Efficient Mooring Systems for Semisubmersible Floating Offshore Wind Turbines

Abstract

This thesis examines critical components of the mooring system for Floating Offshore Wind Turbines including chain cables, anchors and soil. The mooring line is investigated using OrcaFlex models to assess the characteristics of both catenary and semi-taut mooring system. Then, the analysis is advanced to look into the effects of water depth variation on the performance of the mooring system. The continental shelf located at the northern California coastal area is selected as a study region. Based on the information of macro-scale study on the region, soil properties are developed to aid in understanding the performance of the mooring system. Combining the results from the mooring analysis and soil data base, considerations for appropriate anchor types are presented. The anchor types include: driven piles, drag embedment anchors, and direct embedment plate anchors. This study seeks to provide a novel mooring and anchor concept which can be used to design efficient mooring systems relevant to Floating Offshore Wind Turbines.