Rope Parts and Types

If you've ever wondered what's in a rope, here's a brief breakdown from a ropes 101 kit from Edelrid, see it here for more information.

Raw material: The basic raw material used to make all climbing ropes are ultra-thin filaments made of high-quality polyamide 6.6 (nylon). They are used to make both the core and the sheath. We would like to show the journey that each individual ultra-thin filament undertakes before it becomes a rope. In keeping with the kernmantel concept, we have broken the manufacturing process down into different stages for the core and the sheath.

Core: Up to 135 of the ultra-fine polyamide filaments are twisted together to make a strong yarn. A number of these yarns are then combined (twisted) in a multistage process to make a core strand. The process is called twisting. It’s this twisting process for the strands in the core that gives the rope its dynamic elongation, i.e. the ability to act like a spring when shock loaded. The number of twists over a given length determine the mechanical elongation and strength of a rope. A rope may contain up to 2,000 meters of these core strands.

Sheath: The same principle is used to make the sheath as the core strands. Two to four colored twisted yarns are combined (twisted together) and wound onto spools. To ensure that the sheath yarns have the same characteristics as the core strands, they too are placed in the autoclave to shrink. To guarantee that the sheath strands are uniformly conditioned in the autoclave, they first have to be unravelled. This is done using a special machine that unravels the strands into loosely coiled lengths, or skeins. Once these skeins have been autoclaved, they are unravelled again and then spun back onto the spools ready for the next step.

Rope Types

Single ropes: Single ropes are the most common type of climbing rope. They are the classic climbing rope, as it were. Single ropes come in different lengths and diameters and cover a range of different applications. They are classic sport climbing ropes, for both outdoor and indoor use, and are also used for alpine climbing and mountaineering and by big wall climbers. One of their main advantages is their simple and uncomplicated handling. EDELRID manufactures single ropes in diameters from 8.9 mm to 10.5 mm. They weigh in at 52 to 69 grams per metre. Single ropes with a thicker diameter are generally stronger and can withstand a greater number of falls. However thicker also means heavier. For intensive use, such as working routes or top-roping, there are robust single ropes with a higher sheath proportion.

Twin ropes: Twin ropes must always be used in pairs. They only offer standardised safety when used as a pair. It is important that twin ropes are always clipped together into each bolt or piece of protection. They have a lighter weight and a thinner diameter. Twin ropes offer greater safety reserves due to increased redundancy that comes with using two ropes. Twin-rope techniques also provides increased safety due to their significantly greater sharp edge resistance as well as reducing the risk of a total failure (stonefall, breaking over a sharp edge). This is why twin ropes are particularly suited to alpine climbing in demanding terrain or for ice and mixed climbing. Using twin ropes also allows you to abseil twice as far, which means that you can escape from a wall quicker. Twin ropes normally have a diameter of 6.9 to 8 mm and weigh around 40 grams per metre.

Half ropes: Half ropes (also known as double ropes) are designed, like twin ropes, to be used as a pair. The same as twin ropes they also only offer standardised safety when used as a pair. However, unlike twin ropes, half ropes do not need to be clipped together into each bolt or piece of protection. This technique is ideal for poorly protected or zig-zagging routes or for traditional climbing (trad). It allows rope drag to be reduced where protection points are spread out and considerably reduces impact force. It follows that climbing with a pair of half ropes requires using a belay device that allows you to manage two ropes simultaneously, i.e. to be able to pay out and take in both ropes. Half ropes are used for the same activities as twin ropes. They have one important difference – half ropes can be used as a single rope to bring up a second. This is particularly relevant when climbing as a party of three and bringing up two seconds. Half ropes range in diameter from 7.5 to 9 mm and generally weigh from 40 to 50 grams per metre.