A STUDY OF DYNAMIC COURSE INSTABILITY THROUGH CAPTIVE MODEL TESTS AND COMPUTER SIMULATIONS

The major findings obtained in this study are summarized as follows: (1) Based on results of the eigenvalue analysis, a summary chart has been made to indicate the directionally stable region (where the abscissa and the ordinate represnt yaw-rate and yaw gains) for three ships. Although inherent dynamic instability can be compensated by adding hydrodynamic damping in forms of yaw-rate gain, a ship with a large degree of inherent instability (e.g., Ship C) requires a large yaw-rate gain to achieve directional stability. And (2) Motion predictions in zig-zag and spiral maneuvers indicate tht Ship C (which has a large degree of instability with approximately 10 degree of hystersis loop) has a tendency to divert from the straight course, having a large overshoot in heading change. Finally, it is recommended that maneuvering performance be thoroughly evaluated at its design stage of ships, particularly of a new design, to ensure satisfactory ship performance.

• Supplemental Notes:
  • Presented at the 14th International Towing Tank Conference, 1975.
• Corporate Authors:

  National Research Council of Canada

  1200 Montreal Road
  Ottawa, Ontario  Canada  K1A 0R6
• Authors:
  • Eda, H
• Publication Date: 1975

Media Info

• Pagination: n.p.

Subject/Index Terms

• TRT Terms: Maneuvering; Ship motion; Simulation; Voyage management systems
• Old TRIS Terms: Course keeping qualities; Course stability; Model testing
• Subject Areas: Marine Transportation; Operations and Traffic Management; Safety and Human Factors; Vehicles and Equipment;

Filing Info

• Accession Number: 00323579
• Record Type: Publication
• Source Agency: Stevens Institute of Technology
• Files: TRIS
• Created Date: Mar 12 1981 12:00AM