Freedom Tower

1 World Trade Center,^[3] or the Freedom Tower, is the main building of the new World Trade Center complex currently under construction in Lower Manhattan in New York City. The tower will be located in the northwest corner of the 16-acre (65,000 m²) World Trade Center site, bound by Vesey, West, Washington and Fulton streets.^[4] Construction on below-ground utility relocations, footings, and foundations for the 1,368-foot (417 m) Freedom Tower began on April 27, 2006.^[5] On December 19, 2006, the first steel columns were installed in the building's foundation. Three other high-rise office buildings are planned for the site along Greenwich Street, and they will surround the World Trade Center Memorial, which is currently under construction. The area will also be home to a museum dedicated to the history of the site.

History

Following the destruction of the World Trade Center towers in the September 11, 2001 attacks, there was much debate regarding the future of the World Trade Center site. Proposals began almost immediately, and by 2002, the Lower Manhattan Development Corporation organized a competition to determine how to use the land. Public rejection of the first round of designs, the "Preliminary Design Concepts," led to a second, more open competition in December 2002, the "Innovative Design Study," in which a design by Daniel Libeskind was selected. This design went through many revisions,^[6] largely because of disagreements with developer Larry Silverstein, who held the lease to the World Trade Center site on September 11, 2001.

A final design for the tower was formally unveiled on June 28, 2006. To satisfy security issues raised by the New York City Police Department a 187-foot (57 m) concrete base was added in April of that year. The final design included plans to clad the base in glass prisms to address criticism that the base looked like a "concrete bunker." Contrasting with Libeskind's plan, the final design tapers the corners of the base outward as they rise. Its designers stated that the tower will be a "monolithic glass structure reflecting the sky and topped by a sculpted antenna." Commenting on a completion date, Larry Silverstein stated "By 2012 we should have a completely rebuilt World Trade Center more magnificent, more spectacular than it ever was."^[7] On April 26, 2006, the Port Authority of New York and New Jersey approved a conceptual framework that enabled foundation construction to begin while a formal agreement was drafted on the following day, the 75th anniversary of the opening of the Empire State Building. Construction began with a formal ceremony that took place when the construction team arrived.^[8] It is projected that steel for the building will be visible above ground in 2008, with a topping out in 2011. The building is projected to be ready for occupancy at some point in 2012.^[2]

Architecture

Freedom Tower design submitted in 2003.

Many remaining vestiges of the concepts drawn from the 2002 competition have since been discarded. Freedom Tower will now consist of simple symmetries and a more traditional design intended to bear comparison with selected elements of the existing New York skyline. There will now be a central spire drawing from precedents such as the Empire State Building and the Chrysler Building (and also visually reminiscent of Tower 1 of the old World Trade Center) rather than an off-center spire intended to echo the Statue of Liberty.

"Freedom Tower will be a symbol of the entire project, as well as marking the memorial, and it occupies a very important piece of New York City property: the sky. We really wanted our design to be grounded in something that was very real, not just in sculptural sketches. We explored the infrastructural challenges because the proper solution would have to be compelling, not just beautiful. The design does have great sculptural implications, and we fully understand the iconic importance of the tower, but it also has to be a highly efficient building. The discourse about Freedom Tower has often been limited to the symbolic, formal and aesthetic aspects but we recognize that if this building doesn't function well, if people don't want to work and visit there, then we will have failed as architects."^[9]

Current design

The Freedom Tower's program includes 2.6 million square feet (241,000 square meters) of office space, as well as an observation deck, world-class restaurants, parking, and broadcast and antennae facilities, all supported by both above and below-ground mechanical infrastructure for the building and its adjacent public spaces. Below-ground tenant parking and storage, shopping and access to the PATH and subway trains and the World Financial Center are also provided.

An 80-foot-high (24 m) public lobby topped by a series of mechanical floors form a 200-foot-high (61 m) building base. 69 tenant floors rise above the base to 1,120 feet (341 m) elevation. Mechanical floors, two floors to be occupied by the Metropolitan Television Alliance, restaurants and observation decks culminate in an observation deck and glass parapet that mark 1,362 feet (415 m) and 1,368 feet (417 m) respectively — the heights of the original Twin Towers. A shrouded antenna structure supported by cables, engineered by Schlaich Bergermann & Partner rises to a total height of 1,776 feet (541 m), which is symbolic of the year the Declaration of Independence was signed (July 4, 1776).

The tower rises from a cubic base whose square plan—200 feet by 200 feet—(61 m by 61 m) is almost as wide as the 208-foot (63 m) Twin Towers. The base is clad in more than 2,000 pieces of prismatic glass; each measures 4 feet by 13 feet 4 inches (1.21 m by 4.06 m) with varying depths. It has been designed to draw upon the themes of motion and light; a shimmering glass surface drapes the tower's base and imparts a dynamic fluidity of form whose appearance will reflect its surroundings. Just as the rest of the building, the base will serve as a glowing beacon. Cable-net facades on all four sides of the buildings, again designed by Schlaich Bergermann, measure 60 feet (18 m) high and range in width from 30 feet (9 m) on the east and west sides (for access to the restaurant and observation deck, respectively) to 50 feet (15 m) on the north side and 70 feet (21 m) on the south for primary tenant access, activate the building at street level.

As the tower itself rises from this cubic base, its square edges are chamfered back, transforming the square into eight tall isosceles triangles in elevation, or an elongated square antiprism. At its middle, the tower forms a perfect octagon in plan and then culminates in a glass parapet (elevation 1,362 feet (415 m) and 1,368 feet (417 m)) whose plan is a square, rotated 45 degrees from the base. A mast containing an antenna for television broadcasters—designed by a collaboration between SOM, artist Kenneth Snelson (who invented the tensegrity structure), lighting designers and engineers—and secured by a system of cables, rises from a circular support ring, similar to the Statue of Liberty's torch, to a height of 1,776 feet (541 m). The spire will be an intense beam of light that will be lit at night and will likely be visible over a thousand feet (305 m) into the air above the tower. New York City is a suitable place to set such a light pointing towards the sky without complaints of light pollution by astronomers, as the night sky in locations near New York City is already far too bright for serious astronomical observers.^[10]

Other new safety features will include 3-foot (90 cm) thick walls for all stairwells, elevator shafts, risers, and sprinkler systems; extremely wide "emergency stairs"; a dedicated set of stairwells exclusively for the use of firefighters; and biological and chemical filters throughout its ventilation system. The building will no longer be 25 feet (7.6 m) away from West Street—with the redesign and smaller base (the same width and length now as each of the previous towers), Freedom Tower will average 90 feet (27 m) away from the street.^[11] At its closest point, West Street will be 65 feet (20 m) away. The windows on the side of the building facing in this direction will be equipped with specially tempered blast-resistant plastic, which will look nearly the same as the glass used in the other sides of the building.

"Ultra-clear" glass, as opposed to reflective or tinted glass, is proposed for the tower's windows. This will benefit internal daylight propagation; however, at this stage it is unclear how the corresponding issue of solar heat gain will be addressed. Although the roof area of any tower is comparatively limited, the building will implement a greywater recycling scheme involving rainwater collection. 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. Like all of the new facilities at the World Trade Center site, the Freedom Tower will be heated by steam, with limited oil or natural gas utilities located on site.^[12]

Height

The World Trade Center's North Tower featured an occupied floor at 1,355 feet (413 m). Though not occupied by office space, Freedom Tower's observation deck is set to be higher, at about 1,362 feet (415 m). Currently, the Sears Tower, Shanghai World Financial Center, and Taipei 101 have occupied floors higher than Freedom Tower. International Commerce Center, Chicago Spire, and the Burj Dubai will have roofs and floors higher than Freedom Tower's highest roofs and floors.

If the spire and antenna height (the criteria of two categories of the Council on Tall Buildings and Urban Habitat) are included, Freedom Tower will stand at 1,776 feet (541 m) (marking the year of the signing of the American Declaration of Independence). Freedom Tower was originally planned to be the tallest building in the world, but will no longer obtain this title, as the Burj Dubai has already broken the record for the tallest building at 2,320 ft (707 m), and it is expected to exceed 2,684 ft (818 m) by the time of its completion in 2009.

The Chicago Spire, previously scheduled for completion in 2012, would also have been taller than the Freedom Tower. If completed, the roof of the 150 floor spire will top out at 2,000 feet (610 m).^[13][14] Due to the symbolism of having an exact height of 1,776 feet (541 m), the height of Freedom Tower will probably not be increased before completion. However, now that work on the Chicago Spire has been suspended, the Freedom Tower may become the tallest building in the United States upon its completion.

Space allotment

As revealed on June 28, 2006, Freedom Tower will have a top floor denoted as 102, though the total number of floors is 82 (possibly with some uncounted floors). This is because the first office floor of the building atop the tall base will be designated as Floor 20. There are 69 office floors atop the base, ending at Floor 88, above which would be broadcasting space on the 89th and 90th floors. Three stories of mechanical space take up a floor count of 9. Finally, a restaurant will take up Floors 100 and 101, and the observation deck is at Floor 102. Six additional floors of mechanical space exist above to Floor 108.^[15] Additionally, roughly 55,000 square feet of retail space will exist below-grade, part of an overall 500,000 square feet of retail space to be spread throughout the site both in the below-grade concourses and on the lower floors of Towers 2, 3, and 4.^[16]

Floor breakdown

The following is a breakdown of floors as noted by SkyscraperPage.com:^[17]

• 1-19 - tower base (including 80 ft tall lobby and 3 mechanical floors)
• 20-63 - offices
• 64 - skylobby
• 65-88 - offices
• 89-99 - mechanical floors
• 100-102 - observation deck and other public facilities to be announced
• 103-108 - mechanical floors

Note that these official designations may not correspond to actual floor levels (in particular at the base).

Tenants

The State of New York has agreed to a 15 year lease of 415,000 square feet (38,550 square meter) of space in the Freedom Tower, with an option to extend the term of the lease and occupy up to 1,000,000 square feet (92,900 square meter).^[18] The General Services Administration (GSA) has agreed to lease approximately 645,000 square feet (59,900 square meters) of space,^[18][12] New York State's Office of General Services (OGS) plans to lease approximately 412,000 square feet (38,275 square meters) of space and the China Center expects to lease approximately 190,000 square feet (17,650 square meters) in the tower.^[12] In April 2008, the Port Authority announced that it was seeking a bidder to operate an 18,000 square foot observation deck on the tower's 102nd floor.^[19]

Construction history

2004 to 2006

The symbolic cornerstone of Freedom Tower was laid down in a ceremony on July 4, 2004^[20] and further construction of the tower was stalled until 2006. The cornerstone was temporarily removed from the site on June 23, 2006.^[21] The project had been delayed due to acrimonious disputes over money, security and design but the last major issues were resolved on April 26, 2006 with a deal between developer Larry Silverstein and the Port Authority of New York and New Jersey. During the summer of 2006, test explosives were detonated at the Freedom Tower construction site, testing the use of charges to clear bedrock for the Freedom Tower’s foundation. Three to four controlled explosions per day followed on alternating weekdays for approximately two months after.

2006 to 2007

On November 18, 2006, 400 cubic yards (306 cubic meters) of concrete were poured onto the foundation of the Freedom Tower carried by as many as 40 trucks. On December 17, 2006, a ceremony was held in Battery Park City, with the public invited to sign a 30-foot (9 m) steel beam.^[22] This beam, the first to be installed, was welded on to the Freedom Tower's base on December 19, 2006.^[23] On January 9, 2007 a second set of beams was welded to the top of the first set.

February 2007 estimates put the cost for construction of The Freedom Tower at $3 billion, or $1,150 per square foot ($12,380 per square meter).^[24] Approximately $1 billion of insurance money recouped by Silverstein is slated for construction of the Freedom Tower.^[24] The State of New York is expected to provide $250 million toward construction costs, and the Port Authority would finance another $1 billion for the Freedom Tower, through bonds.^[25]

In 2007, Tishman Construction Corporation of New York completed a row of steel columns at the perimeter of the construction site. Two tower crane bases were erected, each base containing a functioning luffing-jib tower crane. By the end of 2007, the tower’s footings and foundations were nearly complete.^[26]

Current progress in 2008

Freedom Tower Site on March 8, 2008.

In January 2008, two construction cranes were placed at the construction site of the Freedom Tower. The tower's concrete core began the same year on the basement floors, but began rising in the first months of 2008.^[26] By February 22, 2008, 9,400 tons of the nearly 50,000 tons of steel necessary for the Freedom Tower had been ordered.^[27] By March 13, 2008, the steel for the tower had reached 70 feet (21 m) high, 10 feet (3.0 m) below street level.^[28][29] From late March through early April, a 40-foot (12-meter) tall mockup of a section of the tower's wall with 24 windows was tested by Construction Consulting Laboratory West in Ontario, California. The two weeks of testing were done to make sure the all-glass exterior of the tower will be able to withstand earthquakes and extreme weather conditions.^[30] Testing also took place on another full-scale mockup in a rural area south of Albuquerque, New Mexico. Both mockups passed the tests.^[31] In the middle of April, a batch of concrete had to be replaced after it failed a stress test April 15.^[32]

On May 17, 2008, the tower's steel breached street level when new sections were bolted to two of the 24 jumbo steel columns marking the building's footprint. The new column sections brought the height of the structure up to 15 feet above street level.^[33] In June, the chamfered steel skeleton of the tower's concrete base had begun to take shape.^[34] By the end of the month, the concrete had been poured for the floor of the tower's basement level B3.^[35] In his June 30, 2008 World Trade Center Rebuilding Assessment to New York Governor David Paterson, Port Authority executive director Chris Ward noted that "approximately 90 percent of the Freedom Tower contracts have been bid or are ready to award."^[36] By August, the Freedom Tower had reached 25 feet (8 m) above street level.^[37] During its September 16th meeting, the Port Authority board approved contracts for security and building management systems^[38]; fully 95 percent of contracts needed to complete the tower had now been signed.^[39] The $20 million security contract includes sophisticated video analysis in which computers would alert security personnel to abnormal situations automatically.^[40] On 10 October, Collavino Construction poured an additional 520 cubic yards of concrete for the tower's concrete core, which was thereby raised from four inches below street level to 13 feet, eight inches above street level.^[41]

Future progress

The Freedom Tower had been expected to reach rooftop level by the end of 2010 with topping out expected by 2011. However in an October 2, 2008 follow-up report by Ward, the estimated completion of the tower was pushed back to some time between the second and fourth quarter of 2013 with a total budget of $3.1 billion and the use of 46,000 tons of steel.^[1]

Construction gallery

Controversy

Further information: Controversy surrounding the rebuilding of the World Trade Center

The design of Freedom Tower has generated some controversy due to the limited number of floors in the previous design (82) that were designated for office space and other amenities. The floor limit was imposed by Silverstein, who expressed concern that higher floors would be a liability in a major accident or terrorist attack. In a subsequent redesign, the highest occupiable space became comparable to the World Trade Center.

Soon after the destruction of WTC Towers 1 and 2 there was a persistent public demand^[42] to rebuild the previous twin towers instead of building a single tower. Ian Simpson Architects designed twin towers but the final Freedom Tower design was more favored by officials. Developer Donald Trump also unveiled a twin design, but he was not affiliated with the official project.

Former New York Governor George Pataki faced accusations of cronyism for supposedly using his influence to get the winning architect's bid picked as a personal favor for a close friend.^[43] The chosen name of the "Freedom Tower," attributed to Pataki, has been criticized as Orwellian by a critic for The New York Times.^[44][45]

The base of the tower (fortified because of security concerns) has also been a source of controversy. A number of critics (notably Derek Murdoch in the National Review) have suggested that it is alienating and dull, and reflects a sense of fear rather than freedom, leading them to dub the project "the Fear Tower."^[46][47] Nicolai Ouroussoff, the architecture critic for the New York Times, calls the tower base decorations a "grotesque attempt to disguise its underlying paranoia".^[48]

On April 18, 2008, a homeless man revealed that he found important blueprints about the Freedom Tower in a New York City trash can. The Port Authority called it "a serious security lapse" and has opened an investigation.^[49]

Key people

Larry Silverstein

Larry Silverstein of Silverstein Properties, the leaseholder and developer of the complex, will retain control of the surrounding buildings, while the Port Authority gets full control of the tower itself. Silverstein signed a 99-year lease for the World Trade Center site in July 2001. Silverstein's insurance payout has been a subject of public discourse, as he maintained that the two planes constituted two separate attacks and sued for an extra $3.5 billion. Silverstein has pledged to support the reconstruction and remains actively involved in most aspects of the redevelopment process.

David Childs

David Childs, one of Larry Silverstein's favorite architects, initially came on board thanks to Silverstein's insistence, and developed a proposal for Freedom Tower in collaboration with Daniel Libeskind, a design which was revised in May 2005 to address security concerns. He is currently the project architect of the new Freedom Tower, and is responsible for overseeing the day-to-day design development from rough inception to final completion.

Daniel Libeskind

Daniel Libeskind won the 2002 competition to develop a master plan for the World Trade Center's redevelopment.

Daniel Libeskind won the invitational competition to develop a master plan for the World Trade Center's redevelopment in 2002. He included an initial proposal for the design of Freedom Tower, a building with aerial gardens and windmills with an off center spire. It was also Libeskind who denied a request to place the tower in a more rentable location next to the PATH station and instead placed it a block west because in profile it would line up and resemble the Statue of Liberty. Although these designs have since been changed, his contributions continue to shape the design and development at Ground Zero, as they are revised to meet economic and security realities.

Dan Tishman

Dan Tishman, along with his father John Tishman, builder of the original World Trade Center, is leading the construction management effort for Tishman Realty & Construction, the selected builder for Freedom Tower.

See also

• Buildings and architecture of New York City
• List of tallest buildings in the world
• Memory Foundations
• Tallest buildings in New York City
• Tallest buildings in the United States
• World Trade Center
• World Trade Center Memorial
• World Trade Center site
• World's tallest structures

References

External links

• World Trade Center - Official site for new World Trade Center complex
• Downtown Restoration Program - Port Authority of New York & New Jersey
• Project Rebirth - Documentation of the reconstruction of Ground Zero
• Rebuild Ground Zero