Field studies were conducted of forty-three rubber-tired scrapers of various types and sizes on eleven separate highway construction projects in order to determine the productive capabilities of the machines under various conditions. Supplementary pusher studies were also conducted to aid in evaluating the scraper operations. The types of scrapers studied included standard, elevating, twin-engine and push-pull (tandem). Heaped capacities of the machines studied ranged in size from 20 cubic yards (15 cubic metres) to 54 cubic yards (41 cubic metres). The materials excavated were categorized as either common earth or rock. Haul roads were classified according to overall condition and to percent of grade. Productive work time averaged 69 percent of the Total Work Time Studied (TWTS). The various components of the productive cycle were isolated and analyzed. The scraper "wait for pusher time," the largest minor delay type, was analyzed separately from the remaining minor delays. The amount of scraper wait for pusher time was found to be largely dependent upon the ratio of scrapers to pushers and the overall scraper productive cycle time. Repairs to the scraper units were by far the most time-consuming and frequently occurring type of major delay. Shutdown delays, delays where the work force was dismissed or transferred to another operation, accounted for approximately 75 percent of all major delays. In order to enable a contractor to analyze his own operations, a scraper field data collection sheet--along with an efficiency study form and a descripition of its has been included.

  • Corporate Authors:

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Authors:
    • Clemmens, J P
    • DIllman, R J
  • Publication Date: 0

Media Info

  • Features: Appendices; Figures; Tables;
  • Pagination: 72 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00158152
  • Record Type: Publication
  • Report/Paper Numbers: FHWA DP-PC-920 Final Rpt.
  • Files: TRIS, USDOT
  • Created Date: Dec 8 1977 12:00AM