South Station Expansion Project Appendix 2 - Track Configuration Alternatives Analysis - Tier 1 Screening Technical Report October 2014 Track Configuration Alternatives Analysis – Tier 1 Screening This Page Intentionally Left Blank October 2014 South Station Expansion Massachusetts Department of Transportation Track Configuration Alternatives Analysis – Tier 1 Screening Table of Contents List of Figures ............................................................................................................................................... iii List of Tables ................................................................................................................................................ iv 1. Introduction .......................................................................................................................................... 5 2. Summary of Findings ............................................................................................................................. 5 3. Existing Conditions ................................................................................................................................ 7 3.1 Existing Terminal Interlocking System .......................................................................................... 8 3.1.1 Tower 1 Interlocking ............................................................................................................. 8 3.1.2 Cove Interlocking .................................................................................................................. 8 3.1.3 Broad Interlocking ................................................................................................................. 9 3.2 Current Operating Constraints ...................................................................................................... 9 3.2.1 Interlocking Infrastructure Constraints ................................................................................. 9 3.2.2 Location of Layover Facilities ................................................................................................ 9 3.2.3 Inadequate Platform Size .................................................................................................... 10 3.2.4 South Station Air Rights Project .......................................................................................... 10 4. Track Configuration Alternatives ........................................................................................................ 11 4.1 Unconstrained Rail Alternatives ................................................................................................. 12 4.1.1 Unconstrained Rail Alternative 1 – 20 Tracks at Grade ...................................................... 12 4.1.2 Unconstrained Rail Alternative 2 – Bi-Level South Station ................................................. 14 4.1.3 Unconstrained Rail Alternative 3A – Relocate Amtrak to Cabot Yard ................................ 16 4.1.4 Unconstrained Rail Alternative 3B – Relocate Amtrak to Boston Convention Center ....... 17 4.1.5 Evaluation of Unconstrained Rail Alternatives ................................................................... 18 4.2 Constrained Rail Alternatives ...................................................................................................... 20 4.2.1 Constrained Rail Alternative 1 – Redesign/Redevelopment ............................................... 20 4.2.2 Constrained Rail Alternative 2 – Streamline Operations .................................................... 22 4.2.3 Constrained Rail Alternative 3 – Minimize Disruption to Operations ................................ 23 4.2.4 Constrained Rail Alternative 4 – Maximize Overbuild Potential......................................... 25 4.2.5 Approach (Setup) Interlockings........................................................................................... 26 Cove Interlocking ............................................................................................................................ 26 Broad Interlocking ........................................................................................................................... 26 5. Alternatives Screening ........................................................................................................................ 27 5.1 Rating Criteria ............................................................................................................................. 27 5.1.1 Platform Rating ................................................................................................................... 27 5.1.2 Infrastructure Maintenance Rating..................................................................................... 27 5.1.3 Constructability Rating ........................................................................................................ 28 5.1.4 Capital Cost Rating .............................................................................................................. 28 5.2 Tier 1 Alternatives Screening ...................................................................................................... 28 South Station Expansion October 2014 Massachusetts Department of Transportation Page i Track Configuration Alternatives Analysis – Tier 1 Screening 5.2.1 Platform Rating ................................................................................................................... 28 Platform Accessibility ...................................................................................................................... 28 Berthing Requirements ................................................................................................................... 33 5.2.2 Infrastructure Maintenance Rating..................................................................................... 34 5.2.3 Constructability Rating ........................................................................................................ 34 5.2.4 Capital Cost Rating .............................................................................................................. 35 5.2.5 Summary of Findings ........................................................................................................... 36 6. Next Steps ........................................................................................................................................... 36 7. Figures ................................................................................................................................................. 39 October 2014 South Station Expansion Page ii Massachusetts Department of Transportation Track Configuration Alternatives Analysis – Tier 1 Screening List of Figures Figure 1—South Station Project Site: Terminal, Approach, and Key Facilities ........................................... 41 Figure 2—Existing Rail Infrastructure at South Station Terminal Area ....................................................... 42 Figure 3—Schematic of South Station Terminal Area Existing Interlocking System................................... 43 Figure 4—Impact of SSAR Project on Existing Station Platforms ................................................................ 44 Figure 5—Unconstrained Rail Alternative 1 — 20 Tracks at Grade ............................................................ 44 Figure 6—Unconstrained Rail Alternative 2 — Bi-Level South Station, Cross-Section ............................... 45 Figure 7—Unconstrained Rail Alternative 2 — Bi-Level South Station, Plan .............................................. 45 Figure 8—Unconstrained Rail Alternative 3A — Relocate Amtrak to Cabot Yard ...................................... 46 Figure 9—Unconstrained Rail Alternative 3B — Relocate Amtrak to Boston Convention Center ............. 46 Figure 10—South Station Original Alignment (circa 1899) ......................................................................... 47 Figure 11—Constrained Rail Alternative 1—Redesign/Redevelopment .................................................... 48 Figure 12—Constrained Rail Alternative 2 — Streamline Operations ........................................................ 49 Figure 13—Constrained Rail Alternative 3 — Minimize Disruption to Operations .................................... 50 Figure 14—Constrained Rail Alternative 4—Maximize Overbuild Potential, Detail ................................... 51 Figure 15—Constrained Rail Alternative 4 — Maximize Overbuild Potential ............................................ 53 Figure 16—Potential Berthing Accommodation Innovations ..................................................................... 55 South Station Expansion October 2014 Massachusetts Department of Transportation Page iii Track Configuration Alternatives Analysis – Tier 1 Screening List of Tables Table 1—Existing Compensated Platform Lengths at South Station .......................................................... 11 Table 2—Fixed and Flexible Elements for Unconstrained Rail Alternatives ............................................... 12 Table 3—Comparison of Unconstrained Rail Alternatives ......................................................................... 19 Table 4—Fixed and Flexible Elements for Unconstrained and Constrained Rail Alternatives ................... 20 Table 5—Proposed Platform Accessibility, Constrained Rail Alternative 1 ................................................ 29 Table 6—Proposed Platform