Abstract: An icebreaker hull having laterally projecting hull components which define inclined upwardly and rearwardly sloped faces arranged in part above and in part below the vessels normal water line, and each hull component further including a longitudinally extending face cooperating with the inclined face to define a cutting edge. At least a second pair of similar projecting hull components adjacent the first components to define a second cutting edge downstream of the first cutting edge. One or more of these hull components may be movable from and to positions where they are stowed in streamline relationship to the hull.

Abstract: The prow of the ship with a lower power requirement in open and ice-covered water has a front surface which is forwardly inclined at the top over the entire beam of the ship with marginal cutting edges, preferably on rod-like profiles. The front surface passes into an underwater prow part with frames which are V-shaped at the bottom. The cutting edges above the waterline can forwardly pass into two catamaran-like stems, the front surface being curved in the longitudinal direction. The front surface is carried by thwartships frames, which are horizontal at the bottom in the central part of its longitudinal extension, below the construction waterline and approximately forms a plane there. In the midships longitudinal direction an ice-cutting central skid is provided on the prow. Even in the case of widely varying ice characteristics, favorable conditions are provided for breaking out one-part ice floes.

Abstract: A method of deflecting ice for protecting upright legs of stationary or floating marine structures such as marine offshore drilling platforms or the like against drift ice by suspending a heavy mass along the leg of the structure in the vicinity of the water surface and oscillating this mass so that the oscillating mass periodically hits ice adjacent the leg of the structure whereby the oscillations of the mass are generated within the oscillating mass and the resultants of the active and reactive forces and the center of gravity of a semi-cross-sectional area of the oscillating mass substantially coincide along a vertical line spaced from and substantially parallel to the leg of the structure. The ice deflector assembly includes an annular or U-shaped oscillating body suspended about the leg of the protected structure, the body housing internal oscillation generating means for generating vertical and/or horizontal oscillations of the body.

Abstract: An icebreaker vessel formed of a pontoon-shaped forecastle, a wedge-shaped ship bottom with a center keel, at least one pair of additional marine propulsion and steering systems along the ship bottom on either side of the keel, trimming devices for lifting or lowering the forecastle by predetermined amounts, and driven wheel assemblies mounted along both sides of the forecastle. The pontoon-shaped forecastle portion is of a larger width than the remaining part of the ship's hull. The additional marine propulsion and steering systems may consist of Voith-Schneider propellers or of one or several pairs of jet propulsion units. Portions of the forecastle and the wheel assemblies may be heated by hot cooling water supplied from the vessel's engines.

Abstract: An icebreaker having a cantilever forecastle from which is suspended one sliding carriage or a plurality of sliding carriages. Each sliding carriage mounts one planing tool or a plurality of planing tools with increasing depth of cut, in a tandem arrangement. The suspension means for each sliding carriage may consist of a linkage or of cables or booms. The one or several sliding carriages are yieldingly suspended and may be withdrawn into the ship's hull. The ice cutting operation may be assisted by vibrating the sliding carriage or supplying heat and/or pressurized water to the planing tools.