Patent ID: 7044072

Claim:
In a circular floating hull formed from a plurality of sections attached together end-to-end, one section of the hull comprising: a. a flat circular plate having a central circular cutout; b. a plurality of curved stiffeners attached to said flat circular plate; c. a plurality of radial girders attached to said flat circular plate and said curved stiffeners; d. an inner shell with one end attached to the central circular cutout in said flat circular plate; e. a plurality of rings that extend around the outer circumference of said inner shell and are spaced longitudinally along the length of said inner shell; f. an outer shell with one end attached to the outer circumference of said flat circular plate; g. a plurality of longitudinal stiffeners attached to the inner circumference of said outer shell that stop short of said flat circular plate so as not to penetrate said flat circular plate nor be structurally continuous across said flat circular plate; h. a plurality of lateral supports attached to the ends of said longitudinal stiffeners, said lateral supports configured to act in tension in either axial direction; i. a plurality of rings that extend around the inner circumference of said outer shell and are spaced longitudinally along the length of said outer shell; and j. a plurality of lateral supports attached to the rings on said outer shell and arranged to act in tension in either axial direction.