Engineering Improvisation: Insights From the Cleanup at Ground Zero
Following the World Trade Center attacks on Sept. 11, 2001, engineers and construction workers faced the daunting task of dismantling the World Trade Center complex in order to make room for new construction. Researchers at Rensselaer Polytechnic Institute are applying mathematical methods to describe how these decisions were made, and investigating how the decisions could inform cleanup efforts at future disasters.
The cleanup of Ground Zero required engineers and contractors to remove 1.6 million tons of material from a confined space and under dangerous conditions. They worked around the clock for nine months to complete the project, the scope and size of which were unmatched in modern history. Remarkably, the task was accomplished ahead of schedule, below budget, and without any serious accidents.
If we can pinpoint how and why these individuals performed so well under immense pressure, according to Rensselaer researcher David Mendonça, we can leverage that knowledge to help prepare for future disaster recovery activities, both through training and new technologies. An associate professor in the Department of Industrial and Systems Engineering, Mendonça studies the cognitive processes that underlie human decision making, particularly in post-disaster environments.
Beyond the sheer quantity of debris at Ground Zero, the depth and density of debris presented challenges for engineers on site. Another risk they faced was the threat of the slurry wall collapsing. This slurry wall was a part of the building foundation that held back a potential flood of water from deep underground. With each load of debris removed from the site, the slurry wall became more exposed, requiring extensive bracing to maintain its integrity. The wall had not been designed to function in this way, and so it had to be constantly monitored using an elaborate system of sensors. The engineers paid frequent and careful attention to the slurry wall, making decisions for which there was no historical basis.
Mendonça’s work has been primarily focused on creating mathematical models of the interaction between debris removal activities, the behavior of the slurry wall, and decisions about how to manage the site. To do so, he and his research team collected field data and interviewed engineers and managers who led the cleanup effort. This research offers insights into the rate of learning within an organization, and into the processes that underlie the development of new engineering procedures to deal with emerging design challenges.
Following his work on debris removal at Ground Zero, Mendonça received funding from the National Science Foundation to examine the role of information technology in the management of debris removal operations in Mississippi after Hurricane Katrina. The study helped identify some of the possibilities and limitations for mobile phones and other technologies in managing debris removal particularly when situations on the ground differed radically from the situation planned for by disaster response officials. This summer, he has been looking at data from the cleanup operations in the wake of the recent burst of tornadoes in Alabama.
Mendonça’s work on improvisation in emergency response has led to new theories and models of how humans reason in time-constrained, highly novel situations, both alone and in groups. Mendonça and others are using these models in new research to provide emergency response personnel with computer-generated training environments.