Quebec Bridge: Meaning (information, definition, explanation, facts)

The Quebec Bridge is a Canadian bridge. It is the largest cantilever bridge in the world and crosses the lower Saint Lawrence River west of Quebec City, Quebec. The Quebec Bridge is a riveted steel-truss structure and is 3239 feet long, 94 feet wide, and 340 feet high. It presently accommodates both three highway lanes, one rail traffic line, and two pedestrian walkways. At one time it also carried a streetcar line. Each cantilever span is 580 feet long.

The Quebec Bridge is owned by the Canadian National Railway.

History

The collapse of August 29, 1907

Before the Quebec Bridge was built, the only way to travel from the south shore of the St. Lawrence in Levis to the north shore at Quebec City was to take a ferry. By the 1890s, a bridge was needed. A March 1897 article in the Quebec Morning Chronicle noted:

The bridge question has again been revived after many years of slumber, and business men in Quebec seem hopeful that something will come of it, though the placing of a subsidy on the statute book is but a small part of the work to be accomplished, as some of its enthusiastic promoters will, ere long, discover. Both Federal and Provincial Governments seem disposed to contribute towards the cost, and the City of Quebec will also be expected to do its share. Many of our people have objected to any contribution being given by the city unless the bridge is built opposite the town, and the CHRONICLE like every other good citizen of Quebec would prefer to see it constructed at Diamond Harbor, and has contended in the interests of the city for this site as long as there seemed to be any possibility of securing it there. It would still do so if it appeared that our people could have it at that site. A bridge at Diamond Harbor would, it estimated, cost at least eight millions. It would be very nice to have, with its double track, electric car track, and roads for vehicles and pedestrians, and would no doubt create a goodly traffic between the two towns, and be one of the show works of the continent.

The bridge was built by the federally-owned Quebec Bridge and Railway Company, as part of the government's National Transcontinental Railway, but was contracted to the Phoenix Bridge Company of Pennsylvania. Construction began in 1903 under the direction of famous American engineer Theodore Cooper after the federal government allocated funding. It was designed to span the river's shipping lane and measured 26.5 meters (67 feet) wide, carrying two railway tracks, two streetcar lines, and a two lane road.

By 1904, the structure was taking shape. However, due to miscalculations made during the planning stages, the actual weight of the bridge was far in excess of its carrying capacity. When the bridge was nearing completion, structural problems were noticed, but the local engineering team did not recognize the gravity of the situation. Work continued despite the fact that the consulting engineer ordered all work to be halted on August 27, 1907. On August 29, after four years of construction, the south arm and part of the central section of the bridge collapsed into the river in just 15 seconds. Of the 86 workers on the bridge that day near quitting time, 75 were killed and the rest were injured.

The collapse of September 11, 1916

After a Royal Commission of Inquiry into the collapse, construction started on a second bridge following a similar design. Disaster struck again on September 11, 1916, when the pre-fabricated center section was being lowered into place between the rebuilt iron span. The collapse killed 11 men.

Completion

Construction was ultimately completed in August 1919, at a total cost of $25 million. On December 3, 1919 the second Quebec Bridge opened for rail traffic, after almost two decades of construction. Its center span of 576 meters (1890 feet) remains the longest cantilevered bridge span in the world and is considered a major engineering feat.

Post-completion history

The bridge was declared an historic monument in 1987 by the Canadian and American Society of Civil Engineers. On January 24, 1996, the bridge was declared a National Historic Site of Canada.

• The Quebec Bridge's "sister bridge" is the Firth of Forth Bridge of Scotland.
• A portion of the collapsed bridge has been used over the past century to smelt rings used in the Iron Ring issued in the Ritual of the Calling of an Engineer ceremonies, administered for graduating Canadian engineering students. These portions of the collapsed Quebec Bridge, carried on the little finger of the working hand of every Professional Engineer in Canada are meant to serve as a reminder to engineers of their social responsibilities to follow the ethical requirements of their profession.
• The Pierre Laporte Suspension Bridge opened in 1970 just upstream to accommodate highway traffic on Autoroute 73.