Volunteers from the Structural Engineers Association visited ground zero first in early October and identified a handful of steel samples they wanted to save. The effort, organized by the Structural Engineers Association of New York, is the team's primary source of raw steel evidence from the site. The American Society of Civil Engineers, in coordination with the Federal Emergency Management Agency, has set up a panel of engineering and fire experts who are assembling photographs, witness interviews and other data to try to determine why the towers collapsed. The organized steel recovery effort is one piece of a three-tiered investigation.
THE TWO TOWERS MUD CRACKED
And unexpectedly cracked washers in crucial connections in the towers are being closely scrutinized. Pieces of steel have also been found that were apparently melted and vaporized not solely because of the heat of fires, but also because of a corrosive contaminant that was somehow released in the conflagrations.
Now that it has been found - and spray-painted with the word ''Save'' in florescent orange paint - tests can be conducted to determine whether heat or stress or some design or material flaw might have let it fail.Īnother crumpled steel member set aside at a Keasbey, N.J., scrapyard has markings clearly showing that it ran on the east face of the north tower from the 92nd to the 95th floor, in the center of one impact zone. It ran three stories from the 98th to the 101st floor on the exterior face of one tower, just above the zones struck by jets laden with fuel. Bonilla, with its brackets, bolts and two pairs of winglike steel plates still attached, is a potentially critical discovery. The steel column identified last Wednesday by Ms. But without a doubt, the teams surveying have made some important discoveries. The organizers of the steel recovery effort will not say how many pieces in total have been set aside for future study, saying only that it is more than 100 from among the hundreds of thousands of World Trade Center steel parts. But they concede that there is no way of saying for sure an unknown number of steel columns has been sent off to mills as far away as Asia without ever having been examined or saved.
Through it all, the engineers profess optimism that they are catching and saving what is most useful. Bonilla made her find while the scrapyard workers were on their lunch break. The engineers time their forays to avoid being crushed. Small teams of engineers plot slightly mad dashes, like mountain goats, into mounds of steel to claim pieces of tower columns. But despite promises of a broad federal investigation, and after weeks of calls from victims' families and others to halt the destruction of the steel that could hold all sorts of clues, the half-heroic, half-comic scenes at the Jersey City scrapyard continue to play out. 11, engineers and other experts have been struggling to answer the monumental questions of exactly why and how the buildings, designed to sustain a jet impact, completely collapsed. It was a potentially important discovery, but in part a result of happenstance.įrom the moment the two towers collapsed on Sept. Sharp, after he also squeezes into the gap, confirming the markings Ms. ''The 101st floor,'' says a fellow investigator, David F.
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