Engineering Topic #2: Quebec Bridge Disaster

Topic number #2. The first one was Sputnik 1. Again, if there's anything you think would be a good topic of discussion feel free to post it up here. It can be anything from the Wheel to... well, anything complex

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Background

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. As far back as 1852 a project for a bridge over the St. Lawrence River at Quebec was considered, and again, in 1867, 1882, and 1884.

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.

First design and Collapse of August 29, 1907

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, 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 local engineering team under Norman McLure began noticing increasing distortions of key structural members already in place.

McLure became increasingly concerned and wrote repeatedly to supervising engineer Theodore Cooper, who at first replied that the problems were minor. The Phoenix Company officials were claiming 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.

But the message had not been passed on to Quebec, and now it was too late. 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 near quitting time, 75 were killed and the rest were injured. Of these victims, 33 were Mohawk steelworkers from the Kahnawake reserve near Montreal; they were buried at Kahnawake under crosses made of steel beams.

Second design and Collapse of September 11, 1916

After a Royal Commission of Inquiry into the collapse, construction started on a second bridge. Three engineers were appointed: H.E. Vautelet, a former engineer for the Canadian Pacific Railways, Maurice FitzMaurice from Britain, who worked on the construction of the Forth Bridge, and Ralph Modjeski from Chicago. Vautelet was President and Chief Engineer. 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.

http://en.wikipedia.org/wiki/Quebec_Bridge#First_design_and_Collapse_of_August_29.2C_1907
http://www.mysteriesofcanada.com/Quebec/quebec_bridge_collapse.htm
http://www.civeng.carleton.ca/Exhibits/Quebec_Bridge/intro.html
http://www.ironring.ca/
http://en.structurae.de/structures/data/index.cfm?ID=s0000479

I think this is one of the more spectacular disasters to happen over the last 100 years which is why I put it forward as a topic of discussion. It came down to Cooper's stupidity and arrogance as a person believing that he could do something spectacular, without seeing through the project professionally himself. He wished to obtain all of the credit for little or none of the work, evident since he was only on the site at construction around two or three times. The second disaster points to the dangers apparent in the lifting of bridge spans.

It's also suggested that the ritual of the 'Iron Ring' (linked above) spawned from the disasters at Quebec.

DublinDilbert

Myth wrote: »

It's also suggested that the ritual of the 'Iron Ring' (linked above) spawned from the disasters at Quebec.

I'm not 100% sure of the exact origins of the ring, but i did hear that the steel from a bridge that failed was added into the metal mix used to make the rings... When you become a professional engineer there you also get a stamp / seal which you can stamp passport photos ect for people, kinda like a commissioner for oats.

godtabh

DublinDilbert wrote: »

I'm not 100% sure of the exact origins of the ring, but i did hear that the steel from a bridge that failed was added into the metal mix used to make the rings... When you become a professional engineer there you also get a stamp / seal which you can stamp passport photos ect for people, kinda like a commissioner for oats.

Is this in america? As far as I know a PE is the same as a chartered engineer here. The stamp is used to sign drawings. When I worked there I never heard of stamping passport photos. Why would an engineer do that?

DublinDilbert

kearnsr wrote: »

Is this in america? As far as I know a PE is the same as a chartered engineer here. The stamp is used to sign drawings. When I worked there I never heard of stamping passport photos. Why would an engineer do that?

Nope its in Canada, that's where the bridge above was built. I worked as an engineer there for a few years...

My uncle there is a PE... with your official stamp you can stamp passport photos or other documents to say the people are who they say they are, basically what you get done in a garda station here... the PE is there as a witness that can be traced based on your stamp...

godtabh

DublinDilbert wrote: »

Nope its in Canada, that's where the bridge above was built. I worked as an engineer there for a few years...

My uncle there is a PE... with your official stamp you can stamp passport photos or other documents to say the people are who they say they are, basically what you get done in a garda station here... the PE is there as a witness that can be traced based on your stamp...

I thought you were talking about PE in america. Not sure if they have the same powers