Abstract: A ship's hull has a general frame form defining a bottom surface and two side surfaces. The bottom section of the hull comprises a substantially vertical wedge-formed portion, which extends vertically downwards in the region of the lowest part of the bow portion of the hull. The bow portion follows in horizontal sections, at and below the design water line of the ship, a substantially continuous curved arc. The stem line of the bow extends downwards/rearwards in a small angle to the horizontal plane, in order to enable ice-breaking by means of bending.

Abstract: An off-shore drilling platform or the like supported by support legs standing on the bottom of the sea is converted to withstand ice pressure occurring in ice filled waters by providing those portions of said drilling platform, which are to be protected against ice pressure, with protective structures below the platform. The drilling platform and/or the protective structures are then, when ice occurs, lowered along the support legs to a level where the protective structures partly extend below the surface of the ambient water.