TURNING THE TUG-TOWED SHIPS SYSTEM DUE TO THE STEERING OF THE LAST TOWED SHIP AND THE NEW COURSE KEEPING TEST

The authors have discussed course stability of tug-towed ships system in various issues of the above Journal (No. 42, 43, 44, 46 and 50,) and the turning ability of such a system is also treated in the Journal of The Society of Naval Architects of Japan No. 137 and 138. For the turning of a tug-towed ships system, with the steering of tugboat only, it only exists under the condition which the towing ropes' length is less than the critical towing ropes' length and the system falls into irregular motion when the towing ropes' length is longer than QcmrL. In this paper, turning of this system will be discussed not only due to the steering of tugboat, but also with steering of the last towed ship, also the new orientation test of this system is treated as the steering function of tugboat without any towing constraint. From the calculation results, we obtained the following conclusions: (1) Turning due to the steering of last towed ship also exists when the towing ropes' length is over the critical towing ropes' length Qcmr,L, and the magnitude of it depends on the rudder angle of last towed ship. (2) If the rudder angle of last towed ship is great enough, the system falls into the irregular motion again. (3) For the new orientation test of the tug-towed ships system a stable region of course stability is required. (4) If the steering times for a ship are applied to the tugboat of the tug-towed ships system, desired heading angle for the new course changes together with the increment of the towing ropes' length, desired heading angle decreases as the length of towing rope increases. (5) Preselected heading angle can be provided by the steering times.

• Corporate Authors:

  West Japan Society of Naval Architects

  Kyushu University, Hakozaki C-10-1, Higashi-ku
  Fukuoka-shi,   Japan 
• Authors:
  • Inoue, S
  • Lim, S T
• Publication Date: 1975-11

Media Info

• Pagination: n.p.

Subject/Index Terms

• TRT Terms: Hydrodynamics; Maneuverability; Steering; Towing devices; Tug ship interaction; Tugboats; Turning traffic
• Old TRIS Terms: Course keeping qualities; Course stability; Steering dynamics; Towed bodies; Towline hydrodynamics; Tug maneuverability; Turning characteristics
• Subject Areas: Hydraulics and Hydrology; Marine Transportation; Vehicles and Equipment;

Filing Info

• Accession Number: 00323616
• Record Type: Publication
• Source Agency: Stevens Institute of Technology
• Files: TRIS
• Created Date: Nov 19 1980 12:00AM