Sembcorp Marine and Heerema Marine Contractors showed off Sleipnir, the world’s largest crane vessel that can be used for the setup and decommissioning of offshore oil and gas facilities.
The US$1.5 billion semi-submersible vessel, is equipped with two cranes. The combined lifting capacity of 20,000 tonnes, another industry record.
The Sleipnir, named after Norse God Odin’s eight-legged stallion, was built by Sembcorp Marine at its Tuas Singapore yard.
“We handle many semi-submersibles, but we never handled such a big size before,” said Sembcorp Marine CEO Wong Weng Sun.
Sleipnir is 220m-long and 102m-wide, and has a depth of 49.5m and an operating draught between 12m and 32m. With a displacement of 273,700t, the vessel can accommodate 400 people in single and double cabins, equipped with air-conditioning and heating systems.
A helicopter deck, located at the stern of the vessel, is intended to assist lift-off and landing of a single helicopter of type Augusta Westland EH101 or Sikorsky S-92. 
The dual cranes will provide heavy lift capacity for the installation and removal of offshore structures, including floating platforms, foundations and mooring systems.
The main hoist can lift 1,000mt of loads to a depth of 1km below sea level and is capable of reaching heights of 129m above the waterline. The auxiliary crane hoist has a lifting capacity of 2,500mT at a radius between 33m and 60m.
The cranes also feature a 200mt whip hoist with a maximum radius of 153m. Additionally, the vessel will have one 70mT pedestal-mounted lattice boom crane, capable of reaching depths of 2km.
The Sleipnir heavy-lift crane vessel is powered by 12 8MW, tier III-compliant, four-stroke MAN Diesel & Turbo 8L51/60DF engines, which are designed to run on both low sulphur marine gas oil and liquefied natural gas. With a combined output of 96MW, the propulsion system provides a transit speed of 10k.
Eight 5.5MW WST-65U underwater demountable fixed-pitch, variable speed azimuth thrusters, including four retractable type, installed at forward and aft portions of the vessel ensure better manoeuvrability.
Station-keeping will be enabled by the onboard dynamic positioning system, built in accordance with Lloyd’s Register’s IMO Class 3 is the DP (AAA) notation.
Heerema’s semi-submersible Thialf built in 1985, was the most powerful crane vessel with a lifting capacity of 14,200 tons. A heaviest single lift record was set in 2000 by Thialf for lifting the 11,883 t Shearwater topsides for Shell. Saipem 7000 set a new record in October 2004 for the 12,150 t lift of Sabratha deck. 
Under dynamic positioning, Saipem 7000 set another record in 2010 by lifting the 11,600 t BP Valhall Production topsides. (Source: Heerema/Wikipedia/Strait Times)