DEVELOPMENT AND APPLICATION OF A SHIP MANOEUVRING DIGITAL SIMULATOR FOR RESTRICTED WATERS

This paper reports on two case studies making use of a digital simulator to investigate the manoeuvring motions of ships in canals with shallow and restricted waters. The first case study corresponds to a manoeuvring analysis conducted for the Port of Rio Grande (RS – Brazil), whose aim was to assess the potential impact upon manoeuvres of the presence of a large offshore platform (the Petrobras P-53) which is to remain docked for several months at the Port to complete its construction. The second study made use of the simulator to evaluate the manoeuvring conditions along the approach route and manoeuvring basin of the Port of Ponta do Félix (PR – Brazil). The simulator includes a complete mathematical model of the ship dynamics in the horizontal plane when subjected to wind and current forces. It also comprises detailed models for the action of thrusters and propellers, both fixed and azimuth, employed to control manoeuvres and dynamically position ships, as well as rudders and tugboats. The models used by the simulator allow for the effects of shallow and restricted waters, including the increase in resistance and lateral forces, increase in additional mass and the appearance of lateral and vertical suction (squatting). The simulator is implemented via an interactive interface through which the user is able to apply control actions (rudder angle, main engine, thrusters and tugboats) in real time during manoeuvres, thereby reproducing to some extent the action of a pilot.