An Investigation into the Effect of Bilge Keels to the Roll Motion Response of Fishing Vessel

Stability of a ship is very influenced by ship’s roll motion, which is able to cause the ship to capsize. One of the main component which influence the roll motion, is the usage of motion damper at the ship’s hull. Bilge keel is a kind of passive damper whose construction is easy and does not require special system in the operation. The suitable bilge keel size is able to reduce excessive ship motion response when experiencing excitation force. This paper investigates the influence of bilge keel to the motion response of the ship by using a fishing vessel model with round bilge. The study was carried out by model experiment in the calm water and oblique wave using 6 types of bilge keel variation in its length and width. The results showed that the application of bilge keel is able to reduce about 37% motion response of the vessel; and the increase area of bilge keel also reduce the roll damping to 59%. It also can be concluded that common design bilge keel for merchant ship can be applied to the fishing vessel.