ACOUSTICS STUDIES REPORT NO 8

THE PRINCIPLE SOURCES OF NOISE IN TRANSIT CAR OPERATION ARE THE WHEELS AND THE RAILS, FOLLOWED BY THE PROPULSION SYSTEM AND THE AUXILIARY CAR. TESTS WERE CONDUCTED FOR BART TO DETERMINE MEANS FOR REDUCING AND CONTROLLING NOISE AND VIBRATION FROM THESE SOURCES THROUGH THE USE OF NEW CONCEPTS OF NOISE AND VIBRATION CONTROL, SUCH AS SOUND BARRIER WALLS ALONG THE RIGHT-OF-WAY, WHEEL DAMPING, RAIL DAMPING, AND RAIL FASTENERS WITH VIBRATION AND NOISE-REDUCTION FEATURES. TWO AERIAL STRUCTURES THAT WERE TESTED---A SOLID CONCRETE AND A COMPOSITE CONCRETE-STEEL---EXHIBITED VERY SIMILAR NOISE-REDUCING CHARACTERISTICS. RAIL FASTENERS WITH RESILIENT PADS, IN COMPARISON WITH OTHER RESILIENT FASTENERS, DO NOT PRODUCE ANY SIGNIFICANT REDUCTION IN WAYSIDE NOISE OR VIBRATION LEVEL. ON THE OTHER HAND, TECHNIQUES TESTED ON DAMPED WHEELS SHOW THAT WHEEL SQUEAL LOUNDNESS CAN BE SIGNIFICANTLY REDUCED; HOWEVER, WHEEL DAMPING PROVIDES INSIGNIFICANT NOISE REDUCTION ON TANGENT TRACK. ALSO, AS LEARNED, SOUND BARRIER WALLS CAN PROVIDE A SUBJECTIVE REDUCTION OF 50%, OR MORE, IN TRANSIT CAR WAYSIDE NOISE. /UMTA/

  • Supplemental Notes:
    • PROJ NO CAL-MTD-2
  • Corporate Authors:

    Parsons, Brinckerhoff-Tudor-Bechtel

    814 Mission Street
    San Francisco, CA  United States  94103
  • Publication Date: 1968-6

Subject/Index Terms

Filing Info

  • Accession Number: 00242172
  • Record Type: Publication
  • Source Agency: Urban Mass Transportation Administration
  • Files: TRIS, USDOT
  • Created Date: Feb 23 1973 12:00AM