Abstract: The invention refers to a conveyor incorporating a conveyor belt (1) which runs in a track on a girder (2). The girder (2) is at one or both sides provided with two longitudinal, open ducts (4, 5) which are situated one inside the other and which both can be reached from the outside of the girder (2). Hereby the girder sections can easily be interconnected by means of mounting moldings (8) in one of the ducts (4) at the same time as railings (7) or the like can be mounted in the other duct (5).