Determining the Safest Anchoring Knot in a Fall Arrest System by Means of Static Tests

Abstract

Today, rope access systems (RASs) and fall arrest systems (FASs) incorporate significant technological innovations. This research aims to determine the safest knot to be used in RASs. The most secure knots are those that leave the most resistance in the rope. Static laboratory tests, followed by an extensive statistical analysis of the obtained data, were carried out under controlled conditions. Five types of anchor knots were selected and studied using three rope models with similar diameters, and we analysed the symmetrical versions in the dextrorotational direction. Thirty break tests were performed for each rope model. The total number of breakage tests was 90. The double overhand knot proved to be the safest knot with an average efficiency of 61.82%. A better understanding of the behaviour of knots and their correct use in FASs will be key to accident prevention.

Keywords

• knot efficiency
• construction
• safety
• risk
• personal fall protection systems
• rope access system