Dynamic Rope

A dynamic rope is especially constructed for greater stretch so that energy can be absorbed from a sudden load. Example to absorb the shock of a falling rock climber. Less pressure is put on the climber and the equipment when dynamic rope is used.

Kernmantle ropes are the most common type of dynamic rope, with two distinct features – an inner core or “kern” with an outer braided “mantle”. The core supplies the key strength factor whilst the outer protects the kern and portrays the stretch factor.
Dynamic ropes are made to be supple and to resist cutting over sharp edges. They vary in width from 10 to 13mm as different widths are used for different applications.

Types of dynamic ropes

Single rope – or full rope used for sport climbing is the term used to indicate that it has the full required strength of a mountaineering rope. This rope needs to be able to withstand 5 successive falls whilst holding 80kg (average weight of a man)

Half rope – or double rope used in trad climbing, mountaineering and ice climbing because 2 ropes are used when lead climbing. The half rope is tested with 55kg mass and must be able to resist 5 successive falls

Twin rope – are thin ropes which when leading, are used as if they were a single rope, mainly for ice climbing and long alpine routes. As in the single rope, the twin rope needs to be able to withstand 5 successive falls whilst holding 80kg (average weight of a man)

Walking rope – this is actually a single twin rope used in low impact situations, for scrambling and short roping

Specification
Every dynamic rope needs to conform to specifications standards and carry a quality certification. The most stringent of them is the European standards – the ropes carry a quality certification mark known as the technical reference Standard EN (European Norm) and a CE mark which stands for Conformity to the European Directive.

Identification

Dynamic ropes are manufactured with high tenacity polyamide or polyester filament yarn. They are typically bright multi-coloured mantels usually with contrasting markings.

Fall Factor
The fall factor of access rope determines the fall resistance. The higher the fall factor, the harder the fall. The fall factor is determined by dividing the height of the fall by the length of the rope deployed.

The value of the fall factor is between 0 and 2

For dynamic rope the fall factor needs to be <1.77