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News / Northwest

Washington state is no stranger to bridge disasters

The Tacoma Narrows Bridge collapse four months after opening still remembered as one of engineering's greatest failures

By Mike Lindblom, The Seattle Times
Published: March 27, 2024, 7:48am
2 Photos
The west end of the Hood Canal Floating Bridge at Port Gamble sinks into the water after a windstorm destroyed the 1.3 mile link between Washington's Kitsap Peninsula and the Olympic Peninsula, Feb.
The west end of the Hood Canal Floating Bridge at Port Gamble sinks into the water after a windstorm destroyed the 1.3 mile link between Washington's Kitsap Peninsula and the Olympic Peninsula, Feb. 14, 1979 (AP Photo) Photo Gallery

SEATTLE — From the Hood Canal to the Duwamish River, travelers a continent away from Baltimore understand the disoriented feeling when a bridge collapses into ruins.

However, none of the modern bridge failures near Seattle resembles Tuesday morning’s collapse of the steel-truss I-695 Francis Scott Key Bridge, when a large container ship lost power and hit a bridge foundation.

Six people in an overnight construction crew were missing, and presumed dead as of Tuesday afternoon.

The first question that came to mind for Eric Holdeman, a disaster preparedness expert based in Puyallup, is whether Baltimore’s navigation practices resemble Washington’s. Holdeman points to the skilled and lucratively paid Puget Sound Pilots, who meet thousands of ships offshore from Port Angeles, guiding them through the local waterways.

He said another is tugboat escorts, often seen alongside barges and some ships in Puget Sound, and required by state and federal law for large oil tankers.

“When they invented ships, they invented shipwrecks,” Holdeman said. He worries about overdependence on automated and electronic systems. Redundant networks, which can be controlled if one part fails, are essential, he said.

The Baltimore bridge spans the Patapsco River at the entrance to a busy harbor, which leads to the Chesapeake Bay and Atlantic Ocean. The nearest local scenario to Tuesday’s incident would be if a ship leaving Portland smacked the Lewis and Clark Bridge foundations in the Columbia River, near the Port of Longview.

From 1960 to 2015, there were 35 major bridge collapses worldwide due to ship or barge collision, according to the World Association for Waterborne Transport Infrastructure.

Jeffrey Berman, a University of Washington engineering professor, was struck by footage that showed the Baltimore ship’s forward momentum continuing after impact. “There’s a lot of energy associated with this size, and it’s going to cause a collapse,” for any kind of bridge, he said.

Therefore, the solutions lie mainly in redundant safety and navigation systems, he said.

Newer bridges near ports provide larger in-water foundations that could deflect or damage smaller ships, Berman said. More importantly, the mainspan can be longer and allow a far wider shipping channel than 1,200 feet, and therefore more space between ships and bridge columns.

“The fact is, we’re relying on 1950s infrastructure. If the thing is built today, maybe this doesn’t happen,” Berman said.

Modern bridge failures in Washington state haven’t taken human lives, but collectively lost hundreds of millions of dollars, while wasting untold hours of travel time in detours.

Below is a look back at some local bridge disasters.

I-5 Skagit River Bridge, 2013

Like the Baltimore incident, this disaster involved a steel-truss span that instantly fell. Both involved so-called “fracture critical” bridges, of which thousands were built in the early to mid-20th century. One broken beam can unleash interconnected forces throughout the truss and destroy the whole span.

The I-5 damage was caused by a truck that hauled tall drilling equipment, exceeding the 15 1/2 -foot clearance. The cargo hit an overhead brace, which in turn yanked one of the major truss beams inward, next to the southbound lanes, among other impacts. One of four bridge spans buckled. Two cars fell into the river but miraculously, the three people in them survived with minor injuries.

The Washington State Department of Transportation and contractors built a military-style crossing in four weeks, then a permanent concrete-girder replacement within less than four months. WSDOT later sawed away the arch-shaped braces, and installed straight beams 18 feet above the pavement.

West Seattle drawbridge, 1978

A runaway freighter full of gypsum rammed a steel bridge, but the cause was crew inattention, not mechanical like Baltimore. Captain Rolf Neslund was found negligent by a post-crash inquiry.

The 550-foot freighter’s impact left the drawspan stuck upright for years, which closed four lanes and built political momentum to build a higher crossing. Drivers going both ways crammed into its twin four-lane drawbridge until a 150-foot-high concrete bridge opened in phases during 1983 and 1984.

Neslund’s wife killed him two years later at their home on Lopez Island. A rogue sculpture of the former captain stands today alongside the public bike trail, west of the river. A plaque on the sculpture reads: “Patron Saint of the Broken Bridge.”

Hood Canal Bridge, 1979

Bridges that float can also sink. During a February windstorm, waves more than 10 feet tall sent water into maintenance hatches, while some anchor cables broke, causing hollow pontoons to list. With access to the Olympic Peninsula reduced, the state added ferry service afterward. By 1982, the bridge’s west half was rebuilt with stronger components, followed by a new east half in 2009.

Tacoma Narrows Bridge, 1940

Trouble was brewing from day one, when the two-lane suspension bridge bobbed under traffic loads. It seemed like a summer amusement and inspired the nickname Galloping Gertie.

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November winds near 40 mph caused the deck to buck until it snapped. Dangling pieces and abandoned cars fell into Puget Sound, but there were no deaths, except a dog. A post-disaster investigation led by University of Washington professor F.B. Farquharson — the last person to scramble off the tilting bridge — showed how crosswinds caused a harmonic oscillation, flowing aerodynamically through steel deck beams.

Another factor was its lean 72:1 length-to-width ratio, by a famed bridge engineer obsessed with displaying an elegant shape. The state applied these humiliating lessons to build a stouter bridge in 1950, and a parallel Narrows bridge in 2007.

West Seattle high rise bridge, 2020

Four years ago this week, the city declared an emergency shutdown of its landmark concrete bridge, only 38 years of age, due to cracking.

Shear cracks in the seven-lane crossing were discovered in 2013, but they were tiny, and filled by epoxy, while monitoring increased. In hindsight, the fact they propagated symmetrically, in four weak points that lacked tensioning cables, should have spurred more decisive action. The city and outside experts were examining major repair concepts by mid-2019, until the next March, when the city’s chief structures engineer was horrified to see crack length accelerate by 1 foot per week, and recommended a sudden closure.

Drivers detoured 5 miles and bought “West Seattle Island” swag. City transportation officials favored demolition and steel-arch replacement spans, but Mayor Jenny Durkan opted to strengthen the 1984 structure, accomplished with carbon wrap and 46 miles of high-tension internal cables. Traffic returned in September 2022.

The only similarity to Baltimore is both are major traffic conduits; the I-695 bridge serves 31,000 daily vehicles, while more than double that volume crosses the Duwamish at West Seattle.

I-90 Lacey Murrow Bridge, 1990

Washington state’s second capsized floating bridge was a televised spectacle, locally and broadcast as far away as China. Lake Washington rushed into openings in the pontoons during a repair job, in calm weather, and finger-pointing ensued between the state and a contractor over fault.

Drivers could still cross the lake using the parallel Homer Hadley bridge just completed in 1989, followed by a new eastbound bridge in 1993. Sound Transit is now building the world’s first train route on a floating bridge, but the job won’t be finished until late 2025.

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