Please, plastic – when lives depend on it

People scale the steepest mountains and cliffs and hoist themselves up to dizzying heights, usually relying on a plastic product to save their lives should they fall. The polymer saviour is celebrating its birthday: On 16 February 1937, the US chemical company Du Pont filed a patent application for ‘Nylon’, a versatile and durable synthetic fibre.

Even a small child can balance lightly and confidently on a high wall when guided by an adult’s hand. Without that supporting grip, many a trek along a narrow ridge would be taken on wobbly legs and might well end in a fall, as a view into the steep drop below can cause vertigo and lead to a loss of balance. Experts in tackling great heights, when out in a group, also rely on contact – though not by holding hands. When hiking and climbing in steep and treacherous terrain, a rope provides a sense of security comparable to that of a firm grip. It binds the participants in a mountain hike or climbing tour into a ‘rope team’ or effectively provides a secure hold on a steel piton embedded in the rock face.

Right up until the 1960s, hemp ropes were common and widely used as a means of securing things in alpine environments. The natural fibre, twisted into ropes as thick as a finger, served its purpose even under the greatest strain, until rain and dirt caused the fibres to wear out. This is a process that takes place out of sight and is rarely obvious: even if the hemp rope appears dry on the outside, no one can say for certain what its inner core is like. All too often, the material’s weakness only becomes apparent when the rope is put to the test and subjected to great tensile forces – such as those that occur when a person falls onto the rope from a great height. Right up until the 1960s, it was the case that when a mountaineer suffered a fatal accident in the mountains, it was not uncommon for this to be due to a rope breaking. Even the thickest hemp ropes would give way without resistance and snap if the fibres had rotted.

A synthetic material moulds to the leg and ensures safety on the mountain

In the late 1950s, an invention by the US chemical company E. I. du Pont de Nemours and Company, better known by its abbreviated name DuPont (—which, following its merger with Dow Chemical, initially operated under the name DowDuPont and, since June 2019, as DuPont de Nemours) and its employee Wallace Hume Carothers (1886–1937), to significantly improve safety in high-altitude mountaineering. The material in question is known in chemical terminology as polyhexamethylene adipic acid amide. Plastics experts tend to use the abbreviation ‘polyamide’. To the general public, however, it is better known as nylon (or Perlon): What was woven at that time – that is, around the middle of the 20th century – as an inexpensive silk substitute for ladies’ fine tights or as tear-resistant fabric for parachutes could, as it later transpired, also be spun into high-strength, stable rope material. On 16 February 1937, DuPont filed a patent application for nylon in the USA.