Polar King Subsea Construction Vessel, Norway
Polar King is a purpose-built, remotely operated survey and light offshore construction vessel, built to carry out operations in the North Sea on a worldwide basis. It can also undertake inspection, maintenance and repair operations. The vessel was delivered in March 2011.
Built by CNP Freire Shipyard in Vigo, Spain, the vessel was ordered by GC Rieber Shipping in 2008. Construction began in 2009 following a six month-delay due to the global financial crisis. The project was funded by three Norwegian finance groups - Nordea, Sparebanken Vest and SpareBank 1 SR-Bank on a long-term basis.
In February 2011, GC Rieber announced that Polar King will be charted to Technocean, a subsidiary of Reef Subsea, for a firm charter period of three years, with the option to extend it for two more years. Technocean took the vessel in April 2011.
Polar King design
Certified to IMO SPS 2008 requirements, Polar King is specially designed to operate under all weather conditions with high manoeuvrability and station keeping capabilities. During the design phase, environmental issues such as the installation of a selective catalytic reduction (SCR) system for all generator sets and clean design were addressed. The hull lines are optimised for reduced fuel oil consumption.
Polar King is a Skipsteknisk design ST-254L CD, with an overall length of 110.6m and moulded beam of 20m. The length between the perpendiculars is 97.8m and its depth to the main deck is 9.8m. The vessel has a maximum draught of 7.6m and deadweight of 5,700t. With an area of 960m², the cargo deck has eight evenly distributed strong points that can hold up 25t in any direction.
The deck strength of the aft deck is 10t per square metres and that of the hangar area is 5t per square metre. There is also a helideck capable of accommodating a Sikorsky S-92 helicopter.
The vessel has two moonpools. The 7.2m x 7.2m main moonpool is dimensioned for vertical launch system. The Work ROV moonpool has an area of 5.4m x 5.4m.
>Polar King has two passive anti-rolling tanks and one anti-heeling system with two transfer pumps, each with 200m³ per hour capacity. Additional roll stabilisation, when the ship is stationary or cruising at low speed, is achieved by employing Voith Schneider Propellers.
The tank can store 1,740m³ of fuel oil, 3,500m³ of water ballast and 1,200m³ of potable water.
A total of 112 people can be accommodated on the Polar King in 45 double cabins and 22 single cabins, which are equipped with separate toilets. Facilities include an online room, an offline room, client offices and a conference room.
Polar King propulsion
The vessel has a diesel electric propulsion system with two variable speed reversing AC propulsion motors, each with an output of 3.8MW.
For power generation, the vessel is equipped with six MAN 9L21 / 31 diesel generator sets, each rated for 1,710eKW at 900rpm, and one Cummins diesel generator set rated for 1,200eKW at 1,800rpm.
Of the three Rolls Royce thrusters, two are electric bow thrusters of 1,350kW each, and one electric azimuth thruster of 1,400kW.
Navigation and communications
For navigation and radio communications Polar King is equipped according to Global Maritime Distress Safety System regulations, Area 3 and Naut-OSV notation.
The dynamic positioning system comprises a dual DP-system, a dual HiPAP (high precision acoustic positioning) 500, two Seapath 200 hydro acoustic positioning and seabed mapping systems, one spot beam, one Inmarsat B / Fleet 77 modulator and three motion reference units (MRUs).
Polar King is equipped with a 150t capacity active heave compensated (AHC) knuckle boom crane with a winch installed under deck. The maximum lifting capacity of the main hook is 150t safe working load for 7m-10m radius and 25t SWL for 35m radius.
The maximum effective lifting capacity at 2,000m is approximately 100t. The auxiliary hook has a maximum lifting capacity of 12.5t and the maximum effective lifting capacity at 500m is approximately 10t.
Additional cranes include a folding crane for provision handling and two folding cranes for cargo handling.
Two launch and recovery systems (LARS) are installed on one Work Class ROV hanger. There are also two umbilical winches installed under deck.
Safety equipment includes one fast rescue craft and two lifeboats.