FOTOAN: A Novel Deepwater Anchoring System

The lack of energy resources in shallow water depths made deepwater energy resources exploration as an important step. Deepwater energy devices like floating offshore wind turbines (FOWT), hybrid and integrated energy systems, and mobile offshore drilling units often need anchoring support, which is adaptable to all marine conditions. There are several marine anchor types like drag anchors, suction anchors and self-installing anchors, in which dynamically embedded anchors are popular due to the simple installation procedure. In the taut-leg or vertical mooring systems, these dynamically embedded anchor's performance is unsatisfactory. Also, their excess pore pressure dissipation time after installation in NC clay is higher, which made them lesser attractive. Despite its simplicity, this anchoring concept has not gained widespread acceptance for the above-mentioned reasons. Hence, the present work described the novel anchoring concept of foldable torpedo anchor (FOTOAN) and their working mechanism, theoretical capacity estimation and installation sequence in detail. A limited comparative laboratory study of the FOTOAN to the traditional torpedo anchor in soft clay shows the FOTOAN to be more efficient. In the vertical mooring systems, the performance is improved by 3.5 – 5 times. Thus, the FOTOAN has been promised as an efficient technique for deepwater anchoring applications. Also, the installation sequence of FOTOAN with the aid of two anchor handling vessels (AHV-1 & AHV-2) are presented as an example case study.