for the installation of rail web dampers in the Moselle valley. Under this invitation to tender of DB Netz AG, innovative noise reduction systems on cross town link No. 98 (Löf) were to be installed and tested. The noise emission reduction to be achieved had to be ≥2dB(A). If the measurement was lower than the ≥2dB(A) specified, the contractual requirement was not met and the product had to be removed again within a period set by the customer.
To ensure that the rail dampers achieved the result of greater or equal to 2 dB(A), the following conditions had to be met and proofs provided by the supplier. Before installation of the rail dampers the track must have a vertical track decay rate of, on average, less than 2 dB/m for the third-octave frequencies 500 Hz to 2 kHz.