WSH Guidelines on WAH Personnel Protective Equipment and ...

A Great Workforce A Great WorkplaceTextiles Lifelines‣ Textiles lifeline knots should only tied by the same competent personwho has thorough knowledge of knots and knots tying techniques‣ Knots should never be tied in lifelines made from wire ropesStrength of a rope is reduced at a knot and examples of strength loss due to variousmethods of tying knots in a 10.5 mm low stretch rope (conforming to BS EN 1891:1998),type A are:Types of tied KnotsStrength ReductionBowline 26% to 45%Barrel 23% to 33%Double figure-of-eight 23% to 34%Double figure-of-nine 16% to 32%Double figure-of-ten 13% to 27%As a rule of thumb, a 50% reduction in strength due to the knot should be allowed for togive an adequate margin to cover a worst case situation.© 2012 Government of Singapore 27