Sound Transit Link Light Rail

System-wide Electrical Engineering

Seattle, Washington

As Systems Engineering Consultant, LTK has responsibility for preliminary engineering and preparation of bid documents for vehicles, traction power, train control, communications, fare collection and system-wide electrical for the 14 mile Central Link Light Rail System.

With the project now in construction, LTK is serving in a construction management role for a majority of the systems elements. Key signals and communications elements included in the project are:  

  • A train control system that incorporates cab signal with overspeed protection.
  • A train-to-wayside communications system
  • Integration with street traffic control signals on street running segments
  • Microprocessor interlockings
  • Automatic highway crossing warning systems
  • A fiber optics and data transmission system
  • A new radio system
  • A new central control facility
  • CCTV, telephone, public address and variable message signs

LTK provided electrical engineering, lighting design support and design project management for Sound Transit’s Link light rail project in Seattle, Tukwila and Tacoma since the design commenced in 1998, including conceptual and preliminary engineering, final engineering for at-grade, aerial and underground segments, passenger plazas, operations/maintenance facilities and stations. The design work included:

  • Design of along-track duct banks, vaults and wireways for communications and signals inter-tie cabling as well as 750 and 1500 volt dc traction power feeders.
  • Interfacing between traffic signal and light rail signal systems.
  • Ducts and conduit provisions for signals and communications facilities in station and other facility areas, including:
    • closed-circuit television cameras;
    • variable message signs;
    • public address systems;
    • passenger emergency telephones;
    • emergency/firefighter telephones;
    • intrusion detectors;
    • fire alarm and pre-action fire suppression system devices;
    • fiber-optic and multiconductor telecommunications/data cabling; and,
    • emergency management panels for fire department use.
  • Interfacing with utility companies for medium- and low-voltage services to stations, streetlighting, transit plazas, traction power substations and other system facilities located along the alignment.
  • Electrical service and distribution equipment design, distribution feeders and branch circuits to utilization equipment.
  • Design of standby emergency generation facilities for Beacon Hill Tunnel and Station.
  • Design of street and site lighting for parking lots, pedestrian ways, station plazas, stations, and underground trainways.  This work has included selection of luminaries and luminaire locations, simulation of lighting using AGI32 lighting design software, design of lighting branch circuits and controls, and inclusion of closed-circuit television cables and equipment on the luminaire mounting poles for site surveillance in conjunction with local law enforcement agencies.
  • Performance of specialized power system studies in support of project design concepts including reliability studies of various service alternatives and flicker studies assessing transit load impacts on the utility system.

LTK also provided system-wide electrical and lighting design support during construction services for Sound Transit for the C520, C700, C710, C735, and C810 civil construction contracts.

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