Application Performance of Synthetic Fibre Ropes in Marine Towing Systems

A multi-body coupled mathematical model of a tug–barge–rope system is developed to address the absence of comprehensive parameter design theories for synthetic fibre ropes in marine towing systems and the challenges associated with stability regulation under complex sea states. This study systematically examines the effects of three rope lengths (20, 80, and 120 m) and three fibre materials (nylon, polyester, and ultra-high-molecular-weight polyethylene) on the dynamic performance of a towing system. The mechanical coupling relationships between system components are explored by utilising a dynamic control model. Parametric analysis highlighted the mechanical properties, elongation deformation, and stiffness evolution of ropes of varying lengths and materials during towing operations. The results indicate that short ropes demonstrate high strain sensitivity and instantaneous stiffness, which can readily induce overloads in the power system of the tug. Medium-length ropes, benefiting from viscoelastic deformation, facilitate energy dissipation, thereby mitigating tension fluctuations and enhancing motion stability. In contrast, long ropes result in delayed barge responses owing to stiffness attenuation. This study also revealed that different fibre materials offer distinct advantages in terms of force transmission, vibration suppression, and load-bearing capacity. Based on model analysis and a parametric study, optimal selection schemes for synthetic fibre ropes are proposed. The findings provide a theoretical foundation and practical guidance for the performance optimisation and engineering application of synthetic fibre ropes in marine towing systems, contributing significantly to the advancement of ocean engineering.