A transporting and loading system for rail-supported conveyances using transport vehicles outfitted with a standardized loading platform for ISO containers, particularly for machinery for inspecting and maintaining track installations, is provided. Transporting and loading rail-supported conveyances allowing rail-supported conveyances to be safely transported to places of use at any distance apart without special-purpose vehicles and to be deposited on and picked up from a track installation without external lifting gear is described. The transporting and loading system has a sandwich construction comprising two floor assemblies which conform to ISO container dimensions, an intermediate space between the floor assemblies for drive units, transmission units and control units for the automated movement of the loading and offloading unit, and rails are provided for holding and guiding the rail-supported conveyances on the sandwich construction.