Rail traffic inevitably causes vibration. However, SBB is doing all it can to minimise this problem with the help of modern technology and cost-effective measures.
Metal wheels rolling on rails not only generate noise, but also vibrations that spread through the ground, building foundations and walls and are also transmitted into people's homes. Residents perceive these vibrations are tremors or hear an unpleasant dull humming noise. Measures previously put in place have resulted in a comprehensive refurbishment programme costing billions of Swiss francs.
As part of an EU project, SBB was until the end of 2013 testing low-cost vibration-damping solutions for existing sections of track. In additional investigations, it is examining not only under sleeper pads but also possible measures involving turnouts and rolling stock, for example soft under sleeper pads at points and new wheel materials that are intended to diminish vibrations during transmission. In the long term, the entire network is due to undergo refurbishment at reasonable cost.
Under sleeper pads.
One highly promising technique is under sleeper pads, which SBB has been testing on a heavily used section of the route at the southern foot of the Jura mountains since October 2011. It has installed various types of flexible pads underneath the sleepers along a stretch of about 1,000 metres of track. The ongoing tests are enabling SBB to study how such pad affects the track and how effective it is in reducing vibrations and noise. Unexplained noises are currently being investigated. Under sleeper pads are significantly cheaper than conventional under ballast mats.