Optimisation of ride control operation to reduce motions and loads of high-speed catamarans

This paper considers the optimisation of a ride control system based on a variety of criteria including motions, global loads and slamming. The closed loop performance of a model scale ride control system fitted to a 2.5 m hydroelastic segmented model of a 112 m INCAT catamaran was tank tested using several active feedback control modes and performance was compared to the bare hull responses at two wave heights and a wide range of wave encounter frequencies. Of the feedback algorithms tested, the nonlinear pitch control mode of operation was found almost universally to give the best results, producing reductions of up to 70% in pitch, 40% in vertical bow accelerations, 90% in peak slamming force, 75% in slam induced bending moment, 40% in slam impulse and 90% in total strain energy imparted to hull whipping vibration.