Liquefied gas tank with a central hub in the bottom structure

A marine vessel for production and storage of LNG comprising a cryogenic tank (1) for said LNG, with a planar tank bottom structure (10) supporting a tank wall structure (11), characterised in that

• said planar tank bottom structure (10) has a central single point hub (2) coupled to radial structural beams (3) further arranged for supporting said tank wall structure (11), said central single point hub (2) having a substantially smaller diameter than a diameter of said tank bottom structure (10), said central single point hub (2) adapted for being held by a corresponding hub retainer (20) on a tank support structural floor (23) in said ship, said hub retainer (20) generally providing radially directed retention forces to said central single point hub (2) in the plane of said planar tank bottom structure (10) both when said cryogenic tank (1) is operating at cryogenic temperatures and when empty at ambient temperature.

A marine vessel for storage and regasification of LNG comprising a cryogenic tank (1) for said LNG, with a planar tank bottom structure (10) and a tank wall structure (11) arranged on said planar tank bottom structure (10), characterised in that

• said planar tank bottom structure (10) has a central single point hub (2) coupled to radial structural beams (3) further arranged for supporting said tank wall structure (11), said central single point hub (2) having a substantially smaller diameter than a diameter of said tank bottom structure (10), said central single point hub (2) adapted for being held by a corresponding hub retainer (20) on a tank support structural floor (23) in a ship, said hub retainer (20) generally providing radially directed retention forces to said central single point hub (2) in the plane of said planar tank bottom structure (10) both when said cryogenic tank (1) is operating at cryogenic temperatures and when empty at ambient temperature.

A ship for transportation of LNG comprising a tank (1) for said LNG, with a generally vertical tank axis (9) and a planar tank bottom structure (10) and a tank wall structure (11) arranged on said planar tank bottom structure (10), characterised in that

• said planar tank bottom structure (10) has a central single point hub (2) coupled to radial structural beams (3) further arranged for supporting said tank wall structure (11), said central single point hub (2) having a substantially smaller diameter than a diameter of said tank bottom structure (10), said central single point hub (2) adapted for being held by a corresponding hub retainer (20) on a tank support structural floor (23) in said ship, said hub retainer (20) generally providing radially directed retention forces to said central single point hub (2) in the plane of said planar tank bottom structure (10) both when said cryogenic tank (1) is operating at cryogenic temperatures and when empty at ambient temperature.

A method of installing a cryogenic tank (1) for liquefied gases in a vessel wherein said tank (1) comprises a planar tank bottom structure (10) and a tank wall structure (11) on a circumference of said planar tank bottom structure (10),

• wherein said planar tank bottom structure (10) is provided with a generally central tank bottom hub (2) adapted for being held by a bottom hub retainer (20) on a tank support structural floor (23), said central tank bottom hub (2) having a substantially smaller diameter than a diameter of said tank bottom structure (10), wherein said method comprises hoisting the tank (1) and lowering said tank (1) directly onto said bottom hub retainer (20), with a remainder of the tank bottom structure (10) supported on insulation (8) provided between the remainder of tank bottom structure (10) and the tank support structural floor (23).