EN 15610: Measurement of Rail Roughness for Rolling Noise Prediction

What is EN 15610?

EN 15610 is the European Standard titled “Railway applications – Acoustics – Rail roughness measurement related to rolling noise generation.” It provides the technical specifications for measuring the microscopic irregularities on the rail head—known as Rail Roughness—which are the primary source of Rolling Noise.

When a train wheel rolls over a rail, the combined roughness of both surfaces causes vibrations. These vibrations are radiated as noise by both the track and the wheel. EN 15610 ensures that the rail’s contribution to this noise is measured accurately and consistently, which is vital for Noise Mapping and the certification of new rolling stock.

The Acoustic Importance of Roughness

The standard focuses on roughness in the wavelength range of 1 mm to 250 mm. These wavelengths correspond to the frequency range that the human ear is most sensitive to (the “audible” spectrum) at typical train speeds. Key aspects of the standard include:

• Measurement Methodology: Requirements for using displacement transducers or optical sensors to scan the rail surface.
• Data Processing: How to convert raw surface profile data into 1/3-octave band roughness spectra (expressed in decibels relative to 1 micron).
• Acoustic Pass/Fail: Defining the “limit spectrum” that a rail must meet for it to be considered an “acoustic reference track” during Pass-by Noise testing for new trains.

Applications in Rail Maintenance

Beyond laboratory testing, EN 15610 is an essential tool for Rail Maintenance. Infrastructure managers use the standard to monitor the acoustic degradation of the track. If the roughness exceeds the levels defined in the standard, it triggers Rail Grinding or acoustic polishing to restore the rail surface and reduce the noise impact on surrounding communities.

Alignment with TSI NOI

Compliance with EN 15610 is mandatory for the validation of TSI NOI (Technical Specifications for Interoperability – Noise). When a manufacturer tests a new locomotive or wagon for noise levels, the track used for the test must be measured according to EN 15610 to ensure the results are not unfairly biased by a “noisy” or poorly maintained rail.

Comparison: Direct vs. Indirect Roughness Measurement