For safe rigging of climbs think IDEAS
I – Independence
When we climb on a rope, we often climb at or beyond our limit (unlike lead climbing for example). To that end, when we rig a bottom-rope or top-rope system we rig it knowing that it will very likely be tested and loaded. With this in mind get into a habit of working on a ‘belt and braces’ basis.
Start by looking for two (maybe three if needed) solid independent anchors. By independent we mean two separate rocks, trees etc. If one fails then it should have no impact on the other anchor. The anchors of choice don’t move under any circumstances. Make sure you make your selection carefully and the word “bombproof” should always spring to mind.
Attach to each anchor your static line and tie this into your system so that each anchor is independently attached to the carabiners through which your dynamic climbing rope will pass. When you tie your system ask yourself if each rope can hold the load independently? Knot the rope with a double figure of eight so that there is even independence where the climbing rope runs through the carabiners. And, use two carabiners, hanging over the lip of the rock face with their gates hanging down and back to back. Everything should be rigged with independence in mind.
D – Direction
Consider now the direction of the system. When we rig a top-rope system with a leader bringing up a second we have an ABC system – anchor, belayer, climber. It’s just the same with top and bottom-rope rigs. What we are looking for is a system that when loaded won’t budge at all. Multiple anchors also help afford a degree of stability so that the rope hanging over the lip of the rock-face doesn’t wear through. Think also about the direction that any gear might be pulled when it’s loaded: we don’t want wires or hexes being pulled from their seat!
E – Equalised System
Rig your system so that it is equalised. Having each rope that is attached to each anchor equally loaded means that each anchor is sharing the load. This in turn means that each anchor is even less likely to fail. In the worst case scenario, if an anchor did fail, then we don’t want the other anchor(s) to be shock-loaded. Also, try and not use cams for rigging since they can walk and thus affect the equalisation of the system.
By tying our system so that it is equalised we achieve another crucial layer of safety.