ABSTRACT
At the time of its construction, the 1800 ft span cantilever bridge across the St. Lawrence River in Quebec, Canada was going to be the longest cantilever bridge in the world. However, on August 29, 1907, during its erection, the bridge collapsed killing 75 workers. A commission of prominent international engineers was formed by the Canadian Government to investigate the collapse of the Quebec Bridge. It was decided to build a new, but much heavier and stronger, cantilever bridge adjacent to the old failed bridge. On September 11, 1916, after the center span was raised successfully 12 to 15 feet, it suddenly fell into the St. Lawrence River killing eleven workers and injuring six. The St. Lawrence Bridge Company, which was erecting it, took full responsibility for the collapse of the second bridge and placed orders for the new steel. The new center span was successfully hoisted for the third time and put in place on September 18, 1917 using the same lifting procedure that was used in 1916. The new bridge was opened to traffic 100 years ago, on December 3, 1917. This paper provides the details of the old and new bridges, and the people connected with them.
