Single-point mooring system

Claim 1

Apparatus for mooring a structure floating in a body of water to an anchor point located above the water surface, comprising a substantially rigid anchor structure fixed to the bottom of the body of water and extending above the water surface where it defines a right circular cylinder having a vertically disposed axis, the portion of the structure above the water surface comprising said anchor point, a collar mounted to the cylinder circumferentially thereof for motion angularly about and axially along the cylinder, a pair of rigid supports extending from the floating structure, the supports being spaced substantially equally from and on opposite sides of a roll axis of the floating structure, the spacing between the supports being greater than the diameter of the collar, and resilient connections between the supports and the collar (a) for locating the collar centrally between the supports in a normal state of the mooring apparatus, (b) for affording and accommodating motions of the floating structure, as manifested at the supports, relative to the collar in horizontal linear directions and angularly about the roll axis in surge, sway and roll, and (c) for absorbing the forces manifested between the collar and the floating structure in association with the surge and sway motions, the collar moving on the anchor structure cylinder in response to pitch, heave and heading change motions of the floating structure.

Claim 26

A method of mooring a floating vessel having a ship-like hull configuration to an essentially fixed single-point anchor structure located above the water surface comprising securing to the bottom of a body of water in which the vessel is to be moored a substantially rigid anchor structure which, as secured, extends above the water surface and defines above the water surface a cylinder having a vertical axis, disposing around the cylinder a collar which is movable both angularly about and axially along the cylinder, providing on the vessel at the bow-end on opposite sides of the roll axis thereof a pair of rigid supports which are spaced from each other a distance greater than the diameter of the collar so that, when the collar is disposed centrally between the supports, a clearance exists between the collar, the supports and the vessel, and establishing between the collar and the vessel, considered as the vessel per se and the supports, a plurality of resilient connections in both directions along lines transversely of the vessel and effectively parallel to the roll axis of the vessel in such manner as to support the collar from the vessel along the cylinder, to accommodate rolling motion of the vessel relative to the collar, and to both accommodate and absorb the forces of sway and surge motions of the vessel relative to the collar, and also to transmit to the collar for accommodation by relative motion between the collar and the cylinder vessel motions due to heave, pitch and heading change of the vessel relative to and about the anchor structure.

Claim 27

A method of mooring a floating vessel having a ship-like hull configuration to an essentially fixed single-point anchor structure located above the water surface comprising securing to the bottom of a body of water in which the vessel is to be moored a substantially rigid anchor structure which, as secured, extends above the water surface and defines above the water surface a cylinder having a vertical axis, disposing around the cylinder a collar which is movable both angularly about and axially along the cylinder, providing on the vessel at the bow-end on opposite sides of the roll axis thereof a pair of rigid supports which are spaced from each other a distance greater than the diameter of the collar so that, when the collar is disposed centrally between the supports, a clearance exists between the collar, the supports and the vessel, and establishing between the collar and the vessel, considered as the vessel per se and the supports, a plurality of resilient connections in both directions along lines transversely of the vessel and effectively parallel to the roll axis of the vessel in such manner as to support the collar from the vessel along the cylinder, to accommodate rolling motion of the vessel relative to the collar, and to both accommodate and absorb the forces of sway and surge motions of the vessel relative to the collar, and also to transmit to the collar for accommodation by relative motion between the collar and the cylinder vessel motions due to heave, pitch and heading change of the vessel relative to and about the anchor structure.