ADHESION CHARACTERISTICS

THE PHENOMENON OF ADHESION IS DISCUSSED AS IT APPLIES TO THE THEORETICAL AND OPERATIONAL PERFORMANCE OF RAILWAY WHEELS IN CONTACT WITH RAIL. A SERIES OF COMPREHENSIVE ADHESION STUDIES WERE CONDUCTED AS PART OF THE DEMONSTRATION PROGRAM OF THE BAY AREA RAPID TRANSIT (BART) DIABLO TEST TRACK IN CONCORD, CALIFORNIA. THE TEST WORK WAS CONDUCTED TO ESTABLISH THE ADHESION LIMITS ANTICIPATED ON THE BART SYSTEM, TAKING INTO CONSIDERATION SIGNIFICANT VARIABLES, AND TO PROVIDE A GENERAL SOURCE OF ADHESION DATA FOR THE TRANSIT INDUSTRY. ADHESION REFERS TO THE TANGENTIAL FRICTION FORCE DEVELOPED AT THE WHEEL-TO-RAIL CONTACT AREA WHICH IS ACTIVE DURING ACCELERATION, DECELERATION, AND MAINTENANCE OF TRAIN SPEED. THE RATIO BETWEEN THE ADHESION FORCE AND THE NORMAL LOAD TRANSMITTED BY THE WHEEL TO THE RAIL IS CALLED THE COEFFICIENT OF ADHESION (ANALOGOUS TO COEFFICIENT OF FRICTION). THE PREDICTED ADHESION FOR THE BART SYSTEM, BASED ON TEST TRACT MEASUREMENTS, IS SUFFICIENT TO WARRANT DESIGN CRITERIA BASED ON FULL TRACTION CAPABILITIES OF 3.0 MPHPS IN ACCELERATION AND 2.7 MPHPS IN BRAKING. ADHESIONS TESTS GIVE DESIGN EMPHASIS TO THE FOLLOWING AREAS: EQUALIZATION OF WHEEL LOAD WITH RESPECT TO TRUCK AND CAR SUSPENSION, DEVELOPMENT OF SLIP-SPIN DETECTION AND CONTROL EQUIPMENT, AND DESIGN OF PROPULSION AND BREAKING EQUIPMENT FOR JERK-FREE APPLICATION OF TRACTION TORQUE.

  • Supplemental Notes:
    • Tr 9, 176 PP, 36 FIG, 12 TAB, 7 REF, 1 APP
  • Corporate Authors:

    San Francisco Bay Area Rapid Transit District

    P.O. Box 12688
    Oakland, CA  United States  94604-2688
  • Publication Date: 1968-8

Subject/Index Terms

Filing Info

  • Accession Number: 00241146
  • Record Type: Publication
  • Files: TRIS
  • Created Date: May 26 1994 12:00AM