On July 8, China's largest full-revolving semi-submersible crane vessel, Si Hang Yong Sheng, was delivered in Jiangmen, Guangdong Province, adding another piece of heavy marine engineering equipment to the nation's maritime power development. The vessel has successfully broken through the functional limitations of traditional equipment by integrating a crane with a semi-submersible barge, achieving the combined dual functions of heavy-lift operations and cargo transport.

The Si Hang Yong Sheng was constructed by Jiangmen Hangtong Shipbuilding, a subsidiary of CCCC Fourth Harbour Engineering, and is classed by the China Classification Society. The vessel has an overall length of 110 metres, a moulded breadth of 43.8 metres, and a moulded depth of 8 metres, with a continuous flat deck area of 4,800 square metres.

The vessel further integrates multiple functions, including semi-submersible transport and full-revolving heavy-lift capability. Its stern is equipped with a full-revolving, luffing crane with a maximum lifting capacity of 2,200 tonnes, enabling it to undertake both hoisting operations and the transport of ultra-large and ultra-heavy offshore structures weighing up to 20,000 tonnes.

Li Haifeng, Deputy General Manager of Jiangmen Hangtong Shipbuilding, explained that the vessel is fitted with a fully automatic intelligent ballast adjustment system. Drawing on multi-dimensional data—including real-time sea conditions, hull attitude, and lifting loads—the system calculates the optimal ballast adjustment plan, precisely regulating the vessel's draft and trim angle across various compartments. This achieves autonomous balance control without human intervention, significantly enhancing the safety, stability, and precision of offshore hoisting and loading operations and improving overall operational safety at sea.

Huang Chenguang, the project's Chief Engineer, explained that in addition to its core heavy-lift operations, the Si Hang Yong Sheng can also adjust its draft, submerging the hull steadily to operate as a semi-submersible barge. Once a large structure requiring transport is guided into position, the vessel de-ballasts and rises, capable of steadily lifting a cargo of 10,000 tonnes, thereby achieving full coverage from hoisting to float-on transport.

Following its delivery, the Si Hang Yong Sheng will enhance China's comprehensive support capabilities for the construction of sea-crossing bridges and port terminals, and underpin the development of major projects in emerging sectors such as deep-sea wind power, large-scale marine ranching, and deep-sea resource exploration.