Rope, a full history

Vertical caving terminology and methods > General hardware

Rope, accessory cord, cord, paracord, parachute cord

Also known insultingly as "silly bits of string". Used to make pitches not be dangerous. Let's face it, if you need this one explained, you are beyond help here.

Ropes designed for caving are extremely strong, with a minimum breaking strength around 10 times higher than they will ever experience during use. They are made from a woven "sheath" (or "mantel") of fabric around several "cores" (or "kern"), known as kernmantel construction (or kernmantle if you prefer the USA spelling). The sheath binds the cores together for the best performance, allows the rope to pass nicely through various pieces of equipment, allows the equipment to grip it properly, and protects the cores, while also providing about 20% of the strength. The cores are the actual strong part, providing about 80% of the strength of the rope. While kernmantel is the only construction used for SRT, other constructions may rarely be used for fixed handlines, most commonly hawser laid, with braided/plaited and cable laid occasionally being seen.

Hawser laid ropes are twisted from three strands, with the twists visible on the outside of the rope, very common with low quality ropes sold for household purposes. Shroud laid is the same as hawser laid, but with 4 strands, and might have a thinner central core strand. Cable laid ropes are made from three hawser laid ropes twisted into a final rope, with a much tighter twist. Hawser laid and shroud laid ropes have opposing twist directions for the strands as for the overall rope, usually "left hand" for the strands, and "right hand" for the overall rope, but either direction is possible. Cable laid ropes have one twist direction for the inner strands, opposite for the hawser laid step, then back to the original direction for the overall rope. Braided/plaited ropes are made from several strands that are all woven together like the sheath of a kernmantel rope (but often with much thicker strands) without any cores, passing from the middle of the rope to the outside of the rope at various points in the weave. These may also be known as hollow braided/plaited ropes, if the weave does not cause the strands to pass into the middle of the rope at any point, resulting in a woven tube which can easily flatten into a ribbon. Double braided/plaited or double sheathed braided/plaited ropes are like a braided/plaited rope in the core, with a woven sheath outside, or two layers of woven sheath. They may sometimes have a few non-braided/plaited core strands in the middle of the inner braid/plait, like a standard kernmantel rope. Technically, double braided/plaited ropes are a type of kernmantel rope, as they have both a sheath and core. Hawser laid, shroud laid, cable laid and braided/plaited ropes all expose the strong rope fibres on the outside of the rope at some point, allowing all of them to be damaged by abrasion, potentially weakening the rope significantly; they do not protect the cores. All of them except braided/plaited ropes also untwist significantly when loaded, causing a very uncomfortable spin when used with SRT. Cable laid ropes are normally too thick for SRT, but less prone to untwisting, because the opposing twists fight each other better.

Caving and climbing ropes are purpose made, from nylon (polyamide). Polypropylene rope must be avoided at all costs, as it can melt through when exposed to the heat dissipating from a descender, and is much less resistant to abrasion. It melts at just 160-170°C. However, canyoning ropes are intentionally made with polypropylene cores and a nylon or polyester sheath, so that they can float, but these are then expected to be used in wet conditions with slow abseiling so that they do not heat up enough to melt the cores. The strength of polypropylene rope is slightly lower than an equivalent nylon rope. Polyester rope is often intended for maritime usage, and does not provide the shock absorbancy or flexibility that caving ropes require in Europe, but it is more resistant to abrasion. It is often used in American caving, where ropes are allowed to be worse for shock absorbing. Whichever material is used, ropes are usually cut into appropriate lengths, and the ends are then melted to prevent them from fraying.

"Static/semi-static/low-stretch" (a bit stretchy) ropes are used for SRT, which will stretch about 4% when a person hangs on them (American ropes may stretch a lot less, such as just 3% with a 400 kg load - these provide virtually no shock absorbing qualities). "Dynamic" (more stretchy) ropes are used for climbing or belaying, and will stretch about 10% when a person hangs on them. Ropes are generally white with colour coded stitching showing the diameter for caving, and brightly coloured for dynamic ropes, but static ropes can sometimes be colourful too. Caving ropes are classified by the EN 1891 standard as "type A". There are also intentionally lower quality "type B" static ropes which are not designed for caving, so these are generally marketed for other purposes. However, these may be used for ultralight rigging.

10 mm and 10.5 mm are the most common diameters, 11 mm is very thick and slow, 9 mm and 9.5mm are used sometimes. 7 or 8 mm ropes are used only for expeditions when low weight or low size is important, but they are very fast. Thinner ropes are much weaker, and suffer a more severe loss of strength when damaged. They are normally much easier to damage, since the thinner rope normally has a thinner sheath. Rope diameters are normally measured when holding a 10 kg load, and an unloaded rope might measure 1 mm more than the stated diameter.

Ropes are connected via knots to carabiners and maillons, or more rarely directly to anchors or naturals. Most knots reduce the rope strength by about half, and since knots are needed, the rope strength when it is being used can be considered about half its stated minimum strength. They are always far stronger than they need to be to support a caver, since the movements, shock loads and odd directional pulls on the rope cause the stress on the rope to be a substantially higher than the caver's own weight, and water or damage cause the strength to be decreased. A caver who is abseiling or prusiking will normally put a maximum of just over twice their weight (including wet clothing and any tackle bags they are carrying) on the rope if they bounce around as much as possible, and a common suggestion is that equipment should be rated to at least 5 times the load it is expected to encounter, as a safety margin. 15 kN is generally considered the minimum strength suitable for caving ropes. 8 mm and thinner ropes are usually marketed as accessory cord, meaning that they are intended for hanging equipment from, rather than cavers - these would be the "type B" ropes. Thinner dynamic ropes might be sold as "half rope" or "twin rope", meaning that climbers are expected to rely on two of them at the same time; this is something that makes very little sense with Alpine rigging used in caving but which can be used by some descenders, such as a rack. Thinner accessory cords are normally called paracord or parachute chord, and usually have a more flexible sheath. The following chart gives the strengths for some popular rope brands, but each brand has its own individual ratings:

These ratings are for new rope, not rope that has been used for years, subjected to shock loads, or exposed to the elements. The ratings are also for ropes that are dry. Once wet, a rope loses about 10% of its strength, and caves are often wet places, so this is how caving ropes are expected to be used. A wet rope cannot absorb as many shock loads, but this is something that caving ropes should not experience in normal use anyway, so being wet is not considered to be a problem for caving ropes. A rope that has a damaged sheath can still normally support enough weight to be relied on. However, since a split sheath can slowly creep down the cores, it can make it difficult or impossible to use the rope safely, and makes it far more likely that the cores will now also be damaged. Core strands that are holding a load can cut through surprisingly easily if they come into contact with a sharp surface. You never want to see the cores, and a rope damaged to that degree should be cut into shorter pieces to remove the damaged section.

It is possible for the sheath of a kernmantel or double braided/plaited rope to slip down the cores a little during use, bunching up more at one end than the other, or leaving part of the sheath with no cores. Caving ropes are usually made with a fairly tight sheath to minimise this effect, but in bad cases, the sheath may need to be cut to a better length to match the cores, and the end remelted. The sheath protects the cores, but a rub point can still wear through the sheath. Because the fibres in the sheath all wrap around the cores, all sheath fibres are exposed on the same side of the rope, within a very short distance along the rope. A rub point on one side of the rope can damage all of the sheath fibres, causing the sheath to be severed completely, exposing the cores. When a device such as a descender or ascender pulls on a rope with a severed sheath, the sheath can slip down the cores and bunch up. Once the sheath has been worn through enough to expose the cores, the cores can also be damaged by the rub point, but with kernmantel ropes, only one set of cores is initially damaged at a time because the cores stay at one position in the rope, and the next ones are not exposed until the previous ones have worn through, or the sheath has been severed completely, allowing the cores to spread out on the rub point.

Double braided/plaited ropes have the advantage that they can be spliced much more effectively than standard kernmantel rope, and they hold their shape better when bent at sharp angles. However, they are often less flexible, which makes them less convenient for tying knots, or can make knots more likely to come untied. They can be heavier, and they are not normally as dynamic, making them generally worse for absorbing shock loads. They also have the disadvantage that the core fibres also wrap around, so they are all on the same side of the rope within a very short distance. As a result, a rope rub on the cores on one side of the rope can quickly damage all core fibres at the same time. Many double braided ropes are specifically designed to be used for splicing, which needs the core and sheath to be easily separatable for construction of the splice, and this means that an accidentally severed sheath slides down the cores far more easily than with a rope designed for caving. This is particularly noticeable with ropes designed for sailing. Some ropes use a small amount of glue or extra threads to bind some of the core strands to the sheath, making the sheath far less likely to slip down the cores during use or if it is damaged. This is normally more effective with double braided/plaited ropes than with standard kernmantel rope. Double braided/plaited ropes are often preferred for arboriculture and sailing.

Over the years, being bent and squashed around through regular use (SRT or just being tied in knots) causes damage to the rope fibres. Contrary to popular belief, standing on ropes does no discernible damage, as long as the ropes are not on a sharp surface. The pressure exerted on the rope by SRT is far higher than a shoe. Mud being forced into the fibres by SRT on muddy ropes increases the damage to the fibres of the sheath (but the mud does not seem to reach the cores as long as the sheath is intact), which is why rope washers exist. This causes shrinkage, and turns the rope sheath furry. Once this becomes excessive, it is time to retire a rope, even if it still passes drop testing. If the rope becomes too stiff to pass easily through a descender, or such that it feels like "wire", it is time to retire it. If a rope develops soft spots, so that it no longer holds its round shape, and can be squashed between fingers much more than the rest of the rope, it should be retired immediately or cut into smaller pieces to remove the soft section, since even though it probably can still hold a person, it has been weakened significantly at that point. If a static/semi-static rope has been subjected to a significant shock load, it should be retired immediately. Manufacturers are not keen to say exactly what counts as a shock load bad enough for this to be needed, but anything above fall factor 0.3 might be considered bad enough (for European ropes). Fall factor 1 is definitely bad enough.

Ropes are extremely susceptible to certain chemicals, particularly acids below pH 4, alkalis above pH 12, sulphuric acid (battery acid in car batteries and old caving lamps, some drain unblockers, some aquarium cleaners), hydrochloric acid (stomach acid, concrete cleaner, rust remover), nitric acid (dishwasher liquid, household cleaners), sodium hydroxide (caustic soda, lye, drain cleaner, various kitchen cleaners) and hydrogen peroxide (various kitchen cleaners, hair bleach, whitening toothpaste, contact lens cleaner, acne treatment, glow sticks, some aquarium medications, plastic restorers), where the rope is dangerously weakened and the damage is not externally visible. Other dangerous chemicals are formic acid (wart remover, limecale remover, ant bites), phosphoric acid (concrete cleaner, fertiliser, preservatives), particularly strong vinegar (fish and chips, ketchup, salad cream, glass cleaner, silicone), most other acids (including ant poison and climbing grip cleaner), bleach, petroleum jelly (vaseline), iodine (wound cleanser), fluoroalcohols (uncommon solvents) and phenols (some disinfectants and strong detergents). Any rope that has been exposed to these chemicals needs to be retired immediately. Drink, fruits and sweets that contain citric acid (orange juice, lemon juice, most soft drinks, sour sweets), malic acid (apple juice, sour sweets) and tartaric acid (grape juice, wine) also have a weakening effect, and while this is typically less severe than some other acids, it depends on the concentration, and the length of time that they are in contact with the rope. Petrol and oil seem not to have any serious effects, however. Tomato juice and coffee are not acidic enough to be considered harmful. Polyester copes with slightly stronger acids and alkalis than nylon, and polypropylene copes with even stronger.

Wet ropes are supposed to be gently dried over the course of a few days at room temperature (40°C is as high as it should get, and it is better to be below 30°C). They should not be dried with heat, such as by putting them on a radiator (60-90°C), in a tumble drier (70-75°C) or out in the sunshine. According to Mammut, this is because the heat causes fibres to become more brittle, and wet fibres are more vulnerable than dry ones. The rope will lose some of its dynamic properties, and age prematurely, becoming stiff and furry, with associated shrinkage, considerably faster than if it had been dried correctly. This will cause the rope's strength to be reduced, and make it less able to survive a shock load afterwards. Even when dry, repeated exposure to high temperatures eventually degrades the rope's strength or shock absorbing abilities. For this reason, Mammut recommends storing ropes between -10°C and 30°C. Anecdotal evidence from people who have made that mistake suggests that short term accidental exposure to the heat of a radiator (such as a few days) does not appear to cause significant damage to a dry rope, but testing has shown that the rope has reduced performance similar to it being wet if it is actually used at those temperatures. Ropes tested at 50°C show the same results as ropes tested at room temperature. Hot or boiling water should be avoided, temperatures of 150°C or more will damage a rope to the point that it loses around half its strength, and very high temperatures of 220°C or more, such as a flame or hot oven, will melt rope. Exposure to sunlight for a long amount of time degrades ropes, largely because of ultraviolet (UV) light, with the sheath being affected much more than the cores. Testing with ropes kept in Mediterranean levels of sunshine for 3 months showed a loss of strength by around 10%, and reduction in shock absorbing abilities by 25-50% (in terms of drop testing). A day in the sun at the top of a surface shaft is negligible, but several months is not good. Ropes left underground for years or even decades in cold, dark, damp conditions are often still usable, as long as they have not been damaged through use or from being swung into a wall by moving water.

Accessory cord can be made from higher performance materials. High-modulus polyethylene (HMPE), also known as ultra-high-molecular-weight polyethylene (UHMWPE), commonly known by the brand names Dyneema, Spectra or AmSteel, may be used to make especially strong cords and slings. It is stronger and lighter than steel for its size, and does not decay when exposed to UV from sunlight. It is not suitable for SRT because it is extremely slippery and does not provide enough friction for use with descenders. Even if it did, the heat from the descender could melt it, since its melting point is even lower than polypropylene, at just 140-150°C. Knots do not grip well, and can slip during use when loaded. Knots also weaken it very significantly, as much as 70-80% for some knots that are used for SRT, so it needs to be stitched or spliced instead to make loops. Dyneema cord can be as much as three times as strong as nylon for the same cross section, though with kernmantel construction, it might be around twice as strong (so an unknotted 5 mm Dyneema cord is about as strong as 7 mm nylon cord). That benefit is lost completely once it is knotted, and with many knots, it will then be significantly weaker than nylon. Like steel, it does not stretch significantly at all, so it has no ability to absorb shock loads, and would result in severe injuries if anything goes wrong, such as a failed anchor. When shock loaded, its strength is significantly lower than its normal maximum, and its maximum strength can only be obtained during an extremely slow pull. Aramids such as Kevlar, Twaron and Technora may be used for some climbing accessory cords and sailing ropes, or for protecting heavily worn parts of SRT gear, but are not used for SRT ropes for the same reasons. While they can cope with far higher temperatures than other ropes, they deteriorate very quickly when exposed to UV in sunlight. However, they are sometimes used in the sheaths of canyoning ropes, and replaced regularly to avoid the issues with UV damage.

History

How long ago were ropes made? I dunno, how long is a piece of string? Ropes were originally made from plants, animal skin, hair or sinew twisted into a long thread. This was developed separately by many cultures around the world, and used to tie primitive axe-heads to sticks, tie animal skins into clothing, restrain animals, hold pottery, haul blocks and build bridges. A probable needle was found in Sibudu Cave, South Africa, dating from 59000 BCE. The thread is likely to have been made from sinew or plant fibres, but no specific evidence was found. The earliest known example of rope was created by Neanderthals in 48000 BCE, and was found in the Abri du Maras cave in the Ardèche region of France. It was made from tree bark fibres, and was probably hawser laid or two-ply, but is far too small of a sample to be certain. A sewing needle from the same era was found in Денисова пещера (Denisova Cave) in Siberia, Russia, which had been made by Denisovans, rather than humans. This implies that they were using a thread of some kind, but no further details are known. Another from 47000-42000 BCE was found in Пещера Страшная (Strashnaya Cave), Siberia, Russia. Another needle from 45000-39000 BCE was found in Potočka zijalka (Potok Cave) in Slovenia. Tools for making actual rope (not sewing thread) were found in the Hohle Fels cave in southwestern Germany, dating from 38000 BCE. The Caucasus mountains have evidence of needles dating from 38000-33000 BCE. Needles from either 33000-27000 BCE or 28000-21000 BCE (depending on the accuracy of the analysis) were found in caves at 小孤山 (Xiaogushan) in China. Flax was being used to make ropes in Dzudzuana Cave in Georgia, Europe, in 32000 BCE. Needles were widely used throughout Africa, Asia and Europe, but they were used with very fine threads, rather than rope.

Imprints in clay show that rope was used in what is now the Moravia region of the Czech Republic in 26000 BCE. The same region has imprints of fishing nets with knotted strings made from hemp and nettles in 25000 BCE. Remains of three pieces of twisted fibre cords dating from 17000 BCE were found at Ohalo II, in the Sea of Galilee in Israel. Fragments of rope from 15000 BCE were found at the Lascaux caves in southwestern France. Fishing cords of an unknown fibre were made in 10000 BCE in Israel. Ropes were made from grass at the Coves de Santa Maira caves in Valencia, Spain, in 10000 BCE. Hawser laid and two-ply rope was made from dogbane (Indian hemp) in Lamona Rockshelter, Washington, USA, in 8000 BCE. Hemp was used for textiles in China since 8000 BCE. In 4200-2700 BCE, Neolithic miners at Rijckholt Flint Mine (now Netherlands) are thought to have used ropes to access their mines, but there is no known evidence of what the ropes were made from. Ropes of unknown construction were also used at Harrow Hill, Cissbury Ring and Grime's Graves in southern Britain in 4000-2200 BCE, 4000-3500 BCE and 2650-2300 BCE respectively (various sources say they were probably made from plaited leather, but there is no actual evidence to support that conjecture). Egyptians were making ropes from reeds in 4000 BCE, particularly hawser laid ropes made from papyrus. By 4000 BCE, braided/plaited ropes were being made in Asia. Twine cords made from flax, dating from 3900 BCE were found at Lake Constance, Germany. Leather was used to make cords for such a long time that its earliest known use cannot be known. However, a pair of leather shoes were found in the Areni-1 cave in Armenia, dating from around 3500 BCE, which were laced using leather cords. The oldest leather known from Britain dates from 2576-2464 BCE. Ötzi the Iceman from Italy had a hawser laid sinew bowstring, in 3230 BCE. Swiss Corded Ware people had many samples of hawser laid and two ply cords, dating from 2800 BCE, which they then spread to a large part of Central, Eastern and Northern Europe. Hemp rope emerged in 2800 BCE, in China. It was then used in Egypt in 1500 BCE, using specialised rope making tools that they had developed. Egyptian ropes were typically hawser laid or two-ply, and use the same approach as modern hawser laid ropes. Bamboo rope appeared so long ago in China that there is no known record of when it was first created, but it was used to make strong ropes around 1 CE, which could be used to make bridges. A 4.5 metre long piece of bronze cable was found preserved in Pompeii, from 79 CE. It consisted of three strands twisted together in exactly the same way as a hawser laid rope, where each strand was made from 15 wires, a 3×15 configuration, giving a diameter of 8 mm. The hand crank used to make hawser laid rope did not appear in Europe until much later, after the end of the Roman empire. Wire making took place in Nurnberg, Holy Roman Empire (now Germany) a person making wire between 1388 and 1423. Ropes became a fundamental part of ships, whose significance grew exponentially during the Age Of Discovery (1500s to 1700s), and this is where a lot of the techniques used in SRT first appeared.

Initially, vertical caving was done using hemp ropes and hemp rope ladders, typically hawser laid. Actual hemp had been used for sailing for centuries, and would have been used for the early phase of vertical caving. In many cases, it was referred to as Italian hemp, due to that being the source of high quality hemp, but it is the same plant that may be grown in other countries. Sisal, made from Mexican agave plants, became available in 1810, and will also have been used for caving, initially in North America. In 1832, wire cables were claimed to have been developed in England. In 1834, mining engineer Julius Albert developed a modern steel cable in the German confederation, now Germany. It had a hawser laid construction with each strand made up from 4 wires, a 3×4 configuration, with a diameter of 19 mm and length of 600 metres. The idea was that when the strands weakened and snapped, the others would continue to work, and the damage could be seen so that the cable could be replaced, while the existing chains failed catastrophically. In spite of this being frequently stated as a new invention, it is the same construction (just a different material and number of wires) as the Romans had been using. Presumably the English cable used the same approach, but no details were given. In 1837, French explorer Stanislas Marie César Famin described Colombian ropes, which were made from liana, agave or strips of leather. Manila hemp had been used by Spanish sailors from 1600, but only became common in America from 1812 onwards, and Europe after 1869. Manila hemp is not hemp at all, but actually from the abacá banana plant, though it functions the same way. This soon accounted for the majority of ropes used for caving. From 1838 onwards, ropes made in Britain from Indian jute became available, but it is not known if these were ever used for caving. Hemp, Manila hemp and jute are all very similar in appearance, while sisal typically results in much lighter coloured and smoother ropes, and users would have known it was different. Lighter cotton and darker jute remain the most common materials for natural twine, with cotton being softer and far easier to break, and jute appearing significantly more hairy and chaotic. The different materials can be approximately ranked in terms of relative strength compared with hemp at 100%, as Manila hemp 90%, sisal 80%, flax 70%, jute 60% and cotton 40-50%, though the actual strength will depend on the manufacturing process. The resistance to abrasion, water and UV also decrease in that order. This explains why hemp was often preferred, and cotton was not used for mountaineering and caving. However, the other materials were still used because of their availability and cost.

A woven sheath had been used in 1845 with hose pipes by American Horace H. Day. The idea behind kernmantel rope, a protective, woven sheath over a stronger core, seems to have originated with flexible drive belts for machines, first patented in 1854 by American Harry H. Matteson, using a woven sheath made from natural fibre over a tougher core made from strong material such as bamboo, rattan or whalebone. Waterproofing liquids could fill the gap between the core and sheath. By 1858, braided/plaited ropes were being regularly manufactured, with American James A. Bazin suggesting a new construction method and machines to produce it. By 1859, kernmantel construction was being used with telegraph cables, optionally using wires for the sheath. (The idea of a woven sheath was also used for packing or wrapping pipes, metal rods or asbestos rods, for industrial purposes, from around 1865.) High quality mountaineering ropes are likely to have originated as fire brigade equipment. Austrian fire brigades were using 9 mm hemp rope for hauling equipment and lowering people in 1877. Also in 1877, fire brigate supplier Conrad Dietrich Magirus from Ulm, German Empire (now Germany), published recommendations for fire brigade ropes. The 17 metre normal length, thread count of 36 and 48 for the two sizes, diameter of the smaller size and weight of the larger size were given, which allows some calculations. Every year, they were tested for strength, using the actual rope, not an offcut. They needed to hold a 300 kg static load, and survive a 75 kg drop test of a 1 metre fall, on the full length of rope, which gives a fall factor of just 0.06. A new rope might survive a fall factor of 0.12. The actual strength of the rope is not stated, but can be calculated based on the quoted thread strength. The knotted strength cannot be calculated, but is estimated based on a typical factor of 65%:

Kernmantel construction with a sheath made from wires or natural fibres to protect central cores was already in use with electrical cables in the USA by 1880, and by 1885 there were already several methods to do so. In 1881, the German and Austrian Alpine Association were using 18 mm Manila hemp rope, which weighed about 133 g/m, for crevasse rescue. The supplier in Vienna, Austria, would colour code a rope thread, and supplied it in 30 metre lengths, which was stated as a normal length. In 1883, American Edward Maynard developed a double braided/plaited rope for use as window sash cord, a type of pull cord. He stated that braided/plaited ropes often had core strands in order to keep the shape of the rope, resulting in a kernmantel construction, but that when pulled hard, the shorter cores would snap, leaving only the woven sheath. His double braided/plaited rope would have the same core and sheath lengths under tension, which would allow the cores and sheath to both support the load at the same time, resulting in a stronger rope. Also in 1883, an American fire escape patent specifically asked for a braided/plaited rope when abseiling, since it would avoid the spinning effect from hawser laid rope. Splices in braided/plaited ropes were described in 1884 by American Leedham Binns. In 1886, American Frank M. Beckford developed a rope using kernmanel construction, with the sheath made from wire, and the core providing most of the strength. The core could be any construction, including parallel strands or hawser laid.

Starting from about 1889, French caver Édouard-Alfred Martel used 14 mm hemp rope for winching. Also in 1889, American inventor Joseph Williams Jr. patented a rope with multiple core strands, and a woven sheath, like a modern kernmantel rope, as well as a variation that used multiple woven layers, like a double braided/plaited rope, or multiple layered braided/plaited rope. The gaps between layers were filled with lubricant that would be squeezed out as the rope was used, and the rope was intended for industrial usage, not caving or mountaineering. Rayon was created from plant cellulose by British chemist Charles Frederick Cross in 1892, but although it is used for ropes, there are no records of it having been used for caving. It was more instrumental in demonstrating how synthetic fibres might be made. (It was used in the original Cordura, but that was probably not used for caving, since it was replaced with nylon in the 1960s.) In 1893, American Hugh Coyle patented a rope with a hawser laid core and woven sheath, as a similar idea to kernmantel rope. In this case, the gap between the core and sheath was filled with a fire resistant lubricant (asbestos!) which would squeeze out of the rope as it was used for abseiling. This idea appears to be a direct copy of the idea Joseph Williams Jr. had patented, but using a different core design. By 1901, kernmantel construction was used for pull cords by American William A. Tucker, with a hawser laid cable core, and fabric sheath. The Bavarian section of the German Alpine Club in München detailed their use of ropes in a series of booklets, starting with one called Seilknotten in 1905, which listed only the knots they used. In 1907, the booklet was renamed to Anwendung des Seiles ("applications of rope"), and gave more details. It did not specify the rope construction, except to say that 5 mm red avalanche cord should be towed behind each person to help locate them in an avalanche, when crossing snowfields. In 1910, Anwendung des Seiles recommended that ropes should be made of Manila hemp. Ropes used for abseiling and lifelines should be either hawser laid or braided, 11-13 mm in diameter. They were normally 20-30 metres long. Slings could be made from 7 mm rope. Braided ropes were said to be less durable. Standard rope care involved drying it thoroughly to prevent it rotting, and greasing it slightly with petroleum jelly to keep out water, which must have made the ropes much faster, and harder to grip. In 1910, kernmantel construction was still being patented for cables.

In 1913, a publication called On Ropes And Knots edited by British mountaineer John Percy Farrar (with much of the content provided by British mountaineer Oscar Eckenstein), provided details of advances in mountaineering ropes, which were tested in 1911. It clearly showed that what were referred to at the time as "woven" ropes, were in fact kernmantel ropes, over 40 years before they are commonly said to have been invented. They were not simply braided/plaited ropes, as they had a core made from a number of separate yarns. It does not say if the core yarns were arranged in a linear manner like a normal kernmantel rope, or woven like a double braided/plaited rope, but either way, they had several core yarns, and a woven sheath. In each case that was described, the core used about half as many threads as the sheath, which is a significantly thinner core than a modern kernmantel rope, since the core strands were primarily used to give the rope its shape, rather than for strength. These ropes were made in Austria, Bavaria in the German Empire, and Switzerland, and had clearly become a normal rope construction by 1911. The core and sheath may be made from different natural fibres (such as Manila hemp and hemp respectively), and the sheath could have one yarn made from a different fibre, to produce a dashed pattern, just like a modern rope. They were soft, but less than half as strong as hawser laid ropes. Several ropes were tested, showing huge inconsistencies in the resulting strengths from ropes produced by different manufacturers, but the report only gave full details for 4 of them that were considered good, each of which was above 11 mm in diameter. The strongest rope tested was made for the British Admiralty. No details were given of whether the strength of the rope was measured with or without knots, but subsequent tests were used to assess how much various knots weakened the rope, suggesting that the initial strength tests were measuring the unknotted strength of the rope. The following table gives the measurements of the ropes themselves, as well as what they would give for a now-common 10 mm diameter, to allow easy comparisons:

In 1915, dedicated avalanche cord appeared, made from red dyed hemp rope. In 1920, a German and Austrian climbing newsletter article by Hermann Amanshauser (later a Nazi SS officer), described the requirements for climbing ropes, and is the earliest widely distributed climbing publication to describe in detail how they could be used for climbing and belaying with pitons and carabiners. Ropes were only allowed to be made of "grey hemp", which is presumably standard hemp. Hawser laid ropes were the only good types, even though others said they twisted too much, and were too stiff. He stated that although it was hard to find good ones, they did exist, and could be stronger, easier to grip, more abrasion resistant, and cost less than other ropes. Braided ropes could be acceptable if they did not have any core strands, but were typically lower quality. Nevertheless, mountaineers apparently preferred them. "Woven" ropes made from a hawser laid core and braided sheath were considered unsuitable, since the core and sheath would never stretch to the same lengths as each other under load, and one invariably took the strain before the other, causing it to snap at a relatively low force. The suggested length for climbing ropes was 20 metres, but 30 or 40 might be used for particularly tall climbs. With tall or difficult climbs, ropes should be used in pairs, suggesting that the use of twin ropes may have started, though since rope diameters were not stated at all, it does not say if they were thinner than normal ropes, and it is unlikely that they were any different.

During the 1920s, the catalogues of Sporthaus Schuster in München, Germany, listed hawser laid and braided/plaited hemp rope in 10 mm and 13 mm diameters, hawser laid Manila hemp rope in 10 mm and 13 mm diameters, 5 mm accessory cord probably made from hemp, and 5 mm avalanche cord. In 1922, Anwendung des Seiles recommended hemp rope or Manila hemp rope, 11-12 mm in diameter, normally 20-30 metres long. Ropes should be hawser laid or braided, but braided was still stated as being less durable. 7 mm rope could be used for slings. Ropes should be replaced before they get old enough to become brittle. By 1924, Sporthaus Schuster had added 7 mm accessory cord. That edition was the first to show ropes being used in the half rope arrangement, with two being used at the same time from different directions to catch a falling climber. However, at that stage, the ropes were the same ropes that would be used on their own, and were not dedicated twin ropes. By 1926, Anwendung des Seiles had changed its recommendation, now saying that only hemp was acceptable, Manila hemp and sisal were not as good. Hawser laid ropes were good for climbing, braided ropes were not as durable but could be used for glacier crossings, while woven ropes were not good. Woven ropes were specified as having a 5 mm hawser laid core, with a braided sheath, which is a type of kernmantel construction. Only 12 mm rope was recommended for most uses, while 7 mm rope was still considered good enough for slings. By 1928, Sporthaus Jungborn in Dresden, Germany, was selling hawser laid hemp rope in 10-18 mm. American chemist Wallace Hume Carothers made the first steps towards polyester production in 1929.

In 1930, Anwendung des Seiles was updated again, with more details. Hawser laid ropes were used as a lifeline, because they resisted tearing better, while more comfortable braided/plaited ropes were used to tie mountaineers together to cross glaciers, because they did not tangle as much. 20-25 metre lengths were common, but 30-40 metre lengths might be used for more extreme climbs. Hemp was preferred, while Manila hemp and sisal were not considered to be as good. 12 mm rope was recommended. 7 or 10 mm rope could be used to make slings, a sit harness for abseiling, or footloops. Ropes that started to twist and tangle could be soaked in warm water for long periods, then stretched to restore them. Nylon was then invented by Wallace Hume Carothers working at American chemical company DuPont in 1938. British chemists John Rex Winfield and James Tennant Dickson created polyethylene in 1939. British chemists W.K. Birtwhistle and C.G. Ritchie then helped John Winfield and James Dickson create Polyester at Imperial Chemical Industries in 1939. During the 1940s, strong telephone wire was occasionally used as a lifeline, either as the main lifeline, or the telephone's wire might be used as a secondary lifeline next to the main lifeline, because it did not untwist and cause the caver to rapidly rotate when it caught them during a fall. This approach was used both in Europe (especially France) and America.

Nylon was used to make stockings in 1940, and a parachute in 1942. The invention of nylon rope was, among other things, specifically for caving by French caver Pierre Chevalier. He produced the nylon intended for ropes in 1942 (Subterranean Climbers, Pierre Chevalier, 1975) while working at the company Rhône-Poulenc near Grenoble in France, with the ropes made by the Joanny rope manufacturing company. The first nylon rope still used the twisted/laid technique, was 10 mm in diameter, and could hold 1 tonne. It was first tested in the Dent de Crolles cave system in late 1943, with the first recorded use being as part of a maypole climbed by French caver Charles Petit-Didier, during a caving trip with Pierre Chevalier, and French cavers Fernand Petzl, Annette Bouchacourt and Joseph Prunier. Nylon for parachute cords was under development by American Viscose since 1942, and was actually used for parachute cords and glider tow ropes in 1943, followed by military climbing ropes before 1945. It is hard to say whether France or America actually developed some kind of nylon cordage first, since they were both developing it at the same time and each of them took some time to perfect the process, but nylon rope (specifically) was developed in France first. In 1942, Anwendung des Seiles was updated again. Most of the advice remained the same, but rope for slings should be 7-10 mm, with 10 mm being preferred. The diameter of avalanche cord was no longer specified. In 1944, French caver Henry P. Guérin stated that Manila hemp was preferred over actual hemp, because it was more resistant to rotting, but nylon was even better. Braided/plaited ropes were said to be worse than hawser laid or shroud laid, because the strands that were woven inside the middle of the rope could not be inspected for damage. He also advised using coloured string as rope labels and a marker in the middle of the rope, as well as regular checking for rope condition, and pull testing. His suggestion was to have rope lengths of 20 m, 30-40 m, 50-60 m, 70-80 m and 100 m. In 1944, the following rope strengths were in use in France, where 9-14 mm ropes were used for ladders, lifelines and SRT, and 7 mm ropes were used as accessory cord and prusik loops:

French mountaineers were already testing Pierre Chevalier's nylon ropes by 1945. In 1945, the American National Bureau of Standards showed in testing that nylon ropes were stronger and vastly superior to hemp ropes at absorbing shock loads, and these results were published in 1947. DuPont purchased the rights to polyester in 1946. The first commercial nylon ropes were sold for maritime usage in America by AMCO (now American Ropes) in 1948, and commercial climbing ropes soon followed. In 1950, the British Mountaineering council (BMC) published their standards for mountaineering ropes. They described ideal ropes, but specified minimum performances that were slightly less than the ideals. Only hawser laid rope was acceptable, and must be made from Manila hemp, Italian hemp, flax or nylon. Nylon was treated as an afterthought. Rope diameters were not expected to be exact, only the weight mattered. For its weight, the nylon rope of the time was only slightly weaker than a modern nylon rope, while the other ropes were about half as strong. Nylon ropes must not get more than 25% heavier when wet, other ropes must not become more than 50% heavier when wet. Nylon ropes must stretch 35-40%, while other ropes must stretch by 12.5% at least (but normally 15%) at their maximum load. Non-nylon ropes must stretch half that amount at quarter of their maximum load. The extra strength of nylon meant that a nylon rope of the same weight was expected to give nearly double the stretch at the same load as a hemp rope, resulting in a significantly lower shock load. A nylon rope could also be much thinner and lighter for the same overall strength, and would therefore be even more stretchy, so it worked out as around 2.3 times as stretchy for the same strength of rope.

The following are examples of the ratings of actual nylon mountaineering ropes available in Britain in 1950:

DuPont released their own version of polyester in 1950, sold it publicly for use in textiles in 1951, and created another version of polyester in 1952. Almost all fabrics used to make SRT gear were subsequently made from either nylon or polyester. John Paul Hogan and Robert Banks made the first steps towards polypropylene in 1951. Norwegian company Timm Ropes created the first polyester rope in 1952. At that stage, most cavers were using hawser laid hemp rope, and British caver C. Lewis Railton tested a rope which was being used as a lifeline, and reported that it was considered satisfactory, as it could hold 408 kg (4 kN), about a quarter of what a modern rope is expected to hold. Splices in braided/plaited ropes were again described in 1952 by German Hermann Crasmoeller.

After having been used for hose pipes in 1845, drive belts in 1854, cables in 1858, ropes and pull cords repeatedly from some time before 1883, and for mountaineering ropes by 1911, kernmantel construction had been patented yet again in 1949 with cables, just in case anyone needed to be reminded about the idea. Kernmantel construction for ropes was patented in 1953 by German company Geo Gleistein & Sohn, now known as Gleistein. It was suggested as a way to protect a hawser laid core (either the whole rope or just segments of it) using a braided/plaited sheath made from nylon, or another tough synthetic material, and was stated as being useful for many things, including mountaineering. Though the idea of a hawser laid core and woven sheath had been used before, this is the first time that the fabric sheath of a rope is known to have been used primarily for protection of the core from abrasion, without performing a substantial load bearing function itself. Kernmantel rope for mountaineering was made in 1953, by German company Edelmann & Ridder, which later became known as EDELRID (the trademark Edelrid was used for shoelaces around 1920, registered in 1961, granted in 1962, and EDELRID was registered as an additional company name in 1965, and then used for the company in 2006). Austrian company Edelweiss (now owned by French company Béal) also like to claim it as their invention in the same year, and it is not known whether each company independently came up with the idea, or whether one created it first and the others copied it and managed to develop it into a rope that could be sold first. Neither Edelweiss nor Edelmann & Ridder patented it, in spite of Edelmann & Ridder patenting their other inventions, which suggests that neither of them created it first. EDELRID typically say that they "develop[ed] the first marketable kernmantle rope", rather than claiming to have invented it, and in personal correspondence, they stated that this is because they do not have any formal evidence that they invented it. Although some of their pages do say they invented it, that is likely to be individual authors making mistakes. The fact is that kernmantel ropes with a woven sheath and separate core strands had already been in use with mountaineering for over 40 years by that point, and none of these companies can claim to have originally invented it in 1953. However, this did mark the turning point, where ropes with multiple load bearing core strands, and a woven sheath used primarily for protection of the cores, became seen as a recommended construction for climbing ropes.

Polyester ropes were first made in 1953, and high density polyethylene was also created, which would later be used for ropes. In America, cavers had been using hawser laid hemp ropes for lifelines and handlines, and then also for SRT since 1951, but these were easily damaged by descenders, and caused cavers to spin in circles while using them. During the mid 1950s, some cavers switched to braided/plaited Goldline ropes. Giulio Natta and Karl Rehn made further progress with polypropylene in March 1954, and Italian company Montecatini started using it to make ropes from 1957. These were sometimes used as lifelines. British company Marlow started making polyester ropes in 1957, which were not intended for caving, but were sometimes used later by cavers. Polyethylene ropes were first produced in the same year. Also in that year, the idea of colouring the core and sheath differently to make damage more visible, and having ropes of different colours, was patented by Glanzstoff, at that time a German company run by the same family as Edelmann & Ridder. American cavers started using Sampson Cordage braided/plaited half inch (12.7 mm) nylon ropes some time after 1958, which were intended for sailing, and abraded far too fast when used with their indestructible rope technique.

In 1959, the idea of bicolour rope was patented by Edelmann & Ridder and Glanzstoff. The International Climbing and Mountaineering Federation (Union Internationale des Associations d'Alpinisme, UIAA) started creating safety ratings for ropes from 1960, and while not a legal body, this rating was used in many countries around the world, including Britain and other European countries, Canada, the USA and New Zealand (but not Australia); places where SRT developed. Polypropylene ropes (which are not suitable for SRT) emerged in 1960. Double braided/plaited rope was produced by Americans Ken Fogden and Arthur Chance at Samson Cordage in 1960, over 65 years after its use in window sash cords. By 1963, the early British adopters of SRT started using nylon hawser laid ropes, since kernmantel ropes could only be bought on trips to the European continent. Dynamic ropes were invented separately by German company Edelmann & Ridder (EDELRID) and Swiss company Mammut, in 1964. However, it was still not uncommon for climbers to buy nylon hawser laid rope for use as a lifeline for quite a while. In 1965, the first aramid known as Kevlar was created by American Stephany Kwolek at DuPont. It was used in industrial cables starting from 1967. In 1967, a British caver had died while abseiling down a mine shaft, after a hemp rope snapped at the lip of the shaft. British cavers were using both hawser laid and kernmantel rope by 1968. During the 1960s and 1970s, British climbers continued to use hawser laid ropes, with the following ropes and sizes being common:

In 1969, American cavers found the discontinued BlueWater rope whose manufacturer had closed down. A new company called BlueWater was created by American caver Dick Newell, using the old company's equipment to produce dedicated caving ropes, with kernmantel construction, polyester sheath and nylon cores, called BlueWater II. Their quality was significantly superior to the European ropes of the time, with predictable diameters and dynamics. The British Standards Institution standard for hawser laid nylon mountaineering ropes came into force in 1970. During the 1971 and 1972 British caving expeditions to Ghar Parau in Iran, a mix of 12 mm polypropylene (probably kernmantel) and 10 mm hawser laid nylon rope was used, for both lifelines and SRT. However, for the 1972 expedition, they used 12.1 mm braided/plaited nylon ropes, stating that the kernmantel ropes spun too much, were dynamic enough (they were dynamic ropes) to generate too much bounce, and were too expensive considering how easily they abraded when used with indestructible rope technique. They also used polypropylene ropes for shorter pitches. The University of Bristol Spelaeological Society expedition to Slovenia in 1972 used 10.1 mm hawser laid (for lifelines) and braided/plaited (for SRT) polypropylene rope, for the same reason. Also in 1972, Nick Reckert of the Cambridge University Caving Club wrote about methods and equipment for potholing. He stated that nylon is safe to use for ropes, while polypropylene melts when used with descenders. Kernmantel construction was recommended for abseiling, and 10-11 mm diameter was best. Ropes should be replaced after 50 abseils or 2 years, according to mountaineers. Aramids were used to make actual rope by American company Philidelphia Resins in 1972. Twaron, made by Dutch company Akzo, appeared in 1973, soon named Arenka. It was industrially produced in 1977, renamed to Twaron in 1984, mass produced in 1986 and finally sold commercially in 1987. During the 1970s, British cavers were using kernmantel polypropylene maritime ropes made by Marlow, since they were more static than the other European ropes, but they were not heat or abrasion resistant enough. In 1974, a British caver died after melting through a hawser laid polypropylene rope while abseiling on a figure of 8 descender down the Main Shaft of Gaping Gill, and British cavers were warned not to use polypropylene ropes. The polypropylene rope had been intended for use as a lifeline, and had suffered significant abrasion, which contributed to how quickly it melted through (which is why they should not be used even as lifelines, to avoid someone thinking they can be used for other purposes).

As a result of their better quality and resistance to both heat and abrasion, cavers started importing BlueWater II rope into Europe around 1974, which prompted European companies to start producing better quality ropes, so that European ropes could have predictable performance too. French caver Georges Marbach, one of the early importers of BlueWater II, found the cost too high, and decided to start producing Techniques Sportives Appliquées (TSA) rope instead. Bob Mathews of Cambridge University Caving Club described (personal communication) looking into the options for ropes in 1974. Polypropylene was deemed to be at risk of melting from hot descenders. Nylon was good for abseiling and traverse lines, but all known nylon ropes at the time were climbing ropes, which were too dynamic for prusiking. A version of polyester called Terylene was deemed good as long as it had been pre-stretched, but the only known ropes of this type were made for sailing, specifically for halyards (ropes used to haul up a sail). Hawser laid ropes spun too much. He had mistakenly thought that kernmantel rope would allow dirt to get into the cores and that the core fibres could move too much, grinding against the dirt, and becoming damaged. Instead, he had assumed that double braided rope made for sailing would be the best option, not realising the issues it had with the core and sheath being able to slide over each other too much. 12 mm rope was thought to be the best option. The ropes used were made by either British company Bridon Ropes or Marlow Ropes. This was said to be consistent with what other cavers were using at the time.

A British caver died whilst prussiking up a shaft in the Spanish Cueva de Liordes in 1975 while using a rope that did not have much abrasion resistance (presumably polypropylene) against a rub point without adequate rope rub protection. Other near misses happened when rope rub protection failed, such as one Brtish incident in Dale Head Pot in 1975 where a Cambridge University rope suffered a severed sheath while Nick Reckert was prusiking, slipping far down the cores, and even though the injuries were not severe, cavers shunned kernmantel ropes as a result. However, the rope used was actually one of Bob Mathew's double braided polyester sailing ropes, which will have been designed to have a sheath that could move easily to allow splicing. Another event happened at Nick Pot around the same time, where a rope was severely damaged by a rub point, which only survived because it was a BlueWater polyester rope. Marlow were advertising their polyester ropes to cavers in 1977. High quality Edelrid nylon kernmantel ropes came onto the British market shortly afterwards. British cavers preferred the European ropes by the late 1970s and early 1980s, since their flexibility made them better for Alpine rigging. During the late 1970s, Australians were using polypropylene ropes for short pitches. BlueWater started making the first American dynamic rope in 1982. Technora was made by Dutch company Teijin 1987.

The American Society for Testing and Materials (ASTM International) published their standard for testing rope strength in 1983. The American National Fire Protection Association (NFPA) first published their rope standards in 1985. Dutch State Mines created Dyneema in 1989. The International Organization for Standardization published their standards for nylon and polyester ropes in 1990. The European rope standards for SRT rope and dynamic rope were created in 1997, but were subsequently changed to allow the use of thinner SRT rope for caving (because the standards for caving were made without initially consulting cavers), and actually came into force in 1998. The UIAA standards for dynamic rope were published in 1998, and subsequently followed the European standards starting from 2004. ASTM International published their standards for static rope in 2001, replacing their old rope testing standards. BlueWater produced their first all-polyester caving rope some time between 2000 and 2006. The UIAA standards for static rope were published in 2013. Hawser laid ropes continued to be occasionally used underground as fixed handlines, with some still in use at the time of writing in 2023.

This history section only covers ropes. This article also has a detailed history of many of the other devices and techniques that are used for vertical caving.

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