Systems and methods for the ultrasonic disruption of biofilm and algae growth on underwater structures utilize an ultrasonic actuator (10) that produces a natural frequency in the ultrasonic range. In some embodiments, the ultrasonic actuator (10) includes one or more piezoelectric transducers (110).

A scour prevention unit includes a bag body housing block objects in a bag material, and a cloth integrated with the bag body, wherein the cloth is housed in the bag material and is laid below the block objects, or is fixed below the bag body outside the bag body by fixing means.

Methods of removing a film of a biological material from a surface are provided. In embodiments, such a method comprises applying magnetic particles to a surface contaminated with a film of a biological material; and exposing the magnetic particles to a changing magnetic field to move the magnetic particles relative to the contaminated surface, thereby removing the film from the surface.

An energy-supply rotary inertia driver system for an offshore platform includes an annular fixed plate, an active control module, a wind power generation module and a solar power generation module. The system can monitor a motion state of the offshore platform in real time, and can generate a force through the active control module if necessary to apply a force torque of the offshore platform to further achieve the vibration suppression. Moreover, when the offshore platform is under normal operation, the system can act as an energy supply device via wind and solar power generation to feed electric energy to the active control module and other electrical equipment on the offshore platform when needed.

An offshore platform for use in combination with an offshore rig comprises an upper deck defining an upper deck aperture which is alignable with a rig aperture of the offshore rig, when said offshore rig extends over the upper deck, to permit objects to extend between the offshore rig and through the upper deck. The offshore platform further includes a sheath arrangement aligned with the upper deck aperture and extending upwardly relative to the upper deck to be alignable with the rig aperture, wherein the sheath arrangement defines a confinement zone for confining objects which pass downwardly from the offshore rig through the rig aperture.

A load arrangement powers loads on a surface (30) of a marine structure exposed to a fouling liquid (10), and has a transmitter arrangement (110) and at least one carrier medium (100) having embedded loads (20). Front electrodes (130) are arranged to be coupled to the liquid, and back electrodes (120) have back electrically conductive layers embedded in the carrier medium to form, in combination with an opposite area of the marine 5 structure and a dielectric layer (4a), a back capacitor for capacitive transfer of the supply current between the second power node and one pole of the power source coupled to the marine structure. The transmitter arrangement has a supply line (111) and a multitude of transmitters (114) galvanically connected to the supply line. The multitude of transmitters is distributed along the supply line to be arranged near the multiple front electrodes to form 10 short conductive paths (113).

The instant invention describes an anti-biofouling structure for placement onto structures or surfaces that are exposed to aquatic environments. Embedded within the anti-biofouling structure are agents that can diffuse out of the structure and prevent the formation and/or accumulation of plant and animal species build-up that creates biofouling. The instant invention also describes a system for preventing biofouling of an object stored in an aquatic environment which includes the anti-biofouling structure, and a protective cover element constructed and arranged to fit various structures, such as boat propellers.

An offshore oil and gas platform has equipment and piping associated with an oil and gas installation. A method for optimising fire protection for the platform includes arranging the platform to have an evacuation time of at most 15 minutes or less using one or more evacuation route(s) via a gangway or bridge allowing personnel to escape to a vessel or to another platform, determining a maximum evacuation time for the platform, assessing the risk to personnel using the evacuation route(s) in accordance with the determined maximum evacuation time in the event of a fire, and providing passive fire protection to equipment and/or piping on the platform in order to prevent escalation of the fire that would create a risk to personnel on the evacuation route(s) during the determined evacuation time.

A simplified structure allows inspection of the installation strength of an anchor installed underwater. A method includes applying, to an anchor, a lifting force from above a floating body floating on a water surface to submerge the floating body into water, and setting a volume of submergence by which the floating body is submerged to a value to produce a lifting force corresponding to a predetermined installation strength and determining whether the anchor is immovable. The volume of submergence by which the floating body is submerged to produce the lifting force corresponding to the predetermined installation strength is calculated based on the buoyancy acting on the floating body.

The invention relates to an offshore installation, comprising an underwater foundation structure, a construction placed onto the foundation structure, a docking device for a boat, and a device for cathodic corrosion protection for the underwater foundation structure, said device having at least two anodes (2), which are arranged at a distance from each other and are each fastened to a beam (4) or a support of the foundation structure, the extension arms or the supports being connected directly to the foundation structure below the waterline.