Adaptive tension-leg mooring system with sliding counterweights: a novel shallow-water solution for floating offshore wind turbines

Abstract

This study presents an innovative adaptive tension-leg mooring system with sliding counterweights (SC-TLMS), specifically designed for floating offshore wind turbines (FOWTs) in shallow water depths. The proposed system addresses the critical technical and economic challenges associated with conventional catenary systems through a pulley-counterweight assembly that enables adaptive length adjustment and tension stabilization. Comprehensive coupled analyses employing the IEA 15 MW turbine demonstrate that the SC-TLMS achieves a 60 % reduction in maximum mooring tensions and a 65 % decrease in maximum yaw responses compared to baseline catenary system. The system exhibits robust adaptability to tidal variations and diverse metocean conditions, with the enclosed guide rail design effectively eliminating the pendulum motions and seabed collision risks. Operational reliability is ensured through the implementation of spring buffers as displacement limiters. By integrating the shortened mooring line lengths with a reduced seabed footprint, this novel architecture provides a technically viable and economically competitive solution for shallow-water FOWTs.