Sea-Tac Airport will soon lay claim to the longest aerial walkway over an active taxiway on the planet with the upcoming overnight move and installation of a massive center span that will create a pedestrian bridge for the airport’s new International Arrivals Facility (IAF).
The 780-foot walkway will extend over a taxiway connecting the two portions of the new IAF complex that are being constructed adjacent to the existing South Satellite and the main terminal’s Concourse A. The huge center span, weighing as much as 14 blue whales at 1,500 tons, will be transported over a closed runway (video simulation here) via a self-propelled modular transport system from Cargo 2 on the north end of the airfield.
The momentous move of the giant structure across the Sea-Tac airfield is slated to take place very late Thursday evening, Jan. 24, around midnight, and into Friday morning, according to Sea-Tac spokesman Perry Cooper ― though he says the schedule could be pushed back a day or two depending on weather, wind conditions and the status of final preparations.
“The first lift [of the structure into place] could happen the evening of Friday [Jan. 24], again, based on safety checks, calibrations and preparations,” Cooper says. “It may actually go up and down a couple of times to check fit before finally getting set. It will be pretty slow when it goes up, 20 feet an hour, so about four to five hours to lift it into place from the ground.”
The walkway, which would be 150 feet taller than the Space Needle if stood on end, will be high enough and long enough to allow a Boeing 747 to taxi underneath it. The huge center-span structure was assembled on the north end of the Sea-Tac airfield, some two miles away from the IAF complex.
Sea-Tac ranks as the 8th busiest airport in the nation, with 49.8 million passengers served in 2018 ― the eighth straight year of record passenger numbers. International flights accounted for some 5.4 million of those passengers, up nearly 6% year over year. Air Canada's Seattle-Montreal flight set to launch in May will represent the 13th new international service unveiled at Sea-Tac Airport since 2017.
Sea-Tac is slated to open the $968 million International Arrivals Facility to the public this fall. The multilevel facility will expand the number of gates at Sea-Tac that can accommodate international wide-body airplanes from 12 to 20.
Sea-Tac’s existing international facility can now handle between 1,700 to 2,000 passengers per hour at peak periods, Cooper says. The new IAF will expand that to 2,600 passengers per hour at peak ― which Cooper says will go a long way in relieving current facility constraints.
The Port of Seattle, which oversees Sea-Tac Airport, estimates that each new international flight creates about $74 million in economic activity in the Puget Sound region. The two leading airlines serving Sea-Tac (Alaska and Delta airlines) together served more than 70% of the passengers flying via Sea-Tac last year ― with Alaska holding a commanding market share in domestic air service as of year-end 2018, at 52.1%, while Delta dominates international service, with a 31.3% market share.