King County Metro – Interim Base Electrification

King County Metro is leading the transit industry—and the country—with a plan to move to a 100% zero-emissions bus (ZEB) fleet powered by renewable energy by 2035. The Interim Base Electrification Project (IBE) is a critical component of the pioneering infrastructure that will facilitate this zero-emissions initiative. As the first large-scale bus charging facility in the nation, the IBE project will provide parking and charging stations for 120 ZEBs.

Future-thinking, efficient, and flexible design

The design employs an optimized, modular steel gantry truss system that supports an elevated equipment platform for bus charging pantographs, minimizing the carbon footprint of the steel framing and concrete footings for an efficient and quickly constructable structure. Its modularity enables an agile project schedule and future adaptability, while the elevated equipment platform maximizes space efficiency by consolidating equipment on a smaller footprint.

Realizing IBE’s sustainability goals

Given its proximity to the Duwamish River, the project meets Salmon-Safe requirements to protect salmon from harmful chemicals, such as zinc, which can affect spawning. Instead of standard hot-dipped galvanized steel, the project uses steel with a protective paint coating, an environmentally conscious alternative that safeguards the river ecosystem. The result is a facility that will stand the test of time and provide lasting benefits to both the community and the surrounding ecosystem.

Collaborating for the future

Through extensive workshopping, meetings, studies, and collaboration with KCMT, the design criteria were reformulated to optimize implementation. This thorough process validated the height of the truss to accommodate new equipment and established sightlines, pedestrian safety zones, and travel plans. Our meticulous attention to detail enabled KCMT to meet sustainability objectives and set a standard for future projects. Under the visionary leadership of McKinstry and Stantec, the design team diligently advanced the project narrative, ensuring a successful and sustainable outcome.

This state-of-the-art bus charging facility will be a model zero-emission bus facility for KCMT’s electrification goals. The facility is currently under construction and is scheduled to be completed by early 2026.

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