Train noise

Train noise is vehicle noise created by trains. Noises may be heard inside the train and outside. Various parts of a train produce noise, and different kinds of train wheels produce different amounts of noise. Noise barriers can attenuate the noise.

Subways, Light Rail transit and freight trains can send loud train noise into neighborhoods. Organizations such as the World Health Organization and the U.S. Environmental Protection Agency have set guidelines for noise level decibel limits for Rapid Transit

Sources

  • Train noise can be a type of environmental noise. When a train is moving, there are several distinct sounds such as the locomotive engine noise and the wheels turning on the railroad track. The air displacement of a train or subway car in a tunnel can create different whooshing sounds.
  • Trains also employ horns, whistles, bells, and other noisemaking devices for both communication and warning.
  • Trains propelled by electric traction motors often produce electromagnetically-excited noise. This high pitch noise depends on the speed and torque level of the machine, as well as on the motor type[1]. Variable frequency drives use Pulse-width modulation technique which introduces additional current harmonics, resulting in higher acoustic noise. The switching frequency of the PWM can be asynchronous (independent of the speed), synchronous (proportional to the speed), but always results in acoustic noise varying with speed[2].
  • Flange Squeal is the sound of the flanges of the metal train wheelset turning on the train track.

See also

Further reading

  • Correlation between rolling noise generation and rail roughness of tangent tracks and curves in time and frequency domains J Sadeghi, A Hasheminezhad Applied Acoustics 107, 10-18 [3]

References

  1. ↑ "J. Le Besnerais et al., Characterization of the audible magnetic noise emitted by traction motors in railway rolling stock", Noise Control Engineering Journal, ISSN 0736-2501, Vol. 57, Nº. 5, 2009, págs. 391-399
  2. ↑ J. Le Besnerais, V. Lanfranchi, M. Hecquet and P. Brochet, "Characterization and Reduction of Audible Magnetic Noise Due to PWM Supply in Induction Machines," in IEEE Transactions on Industrial Electronics, vol. 57, no. 4, pp. 1288-1295, April 2010. doi: 10.1109/TIE.2009.2029529
  3. ↑ Sadeghi, Javad; Hasheminezhad, Araz (2016-06-01). "Correlation between rolling noise generation and rail roughness of tangent tracks and curves in time and frequency domains". Applied Acoustics. 107: 10–18. doi:10.1016/j.apacoust.2016.01.006.


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