AN ASSESSMENT OF THE CRASHWORTHINESS OF EXISTING URBAN RAIL VEHICLES Volume I: Analyses and Assessments of Vehicles Chapters 1 Through 7 R . J . Cassidy D . J . Romeo , Ql NOVEMBER 1975 FINAL REPORT DOCUMENT IS AVAILABLE TO THE PUBLIC THROUGH THE NATIONAL TECHNICAL INFORMATION SERVICE, SPRINGFIELD. VIRGINIA 22161 Prepared for U.S. DEPARTMENT OF TRANSPORTATION URBAN MASS TRANSPORTATION ADMINISTRATION Office of Research and Development Washington DC 20590 . NOTICE This document is disseminated under the sponsorship of the Department of Transportation in the interest of information exchange. The United States Govern- ment assumes no liability for its contents or use thereof NOTICE The United States Government does not endorse pro- ducts or manufacturers. Trade or manufacturers' names appear herein solely because they are con- sidered essential to the object of this report. 1 *I .457 fjO> Technical Report Documentation Page wr 1 . Report No. 3. Recipient’s Catalog No. fst' UMTA-MA-06-0025-7 5-16. 4. Title and Subtitle AN ASSESSMENT OF THE CRASHWORTHINESS OF 5. Report Date EXISTING URBAN RAIL VEHICLES. November 1975 —* CT ^ I ^ 6. Performing Organization Code f Volume I: Analyses and Assessments of Vehicles, V.l Chapters 1 Through 7 - 3. i i ^-e-f^e rTTmrg O-rg aril tJ t i u Report Nc 7. Authors) - 3- 0 R.J. Cassidy and D.J. Romeo DOT-TSC-UMTA-75-21.I 9. Performing Organization Name and Address 10. Work Unit No. (TRAIS) UM604/R6745 Calspan Corporation* 1 1 . Contract or Grant No. P.O. Box 235 DOT-TSC-681 Buffalo NY 14221 13. Type of Report and Period Covered 12. Sponsoring Agency Name and Address U.S. Department of Transportation Final Report Urban Mass Transportation Administration August 1973 - June 1975 Office of Research and Development 14. Sponsoring Agency Code Washington DC 20590 15. Supplementary Notes U.S. Department of Transportation, transportation Systems Center, *Under contract to: Kendall Square Cambridge. MA Q2142 16. Abstract The crashworthiness of existing urban rail vehicles (passenger cars) and the feasibility of improvements in this area were investigated by Calspan Corporation under contract to the Transportation Systems Center of the U.S. Department of Trans- tation in its role as systems manager for the Urban Mass Transportation Administra- tion's Urban Rail Supporting Technology Program. Both rail-car structural configur- ations and impact absorption devices were studied. From this work, recommendations for engineering standards for urban rail vehicles will be developed. This final report issued under the crashworthiness effort covers: 1. The development of analytical tools to predict passenger threat - environment during collision. 2 . Criteria for predicting passenger injury due to train collisions. 3. An application of injury criteria and analytic models to predict passengei injuries resulting from collisions of trains that represent existing construction types. 4. A preliminary investigation of applying impact absorption devices to transit vehicles. 5. A design study of car structural configurations for improved impact energy management. 6 A review of engineering standards for Urban Rail Car Crashworthiness. The report consists of three volumes: Volume I: Analyses and Assessments of Vehicles, Chapters 1 Through 7 Volume II: Analyses and Assessments of Vehicles, Chapters 8 Through 12, Appendixes and References O Volume III: Train Collision Model User's Manual. Pro 'Vi? 17. K ey Words 18. Distribution Statement i Railway Car Crashworthiness, Train THE PUBLIC Crashes, Transportation Safety, Mass DOCUMENT IS AVAILABLE TO THROUGH THE NATIONAL TECHNICAL Transit, Urban Rail Car, Rapid Transit INFORMATION SERVICE, SPRINGFIELD, Car, Crashworthiness, Commuter Rail Car VIRGINIA 22161 19. Security Classif. (of this report) 20. Security Classif. (of this page) 21. No. of Pages 22. Price Unclassified Unclassified 206 (8-72) Form DOT F 1700.7 Reproduction of completed page authorized PREFACE In support of the Rail Technology Division of the Office of Research and Development of the Urban Mass Transportation Administration (UMTA) , the Transportation Systems Center (TSC) has been assigned systems management responsibility for the UMTA Urban Rail System Supporting Technology Program. As part of this program, TSC is conducting analytical and experimental studies directed towards improved urban rail system safety. A specific goal in the area of safety is reduction of both the number and the severity of injuries that may result from the collision of two trains. On 16 August 1973, TSC contracted with Calspan Corporation to perform this study for the assessment of the crashworthiness of existing urban rail vehicles. This report presents a compilation of relevant background studies conducted prior to the start of this contract and an overall description of the work done during the course of this study conducted for the Rail Technology Division of the Urban Mass Transportation Administration under the TSC Urban Rail Supporting Technology Program. This report is being published in three volumes. Volume I contains analyses and assessments of vehicles, chapters 1 through 7. Volume II contains chapters 8 through 12, all appendixes, and all references. Volume III contains a Train Collision Model User's Manual. The authors take this opportunity to acknowledge the technical contributions to this report made by the program's technical monitor, Dr. Robert Raab of the Transportation Systems Center, U.S. Department of Transportation, Cambridge, Massachusetts; and by the Program Manager, Mr. Frederick Rutyna, also of Transportation Systems Center. The contributions of Mr. David J. Segal of Calspan Corporation are also recognized. Mr. Segal developed the computer program used for the analysis and applied this program to the many cases studied. iii TABLE OF CONTENTS Section Page 1. INTRODUCTION AND SUMMARY 1-1 1.1 Introduction 1-1 1.1.1 Background 1-1 1.1.2 Scope of Report 1-5 1.2 Summary 1-8 1.2.1 Train Crash Injury Criteria Development 1-8 1.2.2 Rail Car Crashworthiness Analyses 1-9 1.2.3 Cost Effectiveness of Structural Improvements 1-13 1.2.4 Specifications and Standards 1-16 2. MAJOR CONCLUSIONS AND RECOMMENDATIONS 2-1 2.1 Major Conclusions 2-1 2.2 Recommendations for Further Study 2-2 3. INJURY-PREDICTION METHODOLOGY FOR TRAIN CRASHES 3-1 3.1 Introduction 3-1 3.2 Present Injury Criteria and Their Applicability to Rail-Car Crashworthiness 3.3 Prediction of Impact Injuries 3-8 3.4 Prediction of Injuries in General Collision Environment 3-14 4. INTEGRATED TRAIN /OCCUPANT CRASH MODELING 4-1 4.1 Introduction 4-1 4.2 Model Description 4-1 4.2.1 Purpose and Overall Operation 4-1 4.2.2 Functioning 4-2 4.3 Application of Model 4-6 5. CHARACTERISTICS OF EXISTING RAILCARS 5-1 5.1 Selection of Representative Cars 5-1 5.2 Car Descriptions 5-7 5.2.1 Silverliner Car 5-7 5.2.2 R-33 Car 5-11 5.2.3 R-44 5-14 v TABLE OF CONTENTS (Cont.) Section Page 5.2.4 BART Car 5-16 5.2.5 Silverbird Car 5-20 5.3 General Crashworthiness Data 5-21 5.4 Generation of Car Structural Model 5-47 5.5 Force Versus Deflection Characteristics 5-50 5.6 Relationship Between Structural Crashworthiness and Generic Construction Types 5-60 5.7 Interior Characteristics 5-70 5.7.1 Silverliner 5-72 5.7.2 R-33 Car 5-73 5.7.3 R-44 Car 5-74 5.7.4 BART Car 5-74 5.7.5 Silverbird Car 5-75 6. STRUCTURAL AND INTERIOR INPUTS FOR COLLISION MODEL 6-1 6.1 Introduction 6-1 6.2 Generalized Inputs Representing Existing Car Construction 6-3 6.3 Inputs Representing Deviations from Existing Car Construction 6-6 7. RESULTS OF CRASH SIMULATIONS 7-1 VOLUME TWO 8. RAILCAR OVERRIDE 8-1 8.1 Introduction 8-1 8.2 Previous Collisions 8-2 8.3 Kinematics of Override 8-11 8.4 Initiation of Climbing Loads Between Cars of the Same Design 8-18 8.5 Climbing Conditions at Successively Severe Stages of the Collision 8-25 8.6 Elementary Override Model 8-31 8.7 Calculation of Override Forces and Motions 8-38 9. PRIORITY AREAS FOR THE DEVELOPMENT OF COST EFFECTIVE IMPROVED CAR STRUCTURES 9-1 9.1 Introduction 9-1 9.2 Relationship of Design Characteristics to Train Crashworthiness 9-2 9.3 Design Concepts 9-7 vi TABLE OF CONTENTS (Cont.) Section Page 9.3.1 Body Construction 9-7 9.3.2 Energy Absorbers 9-18 9.4 Approximate Weight and Cost Estimates of Design Concepts 9-26 9.4.1 General 9-26 9.4.2 Cost Methodology: Initial and Recurring Costs 9-27 9.4.3 Weight and Cost Estimates for Car Body Structural Additions 9-31 9.4.4 Weight and Cost Estimates for Energy Absorbers 9-33 10. PRELIMINARY DESIGN STUDY OF IMPACT ENERGY ABSORBING DEVICE 10-1 10.1 Introduction 10-1 10.2 Energy Absorption Potential 10-1 10.3 Design Investigation 10-10 11. COST EFFECTIVENESS OF STRUCTURAL IMPROVEMENTS 11-1 12. DEVELOPMENT OF UNIFORM STANDARDS 12-1 12.1 Introduction 12-1 12.2 Review of Existing Standards 12-1 12.3 Permanent Standards and Interim Standards 12-11 12.3.1 General Approach 12-11 12.3.2 Scope 12-11 12.3.3 Design Criteria 12-12 12.3.4 Applicability of Design Guidelines, Design Standards and Performance Standards 12-12 APPENDIX A. REVIEW OF INJURY CRITERIA DEFINED IN LITERATURE A-l APPENDIX B. REPORT OF INVENTIONS B-l REFERENCES R-l vii LIST OF FIGURES 3- Figure4- Page 3-15- Train Crash Dynamics 3-7 3-2 Flow Chart, Crash to Injury 3-9 3 Degree of Injury Severity 3-15 1 Simplified Schematic Diagram of Typical Train Configuration Modeled 4-4 1 Exterior of Silverliner Car 5-7 5-2 Interior of Silverliner Car 5-9 5-3 Changing Facing Direction of Silverliner Seats 5-10 5-4 Exterior of R-33 Car 5-11 5-5 Interior of R-33 Car 5-13 5-6 Exterior