The World Trade Center stood for close to 30 years as a symbol of America financial power. Opened in 1970, the World Trade Center became the one of the most visible and iconic sights along the New York City skyline. Since the tragic events of September 11, 2001, the absence of the WTC has left people all over the world over with a deep sense of loss. The World Trade Center ushered in a new era of architectural design that rivaled the world’s great skyscrapers.
The Twin Towers were the most visible parts of the complex. Not as visible but no less important were the low-rise buildings that made up the World Trade Center complex. The construction of the towers was indeed a marvel of modern high-rise construction that set new precedents in skyscraper design. Rising 110 stories above Lower Manhattan, the towers were surrounded by five smaller buildings. The entire complex sat on roughly 22 acres. Like many of the world’s famous skyscrapers, the Twin Towers of the World Trade Center featured observation decks that provided visitors with spectacular panoramic views of the city and beyond.
The idea for a world-class financial center in Lower Manhattan goes back to the mid 1940s though it would almost 20 years before a firm plan was established. The architectural planning started in earnest in 1962 when world famous architect Minoru Yamasaki was hired to design the complex. It would take another three years for construction to begin.
Over the years, the land area at the southern tip of Manhattan Island was expanded by dumping fill materials to the bay formed by the confluence of the Hudson and East Rivers. This practice of expanding land area was not confined to New York City and was used in other large cities like Chicago and San Francisco. For example, the lakefront area of Chicago was filled with the debris from the Great Chicago Fire. After the San Francisco Earthquake, much of the debris from demolished buildings was dumped into San Francisco Bay forming what is now the Marina District.
The construction of skyscrapers always poses special design challenges and the Twin Towers of the World Trade Center were no exception. In order to anchor the foundations for these massive structures it is necessary to build on bedrock. On the WTC site, bedrock was over feet below the surface. The design was further complicated by the sites proximity to the river.
The foundation level of the towers was well below sea level making it necessary to build special retaining walls to hold back the Hudson River. The retaining structure became know The Bathtub. Once again, the land area of Lower Manhattan was expanded when over 1 million cubic yards of material dredged from the WTC site was dumped into the river.
The unique design of the Twin Towers represented a radical departure from traditional skyscraper designs. Prior to the construction of World Trade Center towers, high-rise construction was based on a box frame design. This design, though very strong, was not space efficient with the space on each floor taken up by pillars, limiting the layout of the space. The World Trade Center incorporated a center tube design and exterior framing that resulted in an open floor plan with each tower providing almost 4 million square feet of office space. The entire complex of seven buildings provided over 11 million square feet of office space.
The New World Trade Center
Not long after the Towers were destroyed, efforts began on replacement structures. The new WTC is scheduled to have five skyscrapers and a memorial tower to honor and remember the thousands of people who perished on September 11, 2001.