Method and system for heading control during ship-to-ship transfer of LNG

A system for heading control during ship-to-ship (STS) transfer of liquefied natural gas (LNG) to a floating storage regasification unit (FSRU) moored at a turret buoy comprising:

• the FSRU moored in a water at the turret buoy;
• an LNG carrier (LNGC) moored to the FSRU in a double-banked configuration such that a bow of the LNGC and a bow of the FSRU face same direction at a first heading of a plurality of headings, the LNGC comprising a manifold of a plurality of hoses fluidly coupling the LNGC to the FSRU;
• the LNG flowing from the LNGC through at least one of the plurality of hoses to the FSRU;
• and
• at least two heading control lines coupled to a stern of the FSRU, wherein the at least two heading control lines are adjustable to turn both the FSRU and moored LNGC between the first heading and a selected heading of the plurality of headings.

A heading control method for ship-to-ship (STS) transfer of liquefied natural gas (LNG) while moored on a buoy comprising:

• berthing a FSRU to the buoy at a forward end of the FSRU;
• connecting at least two spread mooring lines to a stern of the berthed FSRU;
• anchoring the stern of the berthed FSRU to a seabed using the at least two spread mooring lines such that a bow of the FSRU is held against a predominant factor;
• calculating at intervals a resultant force of oceanic conditions and weather to determine the predominant factor at a particular time;
• adjusting a length of the at least two spread mooring lines to rotate a direction of the stern of the FSRU about the buoy based on the predominant factor so calculated;
• and
• transferring LNG to the moored and anchored FSRU using STS transfer from a LNG carrier.

A heading control system for ship-to-ship (STS) transfer of liquefied natural gas (LNG) to a floating unit moored at a turret buoy comprising:

• the floating unit moored in a water at the turret buoy;
• an LNG carrier (LNGC) moored to the floating unit in a double-banked configuration such that a bow of the LNGC and a bow of the floating unit face same direction at a first heading of a plurality of headings, the LNGC comprising a manifold of a plurality of hoses fluidly coupling the LNGC to the floating unit;
• the LNG flowing from the LNGC through at least one of the plurality of hoses to the floating unit;
• and
• at least two stern heading control lines anchoring a stern of the floating unit to a seabed, each of the stern heading control lines comprising a winch, a guide, a line locking system and a release coupling;
• and
• wherein the at least two stern heading control lines are adjustable to turn both the floating unit and moored LNGC between the first heading and a selected heading of the plurality of headings.