The new World Trade Centre complex in New York is a tribute to cutting-edge architecture.
Tragedy makes for a cruel teacher. On a freezingly cold morning, it's hard to miss the symbolism of the "survivor tree". The tree was discovered in the rubble of the Twin Towers in October 2001 with snapped roots and a blackened trunk. It was nursed back to health and now stands 35 feet tall at the new site, widely accepted as a symbol of New York City's fabled resilience. It also tells a story of the lessons learned and now incorporated into the rebuilding of the new World Trade Center (WTC) complex in Lower Manhattan.
The new complex, which includes 1World Trade Center, 7World Trade Center, a museum, a memorial and a transportation hub, besides other commercial buildings, is being rebuilt using the most advanced safety systems. Nineteen agencies, two private developers, 101 contractors, 33 architects and 3000 workers have combined their efforts to make the complex safe, sustainable and artistically engaging. 1WTC, the first of the new towers to be rebuilt, stands on a fortress base 200 feet high, constructed from concrete designed to absorb and repel vehicular bomb attacks. The tower is an intricate column of steel and concrete, designed to resist lateral loads. When the planes hit the twin towers, the top floors imploded in a pancake effect.
The trend for new Manhattan office towers after the 9/11 tragedy has been to move away from all-steel structures toward composite systems. So, 1WTC has an extra secure welding of columns and beams. The elevators, along with sprinklers and other safety systems, are encased within a concrete sheath. The stairwells, where many of the 9/11 victims perished, will be pressurised to keep smoke out and are 50 per cent wider than the earlier ones, allowing more people to exit at a time. There is also a separate responder stairwell for rescue crews with a dedicated water-and fire-proof elevator, enabling them to reach the upper floors faster. The new WTC will also be equipped with chemical filters in the air supply system in the event of a biological attack.