An offshore floating production, storage, and off-loading vessel has a monolithic non ship-shaped
hull of polygonal configuration surrounding a central double tapered conical
moon pool and contains water
ballast and
oil storage compartments. The exterior side walls of the
hull have flat surfaces and sharp corners to
cut ice sheets,
resist and break ice, and move ice pressure ridges away from the structure. An adjustable water
ballast system induces heave, roll,
pitch and surge motions of the vessel to dynamically position and maneuver the vessel to accomplish ice
cutting, breaking and moving operations. The
moon pool shape and other devices on the vessel provide added virtual
mass capable of increasing the natural period of the roll and heave
modes, reducing dynamic amplification and
resonance due to
waves and vessel motion, and facilitate maneuvering the vessel. The vessel may be moored by a disconnectable
turret buoy received in a support frame at the bottom of the
moon pool and to which flexible well risers and
mooring lines are connected.