Ship stabilization: automatic controls, computed and in practice

The paper relates in brief the development of the control apparatus by the author for the Denny-Brown type of ship stabilizer from the initial ON-OFF control, to the present proportional control using roll and roll-velocity functions. The use of roll acceleration and a feedback control are also discussed. Predictions of the performance of a stabilizer by step-by-step and analogue methods are given, the functioning of the analogue computer is described and examples of results are included. Some practical results from sea experience and a brief account of the stabilizing demonstration given during the lecture also appear. The paper is complementary to one being presented before The Institution of Naval Architects, which deals more with the ship aspect of the subject.