A FUNDAMENTAL STUDY ON MEASUREMENT OF HULL ROUGHNESS

Sa？etak In this study, an investigation on the hull roughness measurement of a new ship, a 160m class car ferry, was performed. The hull roughness measurement was conducted in the ferry’s pre-coated state before launching. For measurement, the TQC manual and ITTC recommendations were considered, and measurements were made in a total of 230 zones below waterline of the ship. Accordingly, the average hull roughness of the car ferry was 81μm, which is relatively low compared to 150μm, the hull roughness of a new ship proposed by the ITTC. In addition, the measurement uncertainty was calculated using the ISO guidelines, and the effect of the number of zones on the hull roughness measurement was examined. Using the measured average hull roughness, we estimated the resistance performance at the design speed of the ship. Accordingly, it was confirmed that the total resistance of the new ship was reduced by approximately 2% owing to a decrease in its frictional resistance increase