Patent ID: 7950539

Claim:
A load control device for controlling movement of a suspended load of a container crane, said crane comprising a trolley, a spreader and load lines arranged in a four point suspension for lifting a load, the load control device comprising: at least one light source array arranged on the one spreader, the at least one light source array comprising a plurality of light sources extending in at least one direction on the spreader; an optical sensor arranged on the trolley to detect light produced by the at least one light source and thereby movement deflection of a position of an orthogonal axis of a container suspended under the spreader relative to an imaginary center line of the orthogonal axis of the container, wherein the movement deflection is determined based upon differences in the detection by the optical sensor of the light produced by the light sources, wherein the optical sensor is arranged in line-of-sight of two or more light sources of the light source array arranged on the spreader in a first straight line relative to an orthogonal axis of the container, wherein the optical sensor is also arranged in line of sight of at least one third light source arranged on a line which is perpendicular to the first straight line, and wherein the at least one third light source is arranged at a different height to the light source of the first straight line; and at least two actuators attached to at least one load line, wherein at least two of the actuators are arranged to move at least one of the suspension points closer to or farther away from the imaginary center line by shortening and/or lengthening the at least one load line.