Abstract: A semi-submersible offshore platform comprises a main structure comprising two longitudinal lower side beam structures, two transverse lower side beam structures and four columns, the longitudinal and transverse lower side beam structures are located between the four columns connecting the four columns with each other such that the semi-submersible offshore platform exhibits a frame shaped submersible pontoon having a lower central opening the four columns extends upwards from the frame shaped submersible pontoon. The main structure of the semi-submersible offshore platform comprises two longitudinal upper side beam structures and two transverse upper side beam structures, the longitudinal and transverse upper side beam structures are located between the four columns connecting the four columns with each other such that the semi-submersible offshore platform exhibits a frame shaped deck box structure having an upper central opening for receiving at least one structural module.

Abstract: A semi-submersible offshore platform comprises a main structure comprising two longitudinal lower side beam structures, two transverse lower side beam structures and four columns, the longitudinal and transverse lower side beam structures are located between the four columns connecting the four columns with each other such that the semi-submersible offshore platform exhibits a frame shaped submersible pontoon having a lower central opening the four columns extends upwards from the frame shaped submersible pontoon. The main structure of the semi-submersible offshore platform comprises two longitudinal upper side beam structures and two transverse upper side beam structures, the longitudinal and transverse upper side beam structures are to located between the four columns connecting the four columns with each other such that the semi-submersible offshore platform exhibits a frame shaped deck box structure having an upper central opening for receiving at least one structural module.

Abstract: A semi-submersible offshore vessel has a substantially ring-shaped lower pontoon, starboard and port forward columns extending upwards from the lower pontoon, and starboard and port aft columns extending upwards from the lower pontoon. An upper deck structure connects upper portions of the columns with each other. The upper deck structure has a substantially rectangular module recess for receiving one or more operation modules, for example, carrying hydrocarbon-processing equipment. The upper deck structure is generally C-shaped, having a forward torsion box extending transversally between the starboard and the port forward columns of the semi-submersible offshore vessel, and two mutually parallel longitudinal side beams extending aft from the starboard and port forward columns to the starboard and port aft columns, respectively, in such a way that the module recess exhibits an open aft end, the width of which substantially corresponds to the width of an operation module.

Abstract: A semi-submersible offshore vessel (1) comprising: a substantially ring-shaped lower pontoon (2); starboard and port forward columns (6a, 6b), extending upwards from said lower pontoon (2); starboard and port aft columns (6c, 6d) extending upwards from said lower pontoon (2), and an upper deck structure (8) connecting upper portions (10) of the columns (6a, 6b, 6c, 6d) with each other, said upper deck structure (8) having a substantially rectangular module recess (12) for receiving one or more operation modules (14), for example carrying hydrocarbon processing equipment.

Abstract: A node intersection between circular columns and pontoon members at a tendon-moored semisubmersible offshore platform. The pontoon members have a box shape, defined by vertical side walls, a horizontal deck and a horizontal bottom skin, joined together into a foursided frame, via the columns. The node intersection comprises vertical bulkheads within the lower ends of the columns, forming internally intersecting continuations of the vertical sidewalls.