One World Trade Center is the main building of the rebuilt World Trade Center complex in Lower Manhattan, New York City. Construction of One World Trade Center was deferred until 2006 because of disputes between the Port Authority of New York and New Jersey and the developer. Tishman Realty & Construction is the selected builder. The building reached ground level on May 17, 2008, and was topped out on May 10, 2013. One World Trade Center opened to tenants on November 3, 2014, and One World Observatory opened to the public on May 29, 2015.
2004–2007 One World Trade Center is considered the first major building whose construction is based upon a three-dimensional Building Information Model. The symbolic cornerstone of One World Trade Center was laid down in a ceremony on July 4, 2004, but further construction of the tower was stalled until 2006. The cornerstone was temporarily removed from the site on June 23, 2006. The project was delayed due to 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, explosives were detonated at the World Trade Center construction site, testing the use of charges to clear bedrock for the building's foundation. Controlled explosions continued for approximately two months thereafter.
On November 18, 2006, of concrete were poured onto the foundation of the One World Trade Center, 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 steel beam. This beam, the first to be installed, was welded onto the building's base on December 19, 2006.
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 1 WTC at $3 billion, or $1,150 per square foot ($12,380 per square meter). Approximately $1 billion of insurance money recouped by Silverstein in connection with the September 11 attacks is being used for construction of the new One World Trade Center. The State of New York is expected to provide $250 million toward construction costs, and the Port Authority agreed to finance another $1 billion through bonds. 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.
2008 In January 2008, two construction cranes were moved into the construction site. The tower's concrete core began rising in the first months of 2008. By February 22, 2008, 9,400 of the nearly of steel necessary had been ordered. By March 2008, the steel for the tower had reached high, below street level. From late March through early April, a tall mockup of a section of the tower's wall with twenty-four windows was tested by Construction Consulting Laboratory West in Ontario, California. The purpose of the testing was to ensure that the all-glass exterior of the tower will be able to withstand earthquakes and extreme weather conditions. Testing also took place on another full-scale mockup south of Albuquerque, New Mexico. Both mockups passed the tests. In mid-April, a batch of concrete had to be replaced after it failed a stress test.
On May 17, 2008, the tower's steel reached street level when new sections were bolted to two of the twenty-four jumbo steel columns marking the building's footprint. The new column sections brought the height of the structure up to above street level. In June, the chamfered steel skeleton of the tower's concrete base had begun to take shape. By the end of the month, the concrete had been poured for the floor of the tower's basement level B3. In his June 30, 2008 World Trade Center Rebuilding Assessment to the then New York Governor David Paterson, Port Authority executive director Christopher O. Ward noted that roughly 90 percent of the construction contracts had been bid.
By August, 1 WTC had reached above street level. During its September 16 meeting, the Port Authority board approved contracts for security and building management systems, and 95% of the contracts needed to complete the tower had been signed. The $20 million security contract includes sophisticated video analysis in which computers would alert security personnel to abnormal situations automatically. On October 10, Collavino Construction poured an additional of concrete for the tower's concrete core, raising it to just above street level.
2009 By February 11, 2009, the tower was above street level. On July 2, 2009, over of concrete were poured to form parts of the street-level plaza. On August 13, the builders of 1 WTC set a piece of steel into place—the largest column installed yet at the building. Each steel column, made at a factory in Luxembourg, was about long. The columns at the bottom of the tower's foundation were about long.
By November 1, 2009, the twenty-four perimeter columns of 1 WTC were all erected, and construction of the second floor (the first floor above ground level) was nearly complete. In addition, The Port Authority of New York and New Jersey reported in their 2009 Q3 Annual Report that steel erection should commence by January 2010, and that the typical floor construction could begin.
2010 Steel and concrete installation continued in 2010, where two cranes were on site. The fifth floor was finished on January 16. In February, construction began on the sixth floor, the last floor of 1 WTC's base, and the Port Authority announced that the tower's steel superstructure had reached above street level.World Trade Center (Freedom Tower) Lower Manhattan.info. Retrieved 2010-2-4. By the end of March 2010, steel beams began to be erected for the second office floor. In April, the 45-degree octagon was installed, the building's steel frame had reached 26 floors, and concrete was completed on the base structure in the latter part of the month.1 World Trade Center reaches 20th-floor levelSITimes. Retrieved March 20, 2010.
In May 2010, the Port Authority stated that they were building close to one floor per week, and was projected that One World Trade Center would reach 55 stories by the end of 2010.World Trade Center project has begun to take shape New Jersey On-line. Retrieved May 12, 2010. The cocoon system was also installed, marking the first time a cocoon safety system has been installed on a steel superstructure in the city.Port Authority installs cocoon safety system around World Trade Center steel structure NJ.com, May 2010
On July 13, 2010, workers found remains of an 18th-century sailing ship at the World Trade Center site while excavating for the underground Vehicle Security Center for One World Trade Center.18th-Century Ship Found at Trade Center Site. The New York Times. Retrieved July 15, 2010 The remains of a section of the ship's hull and a anchor were found. The hull had been truncated and the beams sawed.Ship Buried in 18th Century Unearthed at WTC SiteFox News Retrieved July 15, 2010 The ship was likely used as landfill material during the early 19th century to help expand Manhattan. Timbers from the ship were removed and sent to a laboratory to try to date the vessel.Buried ship found at World Trade Center site. Los Angeles Times Retrieved July 15, 2010 An additional section of the ship was found on the site in August 2011, giving historians more information about the vessel, which was active around the 1770s.
By October 2010, the tower's steel superstructure reached 44 stories.World Trade Center tower reaches 44 stories high and curtain wall installation this month Rochester Democrat and Chronicle Retrieved October 29, 2010 In November, stainless steel and glass facade panels were being prepared for later installation, with the panels scheduled to be assembled between the 20th and 24th floors.One World Trade Center Prepared to Shine Digital Network Associates Info Retrieved November 17, 2010 On November 13, the first glass facade panels were installed on the 20th floor. Steven Coleman, spokesman for the Port Authority, stated, "Once they get rolling, they'll be able to install glass panels at a rate of one floor per week." By November 17, the tower's steel had reached 48 stories.
The Port Authority announced on December 16, 2010 that 1 WTC had reached the 52nd floor, and had risen to over , marking the halfway point for the construction of the building's steel frame."1 WTC, aka Freedom Tower, reaches halfway mark", The Wall Street Journal/Associated Press, December 16, 2010"Freedom Tower half complete" New Zealand Herald Retrieved December 17, 2010
2011 By February 2011, the tower had reached 56 floors, above grade, while the glass panels reached the 27th floor."Construction Progress Around the WTC Site". World Trade Center Progress newsletter, February 2011, Panynj.gov, accessed May 12, 2011 On May 12, 2011, plans led to install prismatic glass on the building's base were cancelled due to technical problems."Prismatic glass facade for WTC tower scrapped". Huffington Post, May 12, 2011. Retrieved June 19, 2011.
By June 15, 2011, One World Trade Center had reached the 70th floor, the glass facade installation had reached the 45th floor, and concrete flooring had been installed up to the 63rd.World Trade Center Growing This Summer . "World Trade Center Growing This Summer" Retrieved June 1, 2011 On August 1, 2011, concrete workers and carpenters at the tower walked off the job one month after their labor contract had expired. The workers returned to work on August 3.. NY1 News and Time Warner Cable Inc., August 4, 2011Joseloff, Matt and Stephen Nessen.. WNYC News Blog, New York Public Radio, August 2, 2011
2012 Construction slowed from January to February 2012 due to an unseasonably warm winter which caused high winds and icing conditions to form on top of the structure making it hazardous for the construction workers. Further delays were caused by financial problems with a steel supplier which slowed delivery of steel beams to One World Trade Center. It took over two months to complete the 92nd floor. With the weather improving in March and financial issues being resolved, the construction progressed above the 92nd floor. 1 WTC later surpassed the Bank of America Tower as the 3rd tallest in the city. In May 2012, it was announced that the 408-foot spire originally planned to adorn the top of One World Trade will have its radome stripped, revealing the mast of the same height. This announcement was withdrawn in September 2013. On November 12, 2013, One World Trade Center was given the official height by the CTBUH as the Tallest Building in the Northeastern United States. (surpassing the Willis Tower amongst much debate), eleventh tallest in the world, and was given the title of the World's Tallest Spire. (Burj Khalifa, the tallest building in the world, has a shorter spire, despite starting at a higher altitude.)