ANALISA PENGARUH VARIASI SUDUT BILGA KEEL TERHADAP GERAKAN KAPAL CEPAT TIPE CREW BOAT

In the process of ship design and planning, speed, stability, and maneuverability are important factors in determining a ship's operational performance. Fast ships are designed to achieve high speeds, often facing challenges related to stability and maneuverability, especially when dealing with extreme and varied sea conditions during operations. One of the innovations made to improve the stability and performance of fast boats is the addition of a bilge keel. The model in this study is a crew boat type fast vessel with a length of 38 m, a width of 7.6 m, a height of 3.65 m, and a draft of 1.89 m. In the study, the RAO values and wave spectra for each harmonic motion of the ship, namely heaving, rolling, and pitching, will be compared. Next, an analysis of the effect of adding a bilge keel to the crew boat was conducted using four bilge keel angles: 15°, 30°, 45°, and 60°. The installation angle of the bilge keel was measured from the intersection of the ship's center line and water line, with the bilge keel dimensions being 19 m in length, 0.3 m in width, and 6 mm in thickness. From the analysis results that have been conducted, it shows that the addition of the bilge keel has been able to reduce the magnitude of the ship's motion. For the ship's seakeeping analysis results, the response from the heave and roll movements on the bilge keel at a 45° angle showed better responses than other models, with a heave RAO value of 2.369 m/m and a roll RAO value of 4.503 deg/m. Meanwhile, for the pitch movement response, using the bilge keel at a 45° angle yielded a RAO value of 2.815 deg/m.