Building belays during traditional climbing and mountaineering will very often involve equalising slings.
Most often, I use the method that involves tensioning all the strands by pulling them in the direction of the expected load and then grasping all the strands and tying them into a large overhand (sometimes Figure of Eight) knot on the bight. This is the first technique shown in this video.
However, there seems to be something special that occurs in winter whereby the distances and lengths involved rarely allow this method to work. It’s vital, therefore, to know other methods of equalising slings at a belay.
There are several other methods, but two of the most well-known that I find come in handy in winter are these ones, because they need very little of the sling’s length to create. The first involves tying a loose overhand knot in the sling before clipping the second anchor and then adjusting this to create two equally tensioned loops. This is the second technique shown in the video.
A further method involves tying a clove hitch in the sling at the correct point of tension and clipping a large karabiner into this clove hitch. This karabiner is then locked and used as the main ‘power point’ into which other karabiners are then clipped, so the karabiner has effectively replaced the closed loop in the sling that was created during the first method in the video.
All of these techniques are usually covered at relevant points in one of our rock-climbing courses.