Originally Posted by Dac150
I know this is probably not true, but I remeber reading in a skyscraper book that the stilts of the citigroup center were not built to last a long lifespan. It said that because of the the church situation, the stilts were rushed in the design and not properly built to withstand a longterm fulfillment.
I for one don't see how that is possible, but its just some information.
I happen to love this building and it is on of my favorites.
Sort of, it's kind of a winded explanation.
Imagine a table with four legs at the corners. You can put an item anywhere on the surface of the table and it will remain stable. But if you move the legs to the middle of each edge, as is the case of the Citicorp, you cannot put anything to the corners of the table surface.
The engineers of Citicorp responded by designing triangular trusses that spanned the width of each face of the building that pointed downwards; their apex would lead into each stilt, so that downward forces from the corners of the building would be channeled into the stilts. This design was dependant on welded joints, however, during construction, were changed to bolted joints to save money.
I think around 1978 a Columbia engineering student discovered that the bolted joints were inappropriate for the design of the building, and that instigated further investigation and ultimately panic for the engineers of the building. It was soon discovered that in gale force winds (which occur in New York a few times in a lifetime) the bolted joints could fail and the building could collapse. Secretly the engineering team and Citicorp had the building retrofitted with plates at each joint to strengthen them. The reconstruction work was occurring while a hurricane was headed straight towards New York, and at the last possible moment, as the city was prepared to evacuate an 8 block radius of the building, the hurricane turned away and the construction crews finished.
The entire ordeal was kept 100% secret from the public until 1995.
ANYWAYS, this building has a great presence from Brooklyn, where Midtown towers just happen to pop up and dominate the end of many streets:
Bedford avenue in Bedford Stuyvesant quite nicely frames it, but I can't find any of my own pictures of it.
Also I have the 3d puzzle of it: