The tallest maritime crane used in offshore construction is found on the semi-submersible crane vessel called SSCV Selipnir, owned and operated by Heerema Marine Contractors.
The vessel was constructed by Sembcorp Marine in Singapore and entered service in 2019.
The vessel is 220 m long and 102 m wide, with a displacement of 273,700 tonnes and a draft between 12 and 32 m.
It can accommodate 400 crew members and was designed for the installation and removal of jackets, topsides, deepwater foundations, modules, moorings, and other offshore structures.
It minimises offshore assembly processes by allowing for single-lift installation of massive integrated structures.
It has 8 Wartsila azimuth thrusters and 12 dual-fuel engines, which can run on either marine gas oil or LNG, making it the first dual-fuel crane vessel in the world.
The vessel has two main cranes that reach as high as 220 m or 722 feet, making them the tallest offshore cranes, surpassing the height of several iconic buildings.
Each crane has a maximum lifting capacity of 10,000 metric tons, and together they can perform tandem lifts of up to 20,000 metric tons.
The cranes are fully revolving and can enable flexible and precise heavy lifting operations.
The main hoist can lift loads from 20 m below the waterline up to 135 m above it, with auxiliary hoists capable of even greater vertical reach of up to 165m above deck.
SSCV Sleipnir set a world record in September 2019, when it lifted a single module weighing 15,300 metric tonnes for the topsides of Noble Energy’s Leviathan Project in the Mediterranean Sea.
This was the heaviest lift ever performed by a crane vessel and was part of the installation of two main topsides, one weighing 15,300 tonnes and the other 9200 tonnes, which were installed in less than 20 hours, showing Sleipnir’s unmatched capabilities for efficient and swift offshore construction.
Apart from this major milestone, the vessel undertook many other key projects, such as the Tyra Redevelopment Project in the Danish Sea, where it installed and removed jackets and topsides.
In the Shell Brent Alpha Project in the North Sea, it removed the 10,100-tonne Brent Alpha jacket and made a new record for single-lift jacket removal.
The use of Sleipnir enabled the installation of massive, pre-commissioned modules, decreasing offshore time and project costs.
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