The effect of rail shields on railway rolling noise

Abstract

Rail shields have been developed recently which are fitted around the lower part of the rail and are intended to reduce the noise radiated by the rail. Their effect on the sound radiation is investigated theoretically by using a 2.5D finite element/boundary element approach including the acoustic effects of the ground. The insertion loss due to the rail shields is predicted and compared with available measured data and the most important features of the shields are identified. The overall noise reduction when applied to railway track is determined by combining the numerical results with estimates of rolling noise from the TWINS model. The rail shields are effective in the middle frequency range, where the rail is the most important noise source. The overall A-weighted sound level is reduced by 2–3 dB for a track with soft rail pads, and 1–2 dB for a track with stiff pads.