Moreover, the steam railway operation also resulted in the passengers and the train crew on the underground sections being largely unprotected from the smoke. In addition, the soot settled on the seats and soiled them, and thus also the garments of the passengers, even before the journey. In addition, the locomotives also damaged the infrastructure of the railway itself, because the smoke caused the rapid corrosion of the exposed iron structural parts of the superstructure and generated dust that infiltrated the carriages. The problem of rusting intensified due to the water vapour that emanated from the locomotive and in winter from the heating pipes. Due to the dense train sequence in both directions of travel, the resulting strong smoke and steam masses were able to escape the tunnels only very slowly, especially in cloudy and foggy weather. At Ferdinandsbrücke station, the operator even experimented at times with powerful fans to extract the smoke before entering the underground station, but these attempts were unsuccessful.