Measurements of the noise generated by an SD40-2 diesel electric locomotive are described. The noise was measured in three types of moving tests: the first with the locomotive passing a 6-microphone array while under maximum power acceleration, the second with the locomotive simulating the pulling of a train, and the third with the locomotive coasting by unpowered. Stationary noise measurements were made at 16- microphone positions around the locomotive while it was attached to a load cell. The moving tests show that at the lower throttle settings, wheel/rail noise may be an important contributor to the overall locomotive noise signature even at modest speeds (20 mph and above at throttle 1 and 30 mph and above at throttle 4). At throttle 8, wheel/rail noise does not become a significant source until speeds in excess of 50 mph are reached. At throttle 8 and at speeds below 50 mph, noise spectra measured opposite the moving locomotive are comparable to noise spectra measured opposite the stationary locomotive. Diagnostic tests to determine how much the various sources contributed to the overall noise were performed at seven positions on one side of the locomotive. The engine exhaust and intake, the engine/generator, the radiator cooling fans, the dynamic brake fans, the traction motor blowers, the dust bin blower compressor, and structure-borne noise have all been identified. At high throttle settings the exhaust and radiator cooling fans dominate. At low throttle settings the engine/generator, the exhaust and the cooling fans all contribute to the overall noise.

Media Info

  • Media Type: Digital/other
  • Features: Appendices; Figures; Tables;
  • Pagination: 168 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00144092
  • Record Type: Publication
  • Source Agency: Federal Railroad Administration
  • ISBN: DOT-TSC-FRA-76-2
  • Report/Paper Numbers: DOT-TSC-OST-76-4 Final Rpt., FRA-OR&D-76-142
  • Contract Numbers: DOT-TSC-1016
  • Files: NTIS, TRIS, USDOT
  • Created Date: Jan 16 1977 12:00AM