U.S. Department of Transportation Track Buckling Prevention: Theory, Safety Federal Railroad Concepts, and Applications Administration Office of Research and Development Washington, D.C. 20590 Track Systems Safety DOT/FRA/ORD-13/16 Final Report This document is available to the March 2013 public through the National Technical Information Service, Springfield, VA 22161. This document is also available on the FRA Web site at www.fra.dot.gov. iii 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. ii Form Approved REPORT DOCUMENTATION PAGE 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 March 2013 Final Report 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS Track Buckling Prevention: Theory, Safety Concepts, and Applications RR219/R2011; RR319/RR3011; RR419/AB019 6. AUTHOR(S) Andrew Kish and Gopal Samavedam* 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER U.S. Department of Transportation Research and Innovative Technology Administration DDTS.020104 John A. Volpe National Transportation Systems Center Cambridge, MA 02142 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSORING/MONITORING AGENCY REPORT NUMBER U.S. Department of Transportation Federal Railroad Administration DOT/ FRA/ORD-13/16 1200 New Jersey Ave., SW Washington, DC 20590 11. SUPPLEMENTARY NOTES *Foster-Miller, Inc. 350 Second Avenue Waltham, MA 02451-1196 12a. DISTRIBUTION/AVAILABILITY STATEMENT 12b. DISTRIBUTION CODE This document is available to the public through the National Technical Information Service, Springfield, VA 22161 and on the FRA Web site at www.fra.dot.gov. 13. ABSTRACT (Maximum 200 words) This report is a part of the John A. Volpe National Transportation Systems Center’s Track Stability Research Program for the Federal Railroad Administration on thermal buckling of continuous welded rail (CWR) track and its prevention. Presented in this report are the developments of theoretical results and the development and application of the CWR-SAFE computer software model for prediction of CWR track buckling strength. This comprehensive predictive model encompasses several different modules designed to perform both deterministic and probabilistic buckling analyses, based on the dynamic buckling theory previously validated by tests, and predicts safe limits for buckling prevention. The model accounts for all the important parameters influencing track buckling, such as rail size, curvature, lateral resistance, tie- ballast friction, fastener torsional and longitudinal resistances, track vertical stiffness, misalignment amplitude and wavelength, and vehicle parameters. Applications of the model are demonstrated through analyses of parametric sensitivity, development of buckling safety limits in terms of safe and critical temperatures, and evaluation of annual probability of buckling occurrences for typical CWR line segments. The report also presents techniques to determine the input parameters for CWR-SAFE application and a practical methodology for CWR track safety monitoring. A risk-based approach is proposed to provide more flexibility to the industry in achieving a minimum number of annual buckles in a given territory and to provide science-based guidelines for improved slow order policies when operating at elevated rail temperatures. 14. SUBJECT TERMS 15. NUMBER OF PAGES 168 Track Buckling, Lateral Stability, CWR, Buckling Prevention, Buckling Models, CWR Safety and Maintenance, Neutral Temperature, Rail Temperature 16. PRICE CODE 17. SECURITY CLASSIFICATION OF 18. SECURITY CLASSIFICATION 19. SECURITY CLASSIFICATION 20. LIMITATION OF REPORT OF THIS PAGE OF ABSTRACT ABSTRACT Unclassified Unclassified Unclassified NSN 7540-01-280-5500 Standard Form 298 (Rev. 2-9) Prescribed by ANSI Std. 239-18 298-102 iii METRIC/ENGLISH CONVERSION FACTORS ENGLISH TO METRIC METRIC TO ENGLISH LENGTH (APPROXIMATE) LENGTH (APPROXIMATE) 1 inch (in) = 2.5 centimeters (cm) 1 millimeter (mm) = 0.04 inch (in) 1 foot (ft) = 30 centimeters (cm) 1 centimeter (cm) = 0.4 inch (in) 1 yard (yd) = 0.9 meter (m) 1 meter (m) = 3.3 feet (ft) 1 mile (mi) = 1.6 kilometers (km) 1 meter (m) = 1.1 yards (yd) 1 kilometer (km) = 0.6 mile (mi) AREA (APPROXIMATE) AREA (APPROXIMATE) 1 square inch (sq in, in2) = 6.5 square centimeters (cm2) 1 square centimeter (cm2) = 0.16 square inch (sq in, in2) 1 square foot (sq ft, ft2) = 0.09 square meter (m2) 1 square meter (m2) = 1.2 square yards (sq yd, yd2) 1 square yard (sq yd, yd2) = 0.8 square meter (m2) 1 square kilometer (km2) = 0.4 square mile (sq mi, mi2) 1 square mile (sq mi, mi2) = 2.6 square kilometers (km2) 10,000 square meters (m2) = 1 hectare (ha) = 2.5 acres 1 acre = 0.4 hectare (he) = 4,000 square meters (m2) MASS - WEIGHT (APPROXIMATE) MASS - WEIGHT (APPROXIMATE) 1 ounce (oz) = 28 grams (gm) 1 gram (gm) = 0.036 ounce (oz) 1 pound (lb) = 0.45 kilogram (kg) 1 kilogram (kg) = 2.2 pounds (lb) 1 short ton = 2,000 pounds (lb) = 0.9 tonne (t) 1 tonne (t) = 1,000 kilograms (kg) = 1.1 short tons VOLUME (APPROXIMATE) VOLUME (APPROXIMATE) 1 teaspoon (tsp) = 5 milliliters (ml) 1 milliliter (ml) = 0.03 fluid ounce (fl oz) 1 tablespoon (tbsp) = 15 milliliters (ml) 1 liter (l) = 2.1 pints (pt) 1 fluid ounce (fl oz) = 30 milliliters (ml) 1 liter (l) = 1.06 quarts (qt) 1 cup (c) = 0.24 liter (l) 1 liter (l) = 0.26 gallon (gal) 1 pint (pt) = 0.47 liter (l) 1 quart (qt) = 0.96 liter (l) 1 gallon (gal) = 3.8 liters (l) 1 cubic foot (cu ft, ft3) = 0.03 cubic meter (m3) 1 cubic meter (m3) = 36 cubic feet (cu ft, ft3) 1 cubic yard (cu yd, yd3) = 0.76 cubic meter (m3) 1 cubic meter (m3) = 1.3 cubic yards (cu yd, yd3) TEMPERATURE (EXACT) TEMPERATURE (EXACT) [(x-32)(5/9)] °F = y °C [(9/5) y + 32] °C = x °F QUICK INCH - CENTIMETER LENGTH CONVERSION 0 1 2 3 4 5 Inches Centimeters 0 1 2 3 4 5 6 7 8 9 10 11 12 13 QUICK FAHRENHEIT - CELSIUS TEMPERATURE CONVERSIO °F -40° -22° -4° 14° 32° 50° 68° 86° 104° 122° 140° 158° 176° 194° 212° °C -40° -30° -20° -10° 0° 10° 20° 30° 40° 50° 60° 70° 80° 90° 100° For more exact and or other conversion factors, see NIST Miscellaneous Publication 286, Units of Weights and Measures. Price $2.50 SD Catalog No. C13 10286 Updated 6/17/98 iv PREFACE This report provides a current state-of-the-art understanding of continuous welded rail (CWR) response and behavior and its impact on track safety and performance. The report is based on U.S. research over the past 20 years, including the development of versatile computer analysis software called CWR-SAFE. CWR-SAFE is a product of Volpe Center, Foster-Miller, Inc. (FMI), and Federal Railroad Administration (FRA) research under the latter’s Track and Structures Program initiatives in line with the FRA’s Five-Year Strategic Plan for Railroad Research, Development, and Demonstration (2002). The work reported herein was performed with the support of FMI under Contract DTRS-57-99-D-0003, Task Order #14, under the technical direction of Dr. Andrew Kish of the US Department of Transportation’s Volpe Center and FMI’s Project Manager and Principal Investigator, Dr. Gopal Samavedam. The FRA sponsor was Dr. Magdy El-Sibaie of the Office of Research & Development, whose assistance and support is greatly acknowledged. Additional thanks also go to Mr. Wesley Mui of the Volpe Center for performing the CWR-SAFE parametric studies. The report is intended to synthesize into one reference volume the various CWR relevant research results obtained at different periods during a 20-year program duration. The report covers the following research items performed from 1984 to 2004: • Development of vehicle induced (dynamic) buckling theory for the determination of critical conditions leading to track buckling • Identification and determination of track and vehicle parameters in the theory • Development of a versatile computer software (CWR-SAFE) for application of the theory • Parametric analyses of track buckling • Development of buckling safety limits • Tests to validate the theory and safety limits • Determination of annual probability of buckling estimates for typical