Seattle Tacoma International Airport (Sea-Tac) is going through some large-scale renovation that will make it a much more competitive transit hub beginning later this year if construction plans stay on track. The main focus of the renovation is Sea-Tac’s international arrivals facility, which is woefully undersized for the airport’s growing passenger traffic. The new elements include a 450,000-square-foot grand hall for baggage claim and Customs processing, a picturesque aerial walkway connecting South Satellite to the grand hall, and a corridor connecting arriving international passengers on Concourse A. 

We recently walked through the construction site with Port of Seattle staff to see what’s coming. Bottom line: Sea-Tac is going to be able to better handle the midday crush that often happens when Asia-departing flights arrive en masse.

 “The grand hall is sized for 2,600 passengers per peak hour, and we know that the peak is midday,” says Janet Sheerer, IAF project manager, landside, at the Port of Seattle. “There were very few overall design parameters for this project, and that was the biggest one.”

Skidmore, Owings & Merrill LLP (SOM), the architect of the renovation project, and Clark Construction Group, the contractor, ran models to make sure the new facility could handle peak passenger traffic. “They ran robust models based on the type of aircraft, when the flight is arriving, and to figure out where things need to be located and how many bag claim devices are needed,” says Sheerer. “The output from those models is what drove the design.”

Current capacity at the international arrivals terminal is less than half the 2,600-level the new facility promises. The arrivals facility is adding eight international gates, bringing the total to 20. It is also increasing the number of bag claim carousels from four to seven and greatly expanding the area for bag claim from the current 668 linear feet to 1,806 linear feet. That’s almost three times more space. 

The new security corridor along the face of Concourse A will provide eight international wide-body aircraft gates with direct access to the new arrivals facility.  

These improvements come just in time for Sea-Tac. The airport is one of the fastest-growing hubs in North America with passenger traffic jumping more than 40% in the last five years, making it the eighth busiest airport in the US. It also has seen a rise of 107% in international passenger traffic from 2007 to 2017, and several new international routes have been added since then. Now Sea-Tac will be able to better exploit its unique position as the closest US West Coast hub to both Europe and Asia, being located halfway between London and Tokyo. Sea-Tac has added 16 new intercontinental routes in the last 10 years and will likely add more in the next few years. 

“The airlines say, as soon as you get done, we’re coming in with more flights,” says Sheerer.

One of the more ambitious pieces of the new facility is the 85-foot-high aerial walkway, which will weigh 1,565 tons (about the same as 18 Boeing 747s), span 90 feet across, and extend over an active taxiway. It will be suspended by large cables and have the longest clear span of its type. International passengers will use the walkway to get from the South Satellite to the new arrivals facility, traveling across the top of Concourse A. “You’ll be on the moving walkway, cruising down, and to the right and left of you are going to be these big cables,” says Stephen St. Louis, IAF project manager, airside, at the Port of Seattle. “It’s really going to be impressive.”

The walkway is being built via the ABC (accelerated bridge construction) method, where it is assembled offsite and then hauled in to be placed on the taxiway. “We have a seven-day closure. Our taxi lane will be closed for 168 hours,” says St. Louis. “Gatwick completed a similar kind of construction, and their impact was seven days. That’s what we use for our basis. 

“We have communicated with the airlines,” he added, “and they have anticipated that they will have to adjust their schedules. There may be some delays while we have this closure in place.”

During the seven-day downtime, the airport will tug planes out to an engine start-box area, where pilots can fire up their planes. This is a precaution taken to make sure construction workers aren’t impacted by jet blast. 

Part of the arrival facilities are being built in consultation with US Customs & Border Protection.  “They gave us a 500-page book,” says Sheerer. “It tells you everything from the size of the room to what kind of security measures are needed in the room to how many cubicles you have to have and specifically how many processing stations you need. It’s really prescriptive, which, in a way is handy because you know what you need to build.”

The Customs area will include enhanced technology to speed up passport check times. The minimum passenger connection time is expected to drop from 90 to 75 minutes as well. 

The facility renovation is on track to be completed by the end of May. Activation testing will then take place during the summer months before the facility is open to the public this fall.  The Port says it has designed the facility with environmental concerns in mind and hopes to have the facility receive LEED V4 (Leadership in Energy and Environmental Design, Version 4) Silver certification from the US Green Building Council.

The $968 million project is expected to bring in 10,600 new jobs, including the construction jobs required to build the new facility, Port officials say. As with most airport projects, no taxpayer dollars will be used for funding. Instead, the money will come from a combination of airport-generated revenue, passenger facility charges, and revenue bonds, according to the Port of Seattle website. One consultant study that the Port solicited estimates that each new international route generates an average of $89 million in annual economic impact in the Seattle-Tacoma region. 

With this new increased capacity and state-of-the-art Customs technology, Sea-Tac is poised to be a bigger player in international travel. “We’re building this to be as competitive as we can be,” Sheerer says.