| 摘要 |
An offshore system is described that minimizes mooring loads attributable to oscillating wave drift. A tension member (24, FIG. 1), such as a chain, has a lower end (32) fixed to the seafloor and has an upper end portion (40) coupled to the vessel (12), so wave drift that occurs in a storm and urges vessel drift away from a quiescent position, is resisted by tension in the tension member. To reduce the load on the tension member, the vessel is allowed to move while paying out the tension member so it elongates. However, a brake mechanism (70) is applied to the tension member being payed out to slowly pay it out and absorb energy, to thereby damp vessel movement and minimize the maximum mooring load on the tension member. Preferably, at least three tension members (24, 26, 28) extend in different headings from the vessel to fixed locations on the seafloor, so a tension member that is resisting vessel drift extends at a large angle (C) to the vertical.
|
