Collaboration between British and Norwegian organisations has spawned an innovative service operation vessel (SOV) concept to support surging investment in offshore wind farms.
The Diamond SOV melds the respective fields of expertise of the Ulstein Group, DNV, James Fisher & Sons, and Graig Shipping, as the Diamond Consortium, addressing the expanding UK and wider market, and the move to larger turbines further out at sea.
While offering global opportunities, the immediate market target for the Diamond service operation vessel (SOV) concept is clear from this rendering.
The template for the proposed new generation, tailor-made for year-round maintenance and repair tasks, accommodating and ensuring direct, safe transfers of technical personnel, is the Ulstein SX221 design featuring the proprietary TWIN X-STERN configuration.
The main strength of the TWIN X-STERN solution is the very high degree of manoeuvrability and position-holding performance in adverse sea and weather conditions afforded by a hull form that facilitates manoeuvring in either direction, without having to turn, and incorporating four propulsion units—one in each ‘corner’ of the hull. The arrangements promise increased productivity and reduced fuel costs at each offshore transfer, plus improved habitability through less noise and vibration.
The immediate target of the Diamond partners is the UK sector, given the government’s net-zero environmental strategy that looks to have 50GW of offshore wind energy capacity in place by 2030. To that end, the business consortium is currently in discussion with shipbuilders and potential charterers as to potential newbuilds. The first example of the Diamond SOV could be completed by the end of 2024.
Ulstein has one of the industry’s longest track records in offshore vessel design, and also construction, and James Fisher’s group business development director Jim Hey considers the TWIN X-STERN to be the best choice for service operations at offshore wind farms. “The philosophy behind the concept has been successfully applied other vessel segments for many years: developing a specification that meets a market need while allowing for a high degree of customisation and configuration for individual owners and developers,” he said.
The nature of the design and the scalable, modular solution that it presents is regarded by the Diamond Consortium as conducive to the volume, series construction, and time and budgetary criteria, expected to arise by the end of the decade if global offshore wind ambitions are to be realised.
Ulstein Group invented the X-BOW in 2004, and later leveraged this with the X-STERN, both of which have enjoyed wide market success. The TWIN X-STERN was introduced in 2015, designed for offshore operations that require a ship to remain in position in rough weather. The concept also included other technologies to improve operations and cut fuel usage, such as biomechanical walk-to-work (W2W) ramps and cranes, and a new propulsion unit idea. Further refinement has taken place since 2015.
With a significantly reduced, overall energy consumption and increased manoeuvrability, it is claimed that the vessel type will also help developers lower Scope 3 emissions in the construction of marine wind farms. Scope 3 relates to emissions produced from assets not owned or controlled by the reporting organisation, but which impact on the latter’s value chain.
The artist’s impression accompanying the recent announcement depicts two prospective newbuilds named Aberthaw Fisher and Kingsnorth Fisher.
The previous bearers of those names were milestone ro-ro heavy transport ships, Scottish-built in 1966 for the erstwhile Central Electricity Generating Board (CEGB). With operation and management entrusted to James Fisher, the diesel-electric pair carried vital components to the then new breed of power stations being constructed around the British coast.
