The future belongs to a quiet railway. That is why DB has set out to reduce noise pollution for residents along railway lines. Rail traffic noise is to be halved by 2020 (base year: 2000). Noise from rail lines is to be cut by an average of 10 decibels (dB (A)), which is perceived by the human ear as a halving of noise volume. To achieve this goal, Deutsche Bahn is implementing an overall plan with measures involving both the railway network and the vehicle fleet.
There are two pillars to this overall plan: noise control measures on fixed infrastructure along railway lines and noise reduction for the trains themselves. The latter involves noise-mitigation measures on vehicles to tackle noise directly at the source. Retrofitting existing freight wagons with low-noise composite brake blocks known as whisper brakes is central to this. Combined with good track maintenance, this reduces the rolling noise of a passing freight wagon by up to 10 dB (A), thereby halving it.
The solution tackles one of the major sources of noise in rail freight transport. Currently, almost 90% of the wagons used by DB Cargo in Germany have been retrofitted, and all new wagons have long been manufactured with whisper brakes. The entire DB Cargo fleet will be made up of quiet wagons by the end of 2020.
Two incentive systems support the retrofitting of existing freight wagons: the subsidy programme of the German Federal Ministry of Transport and the noise-differentiated track access charges (NDTAC) of DB Netz AG, which impose a surcharge on noisy trains and reward the use of quieter, retrofitted wagons. In addition, the German government has banned the use of noisy freight wagons on the German rail network from the 2020/2021 timetable change. You can read the legislation online here.
Noise pollution prevention in the project
If lines are newly built or substantially modified, the German Pollution Control Act (Bundes-Immissionsschutzgesetz) of 1974 stipulates that residents and the environment must not be harmed by the noise. This applies to all newly built lines, such as the section between Heidenau and Ústí nad Labem. If changes to existing infrastructure are necessary, the law applies only if there is a substantial structural modification. A substantial structural modification involves physical changes to the line itself, such as a significant displacement of the track.
Changes in the number or speed of passing trains, by contrast, do not constitute a substantial structural modification and therefore do not create an entitlement to noise pollution prevention measures. As part of its planning work, DB is currently examining the Dresden–Heidenau section in respect of noise pollution legislation.
Expert opinions on noise protection based on the 16th Ordinance for the Implementation of the German Pollution Control Act (16. BImSchV) will be produced in the course of the project. These will indicate where and to what extent measures are required. A distinction can be made here between active and passive noise protection measures.
The limits to be complied with under the 16th Ordinance for the Implementation of the German Pollution Control Act (Traffic Noise Ordinance) are set out in the legislation.
Noise protection studies have also been conducted for all options in preparation for the regional planning procedure (regional planning procedure documents Part C, Section 4.3 Noise impact around existing settlement areas (p. 52); expert report in Part D.2).
Vibration in rail operations
Perceptible vibrations can sometimes occur in the vicinity of railway lines. Moving trains induce mechanical vibration, which is either transmitted as structure-borne noise through the ground or as airborne noise. Structure-borne noise, which declines with increasing distance from the source, spreads through the ground in waves and can be transmitted into buildings via their foundations. Resonances in walls and ceilings are then perceived as vibration. Audible sound waves generated by ceiling and wall vibration are known as secondary airborne noise.
Like noise control, protection against vibration is regulated by the German Pollution Control Act (BImSchG). In order to avoid harmful environmental effects caused by vibrations, vibration studies will be performed along the route.
These will be evaluated in accordance with the technical regulations of the German Institute for Standardization (DIN) and the guidelines of the Association of German Engineers (VDI), which offset vibrations emitted by existing infrastructure. Measures to reduce and/or disperse these sound waves will be tailored to the specific case.
However, direct impacts on or damage to the structure of buildings – e.g. cracks in masonry or plaster – are not a concern in the case of structure-borne sound waves generated by rail traffic, even in buildings located very close to a railway line.
