8/25/11
Engineering Research
Ms. Carter
Background: The I-35W Bridge ran over the Mississippi river in Minneapolis, Minnesota. It was about 1,900 feet long and was eight lanes wide (MPR News, 2007). The bridge was made up of three parts of steel truss, the deck, superstructure, and substructure. The formation of it was a split deck, meaning the longitudinal trusses were parallel to traffic. The bridge was built and ready for traffic by 1967. The bridge on average would have about 150,000 cars drive across it each day (MPR News, 2007). As years went on, the bridge started to show signs of wear and tear. The concrete was starting to cracks and there were signs of failure all along the bridge. Minnesota Department of Transportation had a decision to make about this bridge. They could either fix the bridge by spending money on it, or leave the bridge alone, saving money but leaving some doubts about it. Well obviously, they choose to leave the bridge the way it was and save some money. On August 1, 2007 the bridge finally collapsed killing and harming innocent citizens.
Topics of Interest:
Materials Engineering: The material engineers probably faced one of the biggest problems out of the whole construction period. They had to make sure the bridge was built with all the correct materials with the right support, but done under the low budget they were given. The components or materials they selected to use had to be able to withstand every day’s wear and tear; as much as the bridge was used they obviously knew that was going to be a hard task to accomplish. In doing so, they knew that eventually some of the materials would start to fail or rust or any type of disruption, meaning that they needed to get materials that could easily be fixed or easily be repaired at a low cost. Most of the materials will need to uphold all the natural weather that will automatically occur on the bridge such as acid rain which could rust or erode pieces of steel. In thinking of this, the engineers needed to come up with a addition to the steel component they were using to at least fight off this acid rain or other weather phases. If the engineers would have came up with these new materials or materials to solve these problems, the bridge most likely could have had a longer life and it would have been easier and cheaper to fix if a problem did go wrong with the bridge.
Mechanical Engineering: Structurally the I-35W Bridge is a force to be reckoned with, with dimensions of 1,900 feet long and eight lanes wide. As stated before, the bridge is a major interstate traffic flow with carrying many people across it every day to and from Minneapolis. The constructors of the bridge knew before building it that it would need to be heavily relied on with safety because of the amount of traffic and how much traffic it could actually get on it at one point. The issue with the engineers and all other skilled workers that were used to come up with this design was that lack of or the technique of trying to save money. The reason for the less money method was that the money being used to build the bridge was a good portion of tax payer money. The engineers had to think of every think possible that could happen to the bridge and fix it to where it would not cause a problem if this thing did happen. They had to take into account all different types of ways to build the bridge, in which they finally decided on a solution of making longitudinal trusses. Also, the engineers had to think about any weather conditions that could cause this bridge a problem. So, the engineers have to design a bridge that could withstand the load of everyday traffic flow and any other scenarios that could arrive.
Engineering economics and ethics: Obviously, since the bridge collapsed the main issue was whether this bridge was built safely for the money that was available. The safety of the citizens and people driving this bridge are always the first priority over the money issue. The NSPE code of ethics states that and makes sure that safety is their major deal. They made sure there was no blurred numbers in the design of the bridge that could possibly cause a failure and that would lessen the expense of the bridge. The designs of the I-35 Bridge somehow snuck in a false or skewed number that allowed them to continue the building of this bridge with the low cost. Eventually it caught up to them, and in result many innocent bystanders were killed and injured as they saved money. The Code of Ethics is there to prevent any company from doing this now and obviously the Code of Ethics was broken by these engineers that allowed the building of the catastrophic I-35W Bridge.
Ethics Violations under NSPE:
Code Violations – Minnesota Department of Transportation
The thing with the Minnesota Department of Transportation was that they did not have to follow the exact rules that all the engineers did. They still have a code of ethics they have to follow and obviously with the bridge collapsing they did not follow them. Some of the things they did wrong were mainly just involving themselves with the engineers and deciding on some of the questions being arose. Since they were grouped together so much, the problems or non following of the code of ethics was put on both of them. The main gut of the problems came from the groups not follow the fundamental ethics which is in Section 1 of NSPE stating that the department was only looking out for what was right for them, not the safety of the citizens being involved. The engineers discussed with the Minnesota DOT about the bridge having some flaws in it and it not being in the best possible shape it can be. After their discussion, they decided to leave the bridge just like it is and save money by not repairing it. The DOT violated Section II.1.d. by associating themselves with this fake business that is not following the code of ethics and trying to slide by to save money. Section II.1.e. states that a company or firm will not aid businesses that they have found to have problems like the engineers during the bridge design which means that since the Minnesota DOT aided them, they violated this code of ethics.
Code Violations – Engineers
Again, along with the DOT the engineers failed to comply with many sections in the NSPE making this bridge design a complete unlawful thing to do. The first section they didn’t comply with is Section I just like the Minnesota DOT. The engineering firm was looking to improve their profit in the project by lowering the safety of the bridge and not putting the well-being of citizens in first. The engineers as well violated Section II.3.a by not providing all the information pertaining to the bridge design and how the testing on it was going. The engineers found flaws with the design and continued to leave them alone and hid that information from everyone which Section II.3.a states that all information must be reported in a objective and informative way.

Works Cited
(2007). Collapse of I-35W Highway Bridge Minneapolis, Minnesota August 1, 2007. Washington D.C.: National Transportation Safety Board.
MPR News. (2007, August 3). I-35W bridge fact sheet. Retrieved August 25, 2011, from Minnesota Public Radio: http://minnesota.publicradio.org/display/web/2007/08/03/bridge_background/?rsssource=1