The floating system is a single column tension leg platform for a floating offshore wind turbine (SCTLP). The single column tension leg platform comprises a central main vertical floating column, a buoyant base attached to and disposed below the central main vertical floating column, a station keeping system attached to the buoyant base, and an inter array cable riser system. The buoyant base is of one of a triangular shape and a circular shape.

A modular structure for being at least partly submerged in a body of water, is disclosed. The modular structure comprises structure elements and strengthening elements providing structural integrity and flexibility, and can typically be a closed structure like e.g. a tank structure. Further, macro structures comprising attached modular structures are presented. Finally, methods for construction of such structures are disclosed.

The invention has for object a system and a method for the realization of floating platforms formed by the aggregation of floating forms in reinforced concrete, the union set of the modules is made integral forming a single plate inserting and pulling special steel cables that cross the entire platform in sheaths arranged in the walls of the modules themselves, the pulled cables, locked in this position, compress the plate to increase resistance, the present method and system are also characterized by the fact that the quota of the platform does not vary with the tides and the loads to which it is subjected.

A method of assembling a floating wind turbine platform includes forming a base assembly of the floating wind turbine platform in either a cofferdam or a graving dock built in water having a first depth. The base assembly includes a keystone and a plurality of buoyant bottom beams extending radially outward of the keystone, wherein longitudinal axes of each of the plurality of bottom beams are coplanar. The cofferdam or the graving dock is flooded and the assembled base assembly is floated to an assembly area in water having a second depth. A center column and a plurality of outer columns are assembled or formed on the base assembly, a tower is assembled or formed on the center column, and a wind turbine is assembled on the tower, thereby defining the floating wind turbine platform.

The floating system is a single column tension leg platform for a floating offshore wind turbine (SCTLP). The single column tension leg platform comprises a central main vertical floating column, a buoyant base attached to and disposed below the central main vertical floating column, a station keeping system attached to the buoyant base, and an inter array cable riser system. The buoyant base is of one of a triangular shape and a circular shape.

The floating system is a single column tension leg platform for a floating offshore wind turbine (SCTLP). The single column tension leg platform comprises a central main vertical floating column, a buoyant base attached to and disposed below the central main vertical floating column, a station keeping system attached to the buoyant base, and an inter array cable riser system. The buoyant base is of one of a triangular shape and a circular shape.

An offshore structure is separated into an upper structure and a lower structure. Part or whole of the lower structure is kept in an upright standing state in water. The upper structure is moved to above the lower structure kept in the upright standing state. A uniting step includes one or both of raising the lower structure to arrange the lower structure on a lower side of the upper structure and lowering the upper structure to arrange the upper structure on an upper side of the lower structure by submerging part of a carrier vessel on which the upper structure is mounted while being held by a pair of arm-shaped structures of the carrier vessel and integrating the lower structure with the upper structure. In this way, an offshore structure is moored safely at an offshore installation site without using a crane vessel.

This invention is directed to a column floater with extended cylinder and a ring buoy-group, which comprises an upright buoy at a water surface, an extended cylinder, a positioning system and a topsides. The top of the upright buoy is above the water surface and a moonpool is either set or not in the center of the upright buoy through the top to the bottom. The extended cylinder, connecting to the bottom of the upright buoy and extending downwards, includes two types of fixed and sliding to form a column floater with fixed extended cylinder and a column floater with sliding extended cylinder respectively. The positioning system is one or two combined of mooring system and DP system. The column floater with extended cylinder is a new type floating platform with multi-purpose, combining advantages of the spar platform and the current cylindrical FPSO, high performance, safety and reliability.

The invention relates to a method of constructing and launching an offshore semi-submersible platform, comprising: a) making said semi-submersible platform in a dry environment by dividing it into a plurality of sub-assemblies each of which comprises at least one of the floating columns and at least one semi-arm of a respective lower structural connection arm; b) providing each sub-assembly in a dry environment with at least one temporary thrust box; c) separately launching in water the individual sub-assemblies; d) adjusting for each sub-assembly the ballast of the respective temporary thrust box so as to obtain a balanced floatation of the sub-assembly; e) bringing the sub-assemblies at the free ends of the respective semi-arms close to each other two-by-two until they are aligned; f) connecting the temporary thrust boxes to each other two-by-two; g) welding the free ends of the semi-arms together; h) removing the temporary thrust boxes.

The invention relates to a method of constructing and launching an offshore semi-submersible platform, comprising: a) making said semi-submersible platform in a dry environment by dividing it into a plurality of sub-assemblies each of which comprises at least one of the floating columns and at least one semi-arm of a respective lower structural connection arm; b) providing each sub-assembly in a dry environment with at least one temporary thrust box; c) separately launching in water the individual sub-assemblies; d) adjusting for each sub-assembly the ballast of the respective temporary thrust box so as to obtain a balanced floatation of the sub-assembly; e) bringing the sub-assemblies at the free ends of the respective semi-arms close to each other two-by-two until they are aligned; f) connecting the temporary thrust boxes to each other two-by-two; g) welding the free ends of the semi-arms together; h) removing the temporary thrust boxes.