When it was built in 1977 , Citicorp Center ( later rename Citigroup Center , now called 601 Lexington ) was , at 59 stories , the seventh - tallest construction in the world . you may pick it out of the New York City visible horizon by its 45 - degree lean top .
( Credit : Wally Gobitz )
But it ’s the groundwork of the building that really make the tower so unique . The bottom nine of its 59 tale are stilt .
( reference : Joel Werner )
This affair does not look inflexible . But it has to be sturdy . Otherwise they would n’t have built it this style .
Right ?
( William J. LeMessurier . Courtesy of Bill Thoen . )
The architect of Citicorp Center was Hugh Stubbins , but most of the reference for this construction is given to its principal structural applied scientist , William LeMessurier .
The design originated with the need to accommodateSt . Peter ’s Lutheran Church , which occupy one corner of the edifice site at 53rd Street and Lexington Avenue in mid - town Manhattan . ( LeMessurier called the a church “ a punk honest-to-god building … the lowest point in Victorian architecture . ”you’re able to be the judge . )
The experimental condition that St. Peter ’s gave to Citicorp was that they build the church a new building in the same location . supply that recess of the caboodle not be touched , he company was free to build their skyscraper around the church building and in the air space above it .
LeMessurier said he get the idea for the design while sketching on a table napkin at a Grecian restaurant .
( Courtesy of David Billington )
Here ’s what ’s go on with this construction :
Nine - tale stilts suspend the edifice over St. Peter ’s church . But rather than putting the pile in the corners , they had to be at the centre of each side to avoid the church .
Having stilts in the middle of each side made the construction less static , so LeMessurier design a chevron bracing social structure — rows of eight - story Phoebe ’s that served as the building ’s skeleton .
But the chevron bracing social organisation made the edifice exceptionally unaccented for a skyscraper , so it would sway in the wind . LeMessurier added a tune mass damper , a 400 - ton gimmick that proceed the construction static .
It was an cunning , cutting edge plan . And everything seemed just fine — until , as LeMessurier tells it , he catch a phone call .
( Courtesy of Diane Hartley )
According to LeMessurier , in 1978 he gravel a phone call from an undergraduate architecture student making a bold title about LeMessurier ’s construction . He told LeMessurier that Citicorp Center could blow over in the wind .
The educatee ( who has since been lost to history ) was study Citicorp Center as part of his thesis and had found that the construction was particularly vulnerable to quartering fart ( farting that hit the building at its corners ) . Normally , buildings are strongest at their corner , and it ’s the vertical winds ( lead that strike the building at its face ) that cause the with child nisus . But this was not a normal building .
LeMessurier had accounted for the vertical current of air , but not the quarter winds . He checked the maths , and found that the student was correct . He compared what speed winds the building could withstand with weather information , and found that a storm substantial enough to tip Citicorp Center hits New York City every 55 years .
But that ’s only if the tuned passel muffler , which keeps the edifice stable , is run . LeMessurier realized that a major tempest could cause a blackout and render the tuned pot damper inoperable . Without the tuned mass damper , LeMessurier calculated that a storm powerful enough to take out the building hits New York every sixteen years .
In other words , for every year Citicorp Center was standing , there was about a 1 - in-16 probability that it would give way .
( Credit : Timothy Vogel )
LeMessurier and his team worked with the Citicorp higher - up to coordinate emergency repairs on the building . With the assistance of the NYPD , they worked out an evacuation plan spanning a 10 blocking radius . They had 2500 Red Cross volunteers on standby , and three different weather service employed 24/7 to keep an eye on possible windstorms . They welded throughout the night and quit at break of the day , just as the edifice occupier returned to work .
But all of this happen in secret . Even as Hurricane Ella was racing up the eastern seaboard .
( FromWikimedia Commons )
Hurricane Ella never made landfall . And so the public — include the building ’s occupants — were never notified . And it just so happened that New York City newspapers were on strike at the time .
The story remained a enigma until writer Joe Morgenstern overheard it being told at a political party , and interviewed LeMessurier . Morgensternbroke the story in the New Yorkerin 1995 .
And that would have been the conclusion of the story . But then this bump :
https://www.youtube.com/watch?v=TZhgTewKhTQ
The BBC air a special on the Citicorp Center crisis , and one of its watcher was Diane Hartley . It turn out that she was the student in LeMessurier ’s story . She never talk with LeMessurier ; rather , she utter with one of his third-year staff member .
Hartley did n’t know that her inquiry about how the edifice share with quarter winds lead to any action at law on LeMessurier ’s part . It was only after seeing the infotainment that she began to con about the shock that her undergraduate thesis had on the circumstances of Manhattan .
( Diane Hartley today . Courtesy of Diane Hartley )
newsperson Joel Werner and manufacturer Sam Greenspan verbalize withDiane Hartley , and Hartley ’s dissertation advisor David Billington . We also speak withMichael Vardaro , who wrote the AIA Trust ’s white newspaper about the case , and to LeMessurier ’s former staff member Joel Weinstein .
Special thanks to Alan Bellows atDamn Interestingfor suggesting this as a 99pi account , and toSimil Raghavanfor helping us chase after down archival audio of William LeMessurier .
Music : “ Wild’n Cuz I ’m Young”- Kid Cudi ; “ A Drifting Up”-Jon Hopkins ; “ Cobweb Collector”- Twink ; “ Aufbruch ” ; “ Its Caption Was A Star”-The Octopus Project ; “ affright Disorder”-Melodium ; “ Dome Nest”-OK Ikumi ; “ brass practice”-Lullatone ; “ Red Air”- OK Ikumi ; “ Grundlsee ” ; “ Sunlight”-OK Ikumi ; “ Making Up mind ” ; “ Dome Nest”- OK Ikumi
This posthas been republished with license fromRoman Mars . It was in the beginning published on99 % Invisible ’s web log , which accompanies each podcast .
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