F O R E W O R D
By Stephan A. Parker Staff Officer Transportation Research Board
TCRP Report 155: Track Design Handbook for Light Rail Transit, Second Edition provides Edition provides guidelines and descriptions for the design of various common types of light rail transit (LRT) track. The track structure types include ballasted balla sted track, direct fixation (“ballastless”) track, and embedded track. The components of the various track types are discussed in detail. The guidelines consider the characteristics and interfaces of vehicle wheels and rail, tracks and wheel gauges, rail sections, alignments, speeds, and track moduli. The Handbook includes chapters on vehicles, alignment, track structures, track components, special trackwork, aerial structures/bridges, corrosion control, noise and vibration, signals, traction power, and the integration of LRT track into urban streets. These chapters provide insight into other systems that impact the track design and require interface coordination. In addition, the Handbook includes chapters on the construction and maintenance of LRT trackwork. This Handbook will be of interest to designers, operators, manufacturers, and those maintaining LRT systems.
In the research effort led by Parsons Brinckerhoff, Brinckerhoff, Inc., the research team collected over 500 documents related to the topic through literature searches and contacts with professional colleagues, agencies, and the industry. The collected information was uploaded to a project collaboration website. Site visits were made to the San Francisco Municipal Railway and the two LRT systems in Germany. In addition, numerous contacts were made by phone or e-mail with operating agency LRT personnel. The primary focus of the first phase of work was to identify opportunities to improve on the first edition of the Handbook (published in 2000 as TCRP Report 57 ), ), collect and analyze information addressing those opportunities, and identify an action plan for the revised Handbook. The second phase was concerned with the production of the revised Handbook, incorporating the findings of the first phase and an d including such additional investigations as might be required, plus the production of a final report documenting all efforts. This Handbook and a PowerPoint presentation describing the entire project are a vailable on the TRB website at http://www.trb.org/Main/Blurbs/166970.aspx.
AUTHOR ACKNOWLEDGMENTS
The research for and development of the Track Design Handbook for Light Rail Transit, Second Edition, was performed under TCRP Project D-14 by a team including PB Americas, Inc. (also known as Parsons Brinckerhoff or PB), Wilson, Ihrig & Associates, Inc. (WIA), Metro Tech Consulting Services, Engineering & Architecture, P.C. (MT), and Track Guy Consultants (TGC). Parsons Brinckerhoff Brinckerhoff was the prime contractorr and Lawrence G. Lovejoy, P.E., was the principal investigator. Subcontractor responsibilities contracto responsibilities included the following: • Vehicle issues were addressed by Metro Metro Tech. Tech. • Noise and vibration investigations investigations were done by Wilson, Ihrig & Associates. • LRT track construction and and maintenance topics were were addressed by Track Guy Consultants.
While all members of the team contributed to virtually all of the individual chapters, the principal and secondary authors of each of the Handbook chapters (and their affiliations) were as follows: Chapter 1 Chapter 2 Chapterr 3 Chapte Chapter 4 Chapter 5 Chapter 6 Chapter 7 Chapter 8 Chapter 9 Chapter 10 Chapter 11 Chapter 12 Chapter 13 Chapter 14
General Introduction: Lawrence G. Lovejoy, P.E. (PB) Light Rail Transit Vehicles: Stelian Canjea (MT) and Lawrence G. Lovejoy, P.E. Light Rail Transit Track Geometry: Lawrence G. Lovejoy, P.E., and Gordon W. Martyn (PB) Track Structure Design: Gordon W. Martyn, Thomas R. Carroll, P.E., and Lawrence G. Lovejoy, P.E. Track Components and Materials: Gordon W. Martyn and Lawrence G. Lovejoy, P.E. Special Trackwork: Lawrence G. Lovejoy, P.E., and Gordon W. Martyn Structures and Bridges: David A. Charters, P.E. (PB) and Jason Doughty, P.E. (PB) Corrosion Control: Geradino A. Pete, P.E. (PB), Herbert S. Zwilling, P.E. (PB), and Lawrence G. Lovejoy, P.E. Noise and Vibration Control: James T. Nelson, P.E. (WIA) Transit Signal Work: Harvey Glickenstein, P.E. (PB), Gary E. Milanowski, P.E. (PB), Thomas R. Carroll, P.E., and Lawrence G. Lovejoy, P.E. Transit Traction Power: Herbert S. Zwilling, P.E., and Lawrence G. Lovejoy, P.E. LRT Track in Mixed Traffic: Jack W. Boorse, P.E., P.L.S. (PB), and Lawrence G. Lovejoy, P.E LRT Track Construction: John Zuspan (TGC) and Lawrence G. Lovejoy, P.E. LRT Track and Trackway Maintenance: John Zuspan and Lawrence G. Lovejoy, P.E.
Technical editing of all chapters was performed by Lawrence G. Lovejoy, P.E. Technical The authors of this second edition would be remiss if we did not recognize the extensive work performed by the team that wrote TCRP Report 57, the first edition of the Track Design Handbook for Light Rail Transit, which was also prepared by Parsons Brinckerhoff under TCRP Project D-6 and published in 2000. Those persons included, in addition to many of the gentlemen named above, Eugene G. Allen, Harold B. Henderson, Theodore C. Blaschke, Lee Roy Padgett, Kenneth J. Moody, Kenneth Addison, Laurence E. Daniels, Alan C. Boone, and Charles G. Mendell.
C O N T E N T S
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Chapter 1 General Introduction
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Chapter 2 Light Rail Rail Transit Vehicles
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Chapter 3 Light Rail Transit Track Geometry
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Chapter 4 Track Structure Design
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Chapter 5 Track Components Components and and Materials
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Chapter 6 Special Trackwork
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Chapter 7 Structures and Bridges
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Chapter 8 Corrosion Control
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Chapter 9 Noise and and Vibration Control
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Chapter 10 Transit Signal Work
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Chapter 11 Transit Traction Power
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Chapter 12 LRT Track in Mixed Traffic
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Chapter 13 LRT Track Construction
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Chapter 14 LRT Track and Trackway Trackway Maintenance
Chapter 1—General Introduction Table of Contents CHAPTER 1—GENERAL INTRODUCTION 1.1 Introduction 1.1.1 Background
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1.1.2 Purpose and Goals of the Handbook 1.1.3 The Handbook User What Is Light Rail? 1.2.1 Background 1.2.2 Light Rail Defined 1.2.3 Light Rail as a Spectrum 1.2.4 Where the Rails and Wheels Meet the Road 1.2.5 The Regulatory Environment Handbook Organization Units of Measurement The Endmark
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CHAPTER 1—GENERAL INTRODUCTION 1.1 INTRODUCTION The purpose of this Handbook is to provide those responsible for the design, procurement, construction, maintenance, and operation of light rail transit (LRT) systems an up-to-date guide for the design of light rail track, based on an understanding of the relationship of light rail track and other transit system components. While this Handbook’s title implies implies that it pertains only to light rail transit, individual principles discussed herein are applicable to a wide spectrum of railway operations ranging from low-speed streetcars operating in city streets up through metro rail and heavy rail transit lines in in exclusive grade separated separated guideways. guideways. Some basic basic principles principles are are universal, and designers of freight and passenger railroad systems will, upon perusal of the Handbook, likely also also find chapters and articles articles of universal interest. interest. The contents contents of the Handbook were compiled as a result of an investigation of light rail transit systems, a review of literature pertaining to transit and railroad standards and methods, and personal hands-on experience of the authors. Current research also has been a source of valuable data. 1.1.1 Background This second edition of the Track the Track Design Handbook for Light Rail Transit builds Transit builds upon the first edition, which is also known as TCRP Report 57 . TCRP Report 57 , published in 2000, was the culmination of the TCRP Project Project D-6, which was initiated in 1995. TCRP Project Project D-6 came about because there was seemingly no consistency in the track design used on those North American light rail transit projects that had been initiated in the 1980s and early 1990s. While much research resea rch had been conducted in an effort to understand the mechanisms involved in track-rail vehicle interaction and its impact on track design, no widely accepted guidelines existed to specifically aid in the design and maintenance of light rail rail transit track. Other than the recomm recommended ended practices of what was then called the American Railway Engineering Association (AREA), there was no up-to-date and commonly accepted resource of track design information to which a North American Ameri can light rail transi transitt designe designerr could refer. Since AREA was primar primarily ily focuse focused d on freigh freightt railroads and since information on possibly more applicable design practices overseas was difficult to obtain and often unavailable in the English language, many light rail transit projects were designed using a hodgepodge of criteria, drawn from widely disparate sources. Light rail transit trans it designers had little choice other than to rely on practices developed primarily for heavy rail transit and railroad freight operations that are not necessarily necessarily well suited for light rail systems. The result result was design criteria that were often internally inconsistent. Moreover, many of those projects, once they had been built, had appreciable maintenance issues due to fundamental inconsistencies between their track designs and the vehicles that were using them. TCRP Report 57 altered altered the field by providing a single source of information, and it was immediately accepted as an authoritative resource. It is upon that foundation that this Second Edition is built. built. 1.1.2 Purpose and Goals Goals of the Handbook Handbook The purpose of this Handbook is to offer a range of design guidelines, not to set a universal standard for an industry that operates in a wide range of environments. The Handbook furnishes
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Track Design Handbook for Light Rail Transit, Second Edition
the reader with current practical guidelines and procedures for the design of the various types of light rail track—including ballasted, direct fixation, and embedded track systems—and offers choices concerning concerning the many issues that must must be resolved during the design design process. It discusses the interrelationships among the various disciplines associated with light rail transit engineering—structures, traction power, stray current control, noise and vibration control, signaling, and electric electric traction power. It also describes the impacts impacts of these other disciplines on trackwork and offers the track designer insights into the requisite coordination efforts between all disciplines. A key focus of the Handbook is to differentiate between light rail transit track and those similar, but subtly different, track systems used for freight, commuter, and heavy rail transit operations. These differences present challenges both to light rail track designers and to the designers and manufacturers of light rail vehicles. There will always be some indeterminacy in the engineering mechanics of light rail transit trackwork because the system system is dynamic and functions functions in the real world. world. LRT track is subject not only to the vagaries of wear and tear but also to the realities of funding for maintenance in a highly politicized politicized environment. Therefore, while while perfection can and should be strived for— particularly during initial construction, when funding is easier to obtain—it can never be achieved. It should also be noted that trackwork for all types of railways traces its heritage back to animalpowered colliery tramways tramways of the late 18th century. century. The fundamental design principles principles that were then selected for those then-new “rail roads” constrain constrain what is practical to achieve achieve now. Some problems of the rail/wheel interface will likely be forever intractable because of decisions made over two centuries ago. Hence, maintenance-free track for a light rail system is not plausible. 1.1.3 The Handbook User
The user of the Handbook assumes all risks and responsibilities for selection, design, and construction to the guidelines recommended recommended herein. No warranties are provided to the user, user, either expressed or implied. The data and discussions discussions presented herein are are for informational informational purposes only. The reader is assumed to be a degreed civil engineer or similarly qualified individual who is generally familiar with trackwork terminology and experienced in the application of guideline information to design. For that reason, a glossary of terms that would be familiar familiar to a trackwork engineer engine er has not been included includ ed herein. Definitions of common trackwork terms terms are included in the Manual for Railway Engineering , published by the American Railway Engineering & Maintenanceof-Way Association (AREMA). (AREMA). Terms that are unique to light rail transit are defined within the the text of the Handbook as they are introduced. Design and construction of light light rail transit projects is a multidisciplinary multidisciplinary effort. effort. The reader is presumed to be the person on the project who is responsible not only for the design and specification of trackwork trackwork hardware, but also for the design of the track alignment. However, LRT projects are not only only multidisciplinary, multidisciplinary, they are interdisciplinary. interdisciplinary. It is not possible possible for any one individual to work separately from the other disciplines.
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