Chun-Ki Lee
The Journal of Mechanical Science and Technology, vol. 22, no. 6, pp.1230-1236, 2008

Abstract : When a vessel navigates in confined waters, such as in a harbour or narrow channel, it is well known among experienced pilots that the ship handling is greatly affected by the hydrodynamic forces and moments acting between ship and bank or sidewall of the channel. The hydrodynamic forces between ship and bank can be assumed to be functions of the water depth, longitudinal and lateral distance along with ship’s velocity. In this research, the characteristic features of the hydrodynamic forces variation during the encounter are described and illustrated, and furthermore the effect of water depth and the spacing between ship and bank with an angle are summarized and discussed. When a vessel is approaching the tip of a wedge-shaped bank, it may encounter a dangerous tendency of collision due to the combined effect of the attracting sway force and a bow-in moment. For water depth to draft ratio (h/d) less than about 2.5, the hydrodynamic force and yaw moment between ship and bank increase sharply as h/d decreases. Also, the hydrodynamic effects decrease as separation between ship and bank ( P S )increases and approach to zero when the vessel moves to the wedge-shaped bank under the condition of 0.5 SP = L.

Keyword : Ship maneuvering; Hydrodynamic force; Bank effect; Separation between ship and bank; Water depth