The present invention relates to an overhead travelling crane (2) for a nacelle (1) of a wind turbine, said travelling crane comprising at least a first suspension beam (3); a second suspension beam (4), said suspension beams being arranged with a space between them; a cross beam (5), said cross beam being movably connected to said first and second suspension beams so that the cross beam can be moved along the suspension beams; and at least one lifting device (6), said lifting device being movably connected to the cross beam. Said first and second suspension beams are parts of concentric circles, said -concentric circles sharing the same center and having different radii. The cross beam may be inclined.