Abstract: A rail carriage group (1) for a crane (3), in particular a gantry crane, which is moveable on rails (2) with a rectilinear rail profile and around at least one curve and in a transition between the rectilinear rail profile and the curve, with at least two, in particular at least four, running wheels (4), the running wheels (4) supporting subframes (5) of the rail carriage group (1), and the subframes (5) supporting a superstructure (6) of the rail carriage group (1), wherein at least one of the running wheels (4), preferably each running wheel (4), is rotatable individually about a running-wheel axis of rotation (7) which is vertical in the operating position.

Abstract: On a gantry crane having a carriage which is used to displace the gantry crane along a straight track formed by parallel rails (1) and which includes a plurality of carriage groups (11), which each have at least two wheels (12) mounted rotatably on a subframe (16) and spaced apart from each other in the longitudinal direction of the respective rail (1) and of which at least two, preferably all, are connected rotatably about a vertical axis (23) to an end carriage (10) of the gantry crane, at least one measuring device (26) is present for at least one carriage group (11) connected rotatably about the vertical axis (23) to the associated end carriage (10). The measuring device can detect a track position of at least one of the wheels (12) of the carriage group (11) with respect to the rail (1) on which it rolls and can output a track position value (a) that corresponds to the respective track position.