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September The 11th 2001 Essay

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Note: All calculations are based off information found on the internet, although the information was gathered for reputable sources and it is believed the information is accurate. It can not be confirmed; therefore, the accuracy of this information cannot be guaranteed. For this reason, this report should not be taken as an all inclusive summary of how, why or what happened, but should be taken as a possible explanation of the events that occurred on September the 11th 2001. 1.0 Background Information 1.1 Construction During post world war II period America entered an economic boom, New York’s economic growth was concentrated in Midtown Manhattan around the 1930’s, because of this the economy in Lower Manhattan dwindled away. As a …show more content…

For the building to meet the Port Authority’s requirement of ten million square feet of office space the building would have to be 110 stories, however to build a structure that tall using existing elevators systems would not be feasible as elevators would take up all the space inside the building making it uneconomic. Yamasaki and his team devised a new system that had express elevators running the length of the building and only stopping at floor that were called sky lobbies, from which local elevators would connect to each floor. The buildings were constructed using framed tube structures, an external lattice of steel that formed a tube around a internal lattice tube core. This lattice tube structure allowed the building to overcome the lateral forces induced on the building by the extreme wind in the area. The construction of this building also used a range of other innovative techniques such as wind tunnel tests and slurry walls. Construction on the North Tower began in August 1968 and the South Tower in 1969, by the end of 1970 tenants had moved in to the North Tower and by 1972 had moved into the South Tower. The extensive use of prefabricated sections was crucial in the buildings fast construction. 1.2 The Attack On the 11th of September 2001, the world of engineering changed forever. It had been a regular Tuesday, but at 8:45am, that all changed. A hijacked American Airlines flight

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