50% reduction in noise disturbance next to railway lines - 13/11/2017

They're called “Railpads”. The main purpose of these rubber dampers is to protect the railway infrastructure components, particularly from vibrations. But the Infrabel specialists have now turned them into an innovative tool! By developing these railpads, the noise emitted by rail transport has been reduced by half (-3 decibels). The system, a European first, will be gradually installed throughout the Belgian network in line with one of the company's priorities: “In tune with society”.

Anti-noise innovation: -3 decibels or -50% less noise

After three years of testing and development, the railway infrastructure operator has unveiled a European “first”: the new generation of railpads. These rubber soles are placed between the concrete sleepers and the rails. They reduce the noise caused by trains and the railway network by around 3 decibels, or 50%. These results, which have been confirmed by two independent bodies, are so remarkable that several foreign network operators have visited Belgium to see how the Infrabel engineers did it.

Limiting noise at source

When trains roll on the tracks - passenger or goods trains - they naturally make noise. However, this noise can also be caused by the railway infrastructure. It’s like a guitar, which makes a noise when you touch the strings. So for several years, in partnership with all the parties concerned, Infrabel has invested in anti-noise measures. This new generation of railpads is the latest victory in the “fight” against noise. The principle is to reduce noise at source as much as possible.

Production of new “noise-reducing” railpads began in February 2017. To date, just over 30km of track has been equipped with it. The aim is to install the system at the same time as renewing the track, i.e. around 120km of track per year, the equivalent of replacing around 300,000 sleepers per year. The railpads cost around 1 Euro per linear metre, so the solution is very economical compared to other anti-noise measures.

Additional anti-noise measures

Infrabel has a special “Noise and Vibrations” division, where experts continuously carry out research, studies and tests. The objective is to find pragmatic solutions to reduce the noise disturbance caused by railway operation. As well as the railpads, Infrabel is also investing in:

1.Grinding rails

The rails are ground as a preventive measure to keep them in an optimum condition and increase their life span. By making them smoother, they vibrate less when a train passes, and therefore produce less noise. Smooth rails are up to 3 decibels quieter than rough rails. All main and high-speed lines undergo systematic grinding. In 2016, Infrabel ground nearly 1,900 kilometres of rail track.

2.Rail dampers

Rail dampers reduce track vibration when a train passes over the top. They are blocks of noise-absorbent material that are placed against the rail. Rail dampers reduce noise from vibrations by around 3 decibels. The disadvantage is that dampers cannot be installed everywhere, they are more expensive and require more maintenance than railpads.

3.Anti-noise screens and walls

When necessary (based on an environmental impact study), Infrabel also places anti-noise screens and walls alongside the railway tracks. These systems are especially efficient (-5 to -10 decibels) when they are placed next to the track, absorbent and raised. Here too, the disadvantage is that the screens are much more expensive and require more maintenance.

In tune with society

The aim of the European Directive on environmental noise is to put in place a common approach that will avoid, prevent and reduce the harmful effects of exposure to background noise. This Directive has been transposed into practical action plans by each Member State, which are assessed every five years and adapted if necessary.

By adding these new railpads to its weaponry, Infrabel is proactively investing in a wide range of anti-noise measures and thereby fulfilling one of the priorities of a public company: in tune with society.