Bohai Sea Submarine Cable Trenching with C750D-III Imaging Sonar
Submarine cable installation is the "lifeline" of marine cable engineering. In nearshore areas, landing zones, and navigable waters, trenching operations are especially critical. Deep-sea trenching generates large amounts of sediment that turns the water extremely turbid, creating "underwater blind spots." Conventional equipment often fails to accurately track the operational route or monitor trench conditions, which not only affects efficiency but may also leave safety hazards. A Bohai Sea submarine cable trenching project deployed a self-propelled cable plow equipped with the C750D-III imaging sonar, successfully overcoming the challenges of turbid underwater trenching and safeguarding the cable installation in the Bohai Sea.
As the primary workhorse for underwater trenching, the self-propelled cable plow possesses powerful operational capabilities, able to adapt to the complex sea conditions of the Bohai Sea and efficiently complete trenching tasks, laying a solid foundation for cable installation.
Equipped with the C750D-III imaging sonar, even in highly turbid environments with massive sediment generated during trenching, stable and clear imaging is maintained. The system captures real-time underwater scenes, provides precise route guidance to keep the plow on track, and simultaneously collects trench condition data — including depth and width — enabling surface crews to monitor underwater operations with full visibility and achieve "visualized" precision construction.
All-Weather Adaptability
The underwater environment is inherently challenging — turbid water, no light, and near-zero visibility. The C750D-III imaging sonar operates independently of sea conditions, enabling 24/7 continuous operation for trenching surveys, real-time monitoring, and post-installation inspection with reliable data output.
Multi-Dimensional Detection
The C750D-III imaging sonar can both detect seabed surface obstacles and monitor trench formation and cable entry status in real time. It provides a one-stop solution covering pre-trenching surveys, in-trench monitoring, cable navigation, post-completion inspection, and long-term maintenance — eliminating the need for multiple observation devices, simplifying workflows, and reducing operational costs.
Safe & Efficient
The C750D-III imaging sonar proactively identifies obstacles such as shipwrecks, reefs, and abandoned pipelines, preventing collision damage to trenching and cable-laying equipment. It also monitors unexpected situations like trench collapse and cable bending in real time, providing early warnings and enabling timely adjustments to reduce the risk of equipment damage and cable breakage.
From "blind trenching" to "precision trenching," from "low efficiency" to "high efficiency," this domestically developed combination of autonomous trenching and advanced sonar imaging has not only solved the industry challenge of turbid underwater trenching in the Bohai Sea, but also demonstrated the strength of China's independent R&D in submarine cable construction equipment. We will continue to advance product technology and service capabilities to keep the "marine arteries" flowing and build a solid foundation for high-quality deep-sea engineering.