There is no question that the life of a caving rope is very tough indeed; stretched, knotted, squeezed in metal devices, soaked, muddied, and hauled over rough rock, the punishment suffered is relentless. Suspended above the abyss by a single vulnerable thread, a cavers' rope is vital to his continued existence, dependence on rope absolute. Yet what does a caver care about the rope that he trusts his life to? Rock climbers carelessly trampling a climbing rope on sharp rubble or dragging it through grit would rightly be considered daft. Many cavers appear to assume that this is acceptable practise, even though the two types of rope are made from the same material.
Choice of Rope
The optimum rope for normal use is 10-10.5mm diameter low stretch nylon rope designed for S.R.T. Strong enough to provide a good safety margin, sufficiently robust enough to withstand several years use, yet relatively light weight (60-70gm/m). This same rope is suitable for all purposes underground (traverse lines, hand lines, lifelining ladder climbs) apart from lead rock climbing.
Such harsh treatment demands the best quality rope available, so buying rope which is unknown and may turn out to be inferior, just because it is a little cheaper, is foolish! It bears repeating that on each pitch the cavers' life depends entirely on the rope, no back up of any sort exists if this breaks.
Special applications call for special ropes; for intensive use by clubs, or use by rescue teams involving heavy loading and where a good grip is called for, 11mm ropes are appropriate. The same applies to very deep tree hanging drops (100m+), especially when to save time these are climbed in tandem. In all these circumstances the reduced bounce and general solidity of the thicker rope is a great comfort, the penalty is extra weight and bulk (70-80gm/m). More serious considerations apply to small diameter ropes, of less than 10mm diameter. Of course 9mm ropes are lighter, more compact, and initially strong enough, but the weight saved is hardly significant, while the reduction in safety margins is considerable, Heavy shock loading and abrasion damage apart, imagine for example, the prospect of mid-rope rescue of an injured caver on a well used 9mm rope! We might well question the wisdom of using a rope which is only safe in certain circumstances. Besides, instead of proving cheaper, because these ropes must be renewed more frequently, over a period they turn out to be much more expensive.
There is also no question that lack of care and attention can be equally dangerous, it is just as important to care for ropes properly as to select a suitable rope in the first place. Make no mistake, cavers neglect the rope only at their peril.
Ropes should always be carried underground in a tackle sack. A well-designed sack, besides being far easier to handle than coiled ropes, largely protects the rope from damage. Surroundings are harsh and it makes much better sense to wear out the sack than the rope. A rope which is muddied on the way to the pitch, has the mud forcibly ground into it in use. Even fine silt rapidly wears out metal equipment and rope alike, and once embedded it is impossible to subsequently remove all the silt particles from the rope.
Lining the sack with a watertight stuff sack closed with a rubber band will exclude water and the damaging grit it carries with it. The rope is both lighter and stronger for remaining dry. On the surface, ropes packed in sacks are protected from sunlight, rather than slung across the top of a rucksack in the full glare of the sun.
Washing and Inspection
After each trip, ropes should be washed and inspected for damage. Apart from normal surface abrasion which is more or less obvious, the worst thing that generally happens to a rope underground is getting it muddy, or more specifically, using a rope which has become impregnated with mud. There after each time the rope is loaded or squeezed through a descender a multitude of microscopic particles of grit are forcibly ground into the fragile yarn filaments and some weakening is inevitable. Thorough washing is important to remove as much as possible of this mud which abrades the internal fibres of the rope, while making it stiff and difficult to handle. A rope cannot be properly inspected for any surface damage which may have occurred until it is clean. Superficial mud can be removed by simply sloshing the rope around in running water, perhaps in a stream by the cave. This is not always sufficient, however, more stubborn dirt calls for pulling the rope a few times through a rope washer, until the water runs clear.
Throughout most of the caving regions of the U.K., streams of fresh water abound in the hills. Following a trip, washing ropes (and why not other equipment too?) in a nearby stream, or one located in a convenient place by the roadside, still dressed in wellies, over suite and gloves, is not an unpleasant task and takes but a few minutes. This is preferable by far to arriving home tired and dumping the gear in a corner, only to be faced later in the week by a heap of muddy rope and by now rusting bolts and Krabs. Far better to wash the ropes before leaving the caving area, so back at base they only require hanging up to dry.
For maximum cleanliness, from time to time, ropes can be washed in a washing machine, normal (cool wash) temperature 30'C. This tends to be a long Job because most machines will only take a few ropes each load. Undue tangling can be prevented by loosely plaiting (chaining) the ropes or stuffing it into a mesh bag. Adding normal amounts of fabric softener in an attempt to keep the rope supple is not harmful, but because the rope's stiffness is due largely to impacted silt particles, this doesn't soften it much either.
To set minds at rest regarding any weakening effects due to repeated machine washing, remember that the same bulk fibre used in caving ropes is that employed in ordinary clothing designed to be washed every few days. Note that because the normal soiling caused underground is neither 'organic' nor greasy, adding detergent is fairly ineffective. Better if ropes are washed in clean water only.
After washing, ropes should be carefully inspected for damage or signs of excessive wear. The best method consists of running the rope through the fingers a little at a time, flexing it and feeling for soft spots or regions of reduced diameter as well as looking for more obvious damage. If necessary, the rope should be cut and remarked before being stored.
Rope materials in general are particularly stable polymers affected by very few common chemicals, never the less, it is well known that nylon is severely affected by quite dilute acids, and that polyester are attacked by strong alkalis. The most likely source of contamination being leaky mining accumulators, a form of lighting still favoured by many cavers in the U. K. In both instances irreversible damage to the fibres takes place within minutes, so subsequent washing is no answer.
Such damage is virtually un-detectable to the eye, which means that the only real safeguard against this insidious menace lies in avoiding any possible contact. Relative 'acid or alkaline-resistance' of different materials has long been a mis-guided factor in many cavers choice of rope and harness. Underground it is quite impossible to always keep rope, cows tails and harness away from the lamp battery while struggling in crawls and awkward pitches. To be sure of remaining safe any item even suspect of being contaminated must be scrapped. So there is no doubt at all about this advice, peace of mind lies only in adopting a more suitable lighting system.
There are two reasons why new ropes are best washed before use. Washing removes the anti-static lubricants used in manufacture and also shrinks the rope. This serves to compact the sheath and tighten it onto the core, stabilising the rope and perhaps improving it's wearing properties a little. Soak the rope in clean water, drain and squeeze out surplus water by pulling the rope through an anchored descender. Repeat process two or three times, each time pulling the rope through the descender in the same direction. Hang the rope up to dry for a few days. Later cut off any loose sheath that may have crept along the rope and melt the ends to prevent any unravelling. This procedure helps prevent sheath slippage during the initial few trips until sheath and core are properly bedded.
With some softer constructions, the manufacturers find it difficult to match the sheath and core tensions exactly, so especially when used for abseiling, the sheath slips a little in relation to the core. This is not much of a problem. For the first few trips just ensure that the rope is rigged with the same end at the top, so the excess sheath bunches at the bottom. When satisfied that no further slippage is taking place, cut off the surplus sheath and re-melt the end. This simple procedure has no affect on the general properties of the rope.
When first soaked all ropes, particularly nylon ropes, can be expected to shrink by various amounts up to 8 or 10%. Obviously it is as well to roughly determine the shrinkage before cutting and marking ropes for length. Never the less, the rope will continue to shrink (at a much lower rate) throughout it's life, mainly due to the effects of the mud which inevitably penetrates the sheath. So it is unwise to place too much reliance on the length marked. New ropes are better in longer lengths. Later they can be cut into shorter pieces, perhaps at a damaged section, or to provide a short (mid-rope) sample for periodic testing.
At a minimum, ropes should be marked to indicate length, type (static or dynamic) and age. It is important that this information remains with the rope throughout it's life. On expeditions to deep cave systems where equipment is pooled, each group should also be able to identify it's own ropes.
There are many different methods of marking, the main criteria being durability and that the information is un-ambiguous and legible. Generally such information is better written (in abbreviations) than coded. For anyone lacking the 'key' a code is meaningless and entirely defeats the object.
One simple method is to bind the rope for about 5cms. from each end with a couple of turns of PVC adhesive tape. The information is written on this with waterproof ink, and protected by a couple of coats of clear plastic adhesive.
This type of marking although crude, is fairly durable and anyhow is very easily removed from time to time. A more sophisticated version entails first binding the ends with PVC tape, which is then marked with strips of adhesive figures such as those used by electricians for identifying cables, held firmly in place by transparent heat shrink sleeving. This method seems ideal, but, in practise in muddy regions a film of dirty water seems to creep beneath the heat-shrink sleeve and eventually obscure the figures.
A final minor point, whatever marking method is used, it is best not to bind the end of a rope in such a way that either increases it's diameter significantly or makes more than a few cms. rigid and so prone to getting caught up in cracks, or Eco anchors on pull through trips.
Ropes are ideally kept in a cool, dark, well ventilated place, loosely coiled and hung on either plastic tubes or un-treated wooden pegs or rope loops. There is no merit in force drying a rope before storing it. Ropes are not harmed if left to dry slowly until the next trip. S. R. T, ropes are designed not to spin under load, but this property leaves them with a tendency to form kinks when twisted. Given that ropes used underground are generally fed loose into a sack and coiled only for storage, it makes no sense to adopt a wrapping method which twists the rope and must later be unwound as the rope is packed. This is the case with the normal mountaineering methods of coiling rope. A more practical method for the caver is to fold the rope into hanks by laying loops across one hand, the finished coil secured with a few turns of rope. It is difficult to hold more than about 40m. of rope in one hand, so a longer rope can be coiled in two halves working from the centre outwards. The whipping is done with the section between the coils. For a very long rope (l00m +) it is necessary to work in stages, laying each coiled section on the ground before continuing with the rest, Handling long lengths of rope (60m.+), the process is made much faster and easier by wrapping the rope around three sturdy pegs fixed to a wall. Apart from a cellar or other dark place, to protect ropes from U/V radiation the rack should be covered with a heavy tarpaulin. Other wise ropes can be stored in lightproof containers such as metal or plastic dustbins.
Anyone un-prepared for this amount of routine maintenance is definitely in the wrong game. A caver's life depends on his rope. Much better to give up caving altogether than to risk killing himself by neglect of his equipment.
All this paints a black picture and cavers might look forward to a short, uncertain future, but in tact rope failure is rare. Even so, how can we tell if a used rope is still safe?
There is unfortunately no simple answer to this question, one which if not on each cavers lips, certainly lurks somewhere at the back of his mind. Underground a number of factors conspire to weaken the rope. From the moment a new rope is un-reeled and hung in a pitch it starts along a path of deterioration which leads inexorably to the dustbin. Ropes still get weakened in spite of all the care taken of them and sooner or later become un-safe for use.
The causes of this weakening fall into three broad groups; some due to short or long term chemical effects (sunlight, water, ageing), others to physical factors (mud, internal wear, use in metal devices), or to gross mechanical damage such as fraying against rock. Only the latter cause is easily recognised and hence the inherent danger of old, used copes. Rope materials, in common with everything else on the face of the earth, deteriorate with the passing of time. Even if the rope remains little used it gradually loses strength over the years.
This 'ageing' process is speeded up enormously by poor storage or prolonged exposure to sunlight.
There are very few signs, least of all the outward appearance of a rope, that give a reliable indication of it's properties. Truth is, there is no practical method of' determining precisely the safe life of a rope, dependant as this is on variations in age and usage.
A heavily used rope showing obvious signs of surface wear, might be only a few months old and still perfectly safe. Whereas an infrequently used rope of excellent appearance but more than ten years old, is quite likely to be dangerous, retaining only a fraction of it's original strength. Nothing short of a test to destruction reveals the true condition of a rope. Consequently rope must either be tested periodically, discarded on the grounds of obvious damage, or scrapped arbitrarily upon a certain age or number of hours use. As a very rough guide, most new(ish) ropes can be used safely until the sheath appears furry and obviously worn, and as a result begins to feel limp and soft. When the sheath no longer effectively protects the core beneath-throw it out. This crude assessment of course takes no account of the weakening effects of age or internal abrasion, we know already the appearance of a rope doesn't reveal much at all, and some types deteriorate much faster with use than others. With regard to age, five years is the recommended maximum, even for a rope that has been little used and correctly stored. This is an arbitrary and doubtless in some cases a conservative figure, but even here, there is no guarantee that it has not been made un-safe by other factors (shock loading for example) long before this time is reached. A far more precise indication of a ropes condition is gained by subjecting a short section of it to a destructive drop test. The best advice is simply to aim for a complete replacement of your ropes every few years. Keeping a fairly small stock of ropes helps ensure that they earn their keep and are worn out before becoming too old. Then either test the rope or give it to the local farmer to fasten his gates with. Beyond this cavers have a clear choice, they can either extend the rope's life, or their own!!