Rope strengths are tested according to Marlow’s QA25 and 26 quality procedures. Generally these procedures are in line with BS EN ISO 2307, however, a number of other internationally recognised test standards are used including EN 1891, EN 892 and EN564
Marlow Ropes generally specify a Minimum Breaking Load (or sometimes an Average Breaking Load). It is the responsibility of the user to determine an appropriate factor of safety and Safe Working Load. This factor of safety must be determined after considering all the risks, the strength reducing factors, and the expected life of the rope. The table on the left shows some of the factors that may affect the determination of the factor of safety.
Most rope strengths in this catalogue are given in kilograms (kg). However, the correct measure of force or breaking strength is Kilonewtons (kN). Conversion factors from one to the other are:
Kg to kN x 0.00981
kN to kg x 101.972
Rope mass is determined be weighing a sample of rope whose length has been measured at a reference load. For most ropes this load is calculated as:
Reference Load (kg) = D2/8
Where: D is the rope nominal diameter (mm)