EXPOSURE TO IMPULSIVE INFRASOUND

The passage of a train through a tunnel generates a complex pattern of pressure waves. Attention has traditionally focused on potential negative effects on train stability and on exposed structural elements (e.g windows). Much less consideration has been given to the possibility that aural discomfort and/or disturbances can result, due to the pressure waves generated by the head and the tail of the train. Such disturbances might affect passengers and train conductors alike. The latter are clearly in a more hazardous position as they are daily exposed over very long timescales. Although the problem is more acute in the last generation of very high velocity trains (v >= 300 Kmh), it is nevertheless significant even at more moderate speeds, such as those (around 160 - 200 Kmh) of contemporary passenger trains of traditional design. Additionally, these latter trains are usually less airproofed, hinting at larger amplitudes of pressure waves inside the cars. In this paper are presented measurements of low frequency pressure waves aboard postal freight and InterCity passenger trains. Equivalent sound pressure levels along the entire rail journey are below 80 dBA, implying that effects on the auditory system due to conventional "sonic" pressure waves are negligible. For the covering abstract see IRRD E104312.

Language

  • English

Media Info

  • Features: References;
  • Pagination: p. 277-82

Subject/Index Terms

Filing Info

  • Accession Number: 00790193
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • ISBN: 0-9622072-3-3
  • Files: ITRD
  • Created Date: Apr 11 2000 12:00AM