1.0 Terms of Reference
This formal report has been written for students, government agencies and engineering development companies. Forecasting it to be completed before the 18th May 2015, It serves the purpose of assisting and providing insight to people conducting researches pertaining to this specific topic, whether it is to understand the previous errors made in construction or to improve static structural building standards based on history failures. As acknowledged by the writer, this chosen topic is one of which contains ample debates ranging from a diverse band of perceptions. Hence, the scope of this report will purely cover how the World Trade Centre collapsed on September the 11th 2001 from scientific; mathematical, structural and
…show more content…
Key words inputted for search in various search engines included but were not limited to: New York City engineering failures; World Trade Centre collapse; Structural analysis of the Twin Towers disasters. Search engines used were Google, Bing, Yahoo and Ask. Once information was retrieved and examined for relevance they were read, understood, paraphrased and concluded for the writing of this report.
3.0 Findings
On September 11th 2001 two Boeing 767 planes of mass 200 ton loaded with 90,000L of jet fuel crashed into the Twin Towers of the World Trade Centre. Between 9:59am and 10:28am both towers collapsed.
3.1 Collapse of the Twin Towers Due to Aircraft Impact and Jet Fuel Explosion
3.11 The impact
Although the World Trade Centre (WTC) was initially designed with confidence to stand against the impact of a Boeing 707-320 commercial aircraft, it was hit by a Boeing 767-200. The destructive force from the impacting aircraft contained a 15% extra maximum takeoff weight when compared to the original Boeing 707, which also had a 4% smaller fuel tank capacity. As the plane traveled at 550km/h it had an instantaneous impacting speed of
…show more content…
From the impact and the explosion, sprinkler systems were disabled and rapidly temperature from the fire increased to a maximum of approximately 1000ᴼC. The WTC was constructed from light structural steel with a melting point of 1510ᴼC but this material softens around 425ᴼC and loses 60% of its yield strength above 600ᴼC which consequently weakened the entire structure.
This temperature was reached as the diffuse hydrocarbon fuel when bursting into the atmosphere uncontrollably mixed with the oxidant to satisfactory ratio and would burn at an ambient temperature near 3000ᴼC. However, this is true only for burning under hydrogen; air in this situation was mainly of oxygen and nitrogen. For the release of a molecule of carbon monoxide and di-hydroxide; reaction with two molecules of oxygen and four molecules of nitrogen occurs when compared hydrogen burning where it only requires two molecules in total. This reduces the maximum temperature of the flames down to approximately 1000ᴼC.
3.13 Response of the Interior of the Tower after Prolonged
It’s a normal day at work when suddenly there is an explosion, trapping hundreds of people inside collapsing buildings covered in rubble. Coworkers, friends, and family are gone, never to be seen again, lost to senseless acts of terrorism. In 1993, 1998, and 2000, these events came to pass in the form of terrorist bombings on U.S. targets across the globe. The World Trade Center complex was a symbol of wealth and prosperity, but quickly became the target for radical Muslims and was attacked early in 1993. Despite this attack, the American people did not think that the terrorist organization behind the attack, al-Qaeda, was much of a threat, failing to properly respond to the attack and prepare for the future. Five years later and across the globe, another bombing occurred. This attack targeted the U.S. embassies in the African countries of Kenya and Tanzania. Again, the U.S. was distracted from the incident and did not react in a proper manner. Finally, in 2000, the U.S. was again subjected to a terrorist attack, this time on a naval warship docked in Yemen. The country again looked on in horror as the unthinkable happened, leaving people to again question their safety. Although these attacks on American targets were devastating, the United States should have learned from its mistakes to better prepare and defend against the September 11th attacks.
The bombing of the World Trade Center was nicknamed “the Big One”, causing a sixteen alarm fire. FEMA’s Incident Commander (IC) arrived on the scene at 12:48 and began assessing what needed to be done: over 50,000 people needed to be evacuated, thick black smoke was filling the building and could not stopped, numerous people were trapped in elevators and personnel on the top floors were breaking glass raining it down on personnel on the ground.
Jones, Steven E. “Why Indeed Did the WTC Buildings Completely Collapse?” Journal of 9/11 Studies 3 (September 2006): 1-48. 26 August 2008. http://www.journalof911studies.com/volume/200609/WhyIndeedDidtheWorldTradeCenterBuildingsCompletelyCollapse.pdf.
The official story of 9/11 is a conspiracy theory in that the government claims 19 hijackers conspired together to hijack four planes and create terror in the world. Four American airplanes were hijacked; two were driven into the World Trade Centers and the third airplane into the Pentagon. The fourth airplane suspected target was the White House, but it was diverted by the brave men and women aboard that hijacked airplane, and crashed the airline jet before it could reach its target. It was like time stood still as America watched through television broadcast these unbelievable and horrifying events taking place. The reports told of the smell the jet fuel, burning flesh, and people jumping out windows to their death to escape the flames. When the two bravura structures tumbling down, rescuers, (police officers, firefighters, and ambulance drivers and techs) were caught in the mast and lost their lives doing their job trying to save lives.
Military members and civilians were killed in the Pentagon along with the passengers aboard the airplane. 15 minutes later the South Tower of the World Trade Center collapsed. At 10:30 a.m. the North Tower collapsed, leaving over 10,000 injured civilians and more than 3,000 killed. Meanwhile, while all these events occurred a fourth airplane was hijacked.
Soon after, Flight 175 attacked the South Tower. By the end of the day, both towers had collapsed and other hijacked flights had caused damage. The amount of lives lost on September 11 was substantial; 2,749 people from eighty-three different countries died from the attacks (Facts about the attacks., n.d.). All in all, America has changed forever. Research Many conspiracy theories have been developed concerning what happened to the World Trade Centers on September 11, 2001, but there are a select few that, similar to the truth, cannot be disproved without quite a bit of effort.
Skyscrapers are amazing! Architectural defeats. Wonders of the world. How are they able to withstand even the strongest of winds and earthquakes?
On September 11, 2001, the Islamist terrorist group known as al-Qaeda launched a series of terrorist attacks on the United States of America, specifically in the New York City and Washington D.C areas. Nineteen al-Qaeda terrorists hijacked four planes with the intention of using them as suicide attacks that would crash those planes into designated buildings, or targets. Two of the four passenger jets were flown into the twin towers of the World Trade Center in New York City, both of which collapsed entirely within two hours of being hit. The third plane was crashed into the Pentagon, and the west side of the building, which is the Headquarters of the US Department of Defense, partially collapsed. The fourth hijacked plane was intended for the US Capitol Building in Washington D.C, but instead crashed into a field in Pennsylvania after the passengers of the plane interfered with the hijackers. The attack on September 11th was devastatingly fatal—almost 3,000 people died in the attacks, including all of the al-Qaeda hijackers and every passenger aboard the four planes.
Flight 77, and that the heat and explosion from the initial crash caused the towers structure to
September 11th, 2001 is one of the worst days in the United States of America’s history by far. It all began at 8:45am when a stolen airplane crashed into the north tower of the World Trade Center. Many people believed that this was...
At 8:46 a.m., the United States witnessed the first terroristic attack of many to come when American Airlines flight 11 crashed into the World Trade Center’s North Tower in New York City. Flight 11 impacted the tower between floors 93 and 99 ...
When the design for the World Trade Center was first envisioned, the magnificence of its structure was expected to surpass the greatest feats of Civil engineering in the world. When the Center was completed in 1973 it gained the distinction of being the world’s tallest tower. It gained the type of attention that was given to the Eiffel tower and the Empire State Building as it was too going to break records and inspire greatness by its simple but massive stature. It was to also have social, ideological, political, and economic impact on the US and the world as well as that of its engineering aspects. To America it would represent proudly the might of its capitalist society. It would also be a home of thousands of political and financial employees of the US as well as the nations that participate in trade with the US. The NY and NJ port authorities began contemplating building a World Trade Center in 1961; the same year JFK announced his intent to put a man on the moon before the end of the decade. Such lofty ideas challenged the present technological boundaries and were successful in stretching those walls ever further.
On September 11th, 2001 at the World Trade Center 2,749 people were killed when hijacked American Airlines Flight 11 and United Airlines Flight 175 were crashed into the north and south towers. 412 of them were rescue workers who came to help. 147of them were passengers or crew members on the two flights. 102 Minutes by Jim Dwyer and Kevin Flynn, the title referring to the time between when the first airplane hit the north tower and the south tower collapsed, tells the stories of what is happening inside the Twin Towers on September 11th and the fight for survival under unimaginable conditions.
There were several conspiracies about the planes that attacked the Twin Towers. One of the planes left Boston's Logan Airport at 7:59 a.m. The hijackers zoomed the plane into the North Tower of the World Trade Center at 8:46 a.m. The other plane left Logan Airport at 8:14 a.m. The hijackers flew the plane into the South Tower of the World Trade Center at 9:03 a.m. America had stated that 10 planes were suppose to be hijacked on that day. “Providing new details on the planning of the plot, the commission staff said that al-Qaida planner Khalid Shaihk Mohammed initially proposed a Sept. 11 attack involving 10 planes that would be used to attack CIA and FBI headquarters, unidentified nuclear plants and tall buildings in California and Washington state,” (Brunker). Both planes that flew into the Twin Towers were Boeing 767. The plane was 159 feet long. Another thing that seemed odd was that 9,700 gallons when it should usually have nothing less than 14,000 gallons. The engine was found on Murray Street when it should have been right around the Tower. Things were said about the plane being like a missile since the engine was dropped so far from the Towers. According to German TV footage, the planes front nozzle was caught on fire before going through the building. Conspiracy theories state that there were three things attached to the plan that were likely to explode. After the plane went into the building the plan some how exploded making it look like a missile went into the building or some how it was some sort of bomb. The Federal Emergency Management Agency, FEMA, drew out the plane and the way the plane was flown into the Towers and it did not seem right. The plane propellers of the Boeing 757 were smaller than the hole it actuall...
Firstly I will provided a brief timeline of events beginning with the first WTC collapsing all the way to the built output of the new WTC. I will examine the political effects on the building followed by social and the economic. In conclusion I will state how and how much all these issues have affected the built output.