BURLINGTON — Demolition crews made their way along the Skagit River on Saturday night toward the wreckage of Interstate 5, about 50 hours after part of it collapsed.
Atkinson Construction, hired under an emergency contract by the state Department of Transportation, brought a tug and barge with heavy cutting and lifting equipment and a crane to the scene.
A second barge is set to arrive tonight carrying two excavators, at least one of which will have mounted hydraulic shears that can cut the damaged beams, steel and concrete that now sit useless in the water.
Saturday was the first full day federal officials spent on the scene of the Interstate 5 Skagit River bridge collapse, and it was “busy and productive,” said the chair of the agency investigating the incident.
Investigators from the National Transportation Safety Board have split into two teams: one inspecting the highway and the bridge, and the other looking into what happened on it before and during the collapse Thursday. It fell after a tractor-trailer carrying a load struck the trusses, and two vehicles carrying three people fell into the river. All three people were rescued.
The highway team spent Saturday on what’s left of the bridge and in boats on the water getting close looks at the wreckage.
“When you’re down there that close, the trauma of the bridge collapse is evident,” said NTSB chair Deborah Hersman. “You’re struck by how enormous the structure really is.”
The beams connecting the trussed bridge, called members, are as large as a person.
Gray-green paint has come off many sections of the dropped span, exposing the orange primer beneath, Hersman said.
“You can see that the concrete section of that dropped span has slid off of its girders like icing sliding off of a cake,” she said. “It’s a floating bridge deck and it has completely slipped, in certain sections, right off of the deck.”
The pickup truck, travel trailer and car that fell Thursday night were still half-submerged in the river on Saturday. The car’s airbags were deployed. The pickup’s door was ajar, with the “fast-flowing current swirling in and around it,” Hersman said.
The tractor-trailer that caused the collapse escaped mostly unscathed. The top-right side of the structure it carried is crushed, and while it lost some of its own royal-blue paint, it now contains a few chips of graygreen paint from the bridge.
Crews moved the truck Saturday from the south side of the bridge to a towing yard in Mount Vernon, where it will be measured and examined further.
The span that fell is known in original design drawings for the bridge as Span No. 8. Its six upper frames are damaged to varying degrees, with members buckled and bent. While the second-most-northern frame is of most interest to investigators, it is completely underwater, Hersman said. Only portions of its members are visible.
Frames on the next section, Span No. 7, also show damage from the load hitting them. Investigators will determine whether anything there needs to be replaced and look at tire marks to better piece together the crash, Hersman said.
As for the debris in the water, state crews will demolish and remove it, saving the portions of most interest to federal investigators.
Once the fallen span is removed and inspections are complete, DOT engineers can start planning repairs.
DOT spokesman Bart Treece could not give a repair timeline Saturday, saying it was too early to tell because it was still an emergency situation.
“We’re still in triage mode,” he said.
Likewise, no specific shortterm fix has been identified, he said. Gov. Jay Inslee mentioned Friday the possibility of a Bailey bridge, a type of portable truss bridge developed during WWII. Some agencies have offered to provide one, Treece said.
But a Bailey bridge won’t necessarily happen.
“It’s one possibility, but it’s not the possibility,” he said.
DOT put a Bailey bridge over the Chehalis River after floods destroyed concrete spans there in 2007.
The Skagit River bridge won’t reopen until officials are sure it’s safe, Treece said.
“We drive the same roads as everybody else,” he said. “We roll our families down these roads.”
Meanwhile, the 71,000 vehicles a day that used the I-5 bridge are being rerouted elsewhere. People should add an extra hour of travel time if their plans take them through the area, Treece said.
“The bottom line is: We need to get this route open again,” he said.