Failure Is Always an Option

                                                                    Failure is always an option

                                                                                                                ----Quebec Bridge

                                                                                                               Engr: 2110: 0AAA  Ziyang Xu

  Saint Lawrence River played a key role in the trade of Quebec, due to the low temperature in the winter, the River always filled with ice, and the trade road was completely cut off. Then the Canada Government decided to build a bridge on the river----Quebec Bridge. Funded by Quebec Bridge Corporation and built by Phoenixville Bridge Company, Quebec Bridge was prepared since 1887 with over 30 years’ construction period and cost totally more than $22 million Canadian dollar. Theodore Copper was selected as consulting engineer and this project was the pinnacle of his work. However, this project is full of challenging ----The St. Lawrence River was approximately 3.2 km (2 mi) wide at its narrowest section. Its waters were about 58 m (190 feet) deep at its middle. The velocity of the river reached 13 or 14 km/ h (8 or 9 mi/ h) at times, and the tides ranged as high as 5 m (18 ft) (Collapse of the Quebec Bridge 1907，Cynthia Pearson,2006) and the bridge was lengthened from originally designed 487.7 meters to 548.6 meters, although declared for the sake of project reality, this determination made Copper became the engineer of world longest cantilever bridge. For years, it has been viewed as an engineering marvel, but two collapse incidents occurred during the construction, one was in 1907 and another was 1916. In this paper, we will mainly narrate and explain the generating process of first incident.

  On August 29, 1907, the Quebec Bridge collapsed during its construction (as shown in Fig.1) with causing the death of 75 people and 11 injuries. When analyzing this failure from the perspective of engineering, the major cause was the serious deformation of multiple suspension rods (A9L, 9L and 9R shown in Fig. 2). The reasons triggered the deformation was that, the engineer underestimated the deal load of entire bridge and made design mistake since he was not equipped with professional knowledge about compression bar. As shown in Fig. 2 (A9L, 9L and 9R), the functions of suspension rods are to help (decentralize) the gravity of bridge body forced on pier; however, due to design negligence (the engineer undervalue the mass of the bridge), the forces on these suspension rods surpassed load, as shown in Table-3, the least over loaded elements were overloaded 17 percent, the Anchor arm is overloaded 30 percent. These mistakes finally caused the tragedy.

  Of course, except for the mistake in design, there is also some ethical problem during the construction. The engineer failed to discover problems during construction and did not communicate with company efficiently after finding problems. Therefore, when engineer discussed about solutions, the construction didn’t stop (also containing the issue of limited construction period), which also one of the reason caused the tragedy. Secondly, the main engineering Copper was 60 years old at that time; since he got some physical problems and could not stay at site for a long time, but he had the final decision-making power of whole the project, which indicated that, there was no supervision at construction site and the engineers at the site could not made decision and implement at the first time. As mentioned above Copper changed the design, make the bridge became the longest cantilever bridge also increase the difficulty of the project, which made this project beyond his knowledge and abilities. These problems can all be avoided, if the engineers be fairness and loyalty to the practitioner's associates, employers, clients, subordinates and employees, be fidelity to public needs, devotion to lofty ideals of personal honor and professional integrity, but do not try to reach which is beyond your grasp.

  With respect to the accident in design, excluding condemning, each engineering student shall learn lessons from this failure and drew experience; just as Henry Petroski mentioned in 《Success through the failure The paradox of Design》: “Designs always beget designs. However, since design is a human activity, it is also an imperfect one. Everything designed has its limitations and its flaws. This fact of design is what leads to constant change in the things around us and our behavior involving them. Inventors, engineers, and other professional designers are constantly criticizing the world of things, which is what leads to new designs for new things. The successful new thing is one that does not fail in the way that what it is intended to supersede did. This is why failure is the key to design. Understanding how things fail-and might fail-provides insight into how to redesign them successfully. But today's successful design will be tomorrow's failure, for the expectations of technology are themselves constantly being revised.” (Page 42,43). According to the Quebec Bridge incident, I think each engineering student shall put heart and soul into his/her project because more than put forward design, the more important thing during production is to discover mistake, analyze instantly before incident and propose solutions. In addition, generally, the success of a project depends on teamwork; just as we proposed, the lack of efficient communication also was the cause of incident, so coordinating team also is one of the tasks of each engineer and respect your associates. Secondly, we may face many problems in project, such as engineer’s work achievement, engineering fund and engineering time limit. However, in my opinion, these are not the most important matters, and taking responsibility for security of construction party and users’ safety is our due attitude. Besides we need always maintain modesty in our work, share the idea and the problem with colleague, never do or plan to do the things which is beyond our knowledge just because our arrogant and vanity.