Fire Testing Is Questioned In Findings On Towers

[BootinUp]

A part of an article from the NYT archives

Fire Testing Is Questioned In Findings On Towers

By ERIC LIPTON
Published: August 26, 2004
New York Times

For more than two years, federal investigators have been struggling to resolve a critical and contentious question concerning the collapse of the World Trade Center towers: was the spray-on fireproofing initially placed on the twin towers' innovative lightweight floors sufficient to protect them in a major fire?

Now, a series of federally sponsored tests that ended here today has produced a provocative but complex finding: the fireproofing, as it was installed during the construction of the trade center in the 1960's, met the standards of the day.

But, in a conclusion that may have ramifications for understanding other tall buildings and future structures, investigators from the National Institute of Standards and Technology found that the test used to determine fireproofing sufficiency, then and now, may itself be flawed -- unable to predict accurately what will be required in a real-life fire. As a result, the towers indeed may been more vulnerable to a fire than anyone could have known.

The debate over the sufficiency of the fireproofing on the World Trade Center's lightweight floors -- essentially metal and concrete decks supported underneath by a series of inch-thick zigzagging rods -- intensified in May 2003 when federal investigators concluded that the Port Authority, back in the late 1960's, apparently never performed the formal laboratory fire test on the design. That meant there was no way for the Port Authority to say for sure that the towers' floors would hold up against an extremely intense two-hour fire, as was required then under the New York City building code. The Port Authority, when the towers were built, said it was committed to meeting or exceeding the city code, even though as an agency created by the two states, it was not required to do so.

Thought folks might find this info useful.

[DoYouEverWonder]

1. In 1975 there was a serious fire at the WTC

that spread through 7 floors and spread across more then half of the eleventh floor. The steel and floors did just fine then.

[canetoad]

2. Contemporary NYT piece

[dailykoff]

3. Misleading headline.

The tests found that "the fireproofing, as it was installed during the construction of the trade center in the 1960's, met the standards of the day," i.e., resistance to a 2-hour fire.

The caveat is typical NIST flimflammery and the headline is typical NYT bullshittery.

In any case the fire resistance of the sprayed-on coatings has never been an issue and they've never failed to perform as designed in serious highrise fires, for example the First Interstate fire in Los Angeles and the Meridian Plaza fire in Philly.

Also, there's a lot more to the story, for example the facts that extremely robust and redundant automatic sprinkler systems were installed in both towers after the '75 fire and that the WTC was in the process of upgrading the sprayed-on insulation on every floor.