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LOW←TECH MAGAZINE

Obsolete Technology

Lost Knowledge: Ropes and Knots

Ropewalk factories are some of the most remarkable industrial workshops and buildings in history.

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Image: Rope making.

Ropes and knots are among the most ancient and useful technologies ever developed by man, predating the wheel, the axe and probably also the use of fire. Today, they are fast on their way to become an obsolete technology.

The earliest fossilized fragments of ropes and knots date back 15,000 to 17,000 years, which makes the direct evidence of this technology much older than that of the axe (6000 BC) or the wheel (5000 BC). However, based on indirect evidence (perforated objects, wear marks on artefacts, bone needles, representations in art, etcetera), archaeologists believe that the use of ropes and knots dates between 250,000 and 2,500,000 years old.

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Image: A perforated object.

Speculatively, this might even predate the use of fire (400,000 BC) and coincide with the first crude stone tools. It is interesting to note that modern apes have some very elementary skills at knotting and ropework, which suggests that the beginning of knot tying may well have preceded the evolution of the genus Homo.(source

Few realize the importance that knots and cords have played in human history. It is remarkable that they are not even mentioned in otherwise great books on the history of technology. Yet, it is hard to find any important technology developed over the last 250,000 years that did not, in some way, make use of ropes and knots. Starting in prehistoric times, they were used for hunting, pulling, fastening, attaching, carrying, lifting and climbing.

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Image: Hunting.

Some early examples of their applications are fishing nets, hunting traps, tying stones to sticks to make spears and harpoons, the construction of bows, building shelters, making baskets, fastening clothes, tying animals (and people), harnessing horses and oxen to chariots, and constructing rafts. Cordage of some kind, and the knots needed to make it work, have played a crucial role in the earliest technological development of man.

Hauling and lifting

With the rise of civilization, the ingenuity in the application of ropes and knots was expanded, used for the hauling of canal boats, the dragging of heavy stones along ramps, and the erection of large obelisks (first done by the ancient Egyptians), the development of cranes, lifting devices and catapults (kicked off by the Greeks and the Romans), the construction of enormous rope bridges and rope suspension bridges (which originated in China), the appearance of sailing vessels, and more.

The construction of the noose to hang people was another application of ropes that was invented by “civilized” people, as well as the ringing of church and monastery bells. Although other materials were involved, notably stone and wood, none of these technologies could have worked without ropes and knots. Apart from all these practical uses, ropes and knots also became an important decorative element, especially but not limited to Chinese and Celtic cultures.

Talking knots

Ropes and knots were also used as record keeping devices, best known in the form of the Peruvian “khipu” or “quipu”. The Inca civilization (1400 - 1530) made extensive use of them for accounting and census purposes - recording the contents of storehouses, the number of inhabitants, etcetera (picture credit and more info).

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Image: talking knots.

A khipu consists of a long cord from which hang thinner ropes, sometimes just a couple, sometimes many hundred. These pendant cords are tied in a series of small knots. Originally, they were dyed in rich colors. Because the Inca’s, unlike other civilizations, appear to have lacked a written language, one hypothesis is that these bundles of knotted strings also contain narrative information and can thus be regarded as a form of writing (1 / 2 / 3). The khipu was probably developed in pre-Inca times, because less elaborate knotting recording devices already appeared in primitive societies in China and elsewhere (1 / 2 / 3 / 4.

The hardware: ropes

In rope making, four basic steps are identified: preparing the fibre, spinning the fibres together to form yarns, twisting the yarns in bunches to form strands, and winding the strands in rope (see the illustration on the right).

At each stage the twisting is performed in the opposite direction from the previous stage, in order to overcome the natural tendency for each yarn, strand or rope to unravel. Most ropes consist of three twisted strands (called a Hawser laid rope).

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Image: From fibre to rope.

It is likely that the earliest “ropes” in prehistoric times were naturally occuring lengths of plant fiber, such as vines, followed by the first attempts at twisting and braiding these strands together to form the first proper rope in the modern sense of the word. This must have been a time-consuming process, more related to weaving plant fibers into mats and baskets than to later ropemaking methods (more info: 1, 2, 3 and 4).

For centuries afterwards, ropemaking remained a manual process, without the use of tools. It could be done alone, or by two people working together. In the latter case, one person held the two strands, one of them in his hand and the other tied to his big toe, while his companion standing some distance away twisted them together (source).

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Image: Making bamboo ropes.

Another simple method was used in China when making bamboo ropes. Two workers on a high wooden tower corded bamboo strips which had been cut several metres long and hung down from the working platform so as not to become entangled, see the picture above left (source). The ancient Egyptians (from 4000 BC on) were the first to develop a special tool to assist the making of rope, using a hand held spindle (source). Much later, similar devices appeared in Europe and China (illustration above, right).

Ropewalks

International trade by sailing vessels skyrocketed in late medieval Europe and naturally, so did the demand for ropes. Sailing ships required rope for anchors and rigging (supporting the masts and managing the sails), and could easily carry with them 35 kilometres (around 20 miles) of rope. The arrival of larger sailing vessels (and the growing importance of the mining industry) meant there appeared a need for much longer, stronger and thicker ropes.

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Image; A ropewalk.

This led to the construction of some of the most remarkable industrial workshops and buildings in history: ropewalk factories. Because the spinning of the fibres (illustration above, England, 1770) and the twisting of the yarns and strands (illustrations below) had to be done in a straight line, the length of the rope was set by the length of the workshop. This resulted in strange looking narrow buildings which were typically 350 to 450 metres (1150 to 1475 feet) long by the 18th and 19th centuries, a time when navigation and mining kept pushing the demand for ever longer ropes. One ropewalk factory in Australia at the end of the 19th century was 760 metres long (2500 feet, source).

Several (human-powered) machines were added to make the process more efficient (illustration below - note that the illustrator made the ropewalk look much shorter than it was). At the beginning of the Industrial Revolution, these were scaled up and converted to steam power. In Europe, the US and Australia, some ropewalks remained in operation until the middle of the 20th century, after being converted to be powered by electricity. In some “lesser developed” countries they are still being used.

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Image: Rope making.

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Image; The stages of rope making.

The ropewalk method - which was also in use in China - is very simple. Describing it is a little more difficult. I came across many lengthy and sometimes puzzling explanations, but the one I found in the book “Handbook of Fibre Rope Technology” makes it quite clear (the accompanying illustration comes from the same source):

At one end, there is the jack, which has three hooks that can be rotated. At the other end, there is a carriage with a single, rotatable hook. In stage one, three sets of yarns are pulled off bobbins and are held along the length of the ropewalk.”

In stage 2, an assistant turns the crank handle of the jack so that the yarns are twisted into strands by the rotation of the three hooks on the jack. Twist causes the lengths to contract, so that the carriage has to move along the ropewalk, under the control of the ropemaker.”

In stage 3, the hook on the carriage rotates in order to twist the strands into the rope. In the usual mode of operation, the initial strand twist is made as high as possible without kinking. When the single hook on the carriage is released, the high torque in the strands causes the hook to rotate, and this, in turn, cause the three strands to twist together and form the rope. The ropemaker controls the production of the rope by continually pushing back its form of formation to give a tight structure. Meanwhile, the assistant continues to rotate the crank to make up for the loss of twist in the strands.”

Remaining Ropewalks

Most ropewalks were set up outdoors, sometimes underneath a wooden shelter. Some were housed in a brick or wooden building, which dates back to the beginnings of the 19th century.

The majority of earlier communities, irrespective of their size, had their modest ropewalk. Coastal towns, due to necessity, had several of them. For example: Boston (US) had 14 ropewalks in 1794, Plymouth (UK) had 14 of them in 1816 (source).

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Image: Ropewalk machinery.

Ropewalks were mostly located outside the city or town, because of the fire risk they posed. In wooden structures especially, the combination of dried hemp and the open flames of the tarring vats was very risky (tar, made from pine trees, was used to make hemp cords more water-resistant).

Nothing remains of the smaller medieval ropewalks, nor of many later ropewalks in open air or in wooden buildings. However, some ropewalks housed in brick buildings are still intact. The ropewalk at Chatham Dockyard, UK, constructed in 1790 and the only one which is still producing rope commercially today (see these images) has an internal length of 346 metres (1,135 ft.). In the US, a 250 foot section of an early 19th century rope walk (the Plymouth Cordage Company Ropewalk) is preserved at the Mystic Seaport Museum in Connecticut.

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Image: Rope making factory.

The largest rope walk still standing dates from 1666 and was in operation until 1867: “La Corderie Royale” in Rochefort, France. With an internal length of 374 metres (390 metres external length), it was the longest brick building of the 17th century (aerial view of it above, source) and could produce ropes with a length of up to 246 metres. (Twisting the strands into rope shortened the length of it, naturally. The final rope was about two thirds of the length of the yarns used.)

The software: knots

By themselves, ropes are essentially useless. They have to be tied to something (be it an object, another rope or to themselves) and therefore they need knots to function. A simple comparison would be that if ropes are considered the hardware, knots would be the software. While knotting technology must have been very simple in prehistoric times, it became a highly specialized art over time.

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Image: A collection of knots.

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Image: A big rope.

The sheer number and diversity of knots that was once in use would be bewildering to the modern city-dweller. About 4,000 different knots exist, ranging from the very simple to the extremely complex. Not so long ago, each profession or trade had adopted the knots best suited to its requirements, and knotting was part of their daily lives. Today, only campers, boy-scouts, climbers and sailors acquire some knowledge of this once imperative technology.

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Image: Ship ropes.

There are two reasons for the demise of knotting. Firstly, many technologies that were once dependent on ropes and knots have disappeared. These are most notably sailing ships, but we have also stopped hauling canal boats and using pack trains or catapults (we have bombers and diesel engines now), as well as hundreds of more mundane tools and devices that once made use of ropes.

The demise of natural fibres

Secondly, the hardware has changed. From prehistoric times to midway the 20th century, ropes were made from vegetable fibres (and to a much lesser extent from animal fibres such as sinews and hairs). Egyptian rope was generally made of papyrus plants or date palm fibre. In Eastern Asia, bamboo, grasses, and coconuts were used.

Hemp, which use originated in China in the third millennium BC, became for many centuries the material of choice for rope manufacturing in Europe and, from the 17th century onwards, North America.

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Image; Knotting techniques.

In 19th century Europe and North-America, hemp (and flax) were largely superseded by imported tropical fibres: mainly manila (made from the leaves of the abaca plant), but also coir (made from the shell of coconuts), sisal and henequen. Cotton and jute were also used to make (weaker and less durable) ropes.

Beginning in the second half of the nineteenthy century, many ropes made of natural fibres were superseded by “ropes” made of steel. Elevators, cranes and suspension bridges, for instance, are now fully dependent on steel “wire ropes“, while modern sailing yachts make use of steel wires. Gradually, wire ropes also supplanted natural fibre ropes for mining and mooring purposes.

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Image: Steel wire rope.

Where “real” ropes are still used, for example in the fishing industry, for water sports equipment, parachutes, hot air balloons (illustration below) or for mountaineering (including industrial rope access), they are now almost always made out of synthetic materials, based on refined oil - a trend that kicked off in the 1950s. Today, the market for natural fibre rope has all but disappeared.

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Image: Nets.

Polymer-based ropes are stronger and lighter than ropes made from natural fibres, naturally replacing them in no time. Nylon came out of the laboratory at the end of the 1930s, and today it is the most frequently utilized material for the production of ropes. Polyester and Polypropylene arrived on the market in the 1940s and the 1950s respectively - these materials are not as strong as nylon but much cheaper than natural fibre ropes.

Today we have - among many others - Kevlar, Technora, Twaron, Vectran, Zylon and Ultra High Molecular Weight Polyethylene ropes (the latter are 10 to 100 times stronger than steel). Amazon books arrive in boxes tied together with adhesive tape, gadgets come in boxes held together by plastic strapping. The only natural fibre rope that I could find in my apartment was the cat-scratching post.

Of course, contrary to natural fibre ropes, the manufacturing of synthetic cordage requires expensive, high-tech (and at present digitalized) machinery.

Knot-holding ability

None of these new materials is compatible with knots. This speaks for itself in the case of steel wires, adhesive tape and plastic strappings, but the same goes for synthetic ropes: most have very poor “knot-holding ability” - this is why shoelaces are mostly still made of natural fibres. Knots have thus been replaced by an array of other fastening technologies, made out of plastic, steel or aluminium (illustration below).

Moreover, most natural fibre ropes sold today when compared to those sold one hundred years ago are of inferior quality, and are more likely to be made water-resistant by the use of biocides and chemical preservatives instead of using tar (source, pdf).

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Image: Fastening technique.

Interestingly, natural fibres keep losing terrain to their synthetic alternatives. Manufacturing a wire rope is somewhat similar to making one from natural fibre: the individual steel wires are twisted into a strand, and these strands are again twisted around a core. Until recently, this core was made out of hemp, or another natural fibre, but these days this is becoming increasingly rare. Instead, steel or plastic (Polypropylene or PVC) cores are now commonly used. And if a hemp rope is still used as the core of a wire rope, it is impregnated with PVC (source).

Roped, wired, wireless

Synthetic fibres and steel might be stronger than hemp rope, but this progress comes with a price. Synthetic ropes release toxic fumes when they alight, they are not bio-degradable (which is why they don’t rot) and they cannot be recycled (some of them can in theory, but not nylon, which is the most used).

Natural fibre ropes, on the other hand, were extensively recycled throughout history, either for making new (lesser quality) ropes or to produce “oakum”, which was driven into the seams of wooden ships to render them water-tight.

Both steel and plastic ropes and wires are much more energy-intensive to produce than natural fibre ropes, and they are fully dependent on fossil fuels for their existence (steel could be produced by renewable energies, but in reality this does not happen). It also means that their cost is dependent on the price of oil, which is not the case for locally grown natural fibres.

In short, fastening technologies are now dependent on non-renewable sources, while natural fibre ropes and knots are not. This sounds familiar, because it is true for most of our modern technologies. Of course, because all our machines are adapted to stronger steel and plastic ropes we can’t go back to natural fibre ropes unless we adapt the machinery itself.

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Image: A rope.

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Image; Inca rope bridge.

While ropes have disappeared, our society has become ever more “wired” - the arrival of electricity and modern communications technologies around the turn of the twentieth century have brought with them an explosion of wires or, more correctly termed, cables (because they always consist of bundles of wires).

While I was wandering around my apartment in search of ropes, I had no trouble finding cables. In just one hundred years, we evolved from a “roped” society to a “wired” society. And more recently we seem to have entered the “wireless” age, with mobile phones, internet over the airwaves and - if we let the engineers have their way - wireless electricity. Since all these new applications keep pushing fossil fuel consumption up, it is a safe bet that before the 21st century is over, society will return to ropes, ropewalks and knots.

© Kris De Decker (edited by Shameez Joubert)

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