Viking Prince is one of the few offshore supply vessels (OSV) that runs on liquefied natural gas (LNG). She is provided with winterisation and de-icing solutions for use in Arctic waters. The vessel, delivered in March 2012, became the fifth LNG-powered vessel owned by Eidesvik.
The ship was built by Kleven Maritime at its Norwegian shipyard at Ulsteinvik, Ulstein, Norway. The company was contracted in July 2010 to build the vessel along with another vessel of the same design. The total contract value at the time of agreement was $77.28m (NOK440m). The keel was laid in April 2011 and the vessel’s hull was launched in November of the same year.
Features and main dimensions of the LNG-powered OSV
The DNV-classified OSV is of VS 489 Gas PSV design and is developed by Wärtsilä Ship Design. Salient design features of the vessel include higher energy efficiency, dual-fuel engines that can run on LNG as well as heavy fuel oil (HFO) and marine diesel oil (MDO), and greater vessel performance in terms of fuel economy and cargo capacity.
With dual-fuel technology, the vessel can be switched to diesel mode in case of a shortage in gas supply. Switching from one fuel to another fuel does not reduce speed or power output. Use of LNG will reduce emissions of NOx and CO2 by approximately 85% and 25% respectively.
Viking Prince has a gross tonnage of 5,321t and a dead weight of 6,150t. She is 89.6m long and 21m wide. Her summer draught is 7.6m. Length between perpendiculars and depth to main deck are 79.2m and 9.60m respectively.
The vessel has a cargo deck area of 1,021m² and the cargo rail is 4m in height.
Accommodation and facilities onboard Viking Prince
Viking Prince can accommodate a total of 24 persons in 12 one-man cabins and six two-man cabins. All cabins are provided with toilet and shower facilities.
Public venues include a smoker’s room, a no-smokers room, a laundry and a gymnasium. The vessel also includes a hospital and an office.
Tank storage capacity and discharge rates
The vessel is provided with a hot/cold water tank washing system. All mud, brine and base oil tanks are cleaned with washing water containing chemicals. Separate piping systems for all kinds of liquid cargo are available on the ship.
Tank storage capacities onboard the vessel include 233m³ of LNG, 824m³ of fuel oil, 1,036m³ of potable water, 1,781m³ of drill/ballast water, 1,392m³ of liquid mud, 211m³ of methanol, 300m³ of dry bulk, 1,667m³ of brine, 412m³ of special products and 2,278m³ of ORO.
Fuel oil, fresh water, drill/ballast water and brine are discharged at the rate of 150m³ per hour. The discharge rate of liquid mud and base oil is 100m³ per hour. Methanol and special products are released at the rate of 75m³. These discharge rates are for one pump per tank. The number of pumps varies from tank to tank.
Deck equipment
Viking prince is equipped with two Cargotec harbour mobile cranes. Each crane can lift a load of 5t at 15m outreach. Other equipment onboard include four tugger winches and a pair of mooring winch (fitted aft). An anchor/mooring winch is fitted forward.
Manoeuvring, navigation and communication systems
The vessel is fitted with a Kongsberg K-POS DP-22 dynamic positioning (DP) system that meets IMO’s DP Class 2 requirements and Kongsberg K-Master manoeuvring system.
Advanced navigation equipment include three Anschutz gyrocompass, an Anschutz 20X5 autopilot, two Furuno radars (FRC-2117 and FAR-2137S BB), a Furuno FA-150 Automatic Identification System (AIS), Furuno Electronic Chart Display and Information System (ECDIS), and a Furuno Echo sounder and Doppler log. The vessel also has a Taiyo VHF direction finder, two Gill Ultrasonic wind sensors, a pair of Furuno GP 150 DGPS and a Furuno NX – 700B Navigational Telex (Navtex).
The onboard communications are supported by UHF and VHF radio telephones supplied by Furuno and Motorola. Some other significant instruments include radar transponders, EPIRBs, Inmarst C GMDSS and VSAT antennas.
Machinery and propulsion by Wärtsilä
Viking Prince is configured with a gas electric propulsion system based on Wärtsilä’s Low Loss Concept (LLC). The vessel is fitted with four Wärtsilä main engines, each of which is driven by four Alconza generators.
Two of the main engines are of Wartsila 6L34DF design and the other two are of Wartsila 6L20DF. The combined output of the four engines is 7,332kW (2 x 2610kW and 2 x 1056kW). The main generator sets are of Alconza NIR7172A-10LW (two) and Alconza NIR4561A-6LW (two) models.
In addition, the vessel is provided with a 339kW-rated Volvo Penta emergency generator.
Propulsion is provided by a pair of Steerprop-manufactured azimuth propulsion system. Each propeller is rated at 2,450kW. For better and smooth manoeuvring, the vessel is fitted with two bow thrusters, each rated at 1,000kW, and an azimuth thruster of 880kW.
