VESSEL REVIEW | AQS Trym – Hybrid catamaran workboat for Norwegian aquaculture support company

Norwegian aquaculture services company AQS has taken delivery of a new hybrid catamaran workboat optimised for supporting fish farm operations.

AQS Trym was designed and built by Norway's Skagen Ship Consulting in cooperation with UK naval architecture firm Macduff Ship Design and Turkish shipbuilder TRX Marine, though construction took place entirely at TRX Marine's Yalova facilities. The Bureau Veritas-classed vessel will be operated under time charter in support of local salmon harvester Cermaq Finnmark.

The catamaran utilises a Macduff workboat design developed to serve a range of industries such as offshore energy and marine projects through roles that include anchor handling, supply, and dredging support. As a fish farm support vessel, it will perform towing and installation of cages and pontoons as well as transport of equipment.

"The vessel is equipped with an array of hydraulic equipment to ensure high quality and safe maintenance within the fish farming environment," Ian Ellis, Managing Director of Macduff Ship Design, told Baird Maritime.

The newbuild has an LOA of 18.5 metres, a moulded beam of 12 metres, a moulded depth of 4.6 metres, and a gross tonnage of 310. The hull was designed to withstand temperatures of as low as minus 20 degrees Celsius, making the workboat ideal for supporting operations at fish farms in far northern Norway.

The propulsion system includes two Scania 450kW generators, two 374kW electric motors, two 2,200mm propellers housed in nozzles, and a Bertel O. Steen Power Solutions hybrid package with a total battery capacity of 1,156 kWh. The propulsion can deliver a speed of nine knots and a bollard pull of 21 tonnes, allowing the workboat to be utilised for towing and pushing duties.

Also fitted are bow and stern thrusters to provide additional lateral manoeuvrability when berthing, unberthing, and operating near fish pens. The wheelhouse has windscreens that are reverse-angled to reduce glare while the structure itself also offers a full 360 degrees of visibility to permit the crew to directly supervise any activities on the aft deck.

"The owner's brief was for a high-quality vessel to perform multiple roles whilst maintaining high levels of crew comfort, all within a compact catamaran design," added Ellis. "The vessel was to be battery electric and arranged to have high bollard pull for towing operations. The deck area was to be arranged with two cranes and an array of specialist hydraulic deck equipment, for operations on the newest and largest fish cages. Alongside this there was a requirement for an 80-tonne deck load which would require space and stability."

In Ellis' view, the design posed challenges from all areas with the compact dimension reducing available space whilst new technology within the propulsion system posed its own challenges in arrangement, space, and safety. When combined with the high bollard pull from a relatively low power, all these required significant hull development to ensure all factors could be achieved.

"Above deck, the issues with space continued due to the need for a high specification of deck equipment combined with a large deck load and the requirements to provide excellent living accommodation for the crew. A large and spacious wheelhouse was also required with excellent all-round visibility for the management of day-to-day operations."

The vessel can be used for 24-hour operations, allowing fewer trips to be made to and from fish pens. When using only the electric motors to generate zero emissions at environmentally fragile fish farm sites, the vessel can sail up to eight hours.

"We were challenged by the owners AQS and our partners in Skagen Ship Consulting with regard to incorporation of the latest technology and vessel operational standards within the aquaculture environment," Ellis told Baird Maritime. "As this was the first vessel we have completed within the Norwegian aquaculture sector, the assistance and input of the owners and Skagen Ship Consulting proved vital in ensuring a successful build. We were also pushed with ensuring that the propulsion system worked as intended whilst fitting everything into the compact space. As this was the first fully battery electric vessel we designed, the whole team learned considerably from the experience and has since been able to utilise this in further ongoing projects."

Ellis remarked that as the fish farming and aquaculture industries are seeing rapid change and growth with new and larger technology being utilised all of the time, this vessel with its deck equipment will allow for service and installation of this new technology whilst enhancing crew safety.

The deck equipment includes two Palfinger Marine knuckle boom cranes mounted forward just outside the wheelhouse and on the open aft deck, which can transport various cargo necessary in supporting fish pen operation and maintenance. There is adequate deck space for an array of other equipment from SHM such as a tugger winch, an anchor winch, a working/towing winch, one eight-tonne and two five-tonne capstans, towing pins, and a stern roller.

The electronics suite meanwhile includes a Furuno radar. Even with its compact size, the workboat has considerable tank capacities for fuel oil (25,000 litres), fresh water (7,500 litres), and black water (5,000 litres) as well as accommodations for a crew of six.