Bridge Collapses

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A CHRONICLE OF DISASTERS
A Century of Bridge Collapses
The collapse of the Silver Bridge, 1967

By Glenn Demby.

Friday’s issue of SafetyXChange included a short piece about some of the worst bridge disasters in U.S. history. I want to thank the members of SafetyXChange who wrote to point out that the 1980 collapse of the Sunshine Skyway Bridge in Tampa, listed number one in the story, is not the deadliest bridge collapse in U.S. history. With 46 deaths, the Silver Bridge disaster of 1967 is.

I realize now that the title of Friday’s article was misleading. Instead of “Deadliest Bridge Collapses U.S. History,” I should have called it “Deadliest Bridge Collapses in Recent U.S. History.” So I decided to delve a little deeper into the past. Here’s a chronicle of some of the major bridge collapses that occurred in North America in the 20th century before the incidents described in Friday’s article. Consider it a prequel to Friday’s piece.
1907: THE QUÉBEC BRIDGE (Québec)

Spanning the St. Lawrence River between Québec City and Lévis, the Québec Bridge is the world’s longest cantilever bridge. In the summer of 1907, during construction, an overseer noticed that two girders on the south arm of the bridge were misaligned by a couple of inches and appeared to be bent. He went to New York to report the situation to the consulting engineer. But work continued in his absence and without his permission. On August 29, 1907, the south arm collapsed, killing 76 workers.
1916: THE QUÉBEC BRIDGE (Québec)

No, it’s not a misprint. The same Québec Bridge was the site of a second disaster just nine years later. Construction on the bridge had resumed in 1908, a year after the first collapse. But extra safety and structural precautions were taken. Apparently, they weren’t enough. On of all days, September 11, 1916, with the bridge nearing completion, its center span was being lifted into place when one of the four rocker arms failed. The 5,000 pound span plunged into the St. Lawrence River. 11 workers were killed. The Québec Bridge was finally completed two years later without further incident.
1938: THE FALLS VIEW BRIDGE (Niagara Falls)

The 840 foot Falls View Bridge spanned a gorge near romantic Niagara Falls. That’s why it was nicknamed the Honeymoon Bridge. Sadly, the name Falls View would prove more fitting. The winter of 1938 was unusually cold, even by the standards of upstate New York. On January 23, 1938, huge volumes of ice flowing from Lake Erie tumbled down Niagara Falls and slammed into the abutment of the bridge with great force. The good news: The bridge didn’t collapse right away. Authorities were able to close it. So when the bridge did give way four days later, nobody was killed. Two years later, the bridge was replaced with the Rainbow Bridge, which is still standing today.
1940: THE TACOMA-NARROWS BRIDGE (Tacoma)

The Tacoma-Narrows Bridge’s experimental design was radically light and inexpensive to build. Unfortunately, it proved to be a complete failure. The bridge was only four months’ old when it collapsed on November 7, 1940. Heavy winds had caused the bridge to undulate. Officials closed the bridge at 10 AM. Workmen used tie down cables to try and stabilize the bridge. But their efforts were ineffective. The bridge collapsed a few hours later. The only casualty was a dog trapped in a car that had been left on the bridge.
1967: SILVER BRIDGE (West Virginia)

The Silver Bridge spanned the Ohio River connecting Point Pleasant, WV, and Kanuga, OH. Its designers had chosen to use chains and massive pins rather than conventional wiring techniques to link the bridge’s “eyebars” together. At 5 PM on December 15, 1967, at the height of the Christmas rush, there was an unusually high volume of traffic on the bridge. The extra weight caused a cleavage fracture in one of the eyebars. This in turn, caused one of the pins linking the eyebar to fracture. Unable to support the bridge’s entire weight, the southside chain snapped. Less than a minute later, the bridge fell into the river. The 46 deaths made the collapse of the Silver Bridge the bloodiest bridge disaster in U.S. history.
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-Michael
HM-181 Hazardous Materials Training
OSHA EPA

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PERCENTAGE OF U.S. BRIDGES CLASSIFIED AS FUNCTIONALLY OBSOLETE OR STRUCTURALLY UNSOUND

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-Michael
HM-181 Hazardous Materials Training
OSHA EPA