초록 ▼

A floating offshore structure has a buoyant hull with sufficient fixed ballast to place the center of gravity of the floating structure below the center of buoyancy of the hull. A support structure coupled to an upper end of the hull supports and elevates a superstructure above the water surface. A

A floating offshore structure has a buoyant hull with sufficient fixed ballast to place the center of gravity of the floating structure below the center of buoyancy of the hull. A support structure coupled to an upper end of the hull supports and elevates a superstructure above the water surface. A soft tendon is attached between the hull and the seafloor. A vertical stiffness of the soft tendon results in the floating structure having a heave natural period of at least twenty seconds.

대표청구항 ▼

1. A floating offshore structure, comprising:a buoyant hull adapted to be fully submerged below a water surface in substantially all operating conditions of the floating offshore structure, the buoyant hull having a sufficient amount of fixed ballast to place a center of gravity of the floating offs

1. A floating offshore structure, comprising:a buoyant hull adapted to be fully submerged below a water surface in substantially all operating conditions of the floating offshore structure, the buoyant hull having a sufficient amount of fixed ballast to place a center of gravity of the floating offshore structure below a center of buoyancy of the floating offshore structure; a support structure coupled to the hull, the support structure having a waterplane area which contributes a first vertical stiffness to the floating offshore structure; a superstructure mounted on the support structure; and at least one soft tendon which has a first end attached to the hull and a second end attached to a seafloor, the soft tendon contributing a second vertical stiffness which exceeds the first vertical stiffness, wherein a combination of the first vertical stiffness and the second vertical stiffness provides a heave natural period to the floating offshore structure of at least twenty seconds, the second vertical stiffness being between 100 and 1,000 tons per foot.