Vessel launch: First South Catamaran wind farm vessel for Iceni Marine Services

Iceni Spirit is a South Catamaran 15m Alloy Wind Farm Service Vessel and measures 15.6m length overall, 6.4m beam overall, has a draft of 0.9m and has a lightship displacement (including fluids) of 25 tons.

Iceni Marine Services Ltd is a relatively young company, but with long term experience of operating crew transfer vessels on offshore wind farms. Iceni currently operate an 11m Blyth Workcat GRP catamaran and Iceni Spirit will join the Topline in the Iceni fleet. Iceni Spirit has left the yard and has headed direct to Barrow in Furness to start work on Walney Offshore Wind Farm.

Ben Colman of South Boats Special Projects Ltd said, ‘We are delighted to have built the Iceni Spirit. She is the first 15m vessel to incorporate many of the systems found on the larger 18m and 20m, which makes a very versatile vessel capable of a multitude of different roles on offshore wind farm projects. This is the fourth new launch for 2010, with a further five vessels to be commissioned by June and a target total of 16 wind farm service vessels to be built this year.”

The vessel follows standard South Boats design principles with symmetrical under water sections and asymmetrical wet deck knuckles and spray deflectors. The design includes a high buoyancy bow and triple internal spray knuckles to maintain a suspension of air/water to dampen pitching moments particularly in heavy weather. In addition the hulls maintain a parallel waterline beam through the length of the vessel allowing for good weight distribution around the vessel. The design offers class leading sea keeping, stability, fuel efficiency and manoeuvrability. The sea keeping in particular has been proven in service operating in excess of 1.5m significant wave height.

The vessel is fabricated of aluminium and is generally in accordance with Lloyds Special Service Craft Rules with all metal of marine grade 50830 and 6082T6 extrusions meeting the requirements of Lloyds Register and Shipping and Det Norske Veritas.

The vessel features an ‘Island’ central superstructure with a 20 sq/m working deck forward and 20 sq/m working deck aft. Deck equipment includes a raised Palfinger PK4501M fully folding knuckle boom crane capable of lifting over 750kg’s at 5.3m, hydraulic capstan winch, hydraulic pressure washer and a 240V AC fuel transfer system. The vessel also has a stability book to enable up to 5 tons of cargo to be carried on the forward and after decks, which is unique on a vessel of this size and type. In fact the vessel will still perform at 21 knots when loaded.

The vessel is powered by twin Scania DI12 69M 625mhp diesel engines driving two ZF360A 1.50:1 reduction ratio gearboxes coupled to Ultra Dynamics 452 water jet units. This package offers the vessel a sprint speed of over 24 knots and a 22 knot fast cruising speed.

Iceni Marine Services worked alongside the builder to make the vessel as multi-purpose as possible. Also participating was Devon UK based Hercules Hydraulics Ltd, which supplied a Fuel Delivery System which was designed and fitted with a view to offering the client greater flexibility from one vessel. Hercules supplied and installed the boat’s entire hydraulic system.

The boat can refuel portable generators on the WTGs and sub-stations after the crew transfers have taken place. The vessel’s main diesel tanks have been increased in capacity and pumps which can achieve a 40m head of pressure are fitted below deck then hard piped to the bow of the vessel, where a 30m hose reel and digital flow meter logs all fuel transfers. Having the diesel tanks below decks eliminates the need for large tanks to be placed on deck, allowing more space for other equipment.

The vessel is certified to operate under the MCA Worboat Code, up to 60nm offshore for up to 12 passengers, three crew and 5,000kg of deck cargo.