PASS-BY NOISE ASSESSMENT OF CONTEMPORARY AND LEGACY RAIL VEHICLES ON SERBIAN RAILWAYS

Abstract

Pass-by noise represents one of the key environmental criteria in the approval and operation of modern railway vehicles. In addition to vehicle design, the condition of the track and braking technology significantly influence the measured noise levels. During the type testing of a diesel track inspection vehicle on the upgraded Belgrade–Novi Sad railway line, pass-by noise measurements were conducted on various passenger and freight trains under identical, controlled experimental conditions. This setup enabled a direct acoustic comparison between contemporary and legacy rolling stock, including electric multiple units (EMUs), freight trains with different braking systems, and multiple generations of electric locomotives. All measurements complied with the EN ISO 3095:2025 standard, with track acoustic characteristics validated through rail roughness and track decay rate (TDR) assessments. The obtained results demonstrate substantial differences in environmental noise emission between older and modern rolling stock. Notably, freight wagons equipped with cast iron brake blocks generated approximately 9 dB higher pass-by noise than wagons fitted with composite brake blocks. Furthermore, modern electric locomotives exhibited significantly lower noise emissions than their legacy counterparts. These findings underscore the critical role of advanced braking technologies in mitigating railway noise and highlight the environmental benefits of fleet modernization in achieving compliance with current European Technical Specifications for Interoperability (TSI).