China commissions its largest semi-submersible crane vessel

China has delivered its largest semi-submersible crane vessel by lifting capacity, adding a heavy-lift unit intended to support offshore wind farms, cross-sea bridges, ports and deep-sea resource projects. The Sihang Yongsheng was handed over in Jiangmen, in Guangdong Province, and combines heavy lifting with offshore transportation so it can move and install large marine structures.

The non-self-propelled barge measures 110 metres long and 43.8 metres wide, with a 4,800-square-metre deck able to carry structures weighing up to 10,000 tonnes. At the stern sits a fully revolving luffing crane with a 149-metre boom that can raise cargo to a maximum height of about 172.5 metres, roughly the height of a 50-storey building. When anchored for lifting, the crane can raise up to 2,200 tonnes in a single operation, making it the country's largest fully revolving semi-submersible crane vessel by lifting capacity.

The crane can rotate a full 360 degrees while the vessel remains anchored, allowing it to install large offshore wind turbine foundations, steel structures and heavy bridge sections more efficiently. The vessel can also submerge into semi-submersible mode to transport and position large offshore structures before installation, and an automated ballast system keeps it balanced without manual intervention during complex work.

Engineers on the project said the rotating crane and transport functions were developed to handle increasingly large offshore structures, from wind turbine foundations to heavy bridge sections. Industry observers noted that larger engineering vessels let more offshore projects proceed efficiently, since many big platforms are assembled onshore before being transported and installed at sea, and that building vessels of this scale reflects the shipbuilding industry's move toward more advanced and intelligent manufacturing.