This paper is concerned about the clarifying the minimum resistance hull form by controlling the maximum trim angle change in high speed range. The analyses by using SUMT method based on towing test results of models show higher chine line hull form by more controlling the maximum trim angle change. In order to check against the resistance performance, trial tests of a triple-screw torpedo boat of 35m length with displacement 133 ton using various engine rating were executed. Comparing the trim angle changes with the ones by the regression equation's values based on towing test data of 13 models of 2.5m length with wave-shaped bottoms, we get reasonable results, which enable us to estimate the boat's resistance at maximum speed.
As the equation to presume the resistance performance are the base of calculation of the minimum resistance, Keuning et al propose the equations (Keuning, 1993) composed of three non-dimensional hull form parameters by analysing about 1.5–2.5 m length models towing test data. The three hypothetical effective ones are planing length, planing area and location of center of gravity. A equation have 13 terms including the cubic ones. The selected three parameters is based on Clement's discussion about his data (Clement, 1963). The characteristic of the equations is that they have no term concerning chine line's height or deadrise angle. We have obtained the equations by analysing 13 kinds of 2.5 m models data of towing tests, which varies long or short in length, high or low in chine line height, and large or small in initial trim angle. The five elements of hull form parameters are obtained by factor analyses of the test data, in which a correlation matrix of hull form parameters makes five eigen axes, stronger correlation coefficients with represents of principal dimensions such as shape of bow, hight of chine line, overall length, width and initial trim angle.
