ROTATING TOWER CRANE

The present invention relates to a crane, having a jib rotatable about an upright axis, at which jib a trolley is movably arranged, from which trolley a hoist rope connected to a load hook runs off, as well as a load hook position determining device for determining the position of the load hook. The load hook position may be determined optically by means of one camera only, which camera is mounted on the trolley of the crane and views from the trolley in a predetermined and thus known viewing direction downwards onto the load hook. In doing so, the position of the load hook in the camera image is determined by an image evaluator. To simplify detection of the load hook in the camera image, the image evaluator may include rope run determining means for determining the rope run of the hoist rope running off from the trolley.