VESSEL REVIEW | Charlie Knight – Compact hybrid workboat for Scottish fish farm support duties

Norwegian shipbuilder Salthammer Båtbyggeri (SHB) has completed construction of a new workboat optimised to support operations at offshore fish farms in Scottish waters.

Built to a design by Norwegian designer Tomra Engineering, the 18.5-metre (60.7-foot) Charlie Knight was developed in response to its owner's need for a "Norwegian-style" vessel capable of environment-friendly operations. The workboat also needed to function as a multi-role vessel to suit a range of operational requirements.

"The length of the vessel places it in size between the smaller 15-metre (49-foot) fish farm workboats and the bigger 25-metre (82-foot) service vessels," SHB told Baird Maritime. "Considering its moderate size, the vessel still has much of the same equipment and machinery as on the bigger service vessels. In addition, the powerful side thrusters and propulsion machinery gives it the agility to manoeuvre between the cages in a fish farm even more gently compared to smaller boats."

Low-emission operation combined with heavy lifting capacity

Charlie Knight was built as a general-purpose aquaculture service vessel that will undertake a variety of tasks such as deployment and maintenance of mooring lines and anchors; deployment, replacement, servicing and repair of nets; transport of goods and supplies to sites; fuel and water transfers; heavy lifting operations; towing; and general support. The workboat can also carry a 70-tonne delousing setup consisting of two H2O2 chemical containers and one dosing container.

"The design utilises proven solutions," added Tomra Engineering, "but it was challenging to arrange and find space for all the equipment and machinery, as much of it was intended for incorporation on bigger vessels. Thorough planning and close cooperation with the owner were therefore needed to provide the most ideal solutions."

The vessel's propulsion setup consists of two Scania DI130-092M 410kW (550hp) main engines driving Nogva four-bladed, controllable-pitch propellers via Nogva HC-258 gearboxes. The propellers are housed in azimuthing nozzles provided by Kort Propulsion.

"The engines are equipped with SCR to ensure IMO Tier III compliance," said SHB. "This is mandatory for all new vessels with combustion engine outputs of greater than 130 kW and working within North Sea basin borders. The propellers meanwhile deliver enhanced manoeuvrability and a bollard pull of approximately 15 tonnes."

The vessel is also fitted with a 200kWh battery pack, which can supply adequate electrical power while moored even without relying on the onboard John Deere diesel generators. The battery power can also enable operation of the two Palfinger Marine deck cranes.

"The cranes themselves are placed on the starboard side to provide the best reach," the builder added. "The larger crane is located aft and has a maximum lifting capacity of 3.5 tonnes at a reach of 21.5 metres (70.5 feet). The smaller crane can lift 2.1 tonnes at a reach of 20.5 metres (67.3 feet).

Comprehensive deck and electronic equipment suites

The other deck equipment includes a hydraulically powered winch with an SWL of 25 tonnes, a mooring plate holder, and two vertically mounted capstans. All deck machinery can be controlled from an operator panel in the wheelhouse, as well as from the 110-square-metre (1,180-square-foot) aft deck via a portable radio remote control.

SHB remarked that the deck equipment package from SHM ensures greater safety.

"The main winches are equipped with an emergency release to free the vessel from rope tension if a critical incident occurs," the builder told Baird Maritime.

Charlie Knight also boasts a comprehensive electronics suite that includes a dynamic positioning system, Sailor and Jotron radios, JRC radars, a Simrad autopilot, an Airmar weather station, and an Intellian satellite TV.

"For increased safety and operability in remote areas, the vessel has twin installations of all main communication and navigation equipment, particularly the radars and the VHF radios," SHB said.

The spaces for the four-strong crew include single cabins with separate toilets, a spacious salon/mess, and a galley.