This Week in History
Catastrophe on the Québec Bridge
For the week of Monday August 26, 2002
on August 29, 1907, the Québec Bridge collapsed for the first time, killing 76 workers. The building of this bridge, which was considered at the time to be the eighth wonder of the world, represents one of the greatest civil engineering feats in Canadian history.
Construction began in autumn of 1900. Seven years later, moments before workers were to leave the worksite, the cantilever arm at the bridge's south end broke and thundered down into the water. Only 11 workers survived the crash. Among the victims who drowned or were crushed under tonnes of steel were Canadians, Americans, and several Aboriginals from Caughnawaga (Kahnawaké).
After identifying the accident's causes, which were attributed to an error in how the weight of the structure was determined, the federal government decided to rebuild the bridge. This second bridge is noted for the innovations of its designers, most of whom were Canadian. For the first time on a long-span bridge (194 m), the K-shaped pillar system, which makes assembly easier and ensures the structure's stability, was adopted. Nickel steel, which is stronger and lighter than carbon steel, was also widely used in tension members.
The two cantilever arms were completed on September 11, 1916, and then began the delicate operation to secure the centre span. Suddenly, the 4,985-metric ton arch that was suspended a few metres above water, twisted and crashed to the bottom of the river. Thirteen workers perished in this second accident, caused by a support piece breaking from the elevator system. The span was later reconstructed and attached in September 1917, after four long days were spent raising it in front of an anxious public.
After several tests were performed, the bridge was officially inaugurated on August 22, 1919. At 987 m, it remains the world's longest cantilever bridge. A marvel of Canadian engineering, the Québec Bridge has been designated a national historic site.
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