As part of our ongoing commitment to innovation within the clean energy sector, Houlder has devised an unmanned remotely controlled vessel concept that will cut costs and boost safety for offshore wind farm maintenance. A team comprising Naval Architects Arun Pillai (pictured) Akhil Nair, David Pugh and Marta Więcka with Mechanical Engineer Luiz Deminicis worked on the project.

The work formed part of the joint industry Windfarm Autonomous Ship Project (WASP). This explored the technical, regulatory and societal issues related to using autonomous surface vessels to support offshore wind farm operations and maintenance. The project, part funded by Innovate UK, set out to verify the benefits and build the case for the use of autonomous vessels.

Previous research has found that vessels can account for as much as 60% of an offshore wind farm’s operating costs, of which crewing makes up a significant proportion. These costs could be significantly reduced through crew-free transfer of cargoes between shore and offshore wind turbines. Human error during cargo handling has also been proved to be the primary cause of accidents. Houlder has developed a concept vessel that could improve performance while remaining practical and cost-effective to build and operate.

The autonomous vessel’s design philosophy conforms to that of a remote-controlled cargo vessel with the primary role of delivering small cargoes to windfarms for O&M-related tasks with the potential for   secondary roles such as survey and security work. Redundancy, reliability, simplicity and maintenance considerations are the drivers for its design. The vessel’s displacement is   slightly more than that of the Crew Transfer Vessels (CTV) expected to service the turbines for O&M in the short term. It will deliver cargo to the transition piece platform positioned 15 – 20m above   mean sea level, precluding use of and interfacing with the turbine’s lifting infrastructure. A single tier of the cargo is laid out on the main deck with cell guides used as sea-fastenings. Standardised cargo   units   facilitate cargo-handling automation and weathertight 1 tonne cargo pallets have been considered. Euro pallet sizes have also been checked to confirm that these can be accommodated within the designated cargo area on deck.

The autonomous vessel is not constrained by manning comfort and shift hours. Consequently, speed has been reduced for vessel transit with a resulting reduction in power requirement and machinery space.

Projects aimed at driving efficiencies, such as this, alongside similar innovations in emission reduction and alternative fuel use, are becoming more central to Houlder’s business as clean energy increases in importance.

Contact us through enquiries@houlderltd.com or +44 (0)20 7283 1220 for more information on this or any other of our clean energy naval architecture projects.