Railway Track Inspection and Maintenance Scheduling For Addis Ababa Light Rail Transit Addis Ababa University Institute of Technology School of Civil and Environmental Engineering Railway Civil Engineering By: Kidus Matiwos Railway Track Inspection and Maintenance Scheduling For Addis Ababa Light Rail Transit. By: Kidus Matiwos A thesis submitted to the school of graduate studies, Addis Ababa University, At Addis Ababa Institute of Technology in partial fulfillment of the requirements for the degree of masters of Science in civil engineering. (Railway) August, 2016 Addis Ababa University Addis Ababa, Ethiopia CERTIFICATION I, the undersigned below, certify that I read and hereby recommend for the acceptance by the Addis Ababa University a dissertation entitled: Railway Track Inspection and Maintenance Scheduling for Addis Ababa Light Rail Transit: in partial fulfillment of a degree of Masters of Science in Railway Civil Engineering. Ato Matias Kabtamu Thesis Advisor Date: Railway Track Inspection and Maintenance Scheduling For Addis Ababa Light Rail Transit A Thesis submitted to the school of graduate studies, Addis Ababa University, At Addis Ababa Institute of Technology in partial fulfillment of the requirements for the degree of masters of Science in Railway civil engineering. Date defended: Members of Examining Board: 1. ---------------------------------------- ---------------------------- (Chairman) (Signature) 2. ---------------------------------------- ----------------------------- (Thesis Advisor) (Signature) 3. ---------------------------------------- ----------------------------- (Internal examiner) (Signature) 4. --------------------------------------- ----------------------------- (External examiner) (Signature) Declaration: Kidus Matiwos declares that this thesis titled; Railway Track Inspection and Maintenance Scheduling for Addis Ababa Light Rail Transit, is my original work. This thesis is my individual work and it has not been presented before for any other institute and I will not present it to any other university for similar or any other degree award. Signature Railway Track Inspection and Maintenance Scheduling for MSc Thesis, August 2016 Addis Ababa Light Rail Transit ABSTRACT Ethiopia has recently finished constructing the first Light Rail Transit (LRT), in the history of the country. Our new experience demands other pioneer countries’ huge experience on LRT track inspection methods, frequency and maintenance tolerance limits. In this study, different track safety standards, maintenance standards and best practices from the railroad industry are surveyed to keep the Addis Ababa LRT track performance satisfactory. Rail failures generally occur from fatigue cracks that form and grow in the rail steel as a result of cyclic forces caused by the repeated passage of train over the rails which may cause a train to derail. There are many sources that influence Track defects and failure. These effects include bending and shear stresses, wheel/rail contact stresses, thermal stresses, residual stresses and dynamic effects This study on scheduling inspection of railway track first addresses defects which affect the safe running of the railway. A list of the common defects which may be found whilst inspecting the permanent way are included. After defects are identified, prioritization are made based on their relative perceived urgency. To do that, inspection parameters are discussed with their tolerance limits compared in different railway manuals and standards. Then the unique features of AA LRT are described, such as its track specs, technical and rolling stock parameters. The effect of those unique features on track inspection are also explained. Finally, an optimum frequency of track inspection is provided for the Addis Ababa LRT considering the design and operational parameters of our new light rail and comparing it with other railway standards. It was found that, different railway agencies has different track maintenance tolerance limits and frequencies of inspection based on factors like track class, track material properties, service defect rate, defect experience and defect growth rate. But in the case of AA LRT, since it is a new railway line, defect experience and defect growth rate are not considered to calculate optimum frequency of inspection. Accordingly, fixed schedule are provided based on the most commonly used standards. Current track inspection methods, techniques and best practices in the railroad industry are covered in detail, including visual inspections, several automated and remote inspection options, so that the best inspection technology that suits the Addis Ababa LRT can be chosen to maintain a safe railway network. The cheapest and most efficient way is to catch problems before they get too large, and repair them before they cause a derailment. Inspection methods are chosen considering cost, efficiency, and availability with the specific conditions of the Addis Ababa LRT. KEY WORDS: Railway Inspection, Inspection parameters, Inspection Frequency, Maintenance Priority, Track Defects, Tolerance limits Addis Ababa University Institute of Technology School of Civil and Environmental Engineering i Railway Track Inspection and Maintenance Scheduling for MSc Thesis, August 2016 Addis Ababa Light Rail Transit ACKNOWLEDGMENT I would like to thank all the people who have made this thesis possible. First of all I want to thank Ethiopian Railway Corporation (ERC), for giving us this great opportunity to expand our knowledge on the railway engineering stream. I also must thank my classmates for their advice and on-time information regarding the thesis and their friend ship over the last years. Last but not least, I would like to thank my advisor, Ato Matias Kabtamu for his guidance throughout the project. Addis Ababa University Institute of Technology School of Civil and Environmental Engineering ii Railway Track Inspection and Maintenance Scheduling for MSc Thesis, August 2016 Addis Ababa Light Rail Transit TABLE OF CONTENTS ABSTRACT .................................................................................................................................................................... I ACKNOWLEDGMENT ................................................................................................................................................... II TABLE OF CONTENTS .................................................................................................................................................. III LIST OF TABLES ........................................................................................................................................................... V LIST OF FIGURES .......................................................................................................................................................... V ABBREVIATIONS ........................................................................................................................................................ VI TERMS AND DEFINITIONS ......................................................................................................................................... VII UNIT CONVERSION TABLE ........................................................................................................................................... X 1 INTRODUCTION .................................................................................................................................................. 1 1.1 BACKGROUND ....................................................................................................................................................... 1 1.2 STATEMENT OF THE PROBLEM .................................................................................................................................. 2 1.3 OBJECTIVE OF THE STUDY ........................................................................................................................................ 2 1.3.1 Main Objective .............................................................................................................................................. 2 1.3.2 Specific Objectives ......................................................................................................................................... 2 2 LITERATURE REVIEW .......................................................................................................................................... 3 2.1 INTRODUCTION ...................................................................................................................................................... 3 2.1.1 History of Track Inspection ........................................................................................................................... 3 2.1.2 Why periodic inspection and maintenance? ................................................................................................. 4 2.2 CURRENT TRACK INSPECTION PRACTICES AND TECHNOLOGIES ......................................................................................... 5 2.2.1 Visual Inspections.......................................................................................................................................... 5 2.2.2 Automated Inspection Systems ..................................................................................................................... 7 2.2.2.1 Internal Rail Inspection systems ..........................................................................................................................