The study of the Modification of the Ro-Ro Ferry's Angle of the Entrance Using Statistical Methods and Ship Model Resistance Tests

Aspects of speed and its correlation to ship resistance greatly affect the performance of ferry ro-ro ships. The fixing of the ship's resistance is very significant when related to the ship's economic costs. BTH-BRIN has carried out resistance tests and calculations using the Holtrop statistical method where the resistance result is considered too large. To reduce the resistance, modifications are made, one of which is by changing the angle of the entrance of the ship bow. Again, the Holtrop statistical calculations are then employed to determine the effective angle of the entrance after the ship is modified. Reducing the angle of the entrance of water at the ship's bow is expected to reduce the resistance in terms of the bow wave. It also needs paying attention to the amount of ship payload that has been planned. This paper describes the process of resistance reduction due to the change of the angle of the entrance of the ferry ro-ro ship. Firstly the resistance of the original ship is predicted using the statistical method and a scaled ship model is made and tested in BTH towing tank. Second, the angle of the entrance of the ferry ro-ro ship is modified. Finally, the modified one is predicted statistically based on the Holtrop method. The results of the statistical analysis of the modified angle of entrance showed that the resistance is smaller than the original one.