VESSEL REVIEW | Multi Challenger & Multi Frontier – Norway's FSV Group places hybrid fish farm workboats into service

Norwegian aquaculture support specialist the FSV Group has expanded its fleet with the recent acquisition of two new hybrid-powered workboats.

Multi Challenger and Multi Frontier were designed by Norwegian naval architecture firm Solstrand Trading. The vessels’ hulls were built by Polish shipyard Finomar while final outfitting was undertaken at Sletta Verft’s facilities in Norway.

Compact platforms boasting improved stability

Each workboat has all-steel construction, a length of 20 metres (70 feet), a beam of 10 metres (30 feet), a depth of 4.1 metres (13 feet), a total cargo capacity of 100 tonnes, and a gross tonnage of 218. The hulls have been designed to ensure improved stability and seakeeping for greater safety during operations.

The vessels’ hybrid propulsion arrangements include air-cooled 1,575kWh lithium iron phosphate (LFP) battery packs supplied by Lehmann Marine. LFP batteries were selected due to the lower risk of fire caused by thermal runaway as well as their ability to permit electric-only sailings for sustained periods, thus allowing for continuous operation at fish farms with only minimal noise and residual impact on the surrounding marine environment.

Flexible propulsion arrangement

The batteries on each vessel drive two 374kW electric motors connected to Nogva Heimdal azimuthing propellers to deliver a bollard pull of 10.5 tonnes, whereas hybrid mode will increase the bollard pull to 15 tonnes. Charging of the batteries can be done overnight via shore connection, and a full charge will enable full-day operations.

The vessels are also each fitted with a Scania DI13 425kW diesel generator as a backup and for extending operating range.

Full deck equipment suite

The deck equipment includes a pressure washer and two HS.Marine cranes with lifting capacities of 100 tonnes and 34 tonnes, respectively. MB Hydraulikk meanwhile supplied the winches, capstans, guide pins, and plate locks.

The deck can carry various loads including a small tender and a remotely operated vehicle (ROV) from Akva. The ROV, which can be deployed as an alternative to divers for underwater inspections, will be controlled from a dedicated onboard compartment with video screens and a joystick-fitted operator's chair.

Because the working deck is open, loading and unloading of light cargo can be done even without using the installed cranes.

The wheelhouse on each vessel provides all-round visibility, allowing for operations on the aft deck to be monitored. A rear-facing station allows the bridge crew to supervise towing and crane operations while remaining inside the relative safety of the wheelhouse. The electronics include a Furuno radar.

The interiors feature a Copra Drift HVAC, Roxtec pipe penetrations and cable transits, and fire alarms from Nautus. Exalto windshield wipers are also fitted.

The onboard accommodation on each vessel includes a galley.

Multi Challenger and Multi Frontier are classed by the Norwegian Ordinary Ship Register.

The vessels’ duties will include towing of pens and equipment, maintenance, and cargo transport in support of operations at exposed fish farm sites operated by the FSV Group's clients.