Presentation on theme: "Prepared by: Lawrence G. Lovejoy, P.E."— Presentation transcript:
1Prepared by: Lawrence G. Lovejoy, P.E. FINAL REPORT TCRP Project D-14 [Report 155] - Track Design Handbook for Light Rail Transit 2nd EditionPrepared by: Lawrence G. Lovejoy, P.E.
2TCRP Report 57 Updating Required Over a decade since original publicationDoesn’t reflect other TCRP research since thenStreetcar issues not coveredConstruction & Maintenance not covered in a comprehensive way.
3The D-14 Project Research Team Parsons BrinckerhoffWilson Ihrig & AssociatesMetro Tech ConsultingTrack Guy Consultants
5Changes From Report 57 Chapter 1 – GENERAL INTRODUCTION Increased focus on who the Handbook user isand how he/she fits within an LRT project.Expansion of the definition of what LRT is.Chapter 2 – LIGHT RAIL TRANSIT VEHICLESUpdated discussions about characteristics ofcontemporary LRVs and StreetcarsAdded and in-depth discussion of how toselect an appropriate wheel profile.
6Changes From Report 57 Chapter 3 – LRT TRACK GEOMETRY New discussion provided explaining therelationships between lateral acceleration,unbalance and the jerk rateExpanded discussion concerning track crossleveland limitations on twist in tangent track.Expanded discussion of alignment of freighttracks and shared LRT/Freight tracks.New article on issues where LRT shares acorridor (but not tracks) with a freight carrier
7Changes From Report 57 Chapter 4 – TRACK STRUCTURE DESIGN The entire discussion about Nytram plots,Filkins-Wharton diagrams and related issuesrestructured to introduce basic concepts andbackground information first and only thendevelop the explanation of the methodology.Discussions about restraining rails and theirapplication has been greatly restructured andexpanded with reference to TCRP D-7 project.
9Changes From Report 57 Chapter 6 – SPECIAL TRACKWORK Expanded discussion on types of frogs includingflangebearing and jump frog designs.Revised/expanded discussion on selection ofturnout size.Revised and expanded discussion on switches,including those for embedded track.
10Changes From Report 57 Chapter 7 – STRUCTURES & BRIDGES Rewrote discussions of various types ofLRT structures and how they work.Entirely new discussion on structurescarrying embedded track.Entirely new discussion on open deckstructures and retrofitting existinghighway bridges to carry LRT track.
11Changes From Report 57 Chapter 8 – CORROSION CONTROL Miscellaneous revisions emphasizing inter-disciplinary coordination issues.Chapter 9 NOISE & VIBRATION CONTROLGreatly expanded with extensive text revisions addressing salient issues including wheel/rail contact mechanics. Extensive new graphics.
12Changes From Report 57 Chapter 10 – TRANSIT SIGNAL WORK New text on embedded switch machines.Expanded text on rail bonding for signal andpower current, including reference to TCRPD-7 workChapter 11 – TRANSIT TRACTION POWERExpanded discussion on how track alignmentaffects OCS design..
13New Chapters for 2nd Edition Chapter 12 – LRT TRACK IN MIXED TRAFFICEntirely new chapter with emphasis on trackalignment for streetcar style operations.Chapter 13 – LRT TRACK CONSTRUCTIONEntirely new chapter with emphasis on howLRT tracks of all types are actually built.Chapter 14 – LRT TRACK MAINTENANCELRT track maintenance is typically organizedand how it can be directly affected bydesign decisions..
14Reversed Metric vs. US Traditional Measurement Units Changes From Report 57Reversed Metric vs. US Traditional Measurement UnitsReport 57 was prepared under the old MetrificationPolicy.Second Edition reverses the priority of SI vs. USTraditional units of measurementUS units now first, with SI units [in brackets]EXCEPTION:When the dimension being discussed is metric inorigin (principally for manufactured products) theSI units are listed first followed by a softtranslation to US Traditional Units.
15Challenges that Remain #1:How can we keep the Track Design Handbook for Light Rail Transitup-to-date?
16For questions concerning this presentation or for further information / assistance contact: Lawrence G. Lovejoy, P.E. Senior Supervising Engineer / Professional Associate Parsons Brinckerhoff Four Gateway Center, Suite 1305 Pittsburgh, PA USA Direct line: Cel phone: