MATHEMATICAL MODEL FOR A MANOEUVRING SHIP MOTION IN SHALLOW WATER (3RD. REPORT)

In previous reports the authors presented prediction techniques for the manoeuvring characteristics of a single-propeller single-rudder ship in deep and shallow water. This paper deals mainly with captive model tests and digital simulations carried out on two twin-propeller twin-rudder ships. Conclusions are presented on the effects on manoeuvring of the rudder force and hull damping force. The use of stopping devices such as spoilers, fins or water parachutes to improve turning quality, by compensating for the reduction in propulsive efficiency due to shallow water effects, is suggested.