U.S. Department of Transportation Mixed Freight and Higher-Speed Passenger Trains: Federal Railroad Administration Framework for Superelevation Design Office of Research, Development and Technology Washington, DC 20590 DOT/FRA/ORD-19/42 Final Report October 2019 NOTICE This document is disseminated under the sponsorship of the Department of Transportation in the interest of information exchange. The United States Government assumes no liability for its contents or use thereof. Any opinions, findings and conclusions, or recommendations expressed in this material do not necessarily reflect the views or policies of the United States Government, nor does mention of trade names, commercial products, or organizations imply endorsement by the United States Government. The United States Government assumes no liability for the content or use of the material contained in this document. NOTICE The United States Government does not endorse products or manufacturers. Trade or manufacturers’ names appear herein solely because they are considered essential to the objective of this report. DOT is committed to ensuring that information is available in appropriate alternative formats to meet the requirements of persons who have a disability. If you require an alternative version of files provided in this report, please contact the COR listed in the Report Documentation Page. REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction Project (0704-0188), Washington, DC 20503. 1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE 3. REPORT TYPE AND DATES COVERED October 2019 Technical Report, September 2015 – May 2016 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS Mixed Freight and Higher-Speed Passenger Trains: Framework for Superelevation Design 6. AUTHOR(S) DTFR53-15-C-00023 Tyler Dick, Conrad Ruppert 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION University of Illinois at Urbana-Champaign REPORT NUMBER 205 North Mathews Avenue, MC-250 1245A Newmark Civil Engineering Laboratory Urbana, IL 61801 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSORING/MONITORING U.S. Department of Transportation AGENCY REPORT NUMBER Federal Railroad Administration Office of Railroad Policy and Development DOT/FRA/ORD-19/42 Office of Research, Development and Technology Washington, DC 20590 11. SUPPLEMENTARY NOTES COR: Cameron Stuart 12a. DISTRIBUTION/AVAILABILITY STATEMENT 12b. DISTRIBUTION CODE This document is available to the public through the FRA eLibrary. 13. ABSTRACT (Maximum 200 words) As the demand for higher-speed passenger trains increases, the disparity between freight and passenger operations also increases. On mixed-use rail corridors, the result is a bi-modal distribution of train speeds that complicates design of curve superelevation. To aid in making informed curve superelevation decisions on mixed-use rail corridors, this report synthesizes industry knowledge and tools used to evaluate curve superelevation. This report develops the superelevation bandwidth concept into a framework to optimize superelevation on mixed-use corridors. The framework is presented as both a graphical approach and a mathematical model that can be applied to select superelevation design parameters for multiple curves on a rail corridor. Five case studies illustrating typical design situations encountered in the development of mixed-use corridors are highlighted. Each case study demonstrates how the selection of actual superelevation results in trade-offs between the operation of slower trains with overbalance and imposing curve speed restrictions on faster trains. 14. SUBJECT TERMS 15. NUMBER OF PAGES Superelevation, high-speed rail, freight operations, passenger operations 65 16. PRICE CODE 17. SECURITY CLASSIFICATION 18. SECURITY CLASSIFICATION 19. SECURITY CLASSIFICATION 20. LIMITATION OF ABSTRACT OF REPORT OF THIS PAGE OF ABSTRACT Unclassified Unclassified Unclassified Contents Executive Summary ....................................................................................................................... iv 1. Introduction ................................................................................................................. 1 1.1 Background ................................................................................................................. 1 1.2 Objectives .................................................................................................................... 1 1.3 Overall Approach ........................................................................................................ 2 1.4 Scope ........................................................................................................................... 2 1.5 Organization of the Report .......................................................................................... 2 2. Physics of Superelevated Railway Curves .................................................................. 4 2.1 Basic Quasi-Static Curving Analysis .......................................................................... 4 2.2 Distribution of Lateral and Vertical Wheel Forces ..................................................... 6 2.3 Consideration of In-Train Forces on Ascending and Descending Grades .................. 8 2.4 Maintenance and Safety Considerations ................................................................... 15 3. Design Guidelines and Standards .............................................................................. 17 3.1 FRA Regulations and AREMA Recommended Practices ........................................ 17 3.2 Class I Freight Railway Standards ............................................................................ 18 3.3 Passenger and Commuter Standards ......................................................................... 21 3.4 Summary and Comparisons of U.S. Practice ............................................................ 25 3.5 International Practice ................................................................................................. 31 3.6 Other Practical Constraints ........................................................................................ 32 4. Selection of Superelevation for Multiple Train Speeds ............................................ 34 4.1 Difficulties in Handling Multiple Train Speeds ........................................................ 34 4.2 Running Time and Curve Speed Restrictions ........................................................... 35 4.3 Superelevation Bandwidth ........................................................................................ 36 4.4 Bandwidth and Distribution of Train Speeds: Graphical Approach ......................... 38 4.5 Superelevation Optimization Framework ................................................................. 38 5. Case Studies............................................................................................................... 42 5.1 Freight Corridor with Passenger Traffic ................................................................... 43 5.2 Freight Corridor with Advanced Passenger Trainset ................................................ 44 5.3 Freight Corridor with Higher-Speed Passenger Trains ............................................. 46 5.4 Higher-Speed Passenger Corridor with Local Freight Service ................................. 48 5.5 High-Speed Passenger Corridor with Local Freight Service .................................... 50 6. Summary.................................................................................................................... 53 6.1 Summary of Findings ................................................................................................ 53 6.2 Research Needs ......................................................................................................... 53 7. References ................................................................................................................. 55 Abbreviations and Acronyms ....................................................................................................... 58 i Illustrations Figure 1: Forces on rail vehicle at equilibrium condition produce resultant centripetal force ....... 5 Figure 2: Illustration of (a) forces acting on a rail vehicle while curving at different speeds and (b) vector force addition to produce required centripetal resultant for circular motion ......... 7 Figure 3: Variation in vertical and lateral wheel loads over a range of cant deficiency (a & c) and speed (b & d) for a 286,000 pound railcar on a 3-degree curve ............................................. 9 Figure 4: Influence in-train forces on required superelevation for (a) upgrade and (b) downgrade conditions at the same train speed ........................................................................................ 10 Figure 5: Variation