HILL-CLIMBING ABILITY OF MOTOR TRUCKS

ACTUAL GRADE TESTS, THE MOST IMPORTANT PART OF THE NEW TRUCK PHASE, WERE MADE ON 30 NEW TRUCK CHASSIS. THE RESULTS SHOWED THAT FOR MOTOR TRUCKS EVEN TO APPROACH REASONABLE SPEEDS ON GRADES THAT: GRADES MUST BE REDUCED TO 3 PERCENT OR LESS; OR ENGINE POWER MUST BE MORE THAN DOUBLED; OR GROSS VEHICLE WEIGHTS MUST BE REDUCED EXCESSIVELY; OR SOME COMBINATION OF THE THREE MUST BE USED THAT WILL STILL BE COSTLY TO ALL INTERESTS INVOLVED AND PRACTICALLY IMPOSSIBLE OF IMMEDIATE APPLICATION. DECELERATION TESTS WERE MADE ON EACH NEW TRUCK TO DETERMINE THE COEFFICIENTS OF TRACTIVE RESISTANCE. THE MOST SIGNIFICANT FACT WAS THAT NOT ONLY THE TOTAL TRACTIVE RESISTANCE BUT ALSO THE UNIT RESISTANCE IN POUNDS PER 1,000 LB. VARIED APPRECIABLY WITH WEIGHT. THE EFFICIENCY OF THE TRANSMISSION OF POWER WAS ALSO DETERMINED FOR EACH NEW VEHICLE FROM THE RESULTS OF THE ACTUAL GRADE TESTS. THE EVALUATION OF THESE TWO FACTORS MAKES IT POSSIBLE TO COMPUTE THE PERFORMANCE OF A MOTOR TRUCK FROM ITS SPECIFIED CHARACTERISTICS WITH A FAIR DEGREE OF ACCURACY. THE RESULTS OF THE ACTUAL GRADE TESTS WERE ALSO USED TO DETERMINE THE WORTH OF CHEAPER AND SHORTER METHODS FOR DETERMINING THE GRADE ABILITY OF MOTOR TRUCKS. THE ACCELERATION METHOD PROVED TO BE THE MOST SATISFACTORY AND WAS ADOPTED FOR USE ON THE USED-TRUCK PHASE. /AUTHOR/

  • Supplemental Notes:
    • Vol 21, pp 393-407, 11 FIG, 3 TAB
  • Authors:
    • SAAL, C C
    • Lay, W E
    • Thompson, J T
    • Agg, T R
  • Publication Date: 1942

Media Info

  • Monograph Title: Proceedings of the Twenty-First Annual Meeting of the Highway Research Board Held at the Johns Hopkins University, Baltimore, Maryland, December 2-5, 1941
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00223490
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Aug 29 1971 12:00AM