A Wrightstyle perspective in glass from 9/11 to the Freedom Tower
Wrightstyle is an international steel glazing company which designs and fabricates specialist glazing systems to mitigate against fire or ballistic or blast attack. Tim Kempster is the company’s managing director.
Later this year the world will remember the terrible day ten years ago when terrorists flew fuel-laden airliners into New York’s iconic Twin Towers, and crashed two other airliners in Washington DC and Pennsylvania. It was a co-ordinated and horrific attack that brought war to Afghanistan and Iraq, costing countless more lives and which is still changing the face of the world.
On 9/11 this year, a memorial to the dead will be finally opened, consisting of two pools, each nearly of one acre, set within the footprints of the Twin Towers, with the largest man-made waterfalls in the USA running down their sides. The names of the almost 3,000 people who died in New York, Pennsylvania, the Pentagon, and the February 1993 World Trade Center bombing will be inscribed around the edges.
It will be a symbolic ceremony on 9/11, but an end of the beginning rather than the beginning of the end. Around the memorial, work on new mega-structures will continue for some years. Completion of the centrepiece, One World Trade Center, also known as the Freedom Tower, is scheduled for 2013 – although it’s risen to over 60 storeys, and growing by a storey a week. It is now part of the New York skyline.
Some 2,500 construction workers are employed at Ground Zero, and not all of them above ground. Underground, there are transit links to complete and a cavernous memorial is taking shape. Above ground, an eight-acre landscaped Memorial Plaza is also planned to create a contemplative and quiet area away from the noise and bustle of the surrounding city.
Tragically, it wasn’t the first time that an aeroplane had struck the New York skyline. That first happened in July1945 when a Mitchell B-25 bomber accidentally flew into the Empire State Building, killing 14 people. However, such was the structural overkill of the building that it sustained only relatively minor damage. Ironically, after 9/11, the Empire State Building once more took on the mantle of the city’s tallest building.
The new Freedom Tower, which will take back the title, will have echoes of the Twin Towers. Its base is 200 ft square, the same footprint of the original towers, while its observation deck will be at 1,362 feet, the height of World Trade Center Tower Two, while its glass parapet will be at 1,368 feet, the height of World Trade Center Tower One.
The key word is glass because the new architecture of the World Trade Center comprises 538,420 square feet of glass. That adds up to more than twelve acres, and a testament to the combined efforts of the glass industry over the intervening ten years to design glass and glazing systems of hitherto unimaginable strength.
In urban areas, it’s estimated that between 80-85% of all secondary blast injuries are caused by flying glass. To put that into context, in New York on 9/11, 15,500 windows were damaged within a mile of Ground Zero – nearly 9,000 within half that distance.
The Journal of Performance of Constructed Facilities puts it more graphically: “When a terrorist bomb explodes in an urban area, it produces devastating effects, including structural and non-structural damage to buildings, injuries, and deaths. Numerous injuries in explosions result directly and indirectly from window glass failure.
“Direct glass-related injuries occur when glass shards flying and falling from fractured windows cause lacerations and abrasions. Secondary glass-related injuries occur when the shock front of the blast wave passes into buildings through fenestrations vacated by fractured glazing.”
The glass industry has learned many lessons in recent years, partly in response also to natural threats such as hurricanes, and has worked in partnership with engineers, architects and scientists to build better, stronger and safer glazing systems.
Of course, no facade – of any material - could withstand an assault such as happened on 9/11. However, what the glass industry has managed to achieve are protective levels that would have impossible a decade ago. Companies like Wrightstyle have spent the intervening period better understanding adverse loading and the blast dynamics of different kinds of attack, then building and testing systems to withstand them.
Our test regime, in Europe, the USA and the Far East tests both the glass and its framing system together in integrated units that we have also designed. That element of design compatibility is vital to the integrity of the overall system; and in an uncertain world compatibility is everything. In our biggest test, we subjected our structurally-glazed system to the equivalent of 500 kilos of TNT, acknowledged as an average-sized lorry bomb. The independent, and successful, test took place within a specialist and high-security RAF base in the north of England.
Our high-performance systems, not just for blast mitigation, can be found from Europe to the Middle- and Far East and from the USA to South Africa. We are involved in the London Olympics and were involved in the Athens Olympiad. In such a specialist area of design and supply, it’s a very small world.
The real paradox is that, in an age of terrorism, architects are also looking to introduce more daylight into buildings and to reduce energy consumption and carbon emissions – a new agenda for the glass industry where sustainability and environmental responsibility are also key design criteria.
One World Trade Center will stand at a symbolic 1,776 feet (541 m), marking the year 1776 when the American Declaration of Independence was signed. According to the developers “it will serve as a beacon of freedom, and demonstrate the resolve of the United States, and the people of New York City.”
It could all have been so different. In a submission to a US Senate Committee on Intelligence, Louis J. Freeh, director of the FBI, said that: “loosely affiliated extremists, motivated by political or religious beliefs, may pose the most urgent threat to the United States. Within this category, Sunni Islamic extremists, such as Osama bin Laden and individuals affiliated with his Al-Qaeda organization, have demonstrated a willingness and capability to carry out attacks resulting in large-scale casualties.” He was speaking four months before Osama bin Laden proved him right.
Looking ahead, and with bin Laden gone, we can perhaps begin to reflect on the emerging Freedom Tower, and of the kind of hope that it offers: an architecture that the glass industry has helped to inspire. An architecture born out of enormous suffering, but once more allowing architects to build mega-structures to inspire.
Freedom Tower New York images / information received 260511
Ground Zero New York photo, WTC7 on right: Andrew McRae, 2007
Freedom Tower - Site of World Trade Center
Ground Zero, Lower Manhattan
2004- Daniel Libeskind Architects + David Childs of SOM Architects
Controversial towers to replace the World Trade Centre skyscrapers lost to New York in 2001. The main skyscraper by Libeskind was to be a significant number of feet high - 1,776 feet - to mark a key American date in history - United States Year of Independence; the building was largely handed over to architect David Childs. Designed to be the tallest tower in the world for the site leaseholder - real estate developer Larry Silverstein. The angular design is typical for Libeskind but here echoes the Statue of Liberty. A Snohetta building was also due to appear but the situation is in a state of flux, more online soon - 2006.
Daniel Libeskind was commissioned to design the Freedom Tower after a strongly
contested World Trade Center design competition in Feb 2003, beating architects
such as Norman Foster and in the end winning a two-strong shortlist.
Six teams were shortlisted in Sep 2002 out of over 400 submissions, including: Foster & Partners
Richard Meier Architect
Studio Daniel Libeskind
Gehry Partners LLP and Snøhetta were selected as architects for the World Trade Center cultural complex by Lower Manhattan Development Corporation in Dec 2004
World Trade Center Transportation Hub, New York City, USA
Santiago Calatrava has designed the Transport Interchange on the site, with an
arching skeletal form similar to that used in his French interchange - the Lyon-Satolas TGV Station. The World Trade Center Transit Hub is intended to mimic a flying dove.
In 1946 New York State Legislature set up a WTC Corporation to analyse such a facility. The World Trade Centre idea formed in 1960* and preliminary drawings were drawn up by SOM, who slipped in behind Libeskind 43 years later (via David Childs). Michigan-based Minori Yamasaki and Emery Roth & Sons completed the Twin Towers between 1966 and 1973. Yamasaki had over a hundred schemes, one being a single 150-storey tower. Towers 1 & 2, nicknamed ‘David & Nelson’ after the supportive Rockefeller Brothers became quintessential New York symbols, appearing on a large proportion of postcards.
Key Daniel Libeskind Buildings
Jewish Museum, Berlin, Germany 1998
Imperial War Museum North, Manchester, England 2002
London Metropolitan University, London, England 2004
World Financial Center
1986 Cesar Pelli, Architect
Including the Winter Garden
World Trade Centre - New Museum Complex
2006? Snohetta, Architects
International Freedom Centre + Drawing Centre. Also named the WTC Cultural Center. Snøhetta Architects became well known with their Alexandria library in
Egypt which won a major architecture competition: Snohetta Architects
Snohetta have an architects office in New York based at 50 Broad St
Another featured building by Daniel Libeskind:
Creative Media Centre - Hong Kong Buildings
Another New York building by Daniel Libeskind:
Condominium tower in Union City, New Jersey