Several roll motion reduction devices are reviewed and suggested for the application in FPSO. The firstly suggested solution is the shape of the bilge. The next is a bilge keel. The last suggestion is the ART (antirolling tank). Typical U-tube type ART is designed for a FPSO and examined extensively by model experiment. The model section was made of transparent acryl. Free decay test, forced oscillation test and wave test were carried out at a two-dimensional wave flume. U-tube type ART is effective only when the natural periods of ART and ship are same. Therefore, the divided U-tube type ART with split plate is suggested for the reduction of the roll motion of a FPSO over the wide range of the roll period.
The roll motion of FPSOs should be suppressed effectively to ensure the proper operations of processing, offloading, helicopter landing and supply boat berthing. However, the roll motion is inevitable for FPSOs even if the weather vaning is achieved through the turret-mooring system. Furthermore, the precise estimation of the roll motion is not simple due to the nonlinear viscous damping. So many studies and experiments (Vuguts, 1970; Ikeda, et al., 1977; Iketda, et al., 1978; Schmitke, 1978; Park, et al., 1999; Park, et al., 2000) have been made for the roll motion and many devices (Stiger, 1966; Bell, 1966; Ikeda, et al., 1976; Ikeda, et al., 1993; Lew, et al., 2000; Na, et al., 2003) have been developed to reduce the roll motion. In this paper, several roll motion reduction devices are reviewed and suggested for the application in FPSO. The firstly suggested solution is the shape of the bilge. The next is a bilge keel. The last suggestion is the ART. Typical U-tube type ART is designed for a FPSO and examined extensively by model experiment.
