Seattle-Tacoma Airport: Walkway lifted into place

The pedestrian walkway footbridge designed by schlaich bergermann partner at the Seattle-Tacoma (Sea-Tac) International Airport reached a long-awaited milestone at the end of January when the 1,500 ton, 320-foot center span was lifted into place.

As part of the modernization of the new International Arrivals Facility (IAF), the enclosed aerial walkway connects two existing airport buildings with a vertical clearance of 85 feet above the tarmac. With an overall length of 780 feet and a clear span of 610 feet, the walkway is now the world’s longest structure over an active taxi lane. Given that Sea-Tac is one of the ten busiest airports in the U.S., the construction sequence was carefully considered during the design phase and the resulting structure was fabricated offsite as 17 individual components. The pedestrian walkway and the full IAF project are expected to be completed in late 2020.


The project team includes: schlaich bergermann partner (bridge designer), Skidmore, Owings & Merrill (IAF designer and collaborator on the bridge design), KPFF (bridge Engineer of Record), Clark Construction Group (contractor), The Erection Company (walkway erector), Supreme Steel (steel fabricator), Mammoet (heavy transport), and KCE Structural Engineers (peer review).