Single point mooring with suspension turret

• US 20030154899A1
• Filed: 02/19/2003
• Published: 08/21/2003
• Est. Priority Date: 02/19/2002
• Status: Active Grant

• Current Assignee: SOFEC, Inc. (FMC Corporation)
• Original Assignee: FMC Technologies Incorporated (TechnipFMC, plc)
• Inventors: Boatman, L. Terry, Cottrell, Roy H.
• Granted Patent: US 6,708,639 B2
• Time in Patent Office: Days
• US Class Current: 114/230.12
• CPC Class Codes: B63B 21/507 with mooring turrets

Abstract

An arrangement for suspending a Single Point Mooring Turret from its corresponding vessel, by transmitting a circumferentially uniform axial vertical load without moment through the interface of motion between the vessel and turret, by decoupling mooring system loads, inertial loads and hull deflection induced loads, from transmission across that interface. The arrangement supports the turret through a pendular suspension system which includes bogies, having one or more wheels or rollers per bogie, which roll around the circumference of the moonpool on a rail to allow the bogies to rotate in a horizontal plane which is perpendicular to the center line of the moonpool, and to decouple the bearing loads from radial hull deflection due to ovaling caused by rough seas. Radial flexure is achieved by suspending the turret from the bogie through rocker arms and chains, cables, rods or columns between the bogies and a riser support structure of the turret.

Claims

13. A vessel which includes a large turret that is positioned in a moonpool in the middle portion of a vessel hull where the turret is anchored to a sea floor and includes couplings wherein the vessel is rotatably supported about a primarily vertical axis of said turret said coupling including an axial bearing arrangement characterized by,

a circular rail positioned carried by said vessel in a horizontal plane which is perpendicular to said vertical axis, said rail having an upper facing surface,

a plurality of bogie housings, each housing having downward facing surface and at least one Hillman roller assembly designed and arranged for rolling support between said upward facing surface of said housing,

a first set of rocker beams pivotably connected to said bogie housings,

a second set of rocker beams pivotably coupled to said turret, and

suspension members connected between said first set of rocker beams and said second set of rocker beams.

14. The vessel of claim 13 wherein,

said suspension members are tension members.

15. The vessel of claim 13 wherein,

said suspension members are compression members.

16-1. The vessel of claim 16 wherein,

said suspension members are tension members.

18. A vessel which includes a large turret that is positioned in a moonpool in the middle portion of a vessel hull where the turret is anchored to a sea floor and includes couplings wherein the vessel is rotatably supported about a primarily vertical axis of said turret said coupling including an axial bearing arrangement characterized by,

a circular rail carried by said vessel in a horizontal plane which is perpendicular to said vertical axis, said rail having an upper facing surface,

a plurality of bogie housings, each housing having an upper flexible portion with captive roller assemblies mounted thereon which are designed and arranged for rolling support on said upward facing surface of said rail,

a first set of rocker beams pivotably connected to said bogie housings,

a second set of rocker beams pivotably coupled to said turret, and

suspension members connected between said first set of rocker beams and said second set of rocker beams.

19. The vessel of claim 18 wherein,

said suspension members are tension members.

21. A vessel which includes a large turret that is positioned in a moonpool in the middle portion of a vessel hull where the turret is anchored to a sea floor and includes couplings wherein the vessel is rotatably supported about a primarily vertical axis of said turret said coupling including an axial bearing arrangement characterized by,

a circular rail carried by said vessel in a horizontal plane which is perpendicular to said vertical axis, said rail having an upper facing surface,

a plurality of bogie housings, each housing circumferentially spaced from each other, with each housing carrying a bogie wheel and with each bogie wheel arranged to roll on said rail about a radially oriented pin through said housing, each housing having horizontally extending housing arms which extend in opposite directions from said pin,

a plurality of rocker beams having rocker arms each of which extends from a radially extending rocker beam shaft, each of said rocker beams being positioned between two circumferential spaced bogie housings with a rocker arm of each rocker beam being linked to an adjacent housing arm of a bogie housing, and

wherein each rocker beam shaft is coupled to said turret.