Summary of Citicorp Center | NYC skyscraper saved by a student’s question

Main Ideas and Concepts

• Mistakes in Engineering: The video discusses the critical nature of Mistakes in Engineering, particularly in the context of the Citicorp Center in New York City. It emphasizes that while mistakes are human, they can have severe consequences.
• Citicorp Center Overview:
  • Built in 1977, it spans 1.3 million square feet and cost approximately $880 million in today’s dollars.
  • Designed by architect Hugh Stubbins Jr. and engineer William LeMessurier.
• Structural Challenges:
  • The building's construction was complicated by the need to relocate a church that sat on the site of a major column.
  • A design change involved moving the columns to the edges of the building and using diagonal members for support, inspired by the structure of pine trees.
• Wind Load Concerns:
  • The engineering design had to account for high winds in New York City, with particular attention to how the building would behave under these conditions.
• Critical Student Inquiry:
  • An undergraduate student, Diane Hartley, questioned the structural integrity of the Citicorp Center under specific wind loads, leading to a revelation of a potentially catastrophic design flaw.
• Response to the Mistake:
  • LeMessurier acknowledged his mistake and took proactive steps to fix it by contacting various stakeholders and proposing a solution.
  • Repairs were made discreetly at night over three months without informing the building's occupants.
• Lessons Learned:
  • The importance of admitting mistakes and communicating them to relevant parties.
  • The necessity of having checks in place to ensure the integrity of engineering work.
  • The ethical implications of keeping such critical information secret from the public.

Methodology and Instructions

• Steps Taken After the Mistake Was Identified:
  • Acknowledge the mistake openly and take responsibility.
  • Communicate with stakeholders (insurance, lawyers, architect).
  • Develop a solution to rectify the issue.
  • Assemble a capable team to execute the repairs.
  • Conduct repairs discreetly to avoid public panic, ensuring safety and compliance.
  • Maintain transparency with the team while managing the situation calmly.

Speakers and Sources

• Tyler Lay: Engineering professor discussing the case study.
• Diane Hartley: Undergraduate student whose inquiry led to the discovery of the flaw.
• William LeMessurier: Structural engineer involved in the Citicorp Center's design and subsequent repairs.

Notable Quotes

— 07:20 — « If that building goes and falls over from a wind load, it's gonna take out other buildings around it. »

— 08:01 — « Mistakes you can't live with them, you can't live without them. »

Category

Educational

Video