Aker Artic completes ice-going SOV concept for offshore wind farms

The primary objective was to develop a vessel concept that is as close as possible to an open-water service vessel

Aker Arctic says it has completed the concept design for the first year-round service operation vessel (SOV) for offshore wind farms in seasonally freezing seas, tailored to specific operational areas.

This ice-going SOV, featuring the Double Acting Ship (DAS™) principle, ensures reliable and safe turbine access in all weather conditions, minimizing both construction and operational costs.

Dynamic Positioning (DP), energy-efficient design, and crew comfort are prioritized, making this SOV a game-changer for wind energy investments in ice-covered waters.

Energy-efficient design keeps costs down
The primary objective was to develop a vessel concept that is as close as possible to an open-water service vessel, but also capable of safe, independent, year-round operations without incurring high additional costs or increased fuel consumption.

According to Chief Designer Lars Lönnberg, employing the DAS™ principle – where the vessel advances bow-first in open water and light ice, and stern-first in heavy ice – has been crucial in creating an energy-efficient design.

“With our experience in designing efficient ice-going hulls, we have developed a stern form that breaks ice without using unnecessary power, thus avoiding excessive fuel usage,” adds Project Manager Juuso Lindroos.

The vessel’s ice strengthening and ice class are suitable for operations across the entire Baltic Sea, including the Bay of Bothnia, where winter conditions are the most severe. The final ice-going capability will be determined based on the operational conditions in the target area, with the design tailored accordingly.

Maintaining position ensures safety
Dynamic Positioning (DP) and seakeeping have been special focal points, as the vessel must remain stationary when servicing the turbines. A motion-compensated gangway is the safest means of accessing the turbines, and features such as midship location and winterisation have been included.

A passive roll damping system will ensure calm vessel movements in waves, enhancing safety and comfort for the crew.

Internal logistics and material handling on the vessel were thoroughly assessed. To minimise exposure to harsh environmental conditions, such as wind, rain, and the cold, indoor areas are utilised for movement and material transfer as much as possible.

Stepless logistics is part of the solution, allowing forklifts to carry and move service tools and spare parts without obstruction. There is also a lift for gangway access, with stairs as a back-up for safety.

Innovative propulsion and fuel options
Choices in propulsion and fuel significantly affect energy costs, but also crew well-being. Using a battery-operated electric system reduces noise and engine resonance. A plug-in hybrid system with charging capabilities at the wind farm allows for operations to be powered by batteries day or night.

For longer transfers, engines running on either marine diesel or alternative fuels, such as methanol or ammonia, are essential. Optional space has been allocated for the larger fuel tanks necessary for alternative fuels.

A retractable thruster, quieter than fixed tunnel thrusters, is also part of the low-noise solution. Furthermore, cabins are located high in the superstructure to reduce noise from ice interaction.