Semi-Submerged Ship with Minimum Wave Making Resistance

It is theoretically well known that when the two bodies are running in the same direction and in a pair in water and/or on water surface, sometimes their total wave making resistance becomes smaller than that of the individual body due to the mutual interference of the waves caused.The proposed semi-submerged ship of the least wave resistance consists of the submerged main hull of the so-called Rankine's ovoid and the surface piercing bridge having sectional area of square cosine curve.Theoretically and experimentally, the combined hull form as mentioned above thus proves its capability of reducing the wave resistance tremendously in a certain specific speed range, i. e., the dimensions of bridge can be chosen so that the waves caused by the submerged hull running near surface may be diminished by the waves of the bridge at the specific speed.Furthermore, it is investigated that the upper limit of the optimum speed range of this type of vessel is between 0.35 and 0.40 in Froude's number.