NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.
Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.
An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Reaction of Ceiling Tile Systems to Shocks. Federal Building and Fire Safety Investigation of the World Trade Center Disaster (NIST NCSTAR 1-5D) ***DRAFT for Public Comments***
Published
Author(s)
Richard G. Gann, Michael A. Riley, J M. Repp, A S. Whittaker, Andrei Reinhorn, P A. Hough
Abstract
The degree of damage to the ceiling tile systems of the World Trade Center towers following the aircraft impacts on September 11, 2001, could have affected the rate at which the ensuing fires heated the steel- trussed concrete slab floor systems above. Accordingly, a series of shaking table tests was conducted to estimate the magnitude of distress to the ceiling tile systems that would result in substantial displacement of ceiling tiles. Ceiling tile systems indicative of those used in the core and tenant spaces were subjected to both single and complex impulses of varying magnitude. The systems resisted significant damage up to about 1g applied to the test platform, corresponding to about 2.5g to 3g at the ceiling frame. The data suggest that major system failure would occur at impulse values near 4g to 5g at the ceiling frame.
Citation
National Construction Safety Team Act Reports (NIST NCSTAR) - 1-5
World Trade Center, high rise buildings, building collapse, disasters, fire safety, fire investigations, terrorists, terrorism, ceilings, ceiling tiles, experiments, aircraft impact, concretes, floors, damage
Gann, R.
, Riley, M.
, Repp, J.
, Whittaker, A.
, Reinhorn, A.
and Hough, P.
(2005),
Reaction of Ceiling Tile Systems to Shocks. Federal Building and Fire Safety Investigation of the World Trade Center Disaster (NIST NCSTAR 1-5D) ***DRAFT for Public Comments***, National Construction Safety Team Act Reports (NIST NCSTAR), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=909114
(Accessed October 8, 2025)