SURVEY OF UPHILL SPEEDS OF TRUCKS ON MOUNTAIN GRADES

THE OBJECT IS TO PROVIDE DATA TO DETERMINE HOW FAR A HEAVY TRUCK WILL TRAVEL UP VARIOUS RATES OF GRADES BEFORE REACHING THE CRAWL SPEED. SEVEN TYPICAL FIELD LOCATIONS ON TRANSCONTINENTAL ROUTES WERE STUDIED WITH MOUNTAIN GRADES RANGING FROM PLUS 2 TO OVER PLUS 6 PERCENT. ELEVATIONS VARIED FROM SEA LEVEL TO 7200 FT. WHILE TRAFFIC VARIED FROM 1000 TO 3000 VEHICLES PER DAY. A COMPOSITE SPEED PERFORMANCE CHART WAS PLOTTED. IT WAS DETERMINED THAT ON A 6-PERCENT GRADE A HEAVILY LOADED TRUCK WILL LOSE SPEED AT 23 MPH PER THOUSAND FEET OF GRADE. A DISTANCE OF 1700 FT. IS REQUIRED TO REACH THE CRAWL SPEED OF 7 MPH FROM A LEVEL APPROACH SPEED OF 47 MPH. ALL OTHER COMMON GRADES ARE INCLUDED HERE. WITHIN THE SAME BRAKE HORSEPOWER TO GROSS VEHICLE WEIGHT, GROUP DIESEL AND BUTANE POWERED TRUCKS GAVE A SOMEWHAT BETTER SPEED PERFORMANCE THAN THE GASOLINE POWERED VEHICLES. DRIVER HABITS WERE ALSO FOUND TO INFLUENCE OPERATIONAL PERFORMANCE. NO DIFFERENCE IN SPEED WAS NOTED FOR TRUCKS OPERATING ON THE SAME PERCENT OF GRADE AT DIFFERENT LOCATIONS RANGING FROM SEA LEVEL TO 7200 FT. TRUCKS IN GOOD MECHANICAL CONDITION HAD NO TROUBLE WITH OVERHEATING. /AUTHOR/

  • Supplemental Notes:
    • Vol 29, pp 304-310, 2 FIG, 2 PHOT
  • Authors:
    • Willey, W E
  • Publication Date: 1950

Media Info

  • Monograph Title: Proceedings of the Twenty-Ninth Annual Meeting of the Highway Research Board Held at Washington, D.C. December 13-16, 1949.
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00223504
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Jul 25 1971 12:00AM