Overview
CEN/TR 16978:2016 - "Railway applications - Infrastructure - Survey on isolated defects" is a CEN Technical Report that documents the methodology and results of a European Survey on Isolated Defects (ESID). Prepared by CEN/TC 256, the report supports development of the EN 13848 track geometry series by providing comparative data on isolated exceedances of track-geometry thresholds across participating national networks. Urban rail is excluded.
Key search keywords: CEN/TR 16978:2016, Isolated Defects, track geometry, railway infrastructure, EN 13848, track measurement.
Key topics and technical scope
- Objective: Describe the methodology used to collect and analyse isolated defects (IDs) and present cumulative results across networks.
- Definition of Isolated Defect: A section of a measurement signal exceeding a given threshold (e.g., Immediate Action Limit) with at least one sample; length measured by number of samples.
- Measurement basis: Typical measurement spacing 0.25 m; survey used most recent measurement per location and produced cumulative frequency distributions of length of exceedances.
- Parameters investigated: Eight track-geometry parameters, including:
- Longitudinal level (LL) in wavelength domains D1 (3 m