The shoe derailment device for use in derailing a conductor shoe assembly of a bridge crane from a conductor rail assembly generally has a wedge head provided at a longitudinal end of a body made of an electrically insulating material, the shoe derailment device being securable to the conductor rail assembly in a derailment position in which the shoe derailment device is positioned outside an operating zone of the bridge crane, with the wedge head facing the operating zone in a manner that if the conductor shoe assembly is moved outside the operating zone, into the area occupied by the shoe derailment device, the conductor shoe assembly is derailed from the conductor rail assembly as the conductor shoe assembly engages the wedge head and is maintained in a derailed state by the electrically insulating material when the conductor shoe assembly is engaged with the body.