lose elasticity and the rope becomes stiffer. More dubious are the completely bleached rope rappel slings that can be found on some routes, though even these will normally hold a standard static load. However, caution is required if there are signs of chafing or friction burns.
Tangles are spiral formed twists. A rope that is badly tangled is difficult to use, and when rappelling there is the danger that the strands tangle around each other. Some ropes have a natural tendency to tangle more than others; this often increases with age. However, tangles are often caused by handling mistakes. If a rope is coiled in a ring form (i.e. «mountaineers coil») it forces tangles to form. Rope can be twisted by lowering at an angle over well defined edges or by cross-wise positioned carabiners. Careful handling helps avoid this annoyance.
Practical tip: Pay attention to clean, kink free rope handling, and when taking-in use the «Lap-Coiling» method. With the Munter hitch, keep both ropes absolutely parallel! In order to get tangles out of the rope it is best to let it hang freely. Repeated stacking, pulling the rope over a gentle, dull edge, can help to remove tangles.