The offshore wind business is booming around the world, and the US is no exception. As a result, vessel owners and the companies that contract them are looking for cost-competitive multi-purpose service operation vessels (SOVs) that not only meet their requirements in a cost-effective manner, but ships that are ‘future-proof,’ with environmentally friendly technology that will enhance the performance and service life of their assets.
Wärtsilä Marine Business sales engineer newbuilds Blake Jackson says, “With wind energy now such big business in the US, owners and operators are taking a more strategic, long-term view of potential investments.
“The next generation of vessels has to check all the boxes in terms of IMO emissions regulations and flexible designs, so they can take advantage of technological advances as and when they become available,” he explains.
In addition to the need to comply with ever–more stringent emissions regulations, a trend towards longer charter agreements is also driving this increased need for flexibility.
“We’re seeing proposals for longer agreements, in the region of 15 years, so owners need to think ahead,” says Wärtsilä Marine Business account manager newbuilds George Franssen.
“Financial considerations are another big factor, because funding is easier to obtain when lenders have the security of knowing the vessel has a profitable future beyond the end of the initial charter agreement.”
Working in collaboration with stakeholders including charterers, shipyards, third-party suppliers and operators, Wärtsilä has designed a US–flagged, Jones Act–compliant ‘hybrid’ multi-purpose SOV. When it began developing the design, the company also worked closely with leading classification societies, including DNV GL and ABS, which both provided valuable input into the design.
Using its ‘OPTI Design’ design methodology, the company has applied a data-driven approach that focused on the vessel’s propulsive efficiency, in order to optimise the balance between propeller, engine and hull.
Rather than simply adding a propulsion system to a finished vessel design, with this approach the two are designed simultaneously. Wärtsilä also applied a holistic approach, using computational fluid dynamics and other techniques to optimise the design of the vessel. “This means we can determine the effects of interactions between the propulsion unit and the vessel itself and use the information to deliver optimal efficiency, reduced costs and emissions and maximised performance,” Mr Jackson explains.
The propulsion concept adopted for the SOV uses Wärtsilä’s patented Low Loss Concept (LLC), an energy-efficient power distribution system for electric propulsion applications that has a high level of redundancy.
The design also integrates a range of Wärtsilä’s green systems and solutions, including shore-charging or ‘cold ironing’ as it is sometimes known, and a hybrid powertrain employing a containerised battery-on-board energy storage system. This allows for peak shaving, helping the vessel’s engines to run at optimal load, reducing emissions and maintenance costs. The design also includes space for the integration of potential future powerplant and fuel technology such as hydrogen fuel cells.
Two boat landings enhance the safety and efficiency of operations by providing dedicated safe-passage zones for technicians transferring to and from crew transfer vessels. Wärtsilä SmartDock, an automated system that enables consistent and repeatable docking further increases safety, improves operational performance and reduces fuel consumption and wear and tear. Owners can also benefit from Wärtsilä’s Smart Voyage Optimisation solutions to further improve fuel efficiency and safety.
To ensure safe operations in all sea conditions the multi-purpose SOV has a Wärtsilä dynamic positioning (DP) system that is fully integrated with the vessel’s propulsion system. This supports the use of the ship’s walk–to–work system, a centrally located 3D motion-compensated gangway integrated into the structure of the vessel.
The vessel’s double-decked cargo space is designed to provide ample room for technicians, lifting equipment, parts storage and palletised and containerised cargo. The latter is stored in the dedicated upper deck, which can be fitted with an optional container-handling system.
The 76-m vessel can accommodate up to 60 crew and windfarm technicians and, as Mr Jackson explains, the need for comfort, physical distancing and flexibility in terms of the accommodation layout influenced the design significantly.
“The layout reduces common areas to provide more space in individual cabins, which can be configured for double occupancy if needed. This is another way in which the design allows for greater flexibility should the vessel’s operational profile or application change in the future,” he explained.
“The design also takes into account the need for crew members to maintain a safe distance from one another in logistics and workflows during situations such as the Covid-19 pandemic.”
Once a vessel is in operation, Wärtsilä can provide ongoing support through its lifecycle solutions, which maintain and optimise marine asset performance for their entire operational lifespan. This support can include, for example, guaranteed asset performance with mutually agreed performance targets based on specific business needs.
“We can support owners of this vessel with a comprehensive operation and maintenance agreement to ensure worry-free operation and avoid unexpected surprises related to maintenance costs,” Mr Franssen says.
“The design brings together our expertise in flexible fuel strategies, propulsion, automation, navigation, dynamic positioning and systems integration in a single fit-for-purpose and cost-effective package,” Mr Franssen tells OWJ.
“Thanks to a comprehensive in-depth design process and close co-operation with key stakeholders, we have developed a design that brings operators everything they need and nothing that they don’t.”
“In addition to making it an efficient and futureproof multi-purpose SOV design, this leaner approach also enables the vessel to be built for a considerably lower cost than similar designs, without compromising on capabilities or performance,” Mr Jackson concludes.