Scale model maneuvering tests of an offshore supply vessel equipped with bow and stern thrusters

This paper details the design, instrumentation, and free-running maneuvering tests of a scaled multi-purpose offshore supply vessel (OSV) model built to develop a dynamic positioning system. The model features the full-scale vessel's eight-actuator setup (two propellers, two rudders, and four tunnel thrusters) managed via a hierarchical control architecture combining autonomous high-level control and real-time actuator management. To establish baseline hydrodynamics, resistance and open-water propeller tests were conducted at Istanbul Technical University. Subsequent free-running experiments covered self-propulsion, turning circle, full sway, and full yaw tests. Results show steady turning and tactical diameters vary linearly with rudder angle, whereas advance and transfer show a nonlinear dependence. Additionally, full sway and full yaw tests isolate the thruster system's hydrodynamic contributions, proving its independent capacity for controlled lateral and rotational motion. Ultimately, this dataset establishes a foundational baseline for validating maneuvering prediction models, identifying hydrodynamic derivatives, and developing ship control architectures.