The influence of the inclination of the sides of a ship on her motion in a seaway 1 2

Abstract

The influence of the inclination of a ship’s sides to the vertical in the vicinity of the flotation surface on the motion of the ship in a seaway was discussed by A.N. Kriloff [1], I.G. Boobnov [2] and F. Horn [3]. Their discussions were limited to the calculation of this effect for particular ships only of given dimensions and forms.

The author deduces the differential equations of motion for additional oscillations caused by the above mentioned factor in the way shown by I.G. Boobnov [2] and substitutes the real frame lines at the ship’s ends by approximate analytical curves corresponding to the main characteristics and dimensions of the ship. The inclination of these lines varies considerably.

The author shows (for the case when the length of the waves λ is equal to that of the ship L):

a. that in ships of usual form the influence of the deviation of the sides from the vertical is considerably smaller than that of the Smith Effect, and compared to it can be neglected, and

b. that the ratio $\mathit{T}\mathrm{/}\mathit{L}$ has a contrary influence on the Smith Effect as compared with the correction due to the deviation of the sides from the vertical.