China Commissions Its Largest Semi-Submersible Crane Vessel ‘Sihang Yongsheng’

China has delivered its largest semi-submersible crane vessel by lifting capacity, adding a new heavy-lift vessel that will support offshore wind farms, cross-sea bridges, ports and deep-sea resource projects.

The Sihang Yongsheng was delivered on Wednesday in Jiangmen, Guangdong Province.

Built by Jiangmen Hengtong Shipbuilding, a subsidiary of CCCC Fourth Harbor Engineering Co., the vessel combines heavy lifting with offshore transportation, allowing it to move and install large marine structures.

According to state media, the vessel will be used for offshore wind projects, port construction, cross-sea bridges, marine ranches and deep-sea resource exploration.

The Sihang Yongsheng is a non-self-propelled semi-submersible barge designed for heavy lifting and offshore cargo transport.

It is 110 metres (361 feet) long and 43.8 metres (144 feet) wide, with a 4,800-square-metre (51,700-square-foot) deck that can carry structures weighing up to 10,000 tonnes.

At the stern is a fully revolving luffing crane with a 149-metre (489-foot) boom. The crane can lift cargo to a maximum height of 172.5 metres (566 feet), about the height of a 50-storey building.

When anchored for lifting operations, the crane can lift up to 2,200 tonnes (about 2,425 U.S. tons) in a single operation, making it China’s largest fully revolving semi-submersible crane vessel by lifting capacity.

According to China Media Group (CMG), the crane can rotate 360 degrees while the vessel remains anchored. This allows it to install large offshore wind turbine foundations, steel structures and heavy bridge sections more efficiently.

The vessel can also switch into semi-submersible mode by lowering itself into the water, allowing it to transport and position large offshore structures before installation. Its deck can carry cargo weighing up to 10,000 tonnes.

The Sihang Yongsheng is equipped with an automated ballast adjustment system that calculates operating conditions and keeps the vessel balanced without manual intervention. CMG said the system is designed to improve efficiency during complex offshore construction work.

Huang Chenguang, chief engineer of the project at CCCC Fourth Harbor Engineering’s Hengtong Shipbuilding, said the vessel’s rotating crane and transport functions were developed to handle increasingly large offshore structures.

He said the crane’s ability to rotate 360 degrees while anchored allows it to lift and install large offshore wind turbine foundations, offshore steel structures and heavy bridge sections.

Lin Boqiang, director of the China Center for Energy Economics Research at Xiamen University, said larger engineering vessels allow more offshore projects to be carried out efficiently.

Using offshore wind as an example, Lin said many large platforms are assembled on land before being transported and installed at sea by heavy-lift vessels. Without sufficient lifting capacity, such projects would be difficult to complete efficiently.

He added that these vessels are also used in offshore oil and gas platform construction and cross-sea tunnel projects.

Lin said building vessels of this scale requires advances in integrated system design, propulsion systems, materials and specialised manufacturing processes, adding that China’s shipbuilding industry has continued to move towards more advanced and intelligent manufacturing.

References: interestingengineering, globaltimes