A semi-submersible vessel for loading, storing and transporting liquid has a main hull which lies on the sea bed during loading, unloading and storing of the liquid. This hull is airtight and divided into cargo compartments having outer walls formed as portions of cylindrical shells. A slim superstructure including columns is rigidly connected to and extends upwardly from the main hull and supports a deck structure. The center of gravity of the vessel is always below the center of buoyancy thereof to provide the vessel with a total weight and a weight stability enabling it to rest on the sea bed without anchors, moorings or the like.
A floating plant for offshore liquefaction, temporary storage and loading of LNG, made as a semi-submersible platform with storage tanks for LNG arranged in the submerged section of the platform. The storage tanks are independent spherical tanks which are supported inside the submerged section of the platform and completely surrounded thereby.
An underwater storage structure comprising an internally segmented tetrahedron and/or hexahedron, said self supporting structure having a fluid impermeable covering and an internally segmented skeleton. The structure can be subdivided internally by fluid impermeable coverings allowing ballast, such as water or sand slurry or the like, to be utilized to counter the bouyancy of internal voids formed by the subdivisions of the structure.
