A modern kernmantle rock climbing rope is manufactured from very fine threads of polyamide: that’s nylon to you and me. Nylon is one of those long known polymer materials which even now is being rediscovered, reworked and processed anew to extend its properties and performance. Its use within the manufacture of climbing ropes for the rock, ice, mountain and climbing wall environments is an outstanding example of the way an old material has been taken beyond its original boundaries and limitations.
Manufacturers such as Mammut, Bluewater and Edelrid have refined their ranges of climbing rope products and treatments, to the point where the recreational market is highly competitive. That’s only half the story as enormous quantities of rope are now used in industrial access work and rescue services. Here we are sticking to dynamic climbing ropes.
Although most manufacturers will claim that there is something unique about their braiding process, my research seems to demonstrate that there isn’t a huge difference in the manufacturing techniques. The competitive edge comes from subtle variations in the programming of their braiding machines and the after treatments. A typical example is the Mammut process which is explained in outline on their website.
Mammut uses high quality Polyamide 6 (Nylon) for the production of its filaments, which run the whole 50 – 60m length of a typical rock climbing rope. In the first stage, between two and six filaments are spun together to make a strong yarn. Depending on the precise end use of the rope 4, 5 or 6 yarns are then combined in the next stage to produce a braid. Several braids are then combined to form the core of the rope. This part of the rope’s structure gives it the majority of its strength.
The braiding process gives the braids a crucial spiraling twisted structure, which also increases the rope’s elasticity, an incredibly important factor in protecting Traditional Industrial Sector a falling climber. Without elasticity, the fall would end too abruptly, generating an intolerable shock loading that breaks the rope – or the falling climber.
Additional elasticity is gained in the next stage, which involves the braids being coated and thermally shrunk. Mammut isn’t the only manufacturer to use a variation of both thermal and chemical treatments. It’s hard to find the exact details of what these treatments actually achieve; but the steadily reducing diameter and weight of UIAA approved indoor, mountain, ice and rock climbing ropes points to the fact that the treatment regimes are improving performance of the products. The chemical treatments seem to be water repellant and internal friction reducing, so that individual fibres are more equally loaded.
Finally the rope has its core covered by a sheath of (usually multi-coloured) threads. The colourful exteriors of ropes have become an important factor in these days of double and twin roped climbing styles. Many of us have had the “gibbers” from clipping the wrong rope into a piece of protection when we are strung out at the edge of our ability and scared silly. Colour differences can be a useful safety factor for the stressed climber, whether on the lead or abseiling (rappelling). The wildly different external patterns, which even change at the halfway mark on some ropes, are achieved through careful programming of sheath patterns on the highly capable braiding machines in use in today’s rope spinning sheds.
Different uses, demand a different balance between strength of the core and the toughness of the sheath. A rope that will be marketed as a climbing wall rope; which will have a life of regular falls and constant lowering of exhausted leaders, needs a strong tough Factory Processes sheath to withstand the abuse. On the other hand a rock climbing rope aimed at a high performing pushy climber will need to have incredible lightness and perfect handling characteristics and would not be expected to receive too many falls, before being discarded.
In these days of ever present marketing, you could be forgiven for thinking that the gaudy colours of a climbing rope were simply to catch the eye of the sucker with the wallet. The reality is that they do reflect something of the improved performance, durability and lighter weight of some top end rock climbing rope products.
