PURPOSE: To increase internal volume of a ship body while save its material further obtain its sailing stability, by constituting the ship body of a tanker or the like connecting a semispherical body in the bow side to two semispherical bodies of radius equal to the radius of said semispherical body in the bow side in a shape of isosceles triangle.

CONSTITUTION: A semispherical body 2a in the bow side and two semispherical bodies 2b, 2c in the stern side are arranged in such a manner that each external steel shell parts 1aW1c is overlapped and each of the centers AWC forms an isosceles triangle with the center A as the vertex, and a ship body is constituted by welding places between each of said bodies 2aW2c, while tail blades 4 are arranged to the bodies 2b, 2c in the stern side and a screw 3 is arranged between the both semispherical bodies. In this way, internal volume is rapidly increased while a material in the steel shell part can be saved, and sailing stability in the sea is improved, further a sailing speed is increased and fuel consumption can be saved.