A Theoretical Analysis of Top-rope Climbing Anchors Focusing on Redundancy and Relative Failure Potential

Abstract

With regard to top-rope setups using bolts, two versions of the cordelette, three versions of the quad, and a basic two-sling anchor setup are evaluated using a combinatoric analysis of component redundancy and failure potential. The two-sling setup offers complete active redundancy because each component is duplicated. Two loop knots are required to set up the quad and those knots have no backup. Similarly, the loop knot employed to create the cordelette’s master point of attachment is not redundant. Slings and cords utilized in top-rope anchors can be vulnerable to abrasion damage if the load shifts laterally during falls and lowers. Knots may be particularly susceptible to wear. The bulk and structure of anchoring knots are likely co-determinants of rock chafing and potential system failure. The characteristics of single and double versions of four loop knots are reviewed. Other setup characteristics and contextual factors are considered in this comparison.