Sewn slings: the all-rounders for climbing and mountaineering
There are few pieces of climbing equipment that are as practical and versatile as sewn slings. Sewn runners can be used for self-belay, constructing a pitch or even to extend and fix anchor points. They are made of polyamide or dyneema and come in various, ready-made lengths.
Why are sewn slings stitched?
In the past, sewn slings for mountain sports were bought by the meter and then cut to the desired length. A special water knot was used to convert the open sling into a round sling. However, with the introduction of the much lighter and thinner dyneema material, this design reached its limitations. Despite all the advantages which dyneema offers, this material has one crucial drawback. Dyneema fibers are significantly smoother than polyamide, which causes the material to move in the knot, meaning the sling could loosen up on its own in the case of heavy loads. Since the knot strength of dyneema cannot be guaranteed, it is stitched together in sewn slings.
Which length for which purpose?
Classic sewn slings are one, two or four times the shoulder width, i.e. 60 cm, 120 cm and 240 cm. The shortest slings are predominantly used as self belays or intermediate belays when feeding a rope through an hourglass or around a rocky knoll. The medium slings are the classic belay sling and the long 240-cm slings are primarily used for large jagged rocks.