The manoeuvring behaviour of ships is typically determined by testing ship models at scale in a towing tank, as an alternative to the still time-consuming numerical work by means of Computational Fluid Dynamics. In a towing tank, the ship model is subjected to a series of trajectories, where a towing carriage forces the ship model to follow these trajectories and at the same time the hydrodynamic forces acting on the ship model are registered. This allows to build mathematical models of these forces and to implement these in a ship manoeuvring simulator. The latter allows for adequate training of ship operators, or testing alternative port layouts as a function of the ships’ manoeuvring behaviour, before the ports or even ships are built.

A major disadvantage of towing tanks are their finite dimensions in the horizontal plane. These seem to influence the observed measurements and this influence becomes more important as the water depth decreases, which is precisely the area that benefits most from training and scenario analyses of ports. As a result, the manoeuvring behaviour may contain an inherent error.

The aim of the study is to separate the effects of the ship’s own manoeuvring behaviour from the effect caused by the vicinity of lateral restrictions.