How a student’s phone call avoided a skyscraper collapsed: the history of Citicorp Center

THE Citigroup center in Midtown Manhattan is also known under his address, 601 Lexington Avenue, during which he has been held for 47 years, longer than the New York median was alive. Although always a fairly beautiful building, in a way of the 1970s, it now only comes out slightly on the horizon. At the street level, however, the building continues to turn the heads, placed as it is on a series of columns of appearance on site Placed not at the corners, but in the middle of the walls. A visitor without knowledge of the structural genius passing for the first time the Citigroup Center may wonder why he does not fall – which, for a few months in 1978, was a truly serious concern.

This story, told with a special explanatory liveliness in The new Video Veritasium aboveusually start with a telephone call. An unidentified architecture student obtained a right of William LemesrierThe structure engineer of the Citicorp Center, as he was then called, to relay the concerns he had heard a teacher express about the capacity of the skyscraper still new to resist the “winds in neighborhoods”, which blow diagonally to his corners. LEMESSURIER took the time to browse the student through the elements of its light design which then releases, which included hugs in the shape of a chevron which directed loads of tension to the columns and a mass shock absorbed in concrete of 400 tonnes (or a “large block of cheese”, as it is called) intended to counter the oscillation movements.

Lemesnurier was a professional proud, but her professionalism prevailed over her pride. When he returned to check the plans of the Citicorp Center, he received an unpleasant surprise: the construction company had exchanged the welded joints in these chevron accolades for cheaper locks. His office had approved the change, which made sense at the time, and had also only taken into account perpendicular winds, and not winds, as it was then the standard practice of industry. Carrying out the relevant calculations himself, he determined that the whole tower could be killed – and many in the surrounding area with it – by the kind of winds that have a chance in a given year.

It did not take long to realize that he had no choice but to reveal what he had discovered in Citicorp, whose leadership cooperated with the accelerated semi-class project of strengthening the structural joints of their sparkled emblem. The work could hardly fail to attract the attention of New York press, of course, but it received a low coverage thanks to an impeccably timed newspaper strike, and its completion made the most sure skyscraper in the city. In fact, the history of the Citicorp Center disaster which has not been published publicly A 1995 New York play by Joseph MorgensternThis made a sort of hero among structural engineers. But it was the students who had identified the faults of the building, not only one but two presented themselves later, who personified the life of life to ask the right questions.

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Based in Seoul, Colin MArshall Written and broadcastTS on cities, language and culture. His projects include the substack newsletter Books on cities And the book The stateless city: a walk through Los Angeles from the 21st century. Follow it on the social network formerly known as Twitter in @ColinmArshall.