This report provides the rationale for selecting a final set of noise treatments for the Freightliner Quieted Truck, describes the salient features of the treatments, and presents the noise and performance characteristics of that truck prior to its entering a one-year field test. Using the results of noise level vs. cost optimization study and having the objective of field-testing some innovative noise-control techniques, we built a truck with many minor treatments and the following principal features: a partial engine enclosure lined with sound-absorptive material, a manifold muffler, two-stage engine mounts, and a thermostatically controlled fan. The final truck configuration was 16 dB(A) quieter than contemporary units (generating 72 dB(A) when measured according to the SAE J366b Recommended Practice), obtained 15 to 20% better fuel economy, but had a slightly inferior cooling index.

  • Supplemental Notes:
    • Prepared in cooperation with Freightliner Corp., Portland, Oreg. See also PB-240 010.
  • Corporate Authors:

    Bolt, Beranek and Newman, Incorporated

    50 Moulton Street
    Cambridge, MA  United States  02138

    Office of Noise Abatement

    400 7th Street, SW
    Washington, DC  United States  20590

    Freightliner Corporation

    2525 SW Third Avenue
    Portland, OR  United States  97201
  • Authors:
    • Kaye, M C
    • BENDER, E K
  • Publication Date: 1974-10

Media Info

  • Pagination: 65 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00090417
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: 6
  • Files: NTIS, TRIS
  • Created Date: May 29 1975 12:00AM