MOORING LINE DAMPING DUE TO FIRST- AND SECOND-ORDER VESSEL MOTION

The importance of a catenary mooring system in producing surge damping of a moored vessel has been demonstrated. This paper aims at clarifying the effect of superposed wave frequency line motions upon the low frequency surge damping of the mooring system. A series of experiments has been performed, determining separately the various contributions to the total surge damping. This has been achieved by testing a ship model with and without catenary mooring and with and without artificial excitation of the turret, by calm water surge decay tests and by irregular wave tests. A theory and numerical method is presented for calculating the surge damping due to the mooring system. The numerical results compare very well with experiments as far as a pure sinusoidal low frequency surge is concerned, but not so well in the case of superposed high frequency motions. As an important overall conclusion, the wave frequency motions of the system, as tested, increase the low frequency damping by a factor in the range of 2 to 4 for typical sea states.

  • Supplemental Notes:
    • Conference paper; Paper OTC-6137
  • Authors:
    • Huse, E
    • MATSUMOTO, K
  • Conference:
  • Publication Date: 0

Media Info

  • Features: References;
  • Pagination: 14p.

Subject/Index Terms

Filing Info

  • Accession Number: 00658642
  • Record Type: Publication
  • Source Agency: Maritime Technical Information Facility
  • Files: TRIS
  • Created Date: Jul 21 1994 12:00AM