Cantilever bridge

Quebec Bridge

Canada Sainte-Foy–Sillery–Cap-Rouge national historic site of Canada
Quebec Bridge
Quebec Bridge · Wikipedia

About

The Quebec Bridge (French: pont de Québec) is a road, rail, and pedestrian bridge across the lower Saint Lawrence River between Sainte-Foy (a former suburb that in 2002 became the arrondissement Sainte-Foy–Sillery–Cap-Rouge in Quebec City) and Lévis, in Quebec, Canada. The project failed twice during its construction, in 1907 and 1916, at the cost of 88 lives and additional people injured. The bridge eventually opened in 1919. The Quebec Bridge is a riveted-steel truss structure and is 987 metres (3,238 feet) long, 29 metres (95 ft) wide, and 104 metres (341 ft) high. Cantilever arms 177 metres (581 ft) long support a 195-metre (640 ft) central structure, for a total span of 549 metres (1,801 ft), still the longest cantilever bridge span in the world. (It was the all-categories longest span in the world until the Ambassador Bridge was completed in 1929.) It is the easternmost (farthest downstream) complete crossing of the Saint Lawrence River. The bridge accommodates three highway lanes (there were none until 1929, when one was added; another was added in 1949 and a third in 1993), one rail line (two until 1949), and a pedestrian walkway (originally two). At one time, it also carried...

Before the Quebec Bridge was built, the only way to travel from the south shore of the St. Lawrence in Lévis to the north shore at Quebec City was to take a ferry or to use the wintertime ice bridge. The construction of a bridge over the St. Lawrence River at Quebec was considered as early as 1852. It was further discussed in 1867, 1882, and 1884. After a period of political instability during which Canada had four prime ministers in five years, Wilfrid Laurier, the Member of Parliament for the federal riding of Quebec East, was elected on a Liberal platform in 1896 and led the push to build the Quebec Bridge until he left office in 1911.

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 Quebec Bridge was included in the National Transcontinental Railway project, undertaken by the federal government. The Quebec Bridge Company was first incorporated by Act of Parliament under the government of Sir John A. Macdonald in 1887, later revived in 1891, and revived for good in 1897 by the government of Wilfrid Laurier, who granted them an extension of time in 1900.

Quebec Bridge

In 1903, the bond issue was increased to $6,000,000 and power to grant preference shares was authorised, along with a name change to the Quebec Bridge and Railway Company (QBRC). An Act of Parliament the same year was necessary to guarantee the bonds by the public purse. Laurier was the MP for Quebec East riding, while the president of the QBRC, Simon-Napoleon Parent, was Quebec City's mayor from 1894 to 1906 and simultaneously served as Premier of Quebec from 1900 to 1905. [ citation needed ]

Edward A. Hoare was selected as Chief Engineer for the Company throughout this time, while Collingwood Schreiber was the Chief Engineer of the Department of Railways and Canals in Ottawa. Hoare had never worked on a cantilever bridge structure longer than 300 feet (91 m). Schreiber was assisted until 9 July 1903 by Department bridge engineer R.C. Douglas, at which time Douglas was deposed for his opposition to the calculations that were submitted by the contractors. Schreiber subsequently requested the support of another qualified bridge engineer, but was effectively overruled by the Cabinet on 15 August 1903. Thereafter, QBRC consulting engineer Theodore Cooper was completely in charge of the works. On 1 July 1905, Schreiber was demoted and replaced as deputy minister and chief engineer by Matthew J Butler.

By 1904, the southern half of the structure was taking shape. However, preliminary calculations made early in the planning stages were never properly checked when the design was completed. 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: the bridge’s dead load was proving too heavy, with its own weight being far in excess of its carrying capacity. [ citation needed ]

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 27 August 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 went to New York to meet with him two days later. Cooper 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 went to the Phoenix offices. [ citation needed ]

Cooper's message was not passed on to Quebec before it was too late. Near quitting time on the afternoon of 29 August, after four years of construction, the south arm and part of the central section of the bridge collapsed into the St. Lawrence River in 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.

Quebec Bridge

On 30 August 1907, a Royal Commission of inquiry into the disaster was provisionally appointed by the Deputy Minister in charge of the Department of Railways and Canals (Butler), with the concurrence of the Minister. The Royal Commission, which was granted by Edward VII by advice of his Governor General, Albert Grey, on 31 August 1907, consisted of three members, who were all engineers of good standing: Henry Holgate, of Montreal, JGG Kerry, of Campbellford, Ontario, also an instructor at McGill University, and Professor John Galbraith, then dean of the Faculty of Applied Science and Engineering at the University of Toronto. The Commission document conferred upon the commissioners full powers to summon witnesses and documents, and to express "any opinion they may see to express thereon".

The Commissioners included the hindsight work of consulting bridge engineer C.C. Schneider, of Philadelphia (a fulfillment of the 1903 request of Schreiber, supra), and presented their Report in full on 20 February 1908, which issued 15 conclusions.

The Commissioners attributed responsibility for the failure to two men, consulting engineer Theodore Cooper and Peter L. Szlapka, Chief Designing Engineer for Phoenix Bridge Company:

(c) The design of the chords that failed was made by Mr. P.L. Szlapka, the designing engineer of the Phoenix Bridge Company

(d) This design was examined and officially approved by Mr. Theodore Cooper, consulting engineer of the Quebec Bridge and Railway Company.

Quebec Bridge

(e) The failure cannot be attributed directly to any cause other than errors in judgment on the part of these two engineers.

Cooper escaped penal sanction. It is presumed that Szlapka escaped as well. The Commissioners also found that:

(k) The failure on the part of the Quebec Bridge and Railway Company to appoint an experienced bridge engineer to the position of chief engineer was a mistake. This resulted in a loose and inefficient supervision of all parts of the work on the part of the Quebec Bridge and Railway Company.

The abortive construction of the Quebec Bridge spanned the careers of two Ministers of Railways and Canals, and one temporary replacement, who was on the job for five months immediately preceding the disaster. A popular myth is that the iron and the steel from the collapsed bridge, which could not be reused for construction, was used to forge the early Iron Rings that started to be worn by graduates of Canadian engineering schools in 1925.

Drawing of the original design of Quebec Bridge