Environmental Effects

This chapter begins by listing the environmental factors that affect ship manoeuvrability. The change required in the equations of motion to account for the effect of wind is described. The effect of a current in water is taken into account by considering the motion of the ship with respect to water. A study of ship manoeuvring in waves requires the combined study of both manoeuvring in calm water and ship motions in waves and the computational methods used in such a study are mentioned. Two important effects of waves on ship manoeuvring, broaching and wave drift forces, are briefly considered. The effect of shallow water on the different aspects of ship manoeuvrability is described. The linear equations of motion for a ship moving in a narrow canal are used to obtain some interesting features of such an operation. The operation of a ship close to land and the interaction between ships operating close to each other are also briefly described.