Rope Service Life Prediction

Rope Service Life Prediction

Tension Technology International (TTI) offers professional services to predict the life of and recommend replacement criteria for synthetic fibre ropes in various services.

TTI personnel have conducted inspection and detailed examination on many used fibre ropes from a variety of applications. They have conducted many laboratory cyclic load tests on small and large synthetic fibre ropes of various materials and constructions. They have conducted residual break tests on a number of used marine hawsers and other ropes. The collective experiences and observations enable TTI to provide knowledgeable advice on rope service life and replacement.

TTI personnel prepared the fibre rope inspection and replacement guidelines which appear in the U.S. Coast Guard Guidelines for Deepwater Port SPM Design and the Oil Companies International Marine Forum (OCIMF) Mooring Equipment Guidelines. Those guidelines were originally written over 15 years ago. TTI now has much more knowledge and experience in evaluating rope wear and deterioration and in advising on rope replacement and can provide more up-to-date guidance.

TTI has an extensive data base of cyclic tension load test results for various fibre ropes at various loads and conditions. TTI has developed methods which use these data to estimate the cycles to failure of marine hawsers and other rope systems. Those data and methods can now be used to predict the service life of ropes subjected to tension cyclic loading.

TTI developed OPTI-LIFE. This real time system continuously monitors the load variations in rope and models progressive rope property change and deterioration due to internal abrasion, fibre creep rupture, hysteresis, and axial compression fatigue. For a particular rope design, OPTI-LIFE will predict residual rope life and indicate the point of retirement based on the actual rope loading history.

TTI has used these various service life prediction techniques and supporting data to select suitable ropes for and predict life of Single Point Mooring (SPM) hawsers, riser protection nets, and towed arrays.