The offshore jack-up has a hull and a plurality of moveable legs engageable with the seafloor. The offshore jack-up is arranged to move the legs with respect to the hull to position the hull out of the water. The method comprises securing the vessel with respect to the hull of the offshore jack-up when the hull is positioned out of the water and the legs engage the seafloor. A lifting mechanism mounted on the offshore jack-up engages with a cargo carrying platform positioned on the vessel. The platform is lifted with the lifting mechanism between a first position on the vessel and a second position clear of the vessel.

A fatigue resistant gravity based spread footing under heavy multi-axial cyclical loading of a wind tower. The foundation having a central vertical pedestal, a substantially horizontal continuous bottom support slab, a plurality of radial reinforcing ribs extending radially outward from the pedestal. The pedestal, ribs and slab forming a continuous monolithic structure. The foundation may have a three-dimensional network of post-tensioning elements that keep the structural elements under heavy multi-axial post compression with a specific eccentricity intended to reduce stress amplitudes and deflections and allows the foundation to have a desirable combination of high stiffness and superior fatigue resistance. The foundation design reduces the weight and volume of materials used, reduces cost, and improves heat dissipation conditions during construction by having a small ratio of concrete mass to surface area thus eliminating the risk of thermal cracking due to heat of hydration.

A first permissible operating range of the self-elevating vessel is determined based on a first structural analysis of the self-elevating vessel under a first set of conditions. A structural utilization ratio of the self-elevating vessel is determined based on a second structural analysis of the self-elevating vessel under first and second sets of conditions. Safety of lowering the self-elevating vessel from an elevated state to a first hull draft level is determined when the structural utilization ratio is less than a predetermined value. Safety of lowering the self-elevating vessel from the first hull draft level to a second hull draft level is indicated when positional displacement data obtained while the vessel is at the first hull draft level indicates that the positional displacement of the self-elevating vessel while at the first hull draft level is within the first permissible operating range.

Offshore ocean floating platform with docking bay and upper deck with living premises with laboratory, three submersible plankton pumping towers pumping plankton from ocean water up to 120 deep, with piston with check valve moved within cylinder by double acting telescopic actuator with manned and aerated research submersible vehicle pushed by telescopic double acting actuator from above water lever to ocean floor, with telescopic dual air supply tubes providing atmospheric pressure air from above sea level, with safety return springs Docking bay, hull and Plankton pools made with multiple steel barrels welded to each other arranged in multiple layers. with air blower and default return helical springs, video cameras and water depth gauge. Said towers bottom-end securing to seabed with heavy cement poles with embedded cylinder and piston moving into seabed dirt under ocean water high pressure connected thru holes and with augmented self-drilling plungers with threading helical motion action.

Drilling installation comprising a cantilever with a drilling floor for performing drilling operations; further comprising an independent operations handling system arranged for handling equipment underneath the drilling floor independent of the drilling operations on the drilling floor, wherein the independent operations handling system comprises a handling element for cooperation with the equipment to be handled, wherein the handling element is extendible underneath the cantilever.

A floatable structure is described having a hull and a deck. The floatable structure further includes a mooring system for mooring a second floating structure at a mooring position relative to the floatable structure. The mooring system brings the second floating structure down in the water from an initial floating draft to a larger mooring draft to reduce motions of the second floating structure relative to the floatable structure. A method for mooring a second floating structure using the mooring system is also described.

The invention relates to a crane as a component of a wind farm installation vessel which consists of a vessel body and a plurality of jack-up legs arranged in vertically movable manner thereon, wherein the crane is arranged rotatably about one of the jack-up legs. According to the invention, the crane is rotatably mounted on an eccentric platform which itself is arranged rotatably about the jack-up leg.

An apparatus for use in marine platform jacking is disclosed herein. In one aspect, a jetting valve includes a valve body with a piston assembly disposed therein. The piston assembly is selectively operated to open and close the valve. A biasing member is coupled to the piston assembly. The piston assembly includes a first piston and a second piston. The dual pistons, in cooperation with the biasing member, allow the valve to self-seal thereby preventing entry of a fluid which is external to the valve.

A method for monitoring movement of a cantilever structure of an offshore platform, such as a jack-up platform or a self-elevating vessel, comprising providing a boundary model containing boundary limiting information of positions of the cantilever structure, wherein the boundary limiting information comprises at least position information of boundary limiting elements, such as obstacles; providing, during movement of the cantilever, position information of the cantilever representing an actual position of the cantilever; determining, during movement of the cantilever, a difference between the cantilever position information and the boundary limiting information of the boundary model; providing an output signal when the determined difference exceeds a predefined threshold value.

A coupling system for temporarily coupling a jacket with a foundation pile includes a first flange for mounting with the jacket, a second flange for contacting the foundation pile, and an inflatable spacing member arranged between the first flange and second flange. The inflatable spacing member contacts both the first flange and second flange for supporting the jacket through the spacing member.