Track Stability in Urban Railways with Tight Curves: The Case of the Athens Urban Railway

Continuous welded rail (CWR) tracks have several advantages over the regular rail tracks. They provide comfort, less noise and vibration, while they need less maintenance and exhibit an increased life cycle over conventional tracks. However, temperature changes and subsequent expansion and contraction keep CWR tracks under continuous tension. Therefore, there is always the possibility that CWR tracks loose stability or even fracture. The problem worsens in urban surface railways, where horizontal alignments have smaller radii (under 400 m). The present study presents the theory of CWR and examines the applicability of Meier’s theory on truck stability in CWR tracks, in cases of urban railways. A case study for the Athens Urban Railroad is presented.