[WATCH] Crawfish Robotic Vehicle Climbs Offshore Wind Turbines, Paints Underwater

A new undersea robotic vehicle, known as the Crawfish, has emerged as a potential solution for maintaining offshore renewable energy platforms.

Crawfish: The Underwater Robotic Vehicle

According to New Atlas, this experimental device can climb vertical underwater surfaces and perform painting tasks, offering a promising alternative to conventional maintenance methods.

Offshore energy structures, whether powered by wind, tidal currents, or waves, demand regular inspection, maintenance, and repairs to ensure operational efficiency and longevity.

Traditionally, these tasks have relied on costly and time-consuming diver interventions, posing inherent risks to human safety. The Crawfish comprises two interconnected components developed by researchers at Germany's Fraunhofer Smart Ocean Technologies research group.

At its core lies the BlueROV2 remotely operated vehicle from Blue Robotics, equipped with thrusters and cameras for navigation and observation.

A crawler unit featuring direct-drive elastomer wheels and various tools, including cameras, brushes, and sensor-reading equipment, is attached beneath. With a weight of just 22 kg (48.5 lb), the Crawfish can be deployed into the water by a small team without the need for heavy lifting equipment.

Once submerged, operators can remotely control it from the surface, utilizing the BlueROV2's camera and propulsion system to maneuver towards the target structure.

Once it reaches the vertical surface, the Crawfish uses its thrusters to maintain position and traverse along the surface using its wheeled locomotion system.

Underwater Maintenance Tasks

The Fraunhofer Smart Ocean Technologies research group emphasized the significance of offshore infrastructure in advancing the energy transition. They highlighted the labor-intensive and risky nature of underwater maintenance tasks, prompting the development of the Crawfish to streamline such operations.

The Crawfish's design incorporates four direct-drive wheels, enabling precise control and navigation across various offshore structures, including curved surfaces.

Vertical thrusters provide the necessary contact pressure, ensuring stability irrespective of surface conditions. The team reported successful testing of the Crawfish in the Baltic Sea, demonstrating its versatility and effectiveness in performing maintenance tasks on underwater platforms.

One of the primary applications of the Crawfish is repairing anti-corrosion paint damage, a common issue plaguing offshore structures. Equipped with a brush attached to a linear unit, the Crawfish autonomously repairs coating damage by injecting a specialized two-component coating material at the affected areas.

"A common problem with offshore structures is minor damage to the anti-corrosion paint. Damage to the paint leads to corrosion and premature failure of the structure. An automated solution can be provided by the Crawfish, where a brush attached to a linear unit repairs the coating at the relevant points," the researchers said in a statement.

ComoBelt Sensor Collar

Additionally, the Crawfish can be utilized for monitoring system readouts, such as the CoMoBelt sensor collar, which uses ultrasonic sensor technology to detect weld seam cracks.

The Crawfish can accurately position itself above monitoring points by integrating induction-powered reading heads and transmitting measurement data via WLAN. The Fraunhofer research team underscores its commitment to developing innovative marine technologies and sustainable ocean utilization solutions.

Operating within the Ocean Technology Campus Rostock and leveraging the nearby Digital Ocean Lab, the interdisciplinary team aims to drive advancements in underwater technology through collaborative research efforts.