[HN Gopher] The Skyscraper That Could Have Toppled over in the W...
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The Skyscraper That Could Have Toppled over in the Wind (1995)
Author : georgecmu
Score : 33 points
Date : 2025-06-15 15:40 UTC (7 hours ago)
(HTM) web link (www.newyorker.com)
(TXT) w3m dump (www.newyorker.com)
| georgecmu wrote:
| https://archive.is/3Ed3T
| gosub100 wrote:
| Veritasium covered this recently and did some debunking about the
| original student.
|
| https://youtu.be/Q56PMJbCFXQ?si=pjfmTrrA7JGuTZxd
| socalgal2 wrote:
| I don't know the physics involved nor do I have any knowledge of
| architecture or building construction but when I look at tall
| buildings it's really hard for me to imagine how they remain
| standing.
|
| The bottom floor of a 100 story building is holding up 99 floors
| of weight. The base of a 100 story building it really thin
| relative to it's height. If I built anything out of legos to the
| same dimensions it would not be structurally sound. Well, the
| legos at the bottom would easily hold the weight). Yea I know
| reinforced steel and concrete is not legos. Other examples
| though, every piece of furinture I own has some degree of
| wobbliness. It's easy to see how the pyramids hold up. It's not
| so easy to see how the Vancouver House Building stays up
| (https://en.wikipedia.org/wiki/Vancouver_House). The one in the
| article as well just looks, at the bottom, like it has to tip
| over eventually. (not saying it will, only that it looks like it)
|
| I'm not in any way denying science. I'm only in awe that more
| builings don't fall down. Bridges too. I'm surprised to some
| degree an 93 year old steel bridge being sprayed with salt water
| for the entire time hasn't had its cables snap.
|
| Maybe a need a physics simulation game like 3d world of goo that
| lets me see how such structures hold togehter.
| adgjlsfhk1 wrote:
| I think a lot of the answer here is in the foundation. a 100
| story building isn't sitting on top of the ground. it has
| several stories of foundation below the ground, and likely has
| concrete piles that go hundreds of feet further down.
| EGreg wrote:
| This. It is like roots of a tree for instance. The trunk by
| itself is actually much smaller than the branches -- like the
| opposite of a pyramid.
|
| I guess most of the stress is distributed throughout the
| building frame going into the foundation - like they drive
| those pylons into the ground before building a large
| building.
|
| But still, it could snap from all that stress, like a tree
| that's been felled by the wind...
|
| That is why the other part is that skyscrapers are designed
| to sway in the wind and have the entire structure above the
| ground absorb the kinetic energy and sorta cancel it out
| before it reaches the base.
|
| Some buildings use tuned mass dampers (like the giant
| pendulum in Taipei 101) to counteract swaying by moving in
| opposition to the wind-induced motion.
|
| In fact, a lot of the time the majority of the building's
| outer shell (glass etc) can be blown out by the wind, if it
| is too strong, and the steel structure will then have a lot
| of holes in it for the wind to pass through.
|
| They test these structures for how the wind and water will
| flow around them. Look at the base of the Burj Al Arab, and
| how they built it to withstand the 100-year storm.
|
| https://theskydeck.com/do-skyscrapers-sway/
| ilinx wrote:
| I know virtually nothing about architecture or structural
| engineering, but I imagine all the weight isn't necessarily
| going down from floor to floor, but a lot of the weight is
| attached to support columns, and the floors are built out from
| that.
|
| All the weight is still on those support columns though, and I
| also have a hard time wrapping my head around how something
| like that is possible. Engineering is amazing.
| antod wrote:
| I think what they meant was not literally the bottom floor,
| but the columns at the bottom floor.
| userbinator wrote:
| If you're not familiar with it, steel is actually surprisingly
| strong for its size. Look up "ultimate tensile strength" and
| "compressive yield strength". They are many tens of thousands
| of pounds _per square inch_ for structural steel. Even the
| tensile strength of small fasteners like bolts is very high in
| "human" terms:
|
| https://www.engineeringtoolbox.com/us-bolts-tensile-proof-lo...
|
| _The bottom floor of a 100 story building is holding up 99
| floors of weight._
|
| That's not how it works. All the load of the floors above is
| held by the columns, which go into the foundation.
| i_am_jl wrote:
| >Maybe a need a physics simulation game like 3d world of goo
| that lets me see how such structures hold together.
|
| Bridge Designer, formerly West Point Bridge Designer is a
| physics simulation that does almost that, though is more a
| learning tool than a game.
|
| https://bridgedesigner.org/
| Bengalilol wrote:
| That podcast shines it all
|
| https://99percentinvisible.org/episode/structural-integrity/
| pylua wrote:
| Just walked past this building in person the other day. I had to
| a triple take when I saw the base. It seems very unintuitive that
| it could stand safely.
| belter wrote:
| 2 years ago: https://news.ycombinator.com/item?id=37684604
| throwaway2562 wrote:
| What a great story: remarkable how the New Yorker of 1995 has the
| same efficient but easy-going clarity as 2025.
| riordan wrote:
| Seriously - I find myself coming back to read this once every
| few years because of how riveting the piece is (oh no -just
| realized the pun)
|
| Also I've heard wonderful things about The Great
| Miscalculation[0], a recently released book about the Citicorp
| Tower incident
|
| [0]: https://search.worldcat.org/en/title/1458613829
| paulpauper wrote:
| The irony that this was printed just 6 years before 9/11. The
| lesson is it's hard to anticipate all the possible risks. The two
| WTC towers were engineered to withstand a jet plane impact (a
| 707, which was a common passenger jet at the time in the late
| 60s), just not not a modern airplane packed with fuel at max
| speed.
| crazytony wrote:
| As far as weights go, the 707 and the 767-200s that hit the
| towers were fairly close in size, weight and fuel capacity and
| that is demonstrated by both towers surviving their impacts.
| The problem was the fire and specifically the inability to
| fight the scale of the fire effectively.
| iwontberude wrote:
| And insufficient modelling for the heat of jet fuel mixed
| with office supplies which severely weakened the structure
| allowing it to pancake in a cascading fashion from the first
| support columns to buckle.
| neilv wrote:
| > _On Tuesday morning, August 8th, the public-affairs department
| of Citibank, Citicorp 's chief subsidiary, put out the long-
| delayed press release. In language as bland as a loan officer's
| wardrobe, the three-paragraph document said unnamed "engineers
| who designed the building" had recommended that "certain of the
| connections in Citicorp Center's wind bracing system be
| strengthened through additional welding." The engineers, the
| press release added, "have assured us that there is no danger."
| When DeFord expanded on the handout in interviews, he portrayed
| the bank as a corporate citizen of exemplary caution -- "We wear
| both belts and suspenders here," he told a reporter for the News
| -- that had decided on the welds as soon as it learned of new
| data based on dynamic-wind tests conducted at the University of
| Western Ontario._
|
| > _There was some truth in all this. [...] At the time,
| LeMessurier viewed this piece of information as one more nail in
| the coffin of his career, but later, recognizing it as a blessing
| in disguise, he passed it on to Citicorp as the possible basis of
| a cover story for the press and for tenants in the building._
|
| Seems questionable to lie to conceal that kind of catastrophic
| risk.
|
| Knowing that the skyscraper would fail in some kinds of winds is
| information that could be used by rational people to help protect
| themselves and their businesses.
|
| > _Shortly before dawn on Friday, September 1st, weather services
| carried the news that everyone had been dreading--a major storm,
| Hurricane Ella, was off Cape Hatteras and heading for New York.
| At 6:30 a.m., an emergency-planning group convened at the command
| center in Robertson 's office. "Nobody said, 'We're probably
| going to press the panic button,' " LeMessurier recalls. "Nobody
| dared say that. But everybody was sweating blood."_
|
| > _As the storm bore down on the city, the bank 's
| representatives, DeFord and Dexter, asked LeMessurier for a
| report on the status of repairs. He told them that the most
| critical joints had already been fixed and that the building,
| with its tuned mass damper operating, could now withstand a two-
| hundred-year storm. It didn't have to, however. A few hours
| later, Hurricane Ella veered from its northwesterly course and
| began moving out to sea._
|
| I see gambling people.
|
| Presumably, some were gambling to avoid temporary public disorder
| in the city, or temporary disruption to general commerce there.
|
| But it sounds like others of them wanted cover up a scandal in
| which they and the company were now implicated. And they were
| willing to gamble with other people's lives and businesses to do
| so.
| neilv wrote:
| This is one case in which our layperson's naive intuition
| would've been the right answer (for the wrong reasons):
|
| https://en.wikipedia.org/wiki/File:53rd_St_Lex_Av_td_08_-_Ci...
| sdoering wrote:
| There's a great keynote by Nickolas Means [1] about this building
| and the story around it.
|
| [1]: https://youtu.be/NLXys9vgWiY
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