In 2022, we recognised that the offshore renewables market in emerging territories required an adaptive, end-to-end burial solution.
Our response was the SMD Shallow Water Trencher (SWT).
With it’s modular design, this vehicle can be deployed directly from the beach, operated from a barge, or launched from a shallow hull vessel. This enables precise, controlled trenching in very shallow waters, where conditions are often unpredictable.
Designed for complex operations requiring agility and precision, the SWT is now deployed in numerous regions with fragile seabed conditions, such as Southeast Asia. Projects such as the Xuwen II Offshore Windfarm in the South China Sea highlight how these capabilities are applied in practice.
Delivering Under Pressure
As with many Asian offshore windfarms, Xuwen II faced challenging shallow water conditions, including strong currents, restricted depths and dynamic seabed environments.
Demanding consistent trenching performance, these conditions made the SWT the perfect solution to the client’s strong operational goals. Working within a tight project schedule, it was deployed to trench and bury 9km of armoured power cable 1.8m below the seabed, in water depths of 5–26m and currents reaching 3–4 knots.
Operating in these environments requires a high level of control and reliability, often within constrained working windows. The SWT is engineered to meet these demands, enabling operators to maintain progress, maximise uptime and deliver trenching scopes efficiently.
Engineered to Perform in Shallow Water
The SWT combines our expertise in tracked ROV systems, trenching and cable handling, delivering performance and efficiency offshore, specifically in the conditions at Xuwen II.
The vehicle offers flexibility with cutting and jetting options, customised to each client’s specific burial requirements. On this particular project, twin-legged jetting tools enabled the team to achieve consistent trench profiles at 1.8m burial depths, even in shifting silt and sand. This level of control was critical to ensuring reliable cable protection across the full 9km scope. The ability to operate in both simultaneous and post-lay burial modes also enabled trenching activities to align with installation, supporting efficient delivery against a tight schedule.
The SWT’s compact, space-efficient design was key to offshore execution. With limited deck space on the GSB Huali barge, the system’s reduced footprint and flexible launch and recovery options enabled efficient integration into the vessel setup while supporting safe and streamlined operations throughout the campaign.
Efficiency was equally important. Simplified deployment and a reduced offshore footprint helped minimise overall project costs, while maintaining the reliability and uptime needed to complete the trenching scope within the required timeframe.
Collaboration That Drives Results
At SMD, we build long-standing partnerships through trust and collaboration, delivering efficient, reliable subsea operations with precision and consistency. The Xuwen II Offshore Windfarm stands as a proud example of this.
We strive to continually advance our technologies, applying engineering expertise and a pioneering mindset to ensure solutions like SWT evolve alongside industry needs. As offshore projects become more complex, our vehicles remain one step ahead.
To learn more about SWT, contact Adam Batsford at adam.batsford@smd.co.uk
