-- In the rippling waters of Shengsi, Zhoushan, the ebb and flow of the tides conceal the key to the safety of vital subsea energy infrastructure. Recently, State Grid Zhoushan Power Company has upgraded its flagship “Guo Jiao No.1” fleet with a powerful new asset—a nearshore pipeline detection catamaran unmanned surface vessel. Teaming up with an airborne magnetic survey drone and an underwater patrol robot, the fleet carried out the first integrated air-sea inspection of submarine cables in the intertidal zone of Gouqi Island, Shengsi, Zhejiang.
This pioneering technological deployment—integrating aerial, surface, and underwater systems—marks a significant step forward, officially ushering China’s intertidal submarine cable operation and maintenance into a new era of comprehensive intelligent management and control.
As the vital power “lifeline” connecting mainland China to its offshore islands, over 1,000 kilometers of submarine cables have already been laid in the waters around Zhoushan. However, many of these pass through shallow intertidal zones—areas long deemed operational blind spots due to their inaccessibility: ships can't enter, personnel can't reach, and instruments often produce distorted readings. In traditional operations, large survey vessels are too deep-drafted for shallow zones, small boats lack stability and deliver low-accuracy data due to wave-induced vibrations, and manual inspections require workers to wade during short low-tide windows—posing high risks and low efficiency.
Enter the core technology behind this latest inspection: a domestically developed catamaran unmanned surface vessel (USV), purpose-built to overcome these longstanding challenges.
This 7-meter-long, 3-meter-wide USV draws only 0.5 meters of water and features a catamaran hull that enables it to “beach” and operate in shallow areas unreachable by conventional vessels. Equipped with two 15-kilowatt electric thrusters, it maintains precise cruising speeds of 0–8 knots. Its diesel-electric propulsion significantly reduces vibration and noise, ensuring a stable operating environment for acoustic detection systems. A key innovation is its pioneering forward-facing detection system, offering full-coverage scanning from the bow, keel, sides, and stern. With a bow-side thruster and operational A-frame, it flexibly performs multiple tasks such as cable routing surveys and condition monitoring.
At the inspection site, a striking "air-sea-subsea" collaborative operation unfolded:
In the air, a drone equipped with a high-precision magnetometer swooped in, using a multi-modal fusion algorithm integrating acoustic, optical, and magnetic signals to penetrate sediment layers. It fired 512 sonar beams per second to generate seabed maps with 5-centimeter resolution, transmitting real-time data on cable burial depth and position—free from tidal constraints.
On the surface, the catamaran USV operated in tandem with the Zhudian No. 15, initiating China’s first mother-daughter vessel collaborative survey model. The USV collected high-resolution data and streamed it back to the mothership, where specialized algorithms compiled detailed “health profiles” of the cables.
Underwater, a compact, agile patrol robot—with onboard lighting—navigated through reef-filled zones, conducting continuous inspections for signs of damage or displacement in the cable protection casings, and precisely locating potential risks.
“What used to take a manual team three days to complete can now be done in just half a day with this air-sea collaborative model,” said a submarine cable O&M specialist from State Grid Zhoushan Power Company. Using 5G and satellite communications, the system enables seamless data transmission. Field trials show an over 80% improvement in inspection efficiency, a 60% reduction in operational costs, and a complete elimination of human safety risks. This inspection not only validated the USV’s strengths—low-speed precision cruising, shallow-draft access, and high-accuracy sensing—but also established a standardized operation protocol, laying the groundwork for a future O&M model driven by mother-daughter vessel collaboration and big data analytics.
The successful implementation of this integrated air-sea inspection in the Shengsi waters has broken through the long-standing barriers of intertidal zone maintenance. More importantly, it signals a transformative leap in China’s marine power operations—from risky manual efforts to intelligent, risk-averse systems, and from reactive maintenance to proactive early warning. Looking ahead, State Grid Zhoushan Power Company will continue advancing its “air-sea-land” collaborative maintenance framework, leveraging cutting-edge technologies to strengthen energy security for island economies—and illuminating the green development path of thousands of islands with the power of smart energy.(By Zhang Cifeng and Wu Jiateng)
Contact Info:
Name: jiateng.wu
Email: Send Email
Organization: ZHEJIANG ELECTRIC POWER CORPORATION
Website: https://www.zj.sgcc.com.cn/p1/index.html
Release ID: 89177926
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