Torsion spring torque arm yoke mooring system
AssigneeFMC Corporation
InventorKristen I. Pedersen
Life of this patent
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Abstract
A soft yoke mooring system, with torsional spring devices to provide restoring force to yoke arms coupled to a mooring body. Two torsional spring device types are preferred. A first torsional spring device type includes a plurality of nested tubular shafts, which are coupled end to end to each other in a coaxial array. Torque arms extend from a yoke arm end to one end of the tubular shafts, with the other end of the shafts coupled to a vessel. A second torsional spring device type includes stacks of elastomeric shear unit arrays or blocks of elastomeric material, which are coupled between a torque diaphragm device and a vessel and with the torque diaphragm device coupled by a torque arm to an end of a yoke arm.
Claims52
A mooring system for a vessel comprising,
- a mooring body coupled to a seabed,
- first and second yoke arms having first and second ends with respective first ends rotatably coupled to said mooring body,
- first and second torque arms having first and second ends with said second ends of said torque arms coupled to respective second ends of said first and second yoke arms, and
- first and second torsion spring devices respectively connected between said first ends of said torque arms and said vessel,
- wherein said first and second torsion spring devices are arranged and designed to produce torsion forces between said vessel and said torque arms of a level required to maintain said vessel about an equilibrium position with respect to said mooring body under moderate to severe environmental conditions.
The mooring system of 27, wherein,
- at least one of said elastomeric shear unit arrays has first elastomeric shear units non-uniformly arranged in a circular row and has second elastomeric shear units arranged in a circular arch which is concentric with said circular row, with said circular arch of said second elastomeric shear units positioned to face said first end of said respective torque arm where said torque arm is directly connected to said torque diaphragm device.
Dependencies are inferred from the claim text.