A method for installation of a transition piece on a monopile foundation of an offshore wind turbine along a common axis extending in a longitudinal direction is performed from a floating installation vessel. Buffer elements are arranged around an inner circumference of the transition piece and/or the monopile structure. The transition piece is lifted and lowered onto the monopile structure by use of a crane, and landed onto the monopile structure through the use of the buffer elements. A number of hydraulic cylinder jacks for circumferential alignment of bolt holes are provided in the transition piece and monopile, and alignment tools are used for alignment of the flanges provided on each of the transition piece and the monopile. The transition piece is lifted and the buffer elements are removed after which the transition piece is lowered onto the monopile, and bolts are tensioned fix the transition piece to the monopile.

A method for constructing an offshore wind turbine includes: attaching all or a part of electrical products to a tower on land; stowing, on a work platform, the tower to which the electrical product is attached; and disposing, on a foundation, the tower, to which the electric product is attached, by using a crane of the work platform in the sea. In addition, the electrical products are classified into special high-voltage devices and the other electrical products, the special high-voltage devices are modularized on land, the other electrical products are attached to the tower on land, and the modularized special high-voltage devices and the tower, to which the other electrical products are attached, are disposed on the foundation by using the crane of the work platform in the sea.

A node for a lower structure of an offshore wind power generator according to an embodiment of the present invention relates to a node for a lower structure of an offshore wind power generator, which is manufactured by a casting method, the node including a body part into which a main pipe is inserted, a support part which is formed to be branched from the body part at a predetermined angle with respect to a height direction and into which a branch pipe is inserted, and a reinforcement part that protrudes from the body part, forms a predetermined radius of curvature, and thus reinforces coupling between the body part and the support part.

In an assembly of an offshore support structure for a wind turbine, tubular members are interconnected in grouted connections where a first tubular member has fastened to it a shell-unit comprising a cavity into which an end-part of a second tubular member is inserted and fixed by grouting. The cavity is closed by a rigid entrance-flange that is fastened to the walls of the shell-unit. The design converts forces acting on the second tubular member to compression forces acting on the grout in the cavity.

The present disclosure describes a base structural building module employing a core structural member having an array of upwardly and outwardly and downwardly and outwardly extending braces or arms extending therefrom. Tubular cans are mounted at the ends of each of the upper and lower arms to receive piles. One upper arm is aligned and paired with one lower arm and the pair's respective cans are aligned about their can axis. The modules employ flexible design by varying the lengths of the arms and their respective inclination or declination angles. Modules can be stacked one on top of another (and secured) to form multi-tiered structural building jackets for building vertical structures such as, for example, oil and gas platforms used onshore or offshore as well as other structures. Each tier can also comprise multiple modules joined laterally together to provide a wide variety of potential template configurations and building applications.

A support assembly for an offshore installation is provided, which support assembly includes a transition piece for mounting onto an offshore foundation; a plurality of support shelves, wherein each support shelf extends radially outward from the transition piece; a platform to accommodate equipment of the offshore installation, which platform includes a mounting sleeve dimensioned to fit about the transition piece; and wherein the mounting sleeve includes a plurality of downwardly-extending portions, each dimensioned to fit between two adjacent support shelves; and a plurality of lateral cut-outs, each formed in a downwardly-extending portion and shaped to receive a support shelf. An offshore wind-powered water electrolysis plant including such a support assembly, and a method of installing such a support assembly is also provided.

Assembling a jacket structure that includes two or more legs and crossing braces extending between the legs and forming cross joints. A first component of the jacket structure includes two or more legs and brace structures. Each brace structure includes a first brace and a second brace, sections of the first and second braces being at one end attached to the first leg at respective first and second leg-brace joints. The brace structure and the first leg form an A-frame. A second component of the jacket structure that includes a second set of brace structures and a second part of the brace cross node is further provided. The first component of the jacket structure is mounted to the second component of the jacket structure by joining the first and second parts of the brace cross nodes to form full brace cross nodes.

A tubular joint includes a tubular substrate extending along an axis. The substrate has a first inner diameter. A first tubular brace member is additively manufactured on the substrate and is connected thereto at a proximal end of the first tubular brace member. A second tubular brace member is additively manufactured on the substrate and is connected thereto at a proximal end of the second tubular brace member. At respective distal ends of the brace members, the first tubular brace member and the second tubular brace member have a circular cross-sectional shape having a distal wall thickness and a second inner diameter that is smaller than the first inner diameter. At the proximal ends the of brace members, the first tubular brace member and the second tubular brace member have respective proximal wall thicknesses that are greater than the distal wall thickness.

Provided is a submersible offshore platform configured to be installed at a sea floor installation site and a method of installing the offshore platform. The offshore platform may include: a primary node and a primary column disposed thereon; a plurality of support nodes; a plurality of pontoon sections, each of the plurality of pontoon sections configured to connect the plurality of support nodes to the primary node or to each other; a plurality of buoyant modules, wherein each of the plurality of buoyant modules is detachably connected to a respective support node; and a primary column support system, wherein the primary column support system includes: a plurality of vertical supports fixed around a perimeter of the primary column, each of the plurality of vertical supports having one end connected to the primary column node; and a support structure connecting a top portion of each of the plurality of vertical supports to the primary column.

Provided is a submersible offshore platform configured to be installed at a sea floor installation site and a method of installing the offshore platform. The offshore platform may include: a primary node and a primary column disposed thereon; a plurality of support nodes; a plurality of pontoon sections, each of the plurality of pontoon sections configured to connect the plurality of support nodes to the primary node or to each other; a plurality of buoyant modules, wherein each of the plurality of buoyant modules is detachably connected to a respective support node; and a primary column support system, wherein the primary column support system includes: a plurality of vertical supports fixed around a perimeter of the primary column, each of the plurality of vertical supports having one end connected to the primary column node; and a support structure connecting a top portion of each of the plurality of vertical supports to the primary column.