Kongsberg Ferrotech’s subsea robots fix damage on site

Subsea conditions wreak havoc on underwater assets. Offshore wind turbines are exposed to marine growth, coating damage, material fatigue and corrosion in the splash zone. The same is true for subsea power cables and pipelines.

“Inspection, maintenance and repair of such assets is costly, time-consuming and dangerous,” says Carlsen.

“This is a major problem. In order for offshore wind to become competitive, we must find more intelligent ways to inspect and repair these assets,” he adds.

Kongsberg Ferrotech provides robotic services for subsea assets in demanding ocean spaces. The robots perform in-situ inspection, maintenance and repair (IMR) of underwater installations.

“We bring the workshop to the damage, not the damage to the workshop,” says Carlsen.

Designed for underwater habitats, the robots – named Oktapous, Nautilus and Exoskeleton – are equipped with various inspection and repair tools, depending on the customer’s needs.

For inspections, a wide range of methods are available, from visual inspection to non-destructive testing (NDT) technologies. All inspection data is stored in a digital twin tool for future use.

The maintenance function performs regular tasks to avoid shutdowns and detect defects. “We conduct our robotic services in a single operation, which reduces the complexity of the maintenance process compared to today’s underwater interventions,” Carlsen explains.

As for repairs, they are performed in a digitally controlled environment and reinstate structural integrity using technology such as corrosion protection and additive manufacturing.

The robots can perform all tasks at depths down to 1 500 metres.

The robots vastly increase efficiency in IMR operations, leading to major cost and time savings. “For the first time, subsea IMR can be performed without remotely operated vehicles, divers and other vessel-supported equipment,” says Carlsen.

“This reduces costs by 30 to 70 per cent and cuts the intervention time in half,” says Carlsen. It also avoids asset downtime, preventing lost revenue.

With better efficiency comes a substantial reduction in CO₂ emissions from less manufacturing and transport activity. Worker safety gets a boost as well.

“We have removed human labour from the risky underwater environment. Instead, relevant employees participate from their own workspace or use a smartphone and watch in real time while the robot performs the operations.”

Worldwide offshore wind capacity is expected to grow tenfold between 2021 and 2035, driving the demand for subsea IMR in coming years. “There are over 6 000 offshore wind turbines in the world, and with the current predictions for industry growth, we anticipate a massive market for our robots,” says Carlsen.

Established in 2014, Kongsberg Ferrotech continues to pioneer technology in this area. With Equinor, SINTEF and Gassco as industry partners, the company is developing the Nautilus robot to include advanced 3D printing for in-situ, metal2metal repairs of subsea equipment.

“We will continue to innovate to make our robots, and thus the offshore wind industry, more competitive,” Carlsen concludes.