Charles de Gaulle Airport
Hi and welcome to Failurology; a podcast about engineering failures. I’m your host, Nicole. And I’m Brian. And we’re both from Calgary, AB. Thank you again to our Patreon subscribers! For less than the cost of a coffee, you can hear us talk about more interesting engineering failures!
In place of the engineering news, the E’cole Polytechnique Massacre, also known as the Montreal Massacre, occurred on December 6, 1989 (32 years ago).
The Montreal Massacre was an antifeminist mass shooting in Montreal at an engineering school affiliated with the Université de Montréal. Fourteen women were murdered and 10 women and four men were injured.
There have been debates over various interpretations of the events, their significance, and the shooter’s motives; but many (myself included) see this as a wider societal attack against women. There are other factors such as the shooter’s abuse as a child, that could be to blame, but the fact that he singled out the women in the mechanical engineering class (18% of the class) sends a pretty clear message.
The anniversary of the massacre has been commemorated as the National Day of Remembrance and Action on Violence Against Women.
This incident led to a more stringent gun control law in Canada, it also introduced changes in the tactical response of police to shootings, changes which were later credited with minimizing casualties during the Dawson College Shooting.
Charles de Gaulle Airport Collapse
Now on to this week’s engineering failure; the Charles de Gaulle Airport Collapse in Paris, France.
Terminal 2 at Charles de Gaulle was a futuristic-looking elliptical tube constructed of concrete rings. Designed by Paul Andreu, who also designed the French terminal for the English Channel Tunnel, design based on principles of tunnel construction. Andreu had spent most of his career working on airport designs and had been working on Charles de Gaulle since 1974.
He drew upon the principles for tunnel construction to design a space with no internal supports, so passengers could move easily through the terminal. As there were no internal supports, the outer shell of the building supported all the loads.
Andreu retired in 2003 and this terminal was likely one of his last projects. He has been cited as an example of “architectural hubris” and you will see why before we finish this episode.
A large chunk of Terminal 2E, near gate E50, crashed down in the early morning hours of May 23, 2004. Several people were killed, which occurred less than a year after opening. 11 months to be exact.
flights from Johannesburg and Newark were offloading and a flight to Prague was boarding at the time
90 minutes before total failure, a strip of concrete fell from the underside of the terminal’s shell structure. Then the north wall buckled and the struts supporting the glass pierced through the concrete shell. Then the edge beam of the ceiling collapsed. Passengers saw concrete dust falling and fissures in the roof.
Terminal 2E consists of the main passenger building, concourse parallel to it, and an isthmus connecting the two buildings.
In section, the terminal looked like a deformed tube resting on the flattish side.
The roof is made of 10 sections, separated by glazed strips, each section is further divided into 4-meter bays. The vault supports for each bay are 30cm thick, precast, perforated, reinforced concrete rings.
the entire tube is enclosed in glass, with an external steel tension truss system between the concrete and glass.
The roof is not fixed rigidly to its supports to allow movement from thermal and other forces.
the trusses were supposed to be compressed between the glass and the concrete, but it's believed they pierced the concrete, weakening the connections and the concrete itself
To stiffen the shallow vault, curved steel girders brace the two sides. The tensile girders are held away from the vault by regularly spaced steel struts on 20cm diameter plates embedded in 10cm deep recesses. Where three elevated walkways enter the concourse, at the 20m long collapse area, the lower portions of three sections of shell were omitted for the footbridge access. Steel connections transferred loads from the shortened shells to the full-length ones on either side.
Reasons for Collapse
The collapse of the 33m section killed four people, injured three others, and left a 50m by 30m hole in the tubular design. Official investigation report pointed to design flaws and oversights in construction as contributing factors to the collapse.
A lack of detailed analysis and inadequate design checking allowed the construction of a poorly engineered structure.
the external structure was chosen based on aesthetic appeal, rather than calculated engineering judgement. See also episode 32 about the Big O Stadium in Montreal which suffered from a similar issue.
Architects and engineers from the state-owned ADP ( Aeroports de Paris) designed the building and managed construction, with no distinction between the client and the architect. They were judge and jury, with no one overseeing them. It's not a surprise that corners were cut for a more prestigious or cost-effective design
the construction company worked as close to the limits as possible to reduce costs
The process made it possible to avoid competition for the architectural design of the airport buildings and to ensure that a French airport would be designed by a French architect.
Structural Engineering Failure:
a 300-ton crane was brought in to lift off the heavy slabs of concrete to rescue the passengers trapped underneath
investigators weren’t sure if the cause was terrorism, a bomb, or structural failure
A French court found the Paris airport operators guilty of involuntary manslaughter as a result of the collapse. The ADP had to pay 225,000 euros, and the general contractor, glass and concrete contractors as well as the engineering and inspection firms had to be fined between 100,000 to 150,000 euros.
On March 17, 2005, it was decided that the whole part of terminal 2E that collapsed would be rebuilt at a cost of 100 million euros.
the tube style structure was replaced with a more traditional steel and glass structure
two temporary lounges were created to replicate capacity while the rebuild was ongoing
the terminal reopened on March 30, 2008
New York Times reporter Christopher Hawthorne said “it is in translating the design from one office to the next that mistakes are amplified and become deadly.” File sharing (either PDF drawings or BIM models), peer reviews and overlapping site reviews can prevent future failures from occurring. And remember folks, when someone says the design needs to be checked, do it. It only takes a few minutes or maybe a few hours but it could save lives and probably a lot of money.
So there you have it, the collapse of the Charles De Gaulle Airport Terminal. A number of factors from design, to construction, to cost led to the collapse of a brand new terminal less than a year after it opened. Engineers know better than anyone else, how their designs can fail. and it’s up to us to raise the flag and voice our concerns before failure occurs; public safety depends on it.
For photos, sources and an episode summary from this week’s episode head to Failurology.ca. If you’re enjoying what you’re hearing, please rate, review and subscribe to Failurology, so more people can find it. If you want to chat with us, our Twitter handle is @failurology, you can email us firstname.lastname@example.org, or you can connect with us on Linked In. Check out the show notes for links to all of these.
Thanks, everyone for listening. And tune in to the next episode for a special preview of our three favourite mini-failure episodes to date. Bye everyone, talk soon!