It has now been almost four years since Tishman Construction finished building One World Trade Center in Manhattan, New York. The building stands about 550 feet from the site where the original Twin Towers once stood. Today, that area is now occupied by the National September 11 Memorial & Museum.
When One World Trade Center was being developed, administrators knew that the building would need to include design features that strive to make the building imperishable when compared to the original towers. Considering the fact that the original World Trade Center was attacked twice by terrorists, there is reason to believe that the new tower could fall victim to an attack in the future. For this reason, the building was designed employing contemporary safety and security features, including some that have never been used before in New York City.
One World Trade Center’s fortified base is 186-foot tall and is built of reinforced concrete. The base is specifically built to withstand a bomb explosion stronger than 900 pounds of TNT; the same power of the blast in the 1993 World Trade Center bombing. The walls of the building are 3-foot thick in each of the building’s elevator shafts, risers, sprinkler systems, and stairwells. Additionally, the building’s key feature in strength is that the entire core of the building is made of concrete. The mix of concrete used for One World Trade Center, is the strongest mix of concrete ever used to build a skyscraper in New York City, with the ability to withstand 15,000 pounds of pressure per square inch.
In addition to the concrete makeup of the skyscraper, the steel beams used in the tower are bonded together through bolts and welding, which will help to prevent the building from collapsing after damage, as multiple steel beams will be able to hold the weight of the structure if other beams are impaired in an attack. On 9/11, one of the major difficulties for the building’s occupants and first responders were the narrow stairwells. In One World Trade Center, the stairwells were doubled in width, and there are now separate stairwells specifically made for firemen to prevent cluster during emergencies. Additionally, the stairwells are built with paths that cross over to the nearest stairwell if the one being used is blocked due to damage. All stairwells in the building are pressurized to keep occupants safe from smoke, and are complete with ventilation systems that filter out biological and chemical matter.
One World Trade Center now employs security strategies that were not used before the attacks in 1993 and 2001. The site is now patrolled by New York City police, as well as Port Authority police. Today, all vehicles that enter the premises are scanned for radioactive material before being granted entrance to the building. The building also uses video analytical software that detects suspicious behavior among occupants, while also detecting unattended objects on the premises and in the tower. The software is employed through the use of 400 surveillance cameras.
The combination offered by the safety and security measures of One World Trade Center make it the most sustainable skyscraper in New York, and among the most sustainable buildings in the United States. The building’s success in structural endurance creates a blueprint for contemporary skyscraper design and construction around the globe. Although we will never truly know the strength of One World Trade Center, the design ensures the correction of the many architectural faults that made September 11, 2001 one of the worst days in United States history.