Fibre Optic Sensing as Innovative Tool for Evaluating Railway Track Condition?

The condition and deterioration of a railway track over time has a major influence on its maintenance demands, service life and consequently its life cycle costs. Railway track condition is currently assessed on the basis of manual inspections, wayside equipment and measurements performed by a measurement car. This paper deals with combining the advantages of above assessment technologies, allowing continuous and permanent measurements for the entire network. On the one hand, we use Distributed Acoustic Sensing, a methodology relying on the effect of Rayleigh backscattering. This technology uses fibre optic cables, which are already installed in cable troughs alongside railway tracks and used for telecommunication or signalling. On the other hand, fractal analysis of vertical track geometry allows for a componentspecific condition evaluation, i.e. distinguishing the root cause of an irregularity in track geometry. Correlating both methodologies should show whether or not/to what and to what extent this innovative methodology of using fibre optic cables is applicable for assessing the component specific condition of a railway track. The proposed combination of both methodologies paves the way for real time condition assessment of railway track.