Rail lubrication can reduce the rail and wheel wears, and it mitigates the noise effect, generated by uneven wears and the dynamic rail-wheel contact. Nowadays, clever lubrication devices are used to automate and control the lubrication process. The units are usually installed on curved tracks. Depending on the requirements, the lubrication bars or in some cases only bores deposit the grease precisely at the right positions on the rails. Various types of lubrication devices have been installed in Hungary throughout the country on railway, tram and suburban railway lines. In the course of our research work we carried out a multitude of tests on the noise mitigation with the rail lubrication device installed on a tramline, in the framework of three measurement series. We accomplished noise measurements in case of corrugated and lubricated/non-lubricated rails, grinded rails and finally, grinded and lubricated rails. By comparing the results, the real value of the noise mitigation achieved by the rail lubricated device and grinding can be obtained. We investigated the diminishing effect of noise mitigation by switching off the units and the effect of grinding on the efficiency of the lubrication. In addition, Tatra T5C5 and CAF Urbos 3 trams ran on the line, so the results of the two types are directly comparable. The measurements supported that the rail lubrication and the grinding have adequate noise attenuation effect. We confirmed the expectation that the smoother rail surface improves the noise mitigation of rail lubrication. Finally, we also showed the reduction of tram wheel squeal by analysis of frequency spectra.

noise measurements, tramway, noise attenuation, rail lubrication, grinding