Compact and powerful underwater magnetic robot

Hercules is a belt driven compact magnetic robot developed on the Goliath’s technology concept, but this machine uses only two magnetic belt drive units capable to generate a magnetic traction force up to 1,600 kilograms on ferromagnetic materials. Exceptional turning radius and small footprint allows the machine to maneuver easily around obstacles and narrow passages on the hull structures.

The compact design makes it easier to handle the robot during launch and recovery, where deployment frames can used instead of a crane. The deployment frame can be installed on tank top deck and consist of a simple steel structure frame is divided into modules, each weighing less than 25kg, a limit for a person is allowed to lift offshore without any lifting aids. Such intelligent design allows for quick and easy launch and recovery.

Low profile and open structure design reduce the hydrodynamic drag, making the robot capable of working in the splash zone, in wave conditions up to 3.5m Hs.

Hercules is powered by a topside hydraulic power unit and an on-board valve pack. Hydraulic fluid, power and communication are all transferred to the robot via a single hybrid cable to optimize it for underwater operations: lighter load and extended movement and maneuvering demands (inspections and cleaning).

Hercules mounted on crane deployment frame during a decommissioning project.

Hercules presents a very stable tool platform and can operate disparate accessories. Depending on needs, it can be equipped with either a low-profile frame for front tooling only or a high-profile frame for the cofferdam under the main frame and tooling in front.

The robot performs efficient non-destructive testing, close visual inspection, and offshore hull cleaning, but such versatile technology can well have other applications.

In 2022 the robot, equipped with an abrasive cutting tool, was used at a -90m depth to recover suction anchors from an FPSO decommissioning project. Another interesting project was offshore hull cleaning in the splash zone where Hercules successfully removed significant marine growth before an FPSO was disconnected and towed to a yard for a lifetime extension project. Such an approach: cleaning and leaving marine growth where it naturally belongs, was in line with the recommendations of Norwegian and other national authorities.

Technical data:

Standard dimensions1700 x 1150 x 600 mm
Weight, dry400 kg
Magnetic holding force1600 kg
Depth Rating100m
Payload100 kg
OtherFiber-optic telemetry, hydraulic motors, onboard valve block for tooling. HD cameras.
Available AC/DC power and communicative for tooling.

See Hercules in operation:

Hercules magnetic robot – Heavy marine growth removal offshore from Remotion on Vimeo.


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Hull crack repairs

Underwater Hull Crack Repairs

Inspections under demanding conditions

Sea chest blinding

Offshore Hull Cleaning

downloadable documents

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GA drawing with habitat and cleaning tool