Ocean Marine Services has been a forerunner in the dynamic, fast growing world of offshore wind farms. Ocean Marine Research pioneered ornithological survey techniques and seabed mapping methodology ahead of the first tranche of offshore wind farms. As the workload escalated, directors Nick Longfield and Jason Ledden developed Ocean Marine Services in order to expand the range of activities to encompass diving support, vessel supply, survey logistic sand management services for all offshore projects. With market demand exceeding supply, the company located its newbuild in Turkey for the first of its new fleet of bespoke vessels. The Ocean Dragon is a 26m LOA steel built monohull with a beam of 7.3m and displacement of 148 tons. The ‘Multi-Task Vessel’ is powered by twin Iveco C13 ENT M50 marine diesels, each delivering 500hp at 2,000 rpm and driving 48” diameter fixed pitch propellers in Kort nozzles through ZF W350 gearboxes. The propulsion package delivers 14 knots top speed and a cruising speed of 11.3 knots, and its100hp hydraulic bow thrusters give it exceptional manoeuvrability. The vessel has become first in class in conjunction with RINA and meets the requirements for MCA category ‘1’ for operation of up to 150 miles from a safe haven.
An open aft deck low to the water measures 14m by 7.1m and is equipped with a knuckle boom crane supplied by ACB Hydraulics which will lift four tons at 6m. There is a 12 ton deck winch and an innovative four point mooring system with 650m of cable capacity per winch. This allows Ocean Dragon to position herself safely over a work site without restricting subsea operations. These operations can be conducted with a scope of up to 500m without engaging the main propulsion units and without repositioning the anchor pattern.
Also on deck is a twin anchor windlass and 200kg anchors each with 104m of chain. A 12 ton SWL removable hydraulic ‘A’ frame is mounted on the transom. Its lift point is 3m aft of the stern and the primary deployment point is 3.5m inboard. There is a heavy lift deck roller which runs across the transom and there is also a certified MOB and dive rescue system on board.
The comprehensive range of deck equipment makes for an exceptionally versatile vessel which can undertake diving and ROV deployment, handle both stationary and towed survey equipment, perform anchor handling operations and conduct grapnel towing for seabed clearance and pre-lay cable runs. The bow has been designed to approach and dock with offshore structures such as wind turbines and the vessel can be utilised to fuel generators on offshore structures for temporary or permanent power supplies. It can also undertake towing projects, personnel transfer, standby and support tasks, and cargo transfer. A 5m rib is stowed on board for personnel transfer.
The 30m square open wheelhouse has a central companionway to the main deck and access doors port and starboard to the upper deck bulwarks. This includes helm chairs for the skipper and navigator, a four person work station, computer racking, additional seating and a day bunk.
The main deck features an open galley with seating for eight diners and a pantry. Accommodation on this deck includes a skipper’s cabin, a client’s cabin and shower and toilet. The client’s cabin is equipped with a network feed to the wheelhouse enabling twin display monitors for video or survey information.
The lower deck is comprised of five cabins; three occasional two berth cabins, and two crew cabins, shower and toilet, laundry facilities, a storage cupboard.
Ocean Marine Sevices’ extensive experience in this field has played a significant role in the design and specification of the well equipped wheel house. This incorporates a comprehensive navigation and communication package including a Simrad DGPS with combined echosounder, a Northstar DGPS, a Simrad 48 mile radar, Simrad AP 50 autopilot, and Simrad class ‘A’ AIS.
On board working systems include two hemisphere survey grade DGPS accurate to within one metre, a survey computer with multiple interface capability, a Trimble hydro survey software system, a Kongsberg Simrad ES 60 survey grade twin frequency single beam echosounder and a flux gate gyrocompass. There is a three diver life support surface supply panel, a multi-station CCTV monitoring all winches, the engine room and the deck area, and a personnel UHF system for inter-ship communication.
Ocean Dragon looks set for a busy life as Round 3 of UK offshore wind farms move ever further offshore. Following its first project at Gunfleet Sands the vessel will move on to another major offshore wind farm project.
With large scale wind farm projects ongoing and forthcoming, it is little wonder that Ocean Marine Services is planning to commission two sister vessels to Ocean Dragon in 2010.
