Safety Assessment of Ship-to-Ship Lightering Operations by Means of Collision Danger Zones Due to Interaction Effects (2nd Report: Evaluation of Difficulty of Maneuver)

摘要

This paper proposes a procedure to quantify dangers of maneuveringrnships in ship-to-ship lightering operations. In the previous study,rnoperational limitations as a function of 2-D intra-ship position, due tornstatic mechanisms of hydrodynamic interaction were proposed. Therndynamic evaluation of danger based on maneuver simulations isrnimplemented in the present paper, which focuses on the difficulty ofrnmaneuvering. An automatic control system for following a trajectoryrngiven in a relative coordinate system is applied and the mean deviationrnfrom the trajectory is recorded with changing initial intra-position. Itrnhas been confirmed that maneuvering difficulties may changerndepending on the intra-position of the ships in commencing the finalrnapproach, as well as loading conditions. These results are considered torncontribute to improving safety in performing this operation.