Trajectory planning for Service Ship during emergency STS transfer operation

In this paper trajectory for approaching during emergency STS transfer operation with oil spill is considered as a sequence of navigation manoeuvres in specific navigational environment. The designed way points - ship positions and speed are determined as reference values to support navigator in decision making during steering and to mitigate the risk of collision which mostly results from exceeding the speed limit of approaching. To prevent this, the values of position and speed in each way points are determined with respect to specific manoeuvring procedure during STS approaching and by taking into account constraints resulting from ship’s manoeuvre of stopping and speed deceleration performance included in manoeuvring booklet. Additional constraints result from STS transfer operation guide and navigation practise. The task of trajectory planning is defined as optimization process to minimize trajectory length, course alteration and maximize safety.