TEAR IT UP
Knot breaking by SLACKTIVITY
Author: Daan Nieuwenhuis
Break tests: Daan Nieuwenhuis & Samuel Volery
Pictures by: Daan Nieuwenhuis
Since a few years the low-tension lines have become more of a standard. This new style brings new styles of rigging, one of these is tying knots in the back up webbing. But what does a knot in webbing actually hold? How does the knot influence the breaking strength of the webbing? As SLACKTIVITY we also had the goal to test out multiple knots to connect our back-up webbing to the mainline in our Type B webbings (redTube & pinkTube). This is done by making a knot in your back up webbing, and connect it to a T-Loop with a quicklink.
WARNING: Knots can be complicated and hard to check properly. Don’t use them if you’re not 100% sure that the knot is correct, or if there is nobody that has the knowledge to double check it. Even after tying a knot 20 times, mistakes can still happen. Always double check each other rigs.
Many people who see a highliner on a highline for the first time, think that the forces are very high, especially when falling into the highline (leash fall). Since the slack ("sag") in highlining is not as limiting as in longlining over ground, most highlines are much less biased and this leads to lower forces than you would like.
Check out this video and write out of the tests we did:
Because slacklining is still a young sport and there are still few materials and standards that are geared to the slackline application, material from other applications (from sports and industrial climbing to industrial applications) is used.
Here in this article it is shown that this is carabiners can be used in a few applications while slacklining. Be aware that you never use aluminum carabiners in your rig. They tend to break under cyclid load.
This video shows how the carabiner shape affects the breaking load of triangular loads.
The forces that occur during slacklining are composed of the preload force and the weight of the slackliner. This can be both static and dynamic. It is not possible to determine the forces without measuring device exactly - but one can calculate the forces in static slacklining with a formula approximately.
Here are some basic rules of the forces: