CONTROLLABILITY AT TOO HIGH SPEEDS IN TOO SHALLOW WATER

Nowadays vessels will have to run at higher speeds in shallow water. Furthermore, it is known that vessels lose controllability while sailing at too high speeds in shallow water: squat causes a too large trim forward and instability loops in general grow. The target of the present project was to determine at which water depths and at which speeds the manoeuvrability dominates the behaviour of the trailing suction hopper dredger. For this project, extensive captive static and dynamic model tests were carried out in a range of water depths, with two vessels. A large range of speeds and trim conditions were model tested and a mathematical model was created. The mathematical model is used in fast time simulations to find the limits of controllability.