Security concerns force change in Freedom Tower design

A new design for the World Trade Center in New York City was unveiled at the end of June. The development to replace the original 100-storey WTC twin towers destroyed by terrorists on September 11, 2001 is slimmer than the original 1,776-foot tall skewed “Freedom Tower” designed by architect Daniel Libeskind, who won a competition for the project. Libeskind is now the master planner for the site, and the architect of the tower is David Childs of SOM.
The revised design makes the tower narrower and with a smaller footprint. It has been shifted 65 feet to the east, necessitating new foundations in a complex site of utilities, other new construction under way and subway tracks.
The tower had to be redesigned because of security concerns and to reflect new standards for foreign embassies issued by the U.S. government.
One security concern was the standoff distance from the nearby thoroughfare, West Street-Route9A.
Structural engineers of the project are Cantor Seinuk Group and geotechnical and foundation engineers are Mueser Rutledge.
The tower will have a perimeter-steel moment frame, with a three-foot thick concrete shear-wall core. It sits on a 200-foot square podium, which will have reinforced concrete perimeter walls, clad in stainless steel or titanium.
The anticipated date for topping out is now 2009.