Causes of Major Engineering Disasters Since 1800 - Term Paper Example

Causes of Major Engineering Disasters Since 1800 On September 11, 2001, the world saw not only one of the worst terrorist attacks but also one of the worst engineering disasters in history. The World Trade Center twin towers totally collapsed after being hit by planes in just a matter of minutes. Historically, a few other numbers of engineering disasters have caught the attention of the world not only because of the magnitude of the ensuing damage but also because of the number of casualties involved. Many of these engineering disasters are buildings, bridges, airplanes, space shuttles, nuclear power plants and ships. Many of the causes of these engineering disasters were attributed to human flaws like errors in decisions and negligence, design flaws, material failures, extreme environmental conditions and a combination of any of these factors. Human Flaws Human flaws have been accounted for in a number of engineering disasters, particularly in aeronautics and nuclear plants. Human errors in making critical decisions or simply pure negligence in executing dangerous protocols have caused many engineering disasters to happen costing the lives of many people. One of the major engineering disasters involving human error occurred in the sea. This was the Titanic disaster of 1912. Titanic. The Titanic had the reputation of being the world’s largest ship equipped with the latest in marine technology which made many thought it was unsinkable. It was equipped with 16 compartments which cannot be broken into by water, and could be sealed off from each other with the press of a button. On April 14, 1912, the ship’s side hit an iceberg ripping its side and six of its watertight compartments. In a mere two hours and a half the ship sank head first killing about more than two-thirds of its passengers while the rest were rescued an hour later (Unger 61-62). The immediate cause for the Titanic disaster was failure of the crew to exercise care in an area known to be littered with icebergs. As a matter of fact, another ship it had passed 70 minutes before it hit the iceberg warned the captain to be careful because an iceberg had just damaged its own rudder. The Titanic however, did not decrease its break-necking speed nor were crewmen handed binoculars and told to be carefully on the lookout for them (Unger 62-64). Materials Failure Many engineering disasters were also caused by the failure of materials used in the construction of the device or infrastructure. One of such disaster was the explosion of the space shuttle Challenger in 1986, several minutes after launch. Challenger Space Shuttle. On January 28, 1986, the 25th shuttle mission of the National Aeronautics and Space Administration (NASA) was scheduled to take off. Seventy-three minutes into the take off however, the space shuttle Challenger, carrying seven astronauts, exploded. Previous to the launch, some of the people at NASA argued against pursuing it because of the temperature forecast which was expected to fall below 0 degrees. They argued that the seals, which kept the hot combustion gases from getting out from the inside of the motor, were sensitive to low temperatures. Senior management, however, decided to press on with the launch. During the ignition phase of the launch, the O-rings (see Fig 1) did not seat well because they were too cold and thus let out flame from the rocket booster damaging the fuel tank on the outside. The tank caught fire, exploded, killing all people inside the shuttle and left billions of dollars in damages. The blame was placed on the poor design of the O-ring (Delatte 346-348). Design Flaws Design flaws on device construction occur from time to time but most are discovered and corrected during testing and evaluation of the system before the device is approved or released. When the design flaws however escaped detection during this phase they could resurrect and haunt its makers when a major disaster strikes that takes a considerable number of human casualties (Horenstein 233-234). Such is the case of the Hyatt Regency Crown Center walkways in Kansas in 1981, the Tacoma Narrows Bridge in 1940, and the Hartford Civic Center in 1978. Fig 1 Space Shuttle O-Ring Point & Configuration Hyatt Regency Crown Center Walkways. The Hyatt Regency Crown Center located in Missouri, Kansas opened in September 1980 after four years of construction. The complex consists of a tower which is 40-story high, another separate building serving as a function block and an atrium in the middle of the two buildings. Inside the atrium are walkways, three of them, which connected the tower and the function block at the second, third and fourth levels. Nearly a year later, or on July 17, 1981, the second and fourth skyways collapsed (see Fig 2) taking with them the lives of 114 people and injuring scores of others (Delatte 10). Fig 2 The collapsed Hyatt Regency Crown skywalks The cause of the collapse was traced to the inability of the rods, which held the suspended walkways of the second and fourth levels, to handle the load which at the time of its collapse included 1,500 to 2,000 people who were watching a dance competition held on the atrium ground floor. The fourth and the third level walkways were suspended independently from the ceiling with 32-mm. rods while the second level walkway, directly located below the fourth, was suspended from the latter’s beam. The lack of redundancy of load paths for the rods caused the collapse as the rest of the rods collapsed after an adjacent rod pulled through the beam box (Delatte 11). Tacoma Narrows Bridge. The Tacoma Narrows Bridge was constructed in 1940 and was patterned after short span suspension bridges. To make the bridge graceful and easy to the eyes, there were no stiffening trusses built into the innermost structure of the bridge like short span, suspension bridges except that the Tacoma Bridge was the deemed the longest bridge in that period. Believing that the short suspension bridges’ structural soundness would prove true to the longer version, no calculations as to whether the bridge could hold up even without the stiffening trusses (Horenstein 233). Fig 3 Collapsed Tacoma Narrows Bridge On November 7, 1940, however, the bridge started to swing back and forth and twist with the wind and eventually the center main span of the bridge broke up (see Fig. 3). After investigation, the Federal Works Agency concluded that although the bridge was built to withstand static forces like the wind, its ability to move too much, because of its lightness and narrowness, had ultimately caused too much stress on its suspenders and damaged them (Delatte 30-31). Harford Civic Center. The Harford Civic Center was a unique building in the 1970s in that instead of the I-beam design as frame structure of its roofing, there were instead hundreds of trusses that were interconnected and joined together which gave the roof a visually unique and appealing design (see Fig 4). Engineers relied on computations made on a computer mainframe that did not have the capacity to make detailed calculation like the PCs of today and as a consequence, the computational process involved ignoring “susceptibility of the structure to torsional buckling modes” (Horenstein 233-235). Fig. 4 The frame roofing structure of the HCC Fig. 5 The collapsed roof of the Harford Civic Center A snowstorm, believed to be the largest in five years, poured on Harford on January 18, 1978 and the roof cave in (see Fig.5). Luckily, the arena was empty although hours earlier it was filled with people. The Lev Zerlin Associated, Inc, hired to determine the cause of failure, reported three design flaws: an overloading by 852% in some parts of the roof; an overloading by 213% in another part, and; a 72% overloading in still another part. In addition, there were violations of the American Institute of Steel Construction Code that were found (Delatte 177-179). Extreme Environment Conditions Natural at its relentless worst could bring about engineering disasters. Engineering designs and structures are tested when nature strikes. Storms, typhoons, snowstorms, earthquakes, mudslides and in the case of New Orleans in 2005, hurricanes, can put to a test the structural integrity and soundness of engineering works. New Orleans levee. New Orleans stands on land that was formed by sediment carried to it through the years by the Mississippi River. The city was originally founded on high ground but the underlying land made of soft sand, clay and silt gradually sank placing the entire city below sea level. In 1956, Congress authorized the building of structures to protect the city from flooding and the USACE (United States Army Corp of Engineers), tasked with the job, built three types of walls: I-walls, T-walls and levees (Delatte 289). On August 29, 2005, hurricane Katrina made a landfall on New Orleans and the city was flooded with water up to a depth of 10 feet. Levees and walls were breached (see Fig.6). More than a thousand people died and many perished and damage was pegged at billions of dollars. It was the first time in history that an engineering failure almost wiped out an entire city. The engineering disaster was blamed on the failure to take into consideration the marsh layer of the New Orleans under soil that brought about seepage and subsurface erosion (Delatte 289-290). Nevertheless, the extreme weather condition that the hurricane Katrina brought has also contributed greatly to the New Orleans engineering disaster. Fig. 6 New Orleans Canal Levee after Katrina The major engineering disasters that have occurred since 1800 have been attributed to such causes as human flaws, design flaws, material failures, extreme environmental conditions and a combination of any of these factors. The sinking of the Titanic, for example, was attributed to the negligence of the captain to heed the warning that the ship was cruising an area of the sea that was filled with iceberg. Material failures have taken the lives of the seven occupants of the space shuttle Challenger although a decision error was also known to have been one of the causes. Many engineering disasters can be attributed to the inadequacy of the materials used in the construction of structures or devices. Such was the case of the walkways of the Hyatt Regency Crown whose suspended rods were not able to support the load of hundreds of people who were perched on them, the Tacoma Narrows Bridge and the Hanford Civic Center. In the New Orleans case, both extreme conditions and design failure caused an entire to almost perish. Works Cited Delatte, Norbert. Beyond Failure: Forensic Case Studies for Civil Engineers. ASCE Publications, 2008. Horenstein, Mark. Design Concepts for Engineers. Prentice Hall, 2009. Unger, Stephen. Controlling Technology: Ethics and the Responsible Engineer. Wiley-Interscience publication. Wiley-IEEE, 1994 Read More