Reduced-Recoil-Risk Rope Test Method

Reduced-recoil-risk (RRR) rope is synthetic fiber rope which is designed to have a reduced tendency to completely break suddenly and to recoil catastrophically. The purpose is to reduce the risk of injuries and damage. The RRR rope usually breaks in a cascading manner which provides time to take corrective action or to "get out of the way" This feature also reduces the energy release at break and thus reduces the reach and impact of the broken rope. This paper discusses the new Cordage Institute (CI) RRR rope test method. It explains some of the physics of how such a rope reduces the risks of recoil. It demonstrates how to use the results of the CI test method to evaluate and compare the performance of different RRR rope designs. The additional stretch of the rope from its length at first break to its length at complete failure is an important RRR criteria. It can be used to calculate the time between first break and complete rope failure. Thus it is called warning- time stretch. Rope length is an important parameter. A short rope might not completely fail, but a longer rope of the same design will completely fail at first break. Rope size is another important parameter. For a given length, a small rope might break but a large rope might not. These principals apply to all ropes - fiber and wire, RRR design or not.