Verification of rope discard criteria by post retirement analysis Summary

Rope assessment is a challenging matter, as the target is to use the rope for the safest possible period whilst ensuring smooth and reliable operational conditions. Even if discard criteria prescribed by regulations give some relevant parameters, like broken wire count and measurement of geometrical variations, they do not always provide univocal answers and can raise some concerns in the users. This paper presents the post retirement analysis of an offshore crane rope that was removed from service after a four years of work time basis, and that was thoroughly inspected by means of non-destructive and destructive tests. The measurement of the geometrical parameters and the residual mechanical properties, in particular breaking force, elongation at break and stiffness, allowed the assessment of the actual conditions of the rope and verification of the correlation between discard criteria and residual rope life.

Author: L. Lombardi