Experimental Determination of the Effect of Catamaran Characteristics on Roll Motion and Stability

Initial stability of a ship is very important in terms of her survivability and seakeeping qualities. It influences not only the roll motion characteristics significantly but also the passenger and crew comfort. Roll motion of a ship may present important evidence about her overall stability in a seaway. This paper outlines details of a parametric experimental study which was carried out for determining the effect of catamaran characteristics on roll motion and stability. All relevant terms which affect roll motion were addressed clearly, however only predominant catamaran characteristics were chosen as working parameters. How these parameters affect the roll period, character of the roll motion and the metacentric height have been investigated. The parameters were varied systematically for each specific condition. The catamaran model was forced to roll freely and the roll periods were measured. values for each condition were calculated by using the experimental results. The uncertainty analysis of the experiments was also studied. Finally, the results were presented in graphical forms and discussed in details.