Cable ploughing is a subsea burial method that lays and buries a cable in a single pass. A plough is towed across the seabed by a cable-lay vessel, its share cutting a narrow trench into which the cable is fed, and the displaced seabed falls back to bury it immediately. For long, continuous runs such as export cables and interconnectors, ploughing is often the fastest and most economical burial method, where seabed conditions allow it.
Of all the ways to bury an offshore cable, ploughing is one of the most elegant: it lays and protects the cable in one continuous operation. A plough cuts a trench, the cable drops in, and the seabed closes over it, all in a single pass. For the right routes and ground conditions, it is the most efficient burial method available. This guide explains how subsea cable ploughing works, where it suits, and who delivers it. It is part of our wider guide to subsea cable installation, alongside our pieces on subsea trenching and cable lay.
What is subsea cable ploughing?
Cable ploughing is a method of burying subsea cables in which a specialist plough is towed along the seabed behind a cable-lay or installation vessel. The plough has a share, a blade that cuts into the seabed, that opens a narrow trench. As the plough advances, the cable is fed down through the plough and laid into the bottom of the trench, and the displaced wedge of soil falls back on top to provide instant protection once the plough has passed. Because laying and burial happen together, ploughing is described as simultaneous lay and burial.
How does cable ploughing work?
The plough is connected to the vessel by a tow line, and the cable runs from the vessel down to and through the plough. As the vessel moves forward along the pre-surveyed route, the share cuts the trench, the cable is guided into it, and the seabed naturally backfills behind. To tow a plough that is burying a power cable to a useful depth in a reasonably firm seabed, the vessel needs to be able to apply substantial pulling force, known as bollard pull, which is one reason ploughing is matched carefully to vessel capability and ground conditions. Burial depth is typically in the one-to-three-metre range, achieved in a single pass or, for deeper or harder ground, through multiple passes.
Where is ploughing the best burial method?
Ploughing comes into its own on long, continuous cable runs in suitable seabeds. It is often the primary burial method, and the most economical, for:
- Export cables, the long runs carrying power from an offshore wind farm to shore.
- Interconnectors, the long-distance links between grids or countries.
- Long subsea routes generally, where a continuous, efficient single-pass operation pays off.
Its main limitation is geometry and ground. The typical spacing between offshore wind turbines can make it impractical to tow a plough between them, so inter-array cables are often buried by other means such as self-propelled trenchers. Very hard, rocky or obstruction-strewn seabeds may also preclude ploughing, in which case surface lay followed by post-lay trenching is used instead.
What types of cable plough are used?
Ploughs are engineered for different cables and conditions. Power cable ploughs are built for the inter-array and export cables of offshore renewables, providing burial and immediate backfill. Pipeline ploughs handle larger-diameter pipelines and flowlines, often using multiple passes for pre-lay trenching and post-lay burial. Some ploughs use a vibrating share to ease the blade through the seabed. In every case the principle is the same: cut, lay and backfill in one coordinated operation, with the plough towed and controlled from the surface vessel.
What roles deliver cable ploughing projects?
Ploughing campaigns are delivered by specialist offshore crews. Typical roles include cable and burial engineers, plough and equipment operators, offshore and project engineers, survey engineers and surveyors, cable-lay vessel crew and marine personnel, and offshore managers and client representatives, all working to strict offshore safety and quality standards. These are technical, often rotational offshore roles requiring specific expertise and certifications, the kind of niche talent that benefits from a specialist recruiter.
How WRS supports cable ploughing recruitment
Offshore and subsea work is core territory for WRS. We recruit the specialist talent that cable ploughing and burial campaigns rely on, across offshore and maritime, subsea and offshore wind. Our recruitment solutions and contractor services cover permanent and contract hiring, mobilisation and compliant payroll, so you can crew ploughing projects worldwide with confidence.
If you are staffing a cable ploughing or burial campaign, get in touch to discuss your requirements, or submit your CV if you work in subsea and offshore.
FAQs
What is subsea cable ploughing?
A burial method in which a plough is towed along the seabed behind a vessel, cutting a trench, laying the cable into it and letting the displaced seabed backfill over it, all in a single pass. This is known as simultaneous lay and burial.
Why is ploughing used for subsea cables?
Because for long, continuous runs in suitable seabeds it is the fastest and most economical way to lay and bury a cable, providing immediate protection in one operation. It is widely used for export cables and interconnectors.
When can ploughing not be used?
Where turbine spacing makes it impractical to tow a plough, as with many inter-array cables, or where the seabed is too hard, rocky or obstructed. In those cases, surface lay followed by post-lay trenching or jetting is used instead.
What is the difference between ploughing and trenching?
Ploughing lays and buries the cable in one pass. Trenching is the broader category of seabed excavation and includes post-lay burial, where the cable is laid first and a separate trenching machine buries it. See our subsea trenching guide for more.
How can WRS help with cable ploughing projects?
WRS recruits the specialist offshore and subsea talent ploughing campaigns need, from cable and burial engineers to plough operators, survey and marine crew, across more than 90 countries. Visit worldwide-rs.com or contact us to discuss your project.
