THE EFFECT OF UNIT TRAINS ON STRESS OCCURRENCES IN A CHICAGO AND NORTH WESTERN RAILWAY BRIDGE

This report contains a description and analysis of data obtained on the stringers and floor beams of a Chicago and North Western railway bridge to determine the frequency of occurrence of maximum stresses in these short span bridge elements which carry unit trains as well as regular service freight trains. The results may be summarized as follows: Track without rail Joint: 1. The frequency of occurrence of maximum stress was in the range of 3.0 to 4.0 ksi in the stringers and the floor beam under the combined loading of unit trains and regular service freights and was on the order of 2 to 9 percent of the total occurrence respectively. 2. The loaded unit trains comprised 5 percent of the total cars recorded and produced 46 percent of the maximum stress occurrences greater than 3 ksi in the floor beam and 7 percent in the stringers respectively. Track with Rail Joint: 1. The frequency of occurrence of maximum stress under combined loading of unit trains and regular service freights was on the order of 4 percent for the floor beam and 1 to 3 percent for the stringers of the total occurrence.

  • Supplemental Notes:
    • Conducted under sponsorship of AREA Committee 30 - Impact and Bridge Stresses.
  • Corporate Authors:

    Association of American Railroads Research Center

    3140 South Federal Street
    Chicago, IL  United States  60616
  • Publication Date: 1969-6

Media Info

  • Features: Figures; Tables;
  • Pagination: 12 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00097265
  • Record Type: Publication
  • Source Agency: Association of American Railroads
  • Report/Paper Numbers: ER-87
  • Files: TRIS
  • Created Date: Jul 29 1976 12:00AM