Rapidly measure noise, roughness and track defects with ARRoW

ARRoW is short for “Acoustic Rail Recording on Wheels” and consists of a measurement system on the train and analysis software. The measurement system measures the noise and vibrations close to the wheels of the train, along with the position and speed. The measured noise is not constant, but fluctuates due to the changing properties of the track on which the train runs. By measuring the noise, we can see the change in the typical properties of the track, such as rail roughness or defects. The information gathered can then be used for various applications.


  • track wear monitoring as part of the rail roughness noise measure
  • early detection of wave wear
  • finding test locations to perform noise measurements for trains (according to ISO 3095 and ISO 3381)
  • providing input for EU noise mapping
  • early detection of squats
  • controlling maintenance based on the real track condition instead of periodic maintenance
  • identifying noise “hotspots” in cities and taking action before local residents complain


  • portable: can be temporarily built into existing vehicles; a special measuring vehicle is not required
  • easy to use: built with standard measurement system components and intuitive software for analysis
  • autonomous: no energy supply or position or speed signals required from the vehicle
  • robust: built-in redundancy makes it almost impossible for a measurement to fail
  • reliable: has been successfully used for assignments in the Netherlands and the EU for almost 10 years
  • versatile: can be used for light rail, conventional equipment and high-speed equipment

What do you get?

  • Custom measuring system (data acquisition hardware, measuring computer, microphones, accelerometers)
  • Analysis software: RailInspector

In addition, we can optionally provide the following additional services:

  • In-house or on-the-job training: use of measuring system and RailInspector
  • Design, manufacture and installation of the additional hardware to use ARRoW on a customer vehicle
  • Advice on using the measurement data for your own application
  • Developing additional custom software modules specific to customer requirements (e.g. additional analysis, link with GIS, etc.)

More information about ARRoW and a few application examples can be found in the (English) brochure.

Werken met ARRoW en RailInspector
Arrow brochure