07 March 2010
It is no surprise that humanity has developed rope-making in such a way, and it is unthinkable that there will ever come a time when the common, simple rope will become obsolete. Rope provides us with the means to delve into the deepest cave, to seek out fuel or food in remote places, to move over rugged terrain with everything securely held on pack animals or vehicles. It joins things together, and in doing so keeps things safe. Rope was essential for the block and tackle construction techniques of the medieval stone masons, and the vital tool of the Egyptian labour forces. Thick, strong cord keeps mountain climbers off the ground, and (for the rest of us) those thin, black cords keep our shoes on our feet. And of course, it's only when your pockets are completely rope-free that you realise how useful a length of cord could be...
Vegetable Fibre Cordage
Until this century, rope was made from shredded, combed and graded fibres of plant stems; maybe flax or jute. Alternately, the leaves of sisal or hemp provided a tough, suitable fibre. Fibres attached to seeds, such as cotton, or the fibrous husk of coconut shells (coir) were also suitable.
If plants weren't available, horse, camel or even human hair were just as usable, though vegetable fibres were far more common. For obvious reasons, such ropes are referred to as natural fibre. These fibres were spun clockwise to create long yarns. Several yarns would be twisted anticlockwise to form strands. Finally, three strands would be laid together and spun clockwise to create a typical rope.
The resulting cord was relatively strong, but prone to abrasion, and, in many cases, the natural fibres could become prey to mildew, rot, vermin or insects. It might swell when damp, and in icy conditions could easily freeze and simply break. Nevertheless, in their time, natural fibre rope was an incredibly useful tool, and an important aspect of humanity's historical development.
Some natural fibre rope remains in use. Those thick ropes in the gym are commonly made of high-quality hemp cordage, and coir ropes grace more than one boat fender. On a less practical note, the interior decor of your everyday nautically-inclined theme pub would be far less authentic without their multiple yards of natural fibre rope. (Decide for yourself whether the eradication of nautically-themed pubs would be adequate reason to ban natural fibre ropes...)
As technology improved, so did rope-making. In the 1930s the basic elements for synthetic cordage were discovered and developed. Fine, continuous clusters of multifilaments, less than 50 microns in diameter became a real possibility. The production of coarser monofilaments was perfected, and flat, narrow strings could be produced through careful extrusion of synthetic chemicals.
Such synthetic materials are stronger and lighter than their vegetable counterparts. A three-strand nylon rope is more than twice as strong as a manila one, yet weighs half as much and can last four times longer. They do not lose strength from being wet, have high breaking strength and can withstand sudden shock loading.
This is not to say that synthetic ropes do not have their own shortcomings. They are susceptible to heat, and thus friction can easily cause softening, melting or, most disastrously, parting. That said, polyamide produces the strongest man-made cordage, and Polyester, Terylene, Dacron and polypropylene offer common alternatives. In situations where strength is required and friction can be minimised, synthetic cordage is an unparalleled choice.