The invention relates to an operations vessel for the maintenance, installation and/or disassembly of offshore structures, comprising: a hull equipped with ballast means connected to a control system; at least one working platform supported on the hull by means of one or more support elements; and at least one system for coupling to an offshore structure, wherein said coupling system can adopt, at least, a state in which it is coupled to said offshore structure and a state in which it is not coupled to said offshore structure. Advantageously, the control system and the coupling system are configured in a cooperating manner, in order to adopt at least two working positions of the vessel, wherein the hull adopts an above-water state with the coupling system decoupled, and at least a second working position wherein the hull adopts a submerged state in which the coupling system is coupled to the offshore structure.

The invention relates to a method for the installation of a marine (or in general, aquatic) wind-powered generator tower, wherein said tower advantageously comprises a foundation that is open at the top and equipped with a substantially flat lower slab and a perimeter wall. The method includes, in the different stages thereof, the depositing or removal of ballast material in or from the main cavity of the foundation, and wherein in the absence of said ballast material, the wind-powered generator or the foundation is a floating or self-floating structure. The method is particularly suitable for the installation of wind-powered generators in areas of low depth (or near-shore areas), preferably of less than 15 m.

Offshore structure comprising a pile of a foundation and at least one offshore element, mounted on the pile, forming a slip joint, wherein between an inner surface of the offshore element and an outer surface of the pile: a coating, especially an anti-fouling coating is provided, increasing friction between the said two surfaces and/or preventing corrosion of one or both of said surfaces and/or at least two spaced apart areas are provided with a substance, forming a seal between the said outer surface and the said inner surface, near an upper end of the pile and the off shore element and between a lower end of the off shore element and the pile.

A cleaning device that passively self-adjusts to improve biofoul removal across curved, non-uniform, or irregular underwater surfaces. The cleaning device includes a motor, one or more shafts coupled to the motor and coupled to one another via at least one universal joint, and a cleaning mechanism for removing biofoul from the target surface. The cleaning device includes an alignment mechanism that restricts the cleaning mechanism's movement to improve biofoul removal. The alignment mechanism can include bearings, spring components, dampening material, adhesion components, floatation objects, or a combination thereof.

In order to provide an improved and cost-efficient method for performing an exchange of up-tower main components on an off-shore wind turbine a method is disclosed in during which a non-permanent service platform is temporarily coupled to a wind turbine tower lower section. In addition, a wind turbine structure and a system including such a structure are described, the wind turbine structure and the respective system being designed to allow performing the described method.

Methods of determining an offshore jacket platform’s condition including determining a geometry, a plurality of loads, and a material composition of an offshore jacket platform; obtaining a base shear at collapse when the offshore jacket platform is intact; calculating a residual resistance factor; determining a criticality factor for each of a plurality of members on the offshore jacket platform; determining a structural health condition state; determining the probability of deterioration; and modeling a rate of deterioration. Another aspect of the disclosure includes methods of determining an offshore jacket platform’s condition in case of lack of inspection records including selecting a corrosion wastage model for splash zones and immersion zones, identifying distribution parameters for the legs and bracings of the jacket platform; determining a structural health condition state for leg and bracing; aggregating probable structural health condition states; and modeling a rate of deterioration of the offshore jacket platform.

A rotating grooming brush comprising a brush hub having grooming elements and shroud elements, and method for grooming a surface having an unwanted material thereon. The elements extend from the brush hub and may be positioned near its outer periphery. The elements may be grooming elements forming an array and shroud elements forming a shroud array. A rigid or elastomeric shroud extending from the brush hub surface may optionally be included about the edge of the brush hub, to the outside of the grooming elements. Rotation of the grooming attachment brush causes a low pressure region to build in the central area of the brush. This low pressure region creates a resulting force that forcefully attracts the grooming attachment brush to the surface to be groomed. The resulting force is controlled by the diameter of the brush hub, arrangement, of the elements and the speed of rotation.

A system including a camera configured to capture a first image of an offshore structure and a second image of the offshore structure, and a processor coupled to the camera, the processor configured to receive the first image and the second image from the camera, recognize a first visual pattern in the first image and the second image, extract pixel coordinates associated with a first position of the first visual pattern in the first image and a second position of the first visual pattern in the second image, and determine a first distance between the first position and the second position, or the first position of the first visual pattern and a first position of a second visual pattern fixably attached to the offshore structure in the first image.

In embodiments, motion may be arrested and/or dampened using a motion arresting and dampening device comprising a lifting spreader bar, one or more bar mounted winches, deployment wire, a restorative inflation device, restraining wires and winches, hoses and controller, mechanical connection release system circuitry. Multiple restraints from winches mounted strategically on a vessel crane's boom may be applied to the spreader bar to restrain the bar during the lifting operation. The forces induced into the lifted object by the movement of the crane as it deploys the object into installation position are attenuated by the physical restrain of the adjustable wires. These adjustable wires may also be used to provide rotation of the object during final alignment of the object during installation.

An epoxy grout composition for marine repairs contains: a liquid epoxy resin comprising up to 15 wt. % benzyl alcohol and having a viscosity of 220 to 1100 cps; a liquid hardener comprising up to 25% benzyl alcohol and having a viscosity of 50 to 85 cps and, wherein the total benzyl alcohol content of the combined resin and hardener ranges from 1 to 12 wt. %; and preferably, a particulate inorganic filler comprising 10 to 50 wt. % of particles under 150 μm and 50 to 90 wt. % of particles between 150 μm and 1.18 mm. The composition is particularly suitable for placement in the annular space between a marine structure and a fiberglass composite jacket. The composition may be provided in kit form, with premeasured containers of resin, hardener, and filler. A related method is also disclosed.