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Seattle Madison Corridor ETB Electrification

Elcon was tasked with providing 30%, 60, 90%, and 100% design including plans, specifications, and cost estimates for the OCS from 1st Avenue to MLK Jr. Way. Elcon prepared the project’s design basis memorandum for TPSS and OCS. We also performed 30% traction power design which included a traction power analysis, confirmation of locations for potential traction power substation sites. Elcon also developed preliminary TPSS site plans for equipment arrangement, feeder diagram and layout.

After a decision was made to use battery electric buses, the TPSS element was eliminated from the project. The OCS work involves interfaces and modifications to the existing electric trolleybus operations at various street intersections that employ joint-use OCS, street lighting, and traffic signal poles. Elcon is currently completing the 100% design, and construction is scheduled to start late this summer. Elcon will be providing design support during construction.

Owner: Seattle Department of Transportation

Location: Seattle, WA


  • Electric trolleybus electrification
  • OCS and traction power design and construction support services
  • Joint-use with OCS, street lighting, and traffic signal poles