An underwater storage tank having a flexible multilayer tank containing a working liquid is provided. The flexible multilayer tank has at least one internal electrical insulating layer in contact with the working fluid, at least one external electrical insulating layer in contact with sea water, and at least one intermediate electric conductive layer sealed between the at least one internal electrical insulating layer and the at least one external electrical insulating layer. At least one first electrical connection means is connected to the at least one intermediate electric conductive layer, the least one first electrical connection means being electrically connectable to an electrical grounded measurement instrument to assess physical integrity of the flexible multilayer tank.

An underwater storage tank having a flexible multilayer tank containing a working liquid is provided. The flexible multilayer tank has at least one internal electrical insulating layer in contact with the working fluid, at least one external electrical insulating layer in contact with sea water, and at least one intermediate electric conductive layer sealed between the at least one internal electrical insulating layer and the at least one external electrical insulating layer. At least one first electrical connection means is connected to the at least one intermediate electric conductive layer, the least one first electrical connection means being electrically connectable to an electrical grounded measurement instrument to assess physical integrity of the flexible multilayer tank.

A flexible floating reservoir for storing liquids denser than the environmental body of water, such as sea salt brine, is provided. The flexible floating reservoir is adaptable to environmental body waves, such as sea waves. A method for operating the flexible floating reservoir and an underwater energy storage system that uses the flexible floating reservoir are also provided.

A flexible floating reservoir for storing liquids denser than the environmental body of water, such as sea salt brine, is provided. The flexible floating reservoir is adaptable to environmental body waves, such as sea waves. A method for operating the flexible floating reservoir and an underwater energy storage system that uses the flexible floating reservoir are also provided.

A subsea material delivery structure, including at least one material storage tank, wherein the material storage tank includes a rigid outer container, at least one pressure balanced inner flexible container. A pinch prevention device may be disposed within the at least one inner flexible container to prevent premature closing of a fluid egress pathway.

A subsea material delivery structure, including at least one material storage tank, wherein the material storage tank includes a rigid outer container, at least one pressure balanced inner flexible container. A pinch prevention device may be disposed within the at least one inner flexible container to prevent premature closing of a fluid egress pathway.

A structure for an offshore plant has a plurality of module portions mounted on a structure body in which a storage tank for storing liquefied natural gas is installed. A pump opening serving as the inlet/outlet of a pump for pumping up the liquefied natural gas from the storage tank is formed in the structure body, and the pump opening is disposed between the module portions adjacent to each other.

A ring-wing floating platform is disclosed. The ring-wing floating platform includes a floating hull, a top of the floating hull being above a sea surface and its geometry at a water plane is centrally symmetric, a ring-wing surrounding a perimeter of a bottom of the floating hull with a horizontal projection of concentric annular geometries, a positioning system located at the bottom of the floating hull, and a topsides located above the floating hull and connected to the floating hull by deck legs or installed directly on the top of the floating hull. The axes of the ring-wing and the floating hull are collinear, and their bottoms are in a same horizontal plane. The ring-wing and the floating hull are connected together as a unitary structure by multiple connecting components with an annular gap in-between.

An arrangement and method for releasably securing a plurality of standard-sized containers together, the arrangement comprising at least two planar securing elements comprising an aperture and at least two extension elements emerging from a surface of the planar securing element, each extension element configured to be attachable to at least one container; a first elongated securing element extending across at least two adjacent containers; wherein a first planar securing element is configured to attach to a first container using at least one extension element of the first planar securing element, and a second planar securing element is configured to attach to a second container using at least one extension element of the second planar securing element, and the elongated securing element extending through apertures of the first and the second planar securing element and tightenably engaged to the first and the second planar securing element.

Storage tank comprising—an outer container (2) having a first closable opening (23), and—an inner bladder container (3) disposed within said outer container (2) and having a second closable opening (30), said outer container (2) and inner container (3) being sealed with respect to each other, said inner container (3) being adapted to be filled and or emptied with a liquid through said second closable opening (30), a space (8) between the outer container (2) and the inner container (3) being adapted to be filled with liquid through the first closable opening (23). The outer container (2) is rigid with at least one flexible portion incorporated in the rigid outer container and configured to flex so as to expand and contract to compensate volume variations caused by pressure and or temperature variations to which the storage tank (1) is subjected.