After the destruction that hit New York City so hard on that September morning, the skyline has never been the same.
Standing 1,776 feet, the World Trade Center One being called the Freedom Tower, is projected to be completed by 2012.
Design
As the first office tower to rise on the actual World Trade Center site, Freedom Tower recaptures the New York skyline, reasserts Lower Manhattan’s preeminence as a business center and establishes a new civic icon for our country.
This tall, point tower, in the tradition of great New York City icons such as the Chrysler Building and Empire State Building, evokes the slender, tapering triangular forms of these two great landmarks of midtown and replaces more than one quarter of all the office space that was lost on September 11, 2001.
The tower rises from a simple, subdued, robust base that is a cube whose square plan – 200′ by 200′ – is the same size as the footprints of the original Twin Towers.
Entrances on all four sides of the building further connect the building to its surroundings and activate it at street level: from West Street for the observation deck (with areas for ticketing, security, bag check and shopping); for the restaurant from Washington Place and for the offices from Fulton and Vesey Streets. While incorporating enhanced security requirements, the building remains open and accessible.
The design of the base draws upon the restrained monumentality of the historic commercial buildings of New York City such as the Empire State Building, the Chrysler Building and the Woolworth Building; a shimmering metal surface drapes the tower’s base and imparts a dynamic fluidity of form whose appearance will reflect changes in the light, weather and seasons.
At its middle, the tower forms a perfect octagon in plan and then culminates in a glass parapet (elevation 1362′ and 1368′) whose plan is a square, rotated 45 degrees from the base.
Structure
The robust, redundant steel moment frame, consisting of beams and columns connected by a combination of welding and bolting, resists lateral loads through bending of the frame elements.
Paired with a concrete-core shear wall, the moment frame lends substantial rigidity and redundancy to the overall building structure while providing column-free interior spans for maximum flexibility.
Safety
To satisfy security concerns, the building’s setback distance from West Street (Route 9a) has been increased from 25 feet to an average of 90 feet. Freedom Tower’s cubic base will be clad in luminous materials – perhaps a mixture of stainless steel and titanium – that is simultaneously shimmering, light-reflective, and blast-resistant.
The building incorporates advanced life safety systems that exceed the requirements of the New York City Building Code and that will lead the way in developing new highrise building standards. In addition to structural redundancy and extra strong fireproofing, the building includes biological and chemical filters in the air supply system.
To assume optimum egress and firefighting capacity, extra-wide pressurized stairs, low-level emergency lighting and concrete protection for all sprinklers and emergency risers are being provided, in addition to interconnected redundant exits, additional stair exit locations at all adjacent streets and direct exits to the street from tower stairs. All of the building’s life-safety systems – stairs, communications, risers, sprinklers, elevators – are encased in a core wall that is three feet thick in most places.
This building is being designed to facilitate emergency response with enhanced emergency communication cables, together with a dedicated stair for use by firefighters. These are used in conjunction with enhanced elevators housed in a protected central building core that serve every floor of the building. In addition, “areas of refuge” are located on each floor.