A Study of the Transient Pitching Oscillations of a Ship Available to Purchase

The motions of a deeply submerged body with vertical-plane symmetry, e.g., a submarine, are commonly treated in a manner completely analogous to that used for aircraft motions. The body is assumed to have its lateral and longitudinal modes uncoupled. The small motions are described by a set of force-and-moment equations which are linear, second-order differential equations with constant coefficients. These proportionality constants ("stability derivatives") relate the forces and moments to the instantaneous values of the position, velocity, and acceleration of the body. They are generally experimentally determined in the wind or water tunnel, and the controlled or uncontrolled motions of the craft are predicted based thereon.