Can the Pivot Point be Far Away from the Ship?

摘要

The paper analyses the position changes of pivot point. By analysing the relationship between rate of turn and drift, we may apply a rule when the pivot point is in and when it is out of the ship – forward or aft and how far it is from some point aboardship. It is graphically presented the position change of pivot point when rotating in making headway and sternway and how without pivot point “runs away“ ahead – infinitely far even without external effect (wind and/or current). Some practical analyses of this problem have been provided, for example; when the pivot point can be found forward of the ship's stem in spite of moving astern. Correct estimation of position of pivot point and radius of ship's path is significant for succesful manoeuvring, especially in space limited aquatorium. That's why this paper has its own practical value because it should enable the master or Pilot better managing in practice, especially at low speed and big drift.