Rail dampers are attached to the side of the rail with a regular spacing as can be seen in the photo above. The idea is to attach them at the same length as the wavelength of the noise that is worst.  That wavelength of noise is then “damped” out of the system by the heavy weights attached to the track.

Similar systems have been shown to reduce noise by around 5dB in other installations around the world, notably in the new cross rail project in central London.  However, the measurements we have taken have not been so positive. These dampers were placed on the side of the track right in front of our measuring station. We are able to identify which track the trains are traveling on when we take our noise measurements.  Unfortunately, there has been no indication of any noise reduction from this test installation.

We are expecting a report on the performance of the noise dampers from Sydney Trains by September 2020.