Investigation of Cracks in Acela Coach Car Brake Discs: Test and Analysis. Volume I – Final Report and Volume II – Appendices

In April 2005, visual and laboratory tests identified cracks in the spokes of several brake discs on coach cars within Amtrak's Acela trainsets, the high-speed trainsets operating on the Northeast Corridor. Amtrak decided to halt operations of the Acela fleet until an accurate assessment of the cracked spokes could be made. With the support of the Federal Railroad Administration, Amtrak working in conjunction with Northeast Corridor Maintenance Services Company, Bombardier, Alstom Transportation, the manufactures of the brake system, Knorr Brake Corporation, Faiveley Transport and Wabtec, launched an extensive test program. ENSCO, Inc. was given the responsibility of instrumentation, testing and analysis. The test program was comprised of a three-phase over-the-road test effort, finite element analyses, and a series of laboratory tests. Based on the testing performed and subsequent analysis, the conclusion of the test program is that the mechanical and thermal responses of the spokes of the Knorr-designed brake disc measured during testing with the Acela Express vehicles were within predicted and acceptable values. Although experiencing slightly lower thermal strains, the WABTEC/SAB-WABCO supplied brake disc experienced significantly higher mechanical strains at times. The lower mechanical strains observed in the Knorr designed brake disc, in comparison with those observed in the WABTEC/SAB-WABCO supplied brake disc, associated with the absence of sustained oscillations during braking and the response to vertical shocks are expected to provide a beneficial effect on the fatigue life associated with the Knorr brake disc design as well as a reduction in the likelihood of crack formation. The findings discussed in this report permitted Amtrak to arrive at an acceptable alternative that allowed the Acela equipment to return to service.


  • English

Media Info

  • Media Type: Web
  • Edition: Final Report
  • Features: Appendices; Figures; Photos; Tables;
  • Pagination: 878p

Subject/Index Terms

Filing Info

  • Accession Number: 01051570
  • Record Type: Publication
  • Report/Paper Numbers: ENSCO-DOT-FR-05-07
  • Files: NTL, TRIS, USDOT
  • Created Date: Jun 3 2007 8:01AM