Döscher, MarcusMarcusDöscherBöttner, Carl UweCarl UweBöttnerAbdel-Maksoud, MoustafaMoustafaAbdel-Maksoud2026-07-272026-07-272026-06-30Ocean Engineering 263 (P3): 126686 (2026)https://hdl.handle.net/11420/64043The precise prediction of ship manoeuvring behaviour in shallow water is essential for safe navigation and waterway design. To examine depth-induced changes in ship dynamics, the turning behaviour of the container ship DTC (Duisburg Test Case) was investigated at model scale (1:60) using combined free-running experiments and CFD simulations, with emphasis on extreme shallow water down to (Formula presented) .Free-running manoeuvres were conducted, with measurement of propeller thrust and rudder forces. The CFD model was verified by means of a grid convergence study for a complete turning manoeuvre and validated against experimental data, showing mean deviations of approximately 5% for key manoeuvring parameters, confirming its predictive capability.The results reveal a pronounced deterioration of steady turning performance with decreasing water depth. A reversal in port-starboard asymmetry occurs in shallow water, governed by depth-dependent changes in propeller-rudder interaction and wake distribution. Transient analysis further shows that initial turning ability increases slightly in the transition from (Formula presented) to 1.15, but deteriorates sharply at (Formula presented), identifying a critical threshold. These effects are linked to redistributions of hydrodynamic forces along the hull.The results highlight the coupled influence of water depth and speed, emphasizing the governing role of the depth Froude number on manoeuvring behaviour.en0029-80182026P3Elsevierhttps://creativecommons.org/licenses/by/4.0/Direct manoeuvring simulationsDTCExtreme shallow waterFree-running model testsManoeuvringTurning circle manoeuvresWaterwaysTechnology::623: Military Engineering and Marine Engineering::623.8: Naval Architecture; ShipbuildingNatural Sciences and Mathematics::530: Physics::530.4: States of Matter::530.42: Fluid PhysicsTechnology::627: Hydraulic Engineering::627.2: Underwater EngineeringJournal Article10.1016/j.oceaneng.2026.12668610.15480/882.17607