Patent ID: 6014939
Filing Date: 2000-01-18
Classification: B63B

Abstract:
A universally stable mooring turret comprising:a circumturret cylinder extended vertically downward from a turret base proximate a main deck of an oil-well ship to a bottom of a well-working portion of the oil-well ship;a turret cylinder extended rotationally downward inside of the circumturret cylinder and having a turret flange extended radially outward above the turret base;a turret rotator in rotative communication between the circumturret cylinder and the turret cylinder;the turret rotator being actuated to rotate the turret cylinder in compensating opposition to directional change of the circumturret cylinder resulting from directional change of the oil-well ship;a plurality of horizontal bearings which are extended horizontally from horizontal-bearing pressure cylinders that are attached to bearing bases that are affixed circumferentially to the oil-well ship about an outside periphery of the turret base;a horizontal-bearing race that is oriented vertically on a circumferential portion of the turret flange;the plurality of horizontal bearings being actuated by the horizontal-bearing pressure cylinders to bear against the horizontal-bearing race selectively in response to a horizontal-pressure controller;a plurality of vertical bearings that are extended vertically from vertical-bearing pressure cylinders that are attached to bearing bases that are affixed circumferentially to the oil-well ship about the outside periphery of the turret base;a vertical-bearing race that is oriented horizontally on a bottom circumferential portion of the turret flange;the plurality of vertical bearings being actuated by the vertical-bearing pressure cylinders to bear against the vertical-bearing race selectively in response to a vertical-pressure controller;the horizontal-pressure controller and the vertical-pressure controller being coordinated and controlled by a turret position controller positioned in a control position from which control of the mooring turret is communicated on the oil-well ship;an annular-clearance space intermediate an inside periphery of the circumturret cylinder and an outside periphery of the turret cylinder;the annular-clearance space being sized and shaped for containing the turret cylinder upright vertically while the circumturret cylinder is being tilted randomly from turning, heaving, yawing and moving of the oil-well ship by wave and weather and conditions;the turret cylinder inside of the randomly tilting and turning circumturret cylinder being positioned horizontally by the plurality of horizontal bearings and being positioned vertically by the plurality of vertical bearings in coordinated response to the horizontal-pressure controller and the vertical-pressure controller respectively; andthe turret cylinder being rotatable on the plurality of vertical bearings and being rotatable horizontally intermediate contact surfaces of the plurality of horizontal bearings that are oppositely disposed circumferentially with coordinated bearing control being applied in compensating opposition to vertical and horizontal displacement pressures and in compensating opposition to rotational pressures resulting from wave, weather, ocean-current and ship-steering factors in order to maintain operable concentricity of the turret cylinder in relationship to the circumturret cylinder, in order to maintain operably horizontal and orthogonally vertical attitude of turret-based equipment and in order to compensate for side pressures of mooring lines, risers and other operating equipment suspended from the mooring turret.