Submersible structures

Claim 1

A submersible structure that can be floated to a desired location and then caused to sink so as to rest on the water bed, the structure comprising a reinforCed concrete cellular base, a pluraliity of reinforced concrete hollow containers upstanding from said reinforced concrete cellular base, a solid reinforced concrete perimeter wall also upstanding from the base and completely encircling said containers to form an upwardly open interior space which is capable of holding water, at least one reinforced concrete hollow column extending from the cellular base to above water level in use of the structure, valves and ducting extending from the interiors of the containers and the cellular base to services situated inside the column, whereby, from the floating condition, the structure can be caused to sink by supplying ballast water to said interior space between the containers and the outer perimeter wall, to the interior of the cellular base and to the interiors of the containers, and whereby the structure can be refloated by pumping these zones dry and a separator chamber in said column connected by said ducting to said containers, said separator chamber being at a level in said column to be below the water level in the submerged condition of the structure to reduce by external hydrostatic pressure, the bursting forces due to the storage of liquid in said containers.