Groat Road Bridge: Five bridge failures, past and present
Bridges are kind of important. We walk on them, drive over them. We take pictures of them. Bridges have inspired and mystified the people who build them and the people who use them for centuries. But, these giants of infrastructure are tricky to build and can be fraught with problems, at the design and construction stage, or after they’re open and operational.
Here are five memorable bridge failures, in Alberta and elsewhere.
North Saskatchewan River bridge
On Dec.14, 2003, a 100-tonne steel girder that was designed to support a southbound vehicle deck on Anthony Henday Drive twisted and collapsed. There were no injuries. The girder had to be replaced.
Bonnybrook rail bridge in Calgary
During Calgary's spring floods in 2013, six tanker cars teetered precariously on the sagging tracks of the Bonnybrook bridge, after the piers at the bottom of the river failed. At the time, engineers blamed the bridge’s failure on fast water scouring away gravel under the bridge supports. A Transportation Safety Board of Canada report released in December 2014 said nothing could have reasonably been done to predict the collapse of the rail bridge.
Second Narrows Bridge in Vancouver, B.C.
Known as one of the worst work-site disasters in B.C’s history, the Second Narrows Bridge collapsed while under construction in June 1958, killing 18 workers and injuring more than 70.
The bridge was being built to connect Vancouver with the North Shore and collapsed after a junior engineer made a mistake in the calculations for one of the bridge sections. Canadian folk singer Stompin’ Tom Connors later wrote a song about the disaster, “The Bridge Came Tumbling Down.”
Minneapolis bridge
In August 2007, a major freeway bridge in Minneapolis collapsed into the Mississippi River during the evening rush hour, plunging dozens of vehicles into the water and killing at least seven people. The 40-year-old bridge had been rated "structurally deficient" but was considered safe for use at the time of the collapse.
Tacoma Narrows Bridge
Perhaps the most infamous and dramatic collapse happened in Washington State on Nov. 7, 1940, when a bridge that became known as "Galloping Gertie" twisted and bent before collapsing in a windstorm, just four months after opening. Another bridge, a much safer version, opened in 1950.