Abstract: Unit cranes consist of three hinged arms (13-15), the middle arm (14) being in the form of a polygon comprising a number of units jointed together, the flexibility of the units being arranged by influencing the units internally. The object of the invention is to achieve improved traction curves and speed curves, and this is effected by influencing the movement of the units from the outside by means of a hydraulic mechanism (38).

Abstract: Unit cranes consist of three jointed arms (13-15), the middle arm (14) being in the form of a polygon comprising a number of units jointed together, the mobility of the units being arranged by influencing the units internally. The object of the invention is to achieve improved traction curves and speed curves, and this is effected by influencing the movement of the units from the outside by means of a hydraulic mechanism.

Abstract: A ship's hull designed for traffic in icy waters has a general form defining a bottom that is substantially horizontal in longitudinal section and has a central longitudinal keel line, and, at both sides of the bottom, sides that extend upward from the bottom. The bottom of the hull is formed with a depression at each side of the keel line. Each depression has a rear edge oriented obliquely relative to the keel line and extending to the rear of the hull from an inner location close to the keel line to an outer location farther from the keel line and at which the depression is open towards one side of the hull. The rear edge of each depression forms a substantially vertical guide surface for ice chunks under the hull's bottom.

Abstract: A ship hull has a general frame form defining a bottom surface and two side surfaces. The bottom surface of the hull has a horizontal bottom section that extends longitudinally of the hull midway between the two side surfaces of the hull, and the bottom surface of the hull also has two inclined bottom sections that are located entirely below the design waterline plane and are joined to the horizontal bottom section along respective sides thereof and to the side surfaces respectively. Each join is along a clearly defined longitudinal intersection edge, whereby each side of the hull is divided into at least three clearly defined portions. The width of the horizontal bottom section and of each of the inclined bottom sections is at least 20% of the maximum beam of the hull, and the inclined bottom sections extend over a substantial part of the length of the hull.

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: A method for protecting stationary constructions, located in water and surrounded by water, against strain caused by a moving ice field in said water. A protective structure is arranged around said stationary construction. Said protective structure has a cross-section considerably greater than the cross-section of said stationary construction and it comprises, at the water surface level and below this level, an outer surface which slopes downwards in a direction against the stationary construction to form an ice breaking surface bending downwards ice, which move against said protective structure.