The Zhen Hua 30 Completes China's First 10,000-Ton Offshore Steel Structure Installation

SHANGHAI, Nov. 3, 2025 /PRNewswire/ -- The Zhen Hua 30, the world's largest 12,000-ton self-propelled revolving crane vessel, has successfully completed China's first 10,000-ton offshore steel structure installation. The operation took place under challenging sea conditions off the coast of Yangjiang in Guangdong Province. Using an innovative "float-and-lift" method, the vessel installed lower structures for two offshore converter stations, part of the Three Gorges Yangjiang Qingzhou V and VII projects. This successful installation lays the groundwork for the subsequent placement of the stations' upper modules. 

The Qingzhou V and VII projects represent the world's highest-voltage, largest-capacity offshore flexible direct current (VSC-HVDC) power transmission system. Once operational, it will deliver up to 7.7 billion kilowatt-hours of renewable electricity annually to major population centers. The offshore converter stations will be the largest of their kind worldwide, marking a significant advancement in long-distance, high-capacity power transmission from offshore wind farms.

The foundation installation site lies approximately 74 kilometers offshore, in waters 50 meters deep. The substructure comprises a 10,200-ton jacket secured to the seabed by eight massive steel pipe piles. Each pile measures 115 meters in length and 5 meters in diameter, weighing 907 tons, together forming the core support for the upper module. 

To meet the demands of the complex marine environment, the Zhen Hua 30 adopted a specially engineered float-and-lift technique to overcome two key challenges: the structure's enormous size and the extremely high precision required during installation.

The operation consisted of two technically demanding phases. First, the jacket was lifted and positioned through the combined effect of the crane's lifting force and the jacket's buoyancy, transferring it smoothly from a semi-submersible transport vessel to its designated location. This process required real-time calculation and dynamic control of the relative positions, buoyancy-gravity balance, and wave-induced motion of all involved vessels. Second, during the installation of the 5-meter-diameter steel pipe piles, the team maintained precise lifting height and stability to prevent sway, ensuring each pile was inserted accurately into its predrilled socket—a process that placed stringent demands on the crane's stability and deviation control systems.

Independently developed and built by Shanghai Zhenhua Heavy Industries (ZPMC),the Zhen Hua 30 has once again demonstrated world-class technical expertise in offshore engineering. The successful completion of this float-and-lift installation marks a new technological milestone for China's marine engineering equipment and provides valuable experience for future large-scale offshore converter station projects.