(Updated 11/6/2023)
King County Metro is providing information to contractors interested in a design-bid-build project to upgrade electrical equipment and make structural improvements at the Broad Street Substation. This substation, located at 319 Sixth Ave. N. near Seattle Center, provides power to 14 Metro trolley bus lines throughout North, Central and South Seattle.

Metro has designed a replacement of the Broad Street Substation AC breakers, transformers and rectifiers. The existing DC breakers will remain in place. Each rectifier and transformer will need to be replaced individually while the other remains in service. Design is complete, with advertisement date estimated to occur Q1 2024.

Please see the Technical Scope of Work for more detailed information.

street view of the Broad Street Substation with the Space Needle in the background

Reference documents (PDFs)

Contact information

Randy Poplock, King County Metro Capital Project Manager, randy.poplock@kingcounty.gov.

King County Metro – Broad Street Substation Equipment Replacement Project

Project Background

Metro is currently at 100% design for replacement of the Broad Street Substation equipment, including AC breakers, transformers and rectifiers. The existing DC breakers will remain in place. Each rectifier and transformer will need to be replaced individually while the other remains in service. Bid advertisement is anticipated for Q1 2024.

Funding

This project will have federal (Federal Transit Administration) funding, and is thus subject to FTA requirements, and will be fully funded through the construction, commissioning/startup, and closeout phases.

Budget

The total construction contract value of the project is estimated to be in the range of $5 million to $6 million.

Project Delivery

Design-bid-build, lump sum.

Schedule Assumptions

The tentative schedule is:

  • Advertise: Q1 2024 (date updated Nov. 6, 2023). The project will be advertised through King County’s Procurement website. Visit the web page to register and view solicitations.
  • Notice to Proceed (NTP): Q2 2024 (date updated Nov. 6, 2023).
  • Substantial Completion: NTP + 20-24 months

Scope of Work

Electrical Scope

This scope includes removal of existing equipment, procurement and installation of replacement DC traction power equipment, 125VDC equipment, Remote I/O, updating existing SCADA system, cabling and miscellaneous electrical hardware as well as testing, commissioning, startup and training. It includes two (2) 1.5MW, 26.4 kV to 672 Vdc power conversion systems into the existing Broad Street traction power substation. Each power conversion system, which includes a primary AC circuit breaker, transformer, rectifier, protective relaying, remote I/O will be installed under staged construction whereby one AC to DC rectifier is on-line and continuously feeding the existing trolley system via the existing Broad Street DC feeder breakers.

Please see attached Technical Scope of Work for more detail.

Structural Scope

Structural upgrades, including column reinforcing, concrete curbs and equipment anchorage will be required to accommodate the heavier weight of the new equipment. Some demolition will be required along with need for dust control and regulated material mitigation.

Other Factors

To maintain continuous service, the project construction must be performed in two distinct phases (remove and replace one rectifier at a time without interrupting the other).
Seattle City Light will be performing the Broad Street Substation Inductor Project simultaneously on another part of the building.