Construction of hull of vessel such as tanker

#1. Field of the Invention

#The present invention relates to a construction of hull of a vessel such as a tanker. More particularly, the invention is concerned with a hull having a construction composed of three hemispheres to attain the maximum internal volume with the minimum outer surface area, while attaining a good stability of the vessel.

#2. Description of the Prior Art

#FIG. 1 is a schematic plan view of an embodiment of a hull structure of a tanker or the like in accordance with the invention;

#FIG. 2 is a side elevational view of the hull as viewed in the direction of an arrow II in FIG. 1;

#FIG. 3 is a side elevational view of the hull as viewed in the direction of an arrow III in FIG. 1; and

#Referring to the drawings, a hull is composed of three hemispheres 12a, 12b and 12c the outer surfaces, i.e. steel shell portions, of which are designated at numerals 10a, 10b and 10c. In the drawings, an arrow I indicates the forward or bow direction. Two hemispheres 12b and 12c positioned at the stern side have a substantially equal diameter which can be increased, for example, to about 100 m. The line AB connecting the center A of the bow-side hemisphere 12a and the center B of a stern-side hemisphere 12b has a length equal to that of the line AC connecting the center A to the center C of the other stern-side hemisphere. Thus, the triangle ABC is an equilateral triangle. Three hemispheres 12a, 12b and 12c are connected to one another so as not to leave any gap between adjacent ones.

#In the actual building of this hull, the hemispheres are made wholly from steel sheets. The building of spheres from steel sheets can be made without substantial difficulty by making use of technics commonly used in the building of, for example, ground or underground gas tanks. The connection of three hemispheres to one another can be made easily by welding. According to the invention, the internal volume, i.e. the loading capacity for loading crude oil in case of tanker, can be maximized with minimized surface area, i.e. minimized consumption of the steel sheet. In addition, the structure composed of three hemispheres 12a, 12b and 12c exhibits a superior stability when floated on the sea water for the same principle as a tripod for cameras. In addition, this structure is superior also from the view point of mechanical strength.

#As a modification, in the hull in accordance with the invention, three hemispheres 12a, 12b and 12c can have a substantially equal diameter. In this case, it is possible to connect three hemispheres 12a, 12b and 12c such that the lines AB, AC and BC interconnecting the centers of these hemispheres have an equal length so that these lines in combination form a regular triangle. In such a case, the hull has no specific orientation and exhibits a good grasping characteristics when stationed on the sea. The hull structure of this type, therefore, can be used suitably as an off-shore crude oil storage station.