# Influence of Stray Current on Fastening System Components in Urban Railway Tracks
## 6 Conclusions  
For tracks with discretely fastened rails, the fastening points are \"discharge points\" for the current from the rail to the ground. Therefore, by better insulating the fastening system and ensuring adequate track drainage in a track asphalted into a car-running surface, stray current can be prevented. Despite the significant damage caused by stray currents to the rail and the components of the fastening system, insufficient attention has been paid to the prevention of stray currents. Moreover, the prevention of stray currents is not one of the characteristics that a fastening system must satisfy. The experiments described in this paper have shown that, to prevent stray current corrosion in the track, it is essential to provide adequate drainage so that water does not remain in the track. Under dry conditions, indirect fastening systems with insulated anchor bolts should be used to prevent stray currents. In addition, the elastomeric components of fastening systems must have high electrical resistivity, which was not the case for the fastening systems tested in this study. When direct fastening systems are used, an elastomeric pad should be installed between the rail foot and clip to prevent direct contact between them.  
Stray currents can be significantly reduced by modifying the existing fastening systems in tracks with discretely fastened rails and by improving track maintenance. In addition to reducing stray currents and preventing harmful corrosion degradation of rails and fastening system components, modifying existing fastening systems can also improve ride comfort and reduce high levels of rail traffic noise and vibration.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Conditions**} & \multicolumn{4}{c}{**Fastening System**} \\ \cline{2-5}  & **ZG 3/2** & **PPE** & **DEPP** & **Zagreb 21-CTT** \\ \hline \multirow{2}{*}{Dry condition} & Anchor bolt (part in concrete), Steel plate & Anchor bolt (part in concrete) & T-bolt, Anchor bolt (part in concrete) & Anchor bolt (part in concrete) \\ \hline Water by top of the concrete base & Anchor bolt (part in concrete), Steel plate & Anchor bolt (part in concrete) & T-bolt, Anchor bolt (part in concrete) & Anchor bolt (part in concrete) \\ \hline Water by half height of rail neck & Rail, Steel plate, Steel rib, Anchor bolt & Rail, Clip, Steel plate, Anchor bolt & Rail, Clip, Steel plate, Anchor bolt & Rail, Clip, Steel plate, Anchor bolt \\ \hline \hline \end{tabular}
\end{table}
Table 8: Fastening system components on which corrosion occurs during testing in different conditions.  
**Author Contributions:** Investigation, K.V., S.L. and M.S.; Methodology, K.V. and M.S.; Project Administration, S.L.; Data Analysis, K.V. and M.S.; Supervision, S.L.; Writing-original draft, K.V.; Writing-review and editing, K.V., M.S. and S.L. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research received no external funding.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** Not applicable.  
**Acknowledgments:** The authors would like to thank Zagreb Electric Tram for providing the rail samples and components of the fastening systems used for the laboratory tests. We thank Beton Lucko and GTM for their assistance in preparing the test samples.  
**Conflicts of Interest:** The authors declare that they have no competing financial interests or personal relationships that may have influenced the work reported in this article.