Combination of NDT techniques for site investigation of non-ballasted railway tracks

Rail–wheel interaction monitoring using Acoustic Emission: A laboratory study of normal rolling signals with natural rail defects

“…There is a need [1] to develop new non-destructive testing (NDT) techniques which reduce the human factor aspects of rail monitoring. Colla et al [2] have suggested a combination of existing techniques but, in order to move from scheduled maintenance [3] and/or preventative maintenance [4] to predictive maintenance [5], continuous monitoring (as opposed to discontinuous inspection) techniques are required. The work described here is the first step in the development of a new technique for using Acoustic Emission to enable continuous automatic monitoring of the intensity of rail-wheel interaction at selected points in the rail network.…”

Past, present and future of robotic tunnel inspection

“…Endoscopes or videoscopes consist of rigid or flexible viewing tubes that can be inserted into pre-drilled boreholes of an element under investigation to examine its condition [38,39]. Light can be provided by glass fibers from an external source.…”

Towards Fully Automated Tunnel Inspection: A Survey and Future Trends

“…Endoscopes or videoscopes consist of rigid or flexible viewing tubes that can be inserted into predrilled boreholes of an element under investigation to examine its condition [38] [39]. Light can be provided by glass fibers from an external source.…”