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From the archive: The 9/11 attacks

NCE has dug into its archives from 2001-2005 to bring you a comprehensive look back at our exclusive, in-depth technical coverage of the tragedy and its aftermath.

13 September 2001

The World Trade Center was attacked on Tuesday 11 September in New York, shortly before 9am. Meanwhile, the working day was drawing to a close in London, where NCE was about to go to press with its 13 September issue featuring news on Labour’s first 100 days since re-election, and Coventry City Football Club’s new stadium plans. Of course, when the tragedy began to unfold NCE’s news team quickly gathered analysis from leading engineers and secured technical drawings from the towers’ designer, just in time for the issue to get to the printer.


Central core failure triggered World Trade Center collapses

NCE’s initial news coverage of the disaster, with immediate reaction from engineering experts.


‘A living representation of man’s belief in humanity’

NCE looks at the design, dimensions and specifications of the Twin Towers.


Canary Wharf could survive jet impact — designer

One of Canary Wharf’s consultant engineers tells NCE that the tower could survive an aeroplane attack.


Pentagon suffers partial collapse

NCE reports on damage caused to the Pentagon building in Washington DC by the 9/11 attacks.


Leader: World Trade Center: the structural challenge

Antony Oliver’s leader column considers the “immense” repercussions of the tragedy.


20 September 2001

The following week, NCE brought you in-depth details, analysis and coverage of what had happened, what the immediate recovery concerns were, and what the long-term consequences of the event could be.


US design standards neglected progressive collapse

A Canadian forensic engineer gives NCE his opinion of US tall building standards.


UK set to overhaul codes on disproportionate collapse

NCE looks at the impact of 9/11 on a UK design code consultation that began in August.


Civils flock to aid recovery effort

NCE reports on the recovery roles of structural and civil engineers in New York City.


Flooding and collapse endanger subway

Engineers warn of damage to subway stations in the vicinity of the World Trade Center.


Beware rushing into changing design codes, structurals urge

US and UK structural engineers urge proper assessment before design codes are altered.


Engineers act to avoid foundations collapse

Engineers prepare to shore up a retaining diaphragm wall in the World Trade Center basement.


Americans warned about aircraft risk in 1973

An engineer highlighted the aircraft risk to tall buildings in the year the World Trade Center opened.


Recent Pentagon strengthening saved lives

The Pentagon renovation manager extols the role of recent strengthening work in limiting the tragedy.


Firemen should be consulted during building design

Firemen trained in structural engineering should advise on tall building design, an academic tells NCE.


Evacuation methods face major rethink

Collapse of the Twin Towers was not anticipated in their emergency evacuation plan.


US engineers launch inquiry into Twin Towers collapse

Investigations are launched into failure sequences and structural damage at the World Trade Center and Pentagon.


Gordon Masterton: First Person

ICE structural and building board chairman recounts his experiences since the disaster.


Letters: Evacuation time critical to extent of Trade Center tragedy

NCE readers write in and share their thoughts on the tragedy.


Leader: We must not be afraid to learn

Antony Oliver writes that the consequences of 9/11 will stay with the industry for all time.


27 September 2001

Coverage continued the next week, as engineers got to work on making Ground Zero safe, rectifying infrastructure problems caused by the collapse, and asking probing questions about whether the towers were let down by their design.


Oklahoma bomb lessons were ignored, say engineers

Lessons on progressive collapse from the 1995 Oklahoma City bombing went unheeded, engineers say.


Twin Towers ‘gave out too soon’

The designer of Centre Point, London, criticises the performance of the World Trade Center towers.


Buried drawings hampered rescue efforts

Vital engineering drawings of the Twin Towers were lost for three days because the originals had been kept in the buildings themselves.


Volunteers put under contract

Engineers volunteering their services at Ground Zero were set to be paid retrospectively under new contracts.


Patching up power and transport

NCE writes that a local electricity company has been working to restore power to Manhattan’s business district.


Engineers on the edge

Engineers are making crucial judgments in the search for survivors in the rubble, NCE’s reporter in New York writes.


Damage checklist

NCE gives a round-up of what was damaged on 9/11, where and how badly.


Holding back the Hudson

Engineers fight to secure the World Trade Center foundations against further damage from the nearby Hudson River.


Extreme team sets to work on design solutions

Arup establishes a task force of engineers to find solutions to the structural failures seen on 9/11.


People turning against ‘target’ high rises

The New York Building Congress president says people will no longer want to work in tall buildings following the attacks.


4 October 2001

NCE continued covering the story as a New York task force looks into the attacks, and UK industry figures weigh in on the future of high rise buildings.


WTC task force finds vital role for engineers

The chairman of a New York task force tells NCE about his findings on the role of engineers in disaster management.


Grant funds sought for rail tunnel upgrade

US rail operator Amtrak says it needs funding for improvements due to expectations of increased rail travel and perceived increase in risk following 9/11.


Debate: should the UK build more high rise buildings?

An engineer and a town planner debate the merits of tall buildings in the post-9/11 climate.


11 October 2001

On the one month anniversary of the tragedy, NCE looked at what engineers were doing practically, both as volunteers on site and in discussions with clients at home.


WTC volunteer engineers reduced to eight

The number of engineers working round the clock at Ground Zero is drastically cut.


Can engineers save the megatower?

NCE looks at how designers can reassure clients that megatowers are still economically viable.


18 October 2001

As more weeks passed, industry figures in the UK began to question what would happen if the attacks were repeated here.


UK needs network of disaster planning offices, say experts

Emergency planners say UK local authorities cannot respond adequately to disasters like the 9/11 attacks.


WTC forensic studies will take six months

Detailed forensic investigations at Ground Zero still have some way to go, an expert tells NCE.


25 October 2001

As the end of October approached, plans for Subway repairs and basement stabilisation in New York City became clearer, and the importance of evacuation routes in the disaster was discussed.


LUL blast experts to help with post WTC New York subway repairs

London Underground is to help with blast strengthening work on the New York subway.


WTC basement stabilisation begins

Engineers have begun installing rock anchor tie-backs to the Twin Towers’ basement walls, NCE writes.


Lifts now key to high rise escape, says designer

A tall building designer says evacuation procedures are likely to rely more on the use of lifts, following lessons learned from 9/11.


1 November 2001

In November, NCE reported on ongoing Subway works, and an engineer on the ground gave his first person perspective on what was happening.


Engineers to unplug Hudson tunnels to speed WTC Subway repair

Tunnels sealed off with concrete to prevent flooding after 9/11 are to be unplugged to accelerate railway repairs.


Paul Ashlin: View from Ground Zero

Bovis Lend Lease LMB senior vice president Ashlin describes his ongoing work in New York City.


15 November 2001

An NCE source revealed in mid-November that Canary Wharf designers were looking again at their designs following 9/11. Meanwhile, investigations in the US highlighted some key issues.


WTC lessons prompt Canary Wharf design changes

Sources tell NCE that the design of at least one tall building at Canary Wharf has been altered since 9/11.


Fire protection key to towers’ collapse

Evidence of fire protection failure at the Twin Towers begins to emerge.


Moment connection failures surprise WTC investigators

Investigators say they have uncovered “new and surprising” structural failures in low rise buildings near to the Twin Towers.


7 July 2005

In the summer of 2005 the US National Institute of Standards and Technology (Nist) published its draft final report into the World Trade Center collapses. NCE examined the report to bring you the crucial information for engineers to know.


Cause and effect

NCE gives a summary of the recommendations made in the draft Nist report regarding tall building design.


Collapse mechanisms

NCE lays out what is known about the exact sequence of events that made up the Twin Towers’ collapse process.


22 September 2005

That September, NCE reported on a conference in Washington DC, where disagreements surrounding the Nist report’s findings came to a head. This issue also looked at how the Nist report would affect the future of engineering — and why there was still more to learn.


Row erupts over why twin towers collapsed

British and American engineers have disagreed over the causes of the Twin Towers’ collapses.


All this work is just the start

NCE asks what the Nist report’s recommendations really mean in practice for tall building designers.


Huge investigation but questions remain

NCE looks at how the Nist reached its conclusions, and why they have not satisfied everyone.

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