By Michael Franco, HowStuffWorks.com
In the wake of the wreckage that occurred on Sept. 11, 2001, there's been much talk of reconstruction — both emotional and physical. Now, solid, visual evidence of that reconstruction is beginning to rise like a phoenix from Ground Zero at New York City's southern tip. When completed, One World Trade Center (One WTC) will stand as North America's tallest building — a glass and steel symbol of resiliency, as well as scientific and architectural triumph.
One World Trade Center faced a few challenges along the way. Not only did the $3.1 billion-dollar structure need to be attractive, it had to be the most secure office building ever constructed. In addition, because One World Trade Center is part of the larger reconstruction effort taking place on the grounds of the former Twin Towers, the coordination with other onsite projects presented a logistics nightmare — especially since commuter trains run through the center of the construction at ground zero day and night.
The plans for Ground Zero are finalized, and from them a skyscraper is emerging that will dazzle the eyes and perhaps knock your socks off. Take a tour of One WTC with us and check out some of the coolest features from one of the most-watched construction projects in history.
5. The Bomb-proof Base
Beauty and security — One World Trade Centerdemanded both. The solution was elegantly simple: create a bunkerlike base that could withstand the force of a 1,500-pound (680-kilogram) truck bomb and cover it in prismatic glass that would please the eye and disguise the superstrong blast walls.
This fhttps://www.dnitv.net/fs-tool/content/EditArticle.actionortress foundation stretches 20 stories high and is known as the podium — the base from which the rest of the tower will rise. At 40,000 square feet (3,716 square meters), itâ€™s the same size as the footprint of the original Twin Towers.
The podium owes its strength to a type of concrete known as iCrete, which can withstand a stunning 14,000 pounds-per-square-inch (psi) of pressure — the highest ever poured in New York, according to Lynda Tollner, program director in the World Trade Center Construction Department. Comparatively, normal sidewalk concrete can stand up to 3,000 psi while the concrete used in a typical high-rise won't flinch at 5,000 psi. Did we mention that this special concrete only has 90 minutes to arrive on-site after it has been mixed in Brooklyn?
4. Strong, Speedy and Selective Elevators
In addition to forming the virtually impenetrable podium of One World Trade Center, iCrete also will reinforce the elevator shafts running through the center of the building like spinal columns. The concrete surrounding the shafts is 3 feet (1 meter) thick in some areas and so dense that jackhammers simply bounce off it. By switching the emphasis to the inside of the building, instead of leaving it up to the steel frame to support the structure (as with most skyscrapers), engineers believe One World Trade Center will be sturdier and more collapse-resistant. That said, the skyscraper will still feature 25 tons of steel girders, which will form the building's perimeter.
The elevators themselves will be the fastest in North and South America, according to the ThyssenKrupp Elevator Corporation, the company responsible for manufacturing and installing them.
A total of 71 elevators will operate in the building's core, zipping tourists and employees up and down at the speed of 2,000 feet (610 meters) per minute, the company says. But you won't be able to simply enter these speed shuttles and push a button for your floor — there won't be any. Instead, a unique recognition system will identify each passenger and deliver them only to the floor for which they are authorized.