In March 2026, the Offshore Engineering Department of Shandong Future Robotics completed the special post‑trenching and burial‑depth protection construction for exposed submarine cables at the offshore wind farm in the eastern China seas, ensuring the safe and stable operation of the wind power transmission links.
Located in the eastern waters of Rudong County, Jiangsu Province, the wind farm is recognized as Asia’s first offshore wind power project utilizing flexible DC transmission technology. The primary objective of this project was to perform post-trenching and burial depth restoration for exposed submarine cables, ensuring the long-term safety, reliability, and operational stability of the offshore power transmission network.
Pronounced scouring by strong tidal currents and periodic interference from spring tides drastically reduce effective operational windows.
Frequent heavy fog directly impairs equipment control accuracy and operational safety.
Conventional offshore engineering equipment suffers from operating blind spots in shallow‑water environments, posing great challenges for precision construction.
Dense fishing nets and numerous obstacles in near‑shore waters create high operational risks for equipment, placing extremely high demands on construction planning and on‑site management.
The project contributed to the protection and long-term reliability of one of Asia’s most technologically advanced offshore wind farms, supporting the stable operation of its flexible DC transmission system.
Despite challenging conditions including dense fog, strong currents, shallow-water blind zones, and complex nearshore obstacles, VVLAI successfully maintained precise trenching operations and cable route tracking throughout the project.
The project demonstrated VVLAI’s ability to combine ROV technology, sonar inspection, and cable tracking systems to achieve accurate subsea positioning and navigation in low-visibility marine environments.
VVLAI selects the subsea trenching machine as its primary construction platform. Designed specifically for demanding near‑shore cable protection operations, this equipment delivers outstanding trenching performance, operational stability and precise control in complex marine environments.
The project team conducted detailed analysis of local weather forecasts, tidal patterns, and marine conditions to maximize the utilization of limited construction windows. Construction activities were carefully scheduled to minimize environmental impacts and improve overall efficiency.
Leveraging VVLAI’s independently developed ROV technology and mature cable tracking expertise, the team established a proprietary positioning solution combining:
-Sonar detection systems
-440 cable locator technology
-Continuous subsea monitoring
-Multi-dimensional position cross-verification
This integrated approach enabled precise cable tracking and trenching operations even under conditions of poor visibility and strong currents.
Through autonomous positioning and pre-planned operational route optimization, the team successfully avoided fishing net entanglement, equipment drift, and other environmental hazards. Continuous trenching protection was performed for submarine cables ranging from 120 mm to 248 mm in diameter, ensuring both construction safety and project quality.
The project successfully completed the post-trenching protection of exposed submarine cables, maintaining a stable trench depth of 2.6 to 3 meters throughout the operation. This effectively eliminated potential transmission risks and strengthened the reliability of the wind farm’s power export system.
The successful execution validated VVLAI’s ability to perform precise submarine cable protection operations under a combination of challenging conditions, including dense fog, shallow-water blind zones, strong tidal currents, and obstacle-rich nearshore environments.
The project generated significant practical experience and technical know-how for future submarine cable protection projects. The lessons learned provide valuable references for offshore wind farm cable maintenance, risk mitigation, and full lifecycle asset management.
The post‑trenching project of submarine cables for offshore wind farms in the Eastern China Seas further validates VVLAI’s professional expertise in offshore wind support, submarine cable protection and subsea engineering operations.
By integrating subsea trenching machines with advanced ROV technologies, and intelligent positioning systems, VVLAI successfully delivered safe, precise, and efficient cable burial protection under highly challenging marine conditions. The project reinforces VVLAI’s commitment to supporting the long-term reliability of offshore energy infrastructure and advancing innovative subsea engineering solutions worldwide.
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