3. Design and Operation of an Offshore Support Vessel

Offshore Service Vessels (OSV) are utilized for demanding offshore operations often under challenging conditions, e.g. Anchor Handling Tug Supply vessel (AHTS) supporting offshore drilling rigs and Offshore Construction Vessels performing subsea installation. The OSV case in the HOLISHIP project has addressed both these vessel concepts with the main focus on power system optimization based on the operational profile for the vessel. Regarded as highly specialized vessels, OSV design requires the synchronization of several of disciplines. Thus, a holistic approach, considering Key Performance Indices (KPIs) for several disciplines, was developed and utilized from a conceptual design level to the power system concept verification. Sub-optimization of each module for different KPIs without taking into account the interaction between the modules does not necessarily lead to an optimized overall performance of the vessel and a holistic approach design is highly likely to be beneficial. At the early design stage of a vessel, important parameters are defined having a huge impact on the performance of the vessel according to the KPIs. Changing these parameters at a later stage in the design process is difficult and requires a considerable effort from the multidisciplinary design team. This Chapter presents the holistic design of the OSV application case from main dimension determination to power system design, optimization and verification. Significant improvements for selected KPIs have been obtained comparing the optimized concept with the baseline vessel. The design optimization methods developed here are already being used in other research and commercial projects proving increase efficiency in the early design stage. The methods for virtual verification using dynamic simulations are being further developed and used in other research projects.