The problem of car roll becomes more acute as the height of the center of gravity of the car body and lading is increased by greater car heights; and as car lengths are increased to the extent that the distance between truck centers approximates a standard rail length. While severe car roll is objectionable the most serious immediate consequences are wheel lift and resultant derailments. Commulative roll can develop very quickly to cause wheel lift. With rail joints 3/4-inch low, wheel lift can develop in four rail lengths at critical speed. Wheel lift can also be obtained on track with joints only 3/8-inch to 1/2-inch low if the joint stagger is midway and uniform, all joints are equally low, and the critical speed is maintained for about ten rail lengths. Fortunately, only a small percentage of wheel lifts result in derailments. When car roll is severe enough to cause wheel lift, there is a sizeable lateral force in the direction of the wheels staying on the rail, so that on tangent track, the wheels that are lifted simply come back down on the rail. In addition to the derailment hazard possibility there will be an increase in fatigue failures of journals, wheels and rail near joints as the result of the repeated high wheel loads being sustained due to severe rolling of heavier cars on track with less-than-perfect rail joint conditions.

  • Corporate Authors:

    Symington Wayne Corporation

    2 Main Street
    Depew, NY  United States 
  • Authors:
    • SCOTT, H L
  • Publication Date: 1965-9-23

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00037718
  • Record Type: Publication
  • Report/Paper Numbers: Tech Proc
  • Files: TRIS
  • Created Date: Jul 8 1994 12:00AM