The Quebec Bridge is a road, rail and pedestrian bridge across the lower Saint Lawrence River to the west of Quebec City, and Lévis, Quebec, Canada.
The project failed twice, at the cost of 88 lives, and took over 30 years to complete.
"The Quebec Bridge was included in the National Transcontinental Railway project, undertaken by the federal government. By 1904, the structure was taking shape. However, preliminary calculations made early in the planning stages were never properly checked when the design was finalized (in particular, they were not checked after the span was lengthened), and the actual weight of the bridge was far in excess of its carrying capacity. The dead load was too heavy. All went well until the bridge was nearing completion in the summer of 1907, when the QBRC site engineering team under Norman McLure began noticing increasing distortions of key structural members already in place.
McLure became increasingly concerned and wrote repeatedly to QBRC consulting engineer Theodore Cooper, who at first replied that the problems were minor. The Phoenix Bridge Company officials claimed that the beams must already have been bent before they were installed, but by August 27 it had become clear to McLure that this was wrong. A more experienced engineer might have telegraphed Cooper, but McLure wrote him a letter, and then went to New York to meet with him on August 29, 1907. Cooper then agreed that the issue was serious, and promptly telegraphed to the Phoenix Bridge Company: "Add no more load to bridge till after due consideration of facts." The two engineers then went to the Phoenix offices.
However, the message had not been passed on to Quebec before it was too late. Near quitting time that same afternoon, after four years of construction, the south arm and part of the central section of the bridge collapsed into the St. Lawrence River in just 15 seconds. Of the 86 workers on the bridge that day, 75 were killed and the rest were injured, making it the world's worst bridge construction disaster. Of these victims, 33 (some sources say 35) were Mohawk steelworkers from the Kahnawake reserve near Montreal; they were buried at Kahnawake under crosses made of steel beams.
After a Royal Commission of Inquiry into the collapse, construction started on a second bridge.
The new design was still for a bridge with a single long cantilever span, but a much more massive one.
On September 11, 1916, when the central span was being raised into position, it fell into the river, killing 13 workers.[19] Immediately, fears of German sabotage were reported; however, it was soon clear that another tragic construction accident had befallen the structure (a problem with the hoisting devices). Re-construction began almost immediately after the accident and special permission granted for the bridge builders to acquire the steel that was in high demand because of the War effort. The fallen central span still lies at the bottom of the river. After the bridge's completion in 1917, special passes were required for those wanting to cross the structure. Armed soldiers, and later Dominion Police, guarded the structure and checked passes until the end of the War.
Construction was ultimately completed in August 1919, at a total cost of $25 million and 89 bridgeworkers' lives. On December 3, 1919, the Quebec Bridge opened for rail traffic, after almost two decades of construction. Its centre span of 549 metres (1800 ft) remains the longest cantilevered bridge span in the world and is considered a major engineering feat."
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Le pont de Québec est un pont mixte ferroviaire et routier qui traverse le fleuve Saint-Laurent à l'ouest de la ville de Québec jusqu'à Lévis sur la rive sud.
"Avant la construction du pont de Québec, la seule façon de traverser de Québec à Lévis et vice-versa était de prendre un traversier. L'hiver, un pont de glace permettait de joindre les deux rives. Vers les années 1890, il devint évident qu'un pont ferroviaire était nécessaire.
Le pont fut construit par la Quebec Bridge and Railway Company, de propriété fédérale puisque faisant partie du National Transcontinental Railway.
Vers 1904, la structure prenait graduellement forme. Cependant, à cause d'erreurs de calcul faites durant la phase de planification du pont, le poids réel du pont excédait de beaucoup sa capacité portante. Lorsque le pont fut presque terminé, certains problèmes structurels furent remarqués par l'équipe locale d'ingénieurs, mais personne ne tint compte de la gravité de la situation à l'époque. Les travaux continuèrent malgré l'arrêt complet des travaux, ordonné par un ingénieur responsable, le 27 août 1907.
Le 29 août 1907 à 17 h 37, après quatre années de construction, la partie sud du pont s'effondra dans le fleuve St-Laurent en à peine 15 secondes, et à peine 20 minutes avant la fin de la journée de travail. Des 100 travailleurs qui s'y trouvaient, 76 furent tués, et les autres furent blessés, 33 des victimes étaient des travailleurs Mohawks de la réserve de Kahnawake, qui furent enterrés à Kahnawake sous des croix faites de poutres d'acier. Dix-sept autres victimes étaient originaires des États-Unis, et vingt-six étaient des Québécois en majorité de Saint-Romuald ou de New Liverpool, maintenant des quartiers de Lévis. La tradition orale des Hurons-Wendat de Wendake fait également état de six ou sept victimes provenant de leurs rangs.
Après une commission royale d'enquête sur le désastre de 1907, la construction d'un deuxième pont suivant le même design commença, cette fois avec Ralph Modjeski comme ingénieur en chef. Le malheur frappa à nouveau le 11 septembre 1916 alors que la partie centrale préfabriquée était en train d'être élevée en place entre les deux sections rebâties. L'effondrement tua treize personnes. La travée repose toujours au fond du fleuve.
La construction fut finalement achevée le 20 septembre 1917, au coût total de 25 millions de dollars. Le 22 août 1919, il fut inauguré officiellement par le Prince Édouard de Galles."
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