Patent ID: 6968797

Claim:
A method for installing a self-floating deck structure onto a buoyant substructure, said method comprising the steps of: (a) providing a self-floating deck structure having a bottom surface and a recessed cavity extending upward from said bottom surface of the self-floating deck structure, said recessed cavity comprising an open end, at least one recessed cavity sidewall, and a recessed cavity ceiling surface, said recessed cavity ceiling surface being positioned above a water surface, the intersection of the recessed cavity sidewall and the recessed cavity ceiling surface forming at least one upper circumferential edge of the recessed cavity, and the intersection of the recessed cavity sidewall and the bottom surface of the self-floating deck forming at least one lower circumferential edge of the recessed cavity; (b) providing a buoyant substructure that is capable of being fully submerged below the water surface, said buoyant substructure having a buoyant substructure top surface and a buoyant substructure bottom surface, said buoyant substructure top surface and buoyant substructure bottom surface being connected by at least one buoyant substructure sidewall, the intersection of the buoyant substructure top surface and the buoyant substructure sidewall forming an upper circumferential edge of the buoyant substructure, the buoyant substructure top surface and the buoyant substructure sidewall adjacent to the buoyant substructure top surface being adapted and sized to fit within the recessed cavity of the self-floating deck structure; (c) injecting compressed air or gas into at least one recessed cavity of the self-floating deck structure until a portion or all of the water within said recessed cavity is expelled; (d) positioning said self-floating deck structure adjacent to said buoyant substructure; (e) lowering at least one line connected to at least one lifting device located on the self-floating deck structure and connecting each of line to the buoyant substructure; (f) ballasting the buoyant substructure below the water surface until the buoyant substructure top surface is below the bottom surface of the self-floating deck structure and the buoyant substructure is suspended from the self-floating deck structure by at least one line connected to at least one lifting device; (g) positioning the self-floating deck structure over the buoyant substructure so that the recessed cavity of the self-floating deck structure is aligned over the buoyant substructure top surface; (h) activating at least one lifting device to lift the buoyant substructure top surface up into the recessed cavity using at least one lifting device until the buoyant substructure top surface mates with the recessed cavity ceiling surface at a point above the water surface; (i) connecting the self-floating deck structure to the buoyant substructure by welding or by one or more mechanical devices; and (j) deballasting the buoyant substructure to raise the self-floating deck structure to a predetermined elevation above the water surface.