Engineering Class Project
Introduction Engineers have a huge responsibility to ensure that their structures are safe for the public’s health and welfare. Therefore, the wellbeing of the public can only be maintained if the engineers adhere to the standards and code ethics and maintain their professional obligation in high regard. Maintaining high safety standards goes a long way in ensuring the overall safety of the structure when completed. If the professionals involved do not stick to the codes and Canons, there are high chances that a disaster would occur. Two engineering disasters that have occurred in the US are the collapse of the Tacoma Narrows Bridge and the collapse of the Hyatt Walkway. This project seeks to discuss the important facts about the two engineering failures with a keen interest on the potential ethical issues that led to the disasters. In addition, the write up will address the economic, social, or environmental implications of the disasters and examine possible measures that could have been taken to prevent their occurrence. Background Information On July 17, 1981, there was a tea dance party hosted at the atrium lobby in the Hyatt Regency Hotel, located in Kansas City, Missouri. The hotel had been commissioned about a year before the event.
Like in most parties, people were dancing while others were standing all over. Additionally, some people were having fun on the suspended walkways. Because of too much weight, the connections that supported the walkways on the second and fourth floor failed. Within a short while, the two walkways collapsed on a large crowed of people on the first floor. According to Moncarz (2000), this resulted to the death of 114 people while more than 200 were injured.
Most importantly, this was not the first time that the hotel had collapsed. On 14, Oct, 1979, there was a first collapse while the structure was still under construction; more than 2700 square feet had collapsed as a result of the failure the roof connection. However, the engineers involved promised to review the connections and strengthen the structure. However, the owner of the hotel could not agree to incur additional cost for the process. On the other hand, the first Tacoma Narrows Bridge had been constructed in Washington State. It was a suspension bridge that connected the Kitsap Peninsula to Tacoma city.
There had been high interests in the construction of the bridge way back in the 18180s. However, the parties involved could not agree on what exactly was to be constructed. During the 1920s, government and business interest in a bridge grew and engineers were consulted to present a proper design for a bridge. According to Guyer (2010), Joseph Straus and David Steinman were the two bridge engineers tasked with the job. However, after Steinman had presented his design, the Tacoma Chamber if Commerce suspended his contract in 1931 on allegations that he was not able to raise funds for the project. Later on, Eng.
Leon Moisseiff was a warded a construct for his $8million bridge design. This was much cheaper than the previous design by Eldridge that was worth 11 million. In June 1938, the Public Works Authority approved $6million for the job. Construction commenced in 1938 and was completed within 19 months (Petroski, 1995). The bridge was opened in July 1940 but collapsed after only 5 months; November 1940.
Technical Details That Led To the Collapse During construction of the Hyatt Walkway., the fabricator avoided threading the entire rod so as to install the nut and the washer. Instead, he attached the top ends of the support rods of the third and fourth floor to the atrium roof while the bottom ends were passed through the box beam that had been threaded with the washer and nut. Smilarly, the box beam was attached with a second rod only four inches apart with the first rod. The same design was applied on both the second and forth walkways.
However, in a sworn testimony, the fabricator argued that he had called the engineers and asked for change approvals while the engineers claimed that they never received any call from the fabricator. Even if the engineers had worked with the previous design, the walkways would not be able to support the expected weight. Therefore, they wouldn’t meet the building requirements of Kansas City; the minimum support value should be 151kN and yet the design had 90kN (Moncarz &Taylor, 2000). Documented evidence shows that the beams of the upper bridge box were deformed. This is a clear indication that there was a hanger pullout. Similarly, the rods on the east side were vertical and straight after the failure.
On the other hand, the rods on the west side had an inclination. From the evidence, it is could be stated that the hanger pullout started on the east side. The most symmetrical deformations were witnessed at the central point of the three connections on the east which indicates that the failure started on the east. The construction of the Tacoma Narrows Bridge also had its failures. First, Moisseiff claimed that his design was based on the elastic distribution theory. According to his theory, the main cables were stiff and therefore they would absorb the wind’s static pressure.
This energy would then go to the towers and anchorages. Therefore, he opted for 8ft deep plate girders instead of the 25 ft deep trusses that the Washington Department of Highways had proposed. Moreover, because design had project fairly light traffic to use the bridge, only two opposing lanes measuring 39feet in total, had been constructed (Guyer, 2010). This was relatively too narrow compared to the length. It was a big mistake to use narrow and shallow girders too because the deck was insufficiently rigid and could easily be moved by wind.
Ethical Issues One ethical issue that is clear in the Hyatt Walkway disaster is lack of communication. On one hand, the fabricator says he called the engineers and asked them to change the design while the designers on their part claim that they did not get any communication from the fabricator. One very important code of conduct in engineering is honest and impartiality. Either the designer or the fabricator is not honest with the clients. It is unclear how one could claim to have communicated with the other and the other rejects such claims. In line with honesty, American Society of Civil Engineering (2012) deserves that engineers issues public statements backed by truthful and objective evidences.
Clearly, this was not the case in the disaster. Similarly, the engineering firm confirmed that it received revised designs during construction and even went ahead and stamped. This is a confirmation that they agreed to the new drawings and therefore authorized construction. According to canon 1, engineers are only supposed to seal or approve design documents that are safe for the public based on the accepted engineering standards. It is unfortunate that the engineering firm approved design documents that were not safe for the public welfare. As mentioned above, the revised design document did not conform to the construction requirements of Kansas City.
It was less capable of supporting the desired forces as required by the building codes. Canon 2 requires that engineers should only perform assignments that they are competent to undertake (ASCE, 2012). Therefore, they should be qualified by experience or education to accept technical work. Bridge construction is clearly not an easy task and any engineer willing to take up such a task should be sure of his qualities. The fact that the designers came up with a new design that did not comply to Kansas’ building codes indicates that the designer was incompetent. He therefore acted unethically.
The Tacoma Narrows Bridge also had a number of unethical issues that need to be addressed. To begin with there had been no suspended bridge in Washington before. Therefore, this was a new idea that required that any engineer willing to take up the job must have had the necessary academic qualification and experience (Petroski, 1995). Clearly, Eng. Leon Moisseiff lacked the necessary qualifications because if he did, it would not have collapsed. One peculiar issue about his design is that it was cheaper than Eldridge’s design.
Moreover, his theory of elastic distribution was clearly not practical in this particular situation. Therefore, the problem is that the construction of the bridge was based on theoretical knowledge that, in itself, was inadequate. In such a scenario, experience knowledge should come into play. According to canon 6 of ACSE, engineers are supposed to behave in a manner that will uphold their integrity (ASCE, 2012). Therefore, they should not compete unfairly for constructs. It is clear that Eng.
Leon Moisseiff won the contract because of his cheap price. Unfortunately, he compromised on the quality of the work. This could be termed as a fraudulent act because the client could have picked Eldridge’s design or any other design but was expensive but reliable. Because of Moisseif, other competent engineers missed out on the contract. Although competition for contracts is healthy in any profession, clients should not be driven to take designs that cannot deliver safety and time consideration with reasonable budget.
Sometimes cheap contractors could deliver very poor structures. Economic/Environmental/Social Impacts Both projects definitely had adverse economic impacts. Huge resources had been spent in the design and construction of the projects. It is very unfortunate that all that was destroyed in a few second. In addition, extra resources were spent on court cases looking for compensations. However many expensive legal suits in the Hyatt Walkway were settled away from the courts (Kaminetzky, 1991).
In addition, many principles in the engineering profession were reaped off their licenses because of their unethical behavior. Most of them were accused of gross misconduct, negligence and unprofessional behavior. Therefore, this affected their livelihood because they could not practice the profession that gives them food.However, more important is that many people lost their lives. While the clients could be compensated, the cost of life is irreplaceable.
114 lives were lost in the Hyatt Walkway tragedy while more than 200 others suffered injuries (Kaminetzky, 1991). Several firm that were involved in the project went bankrupt because they had spend so much money but they could not be paid back. In addition, the families of those who lost their lives in the disasters suffered a lot. In the case of the Tacoma Narrows Bridge, tones of steel that had been used for construction were later sold as scrap metal. There was a shortage of steel supply because of the World War II and not construction repairs could be made. Moreover, people were very skeptical of the firms involved and they found it very difficult to earn other contracts (Guyer, 2010).
Conclusion The right thing that could have been done with Tacoma Narrows Bridge project would have been to award the contract to Eldridge. Although it was expensive, it was a better design. Therefore, more experience was needed than theoretical knowledge. Similarly, for the Hyatt Walkway, proper communication between the professions involved and a proper design would have saved the day.