The influence of ground conditions on the performance of shared anchor systems for floating offshore wind

Significant growth of the floating offshore wind sector is anticipated over the next decade as developers target increasingly deeper sites. The efficient design of mooring systems and innovative anchor layouts will be critical in driving down the cost of this technology. Sharing anchors would lead to a reduction in total number of components to be fabricated and installed. It is also perceived that shared anchors may be smaller, facilitating installation by more readily available and cheaper vessels. These shared anchors must, however, be designed to withstand loading from multiple directions and for an increased number of fatigue load cycles. The efficiencies that can be gained from anchor sharing will vary depending on anchor type, mooring line type, applied loading, and ground conditions. This paper presents a study of the anchor types that would typically be considered for three representative sites with a common water depth, but varying ground conditions to include soft clays, dense sands, and shallow bedrock. The suitability of each anchor type for use in a shared anchor system is evaluated for the representative sites, and the anchor performance is compared across the different soil types.