With the continued growth in the size of offshore platforms and deepwater subsea equipment as well as an expected rise in the decommissioning of large production facilities, the need for greater offshore lifting capacity is pressing.

Despite the low oil price environment, Heerema Marine Contractors (HMC) is showing its faith in the long-term prospects for the offshore sector by proceeding with the building of a semisubmersible crane vessel at Sembcorp Marine’s Jurong Shipyard in Singapore. Named Sleipnir, after the swift and strong eight-legged stallion of the god Odin from Norse mythology, the newbuild will have two powerful revolving cranes capable of lifting 10,000 metric tonnes each, both being designed and built by fellow Dutch company Huisman Equipment. The crane boom will have a length of 145 m (476 ft), and with the boom up, the crane will reach a height of 210 m (689 ft) above the waterline.

HMC said the self-propelled vessel—ready for operations by the summer of 2019—also will be used for the installation of subsea structures, foundations, moorings and deepwater
floating structures.

Dual-fuel innovator
Interestingly, power will be generated by MAN Tier-III dual-fuel engines (marine gas-oil and LNG) from MAN Diesel & Turbo, the first time a vessel of this size will feature dual-fuel technology.

Twelve MAN 8L51/60DF four-stroke engines and 12 MAN SCR (selective catalytic reduction) systems will achieve a total power output of about 96 MW. MAN said that, with the exception of power barges, it will be one of the largest engine installations ever aboard a single ship, with the vessel to have four separate engine rooms. Engine delivery is scheduled for first-quarter 2017.

For station-keeping, the Sleipnir will use a dynamic positioning (DP3) or mooring system.

Like a number of other marine construction or transportation vessels coming onto or due onto the offshore market soon, this vessel is raising the bar in terms of scale. At a length of 220 m (722 ft) and width of 102 m (335 ft), the semisubmersible unit will be the world’s largest crane vessel, HMC said, and the unit will help HMC meet demand for lifting capacities currently beyond what it can offer. With a large reinforced work deck, HMC said the Sleipnir also will be able to offer increased efficiency when installing or removing offshore facilities. The company already owns four of the world’s largest heavy-lift vessels: SSCV Thialf, DCV Balder, SSCV Hermod and DCV Aegir.