By Lex Veerhuis, Fugro
In several parts of the world, autonomous vessels are now an operable reality. Uncrewed surface vessels (USVs) combine remote operations and monitoring capabilities with sophisticated sensors and near real-time data analysis. They have the potential to take on many subsea inspection and survey projects from onshore locations, reducing carbon emissions and improving crew safety, and tackling industry-wide challenges like resource limitations and data sharing in the process.
There are numerous marine assets where USVs with electric remotely operated vehicles (eROVs) play a crucial role. These assets include existing oil and gas infrastructure that require regular inspection, service and monitoring. Gathering data on the seabed and condition of the assets is essential to inform decision-making regarding future maintenance and ensure the integrity of critical platforms, subsea constructions and pipelines, some of which may be approaching end of life.
Another example is critical industry tasks such as trans-ocean cable route surveys needed to meet the increase in demand for data communications. The USVs acquire high-resolution data to efficiently visualize cable routes, their depth positions and detect anomalies. These tasks can be completed without health and safety risk and with significant savings of operational costs when compared to executing the same task with traditional survey vessels.
Emissions reductions
USVs also support clients in achieving safer and more efficient data collection operations, while contributing to mutual carbon footprint reduction ambitions.
Industry standards extend to how these vessels are propelled through the water. The exact choice of system will depend on the use case of the USV, in combination with the energy density offered by the fuel. For short endurance USV applications, for example, there is the opportunity for battery-powered propulsion to become feasible. For longer-duration applications, a fuel that’s as dense as possible is needed, which currently makes diesel the most economic. The good news is that USVs use 95% less fuel than traditional survey vessels, so there is already a huge reduction in emissions.
Offshore wind use cases
As experience deploying USVs at offshore wind farms has grown, Fugro has learned to become more efficient working around these structures and in using different satellite beams to avoid the disruption of signal.
The company has been operating USVs in Europe since 2022. The first time the technology was specifically used on a wind farm project globally was in April 2023. This involved the 12-m Blue Essence USV, with a Blue Volta eROV, performing visual inspections. This project consisted of delivering several inspections on the structure of the wind turbines to assess their stability and safety. Using a deepwater multibeam echosounder sensor mounted on the hull of the vessel, a detailed map of the seabed was also able to be captured.
Development of larger USVs
Fugro is working on development of larger USVs, designed for more complex scopes. The 18-m Blue Eclipse will come online in early 2025 with the first commercial work for clients planned later in the year. Equipped with the Blue Amp eROV, which can operate down to 500 m water depths, it is the first in an anticipated global series of long-endurance USVs that will be deployed in the offshore energy sector with comparable ROV inspection performance to regular DP2 vessels.
The broader scope and scale of Blue Eclipse, with up to 20 days estimated endurance, and greater station keeping and payload capability, makes it suitable for projects farther offshore, like the floating offshore wind farm industry. The USVs are controlled from one of Fugro's global remote operations centers, reducing risk for maritime personnel, minimizing exposure hours, enhancing safety and maximizing operational uptime.
Addressing resource limitations
Fugro anticipates that USVs will help alleviate industry challenges such as vessel scarcity, which is an acute problem in some parts of the world. The number of offshore wind projects is increasing and are located further offshore in deeper waters.
At the same time, USVs will not eliminate crewed vessels completely. In fact, for some use cases, there is a multiplier effect to be realized by deploying a USV and crewed vessel in tandem on the same project. More data can be gathered, or a wider area audited in the same amount of time, maximizing the use of resources and providing the answers clients need more quickly.
Real-time data sharing and analysis
Looking to the future, Fugro has only just started to explore the opportunities presented by the real-time data sharing that USVs and remote operations enable. This doesn’t only include survey data but also live video stream data collected by the eROV onboard the company's USVs. It means clients can observe and receive outputs from the inspections as they take place in real time, allowing them to be more responsive and reactive, and take full advantage of the opportunities these inspections offer.
Latest advances allow Fugro to not only analyze and present data to clients via a static report but also provide access to dashboards and visualizations that will allow them to make instant comparisons between inspection intervals, or even forecast future needs for their asset maintenance.
With the advantages they bring around crew safety, flexibility and environmental impact, USVs are set to play a leading role in not just sustainable offshore energy development, but in the maintenance and inspection of many other marine assets. As the collective industry experience in deploying them grows, they look set to become an invaluable part of the marine engineering fleet mix in the future.
