China’s largest full-revolving semi-submersible crane vessel, the Si Hang Yong Sheng, was officially delivered on July 8 in Jiangmen, Guangdong Province, marking a significant milestone in the country’s offshore engineering capabilities.

Built by CCCC Fourth Harbor Engineering’s Jiangmen Hangtong Shipbuilding, the 110-meter-long, 43.8-meter-wide vessel features a continuous deck area of 4,800 square meters and is classed by China Classification Society. It integrates heavy-lifting and semi-submersible transport functions, overcoming the traditional limitations of single-purpose crane ships or semi-submersible barges. The stern is equipped with a 149-meter full-revolving luffing crane capable of a fixed stern lift of 2,200 tonnes—equivalent to hoisting 1,500 passenger cars—with a maximum lifting height of 172.5 meters. In full-revolving mode, the rated capacity is 1,500 tonnes. The vessel can submerge to a maximum draft of 28.6 meters, with a total lifting capacity of 20,000 tonnes, enabling it to transport 11,000-tonne caissons or complete offshore equipment packages.

A key innovation is the fully automated intelligent ballast control system, which uses real-time data on sea conditions, hull attitude, and crane loads to calculate optimal ballast adjustments and maintain autonomous balance without manual intervention. The vessel is also equipped with a foldable crane mast to reduce air draught during ocean towage, allowing unrestricted global transit.

Designed for unlimited navigation, the Si Hang Yong Sheng will support deep-sea wind farm development, cross-sea bridge construction, large-scale port upgrades, and marine ranching projects. Its integrated lift-and-transport model substantially reduces project timelines and coordination costs compared to conventional multi-vessel operations. Built entirely in Jiangmen’s Yinzhou Lake shipbuilding base with predominantly domestic components, the vessel reinforces the Pearl River Delta’s position in high-end marine equipment manufacturing and strengthens China’s competitive edge in Southeast Asian and Belt and Road offshore engineering markets.