Skandi Skolten is a fuel efficient and clean class construction anchor handling vessel (CAHV) built for deep-water mooring and field installation operations. With a bollard pull of 350t, she is one of the most powerful anchor handling tug supply (AHTS) vessels in the world. She is the second in a series of four installer vessels ordered by DOF Subsea.

The contract for the construction of the vessel was awarded to STX Europe (then known as Aker Yards) in 2007. The keel for the vessel was laid in November 2008. She was launched in December 2009 and delivered in July 2010.

The hull of the vessel was built at STX Europe’s shipyard (STX RO Offshore Tulcea) in Tulcea, Romania, and was outfitted at STX Europe’s shipyard (STX Norway Offshore AS Aukra) in Aukra, Norway.

Design and features of the Skandi Skolten

"Skandi Skolten is a fuel efficient and clean class construction anchor handling vessel (CAHV)."

Skandi Skolten is of STX Europe AH 04 design. The AH 04 is an environmentally-friendly design and enables an AHTS ship to undertake field installation operations across the world in a wide range of water depths and environmental conditions.

The low resistance hull shape of the vessel allows her to cruise at greater speeds with low fuel consumption. In addition, the optimised hull shape provides good sea and station-keeping performances, smooth manoeuvrability and good stability.

The vessel features a large working deck remotely operated underwater vehicle (ROV) hangar that can be prepared with launch and recovery systems (LARS) for ROV, with a depth rating of 3,000MSW.

The vessel also features a 21m diameter helicopter deck which is capable of accommodating a Sikorsky S92 helicopter.

One of the most important features of the vessel is her Triton XLX heavy duty work class ROV system designed to provide extended and accurate offshore operations. Its power unit is rated at 150HP and has a payload capacity of 250kg.

The gross tonnage of the vessel is 8,252t and the dead weight is 4,579t. She has an overall length of 108m. Length between perpendiculars is 99m. The moulded breadth and depth to main deck are 24m and 9.8m respectively. Design draft to midship is 7.8m.

Cargo capacity of the construction anchor handling vessel

The vessel features a timber made cargo deck. The main deck measures 1,070m2 in area and has a load carrying capacity of 10mt/m2. The cargo deck also features a 7m x 7m moon pool.

The vessel can store 1,200m³ of marine diesel oil, 1,000m³ of fresh water and 4,000m³ of ballast water.

Deck equipment onboard the Norwegian CAHV

Skandi Skolten is fitted with an active heave compensated knuckle boom crane. Mounted on the starboard side of the main deck, the crane has a load lifting capacity of 250t at 13m radius. An A-frame of 350t capacity is mounted aft.

The vessel is also fitted with two auxiliary deck cranes. Deck crane one has a safe working load (SWL) capacity of 3t at 10m radius, while the second deck crane has an SWL capacity of 20t at 10m radius.

A small stores crane is located on the right side of the vessel. It can lift 3t at 15m radius.

Additional equipments include a main winch of 500t capacity and two secondary winches, each of 170t pull, two hydraulic windlass / mooring and two hydraulic draggers.

Propulsion and manoeuvring of the Skandi Skolten construction anchor handling vessel

The vessel is fitted with two Wartsila 16V32 main engines, each capable of producing 7,680kW and four Wartsila 8L26 main generators, each capable of generating 2,600kW.

"Skandi Skolten is of STX Europe AH 04 design. The AH 04 is an environmentally-friendly design."

There is also an emergency generator of 220kW.

For smooth manoeuvring, Skandi Skolten is equipped with eight side thrusters. These include three Wartsila hybrid propulsion and one retractable thrusters, each of 1,500kW.

The other four are Wartsila Lips Tunnel thrusters fitted stern.

Kongsberg K-POS DP21 Dynamic Positioning (DP) Class-2 control system allows the vessel to automatically maintain her position and heading.

Its reference systems include one HiPaP 500, two differential global positioning systems (DGPS), a Fanbeam and a radius system.