The concept of determining the ship’s route based on the capability plots

Every year, new vessels equipped with dynamic positioning (DP) systems are built in shipyards around the world. Due to the increasing number of offshore vessels, a client hiring a vessel should analyse the vessel's positioning capability charts to determine which water areas the vessel is designed for. These charts are represented as polar diagrams. In the centre of the chart is a shape symbolising the ship's body, and the values on the chart represent the maximum wind speed that can affect the ship at a given angle, at which the vessel will maintain its position. Vessel capability charts can also be used by the crew during thrusters failures to determine at what angle to the wind direction the vessel should stand to minimise the impact of wind forces. Analyses that determine a vessel's ability to keep position can be performed by classification societies or other companies with approval from classification societies. The article presents the concept of a pathfinding algorithm to determines the route of the ship’s passage with minimal energy consumption. The algorithm uses the information about environmental forces affecting the ship and information about thrust allocation obtained from Capability Plots.