PORTLAND, Ore. — The sweeping wooden arches of the Portland International Airport's new main terminal roof are taking shape — but not above the terminal.
Crews from contractors Hoffman and Skanska are building the 392,000-square-foot structure at an outdoor assembly yard to the west of the airport's northern runway, near the Port of Portland fire station.
Once completed, the structure will be "unzipped" into 20 modules and moved across the airfield one piece at a time over a period of a few months, sliding each section into place above the main terminal.
"You'll see us start to move this mid-2022," said Katrina Day, senior project manager for the Hoffman-Skanska joint venture.
The pre-fabrication approach was chosen for safety reasons, Day said, and because it will cause far less disruption to airport operations than if the roof had been built directly above the terminal.
It's also an easier working environment for the construction crews, according to Port of Portland Chief Projects Officer Vince Granato, because the roof is resting on temporary scaffolds that raise it only 13 feet above the ground, rather than the 54-foot height where it'll sit once it's installed.
The wide, arching roof is intended to transform the main terminal into a vast open space without any hard walls breaking it up, Granato said, giving the airport a bigger, warmer and more natural feel.
"Yes, there will be carpet as well," he said, "but also this iconic roof, I think, will be the next great talking point for what this airport will be."
The roof is composed of 400 glue-laminated beams, he said, which were fabricated in Eugene using wood sourced from Oregon and Washington forests.
The beams are pure wood, without any steel component. The project's architects and structural engineers chose that approach because it provides a unique design and fulfills one of the project's overall goals: seismic resiliency.
“(The wooden beams) are actually stronger than if you were to do steel," Granato said. "And so they’re designed to absorb any energy that could come from a Cascadia subduction earthquake."
The project is running 24 hours per day with an overall staff of about 600 workers, Day said — about 100 at the fabrication yard and 500 at the terminal — but it's still going to be a years-long effort.
The main terminal is being expanded farther west, out into part of the space between Concourses C and D. The airport's security check areas will likely be moved over to the expanded area in 2023 or 2024, Granato said, with the overall project aiming to wrap up in 2025.
The airport will keep operating in the meantime, but travelers will need to adjust to changes during construction. For example, the connecting corridor between the Concourses C and D has been closed, he said, so travelers who have passed through security won't be able to get to the concourses on the opposite side of the airport without exiting and going back through the other security line.
The new roof and expanded main terminal are the last and largest components of a $2 billion series of upgrades collectively called PDX NEXT, all of which are intended to increase capacity and provide more flexibility and greater seismic resiliency, Granato said.
The first of the projects was the airport's new Concourse E to the east of the main terminal, which opened last year. Next up will be a new parking garage and car rental facility, coming in November.
The new Concourse B is slated to debut in December, an expanded replacement for the former Concourse A to the south of the main terminal. The rebuilt concourse also frees up space for TriMet's A Better Red project, which will renovate airport MAX station and add a second track on the approach so inbound and outbound Red Line trains will no longer have to take turns.