On the Pivot-Turn Maneuvering of an LNG Carrier Using Tugboats


In a pivot-turn maneuver, initially, two tugboats are located ahead of and near to an LNG carrier. When the tugboats push in the directions of 3 and 9 o’clock in calm seas, the LNG carrier can be pivoted to the right. However, under the effect of wind and the associated drift of LNG, it is not feasible to pivot an LNG carrier in narrow port areas as it would pose a risk to various nearby structures such as the quay. Because the superstructure of an LNG carrier is larger than that of the other ships, only the wind forces in port areas are considered to affect the maneuvering conditions herein, and the tidal current in the port area can be neglected. It is generally difficult to detect the point at which an LNG drifts from the center during a pivot turn based only on the visual evaluation of a crew; moreover, even if crews detect the present position due to drifting using various navigation equipment, such as GPS, ECDIS, the drifting cannot be prevented. However, no studies have yet been conducted regarding the appropriate combination of thrust vectors from two tugboats to reduce drifting. Hence, the authors propose a novel method to minimize drifting and validate this approach using a maneuver simulator.


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  • Accession Number: 01688556
  • Record Type: Publication
  • Source Agency: Japan Science and Technology Agency (JST)
  • Files: TRIS, JSTAGE
  • Created Date: Jul 1 2018 3:01PM