Dynamic response of an anchor-saving shared taut mooring system for ultra-deepwater floating offshore wind turbine arrays

Abstract

Floating offshore wind turbines (FOWTs) deployed in ultra-deep water require mooring solutions that reduce cost and seabed footprint while maintaining robust limit-state performance. This study proposes an anchor-saving shared taut mooring system for a three-turbine array of 15 MW semi-submersible FOWTs at 1500 m water depth, benchmarked against a shared-anchor configuration and a classic individual taut mooring baseline. Coupled time-domain simulations are conducted for representative operating and extreme parked (survival) conditions to quantify peak line tensions, six-degree-of-freedom motions, and sensitivities to chain-polyester segmentation and shared connection-point position. Relative to the individual baseline, the proposed system reduces the peak chain tension of the most heavily loaded shared line by 34.7% and 35.9% in the operating and extreme parked cases, respectively, while maintaining adequate strength margins for all lines. Maximum surge remains below 1.12% and 2.83% of water depth. With only six anchors for three turbines, the proposed shared taut system promotes more uniform load distribution and offers a practical, footprint-efficient option for ultra-deepwater FOWT arrays.