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Tuesday, August 22, 2006

Crisis at Citicorp

In reading articles for this post, I came across an astounding story regarding the Citicorp Center. Built in 1978, this tower is one of the tallest in Manhattan and is considered one of the most important postwar structures in NYC. The building's unusual design with a nine story stilt-style base, allows it to cantilever over St. Peter's Lutheran Church (Citicorp built a new church to replace the original which had occupied much of the block). Very interesting, but here's the real story - unknown to the general public until 1995, nearly 20 years later, unauthorized changes were made to the construction (bolted joints rather than welded). During construction, questions from an architecture student (about the stilt-style construction) prompted the structural engineer, LeMessurier, to recalculate the effects of the change to bolts. He discovered a fatal flaw - the design could not withstand the force of a 70 mph wind, an event which was predicted to occur on average every sixteen years. And, coincidentally a hurricane was approaching NYC. After contemplating suicide (really), he had meetings with the client - emergency repairs were made with workers working around the clock. Steel plates were welded over all 200 bolted joints to reinforce the structure. Read the excellent 1995 New Yorker article about the entire debacle here. BTW, the distinctive angled roof was originally designed for energy saving solar panels, which were never installed.

5 comments:

olivier said...

Superbe photo. J'adore cette immeuble vu de l'ESB ou du Top Of The Rock. Dire que les panneaux solaires n'ont jamais fonctionnes. Et en dessous en effet il y a une superbe eglise avec des concerts d'orgue et de jazz 'the St. Peter’s Church'

luggi said...

Wow. Architects may take the glory, but structural engineers will take the blame.

Brian said...

Never thought about it that way, but you're right, especially if the engineer doesn't escape ):
Brian

Robert said...

Incredible!

Karine said...

Really nice building! I have to say that your blog is really well done, the new design layout and so much information you're providing us with :) This is a really cool blog.