Development of a core mathematical model for arbitrary manoeuvres of a shuttle tanker

A 3DOF still-water manoeuvring mathematical model embracing all regimes of motion of a single-screw shuttle LNG carrier has been developed. Besides four-quadrant models for hull forces, main propeller and the rudder, the model describes also the action of a lateral thruster and of assisting tug boats. Environmental factors include constant wind and constant current. Results of off-line simulations partly compared with available trial data are given.