COMPELLING EVIDENCE of widespread fire protection failure during the September 11 World Trade Center disaster was this week unveiled by the head of the forensic team investigating the twin towers' failure.
Fire protection failure would have led to premature weakening of the WTC towers which were set alight when they were struck by passenger aircraft. One tower collapsed after 51 minutes as people were still trying to escape. The other lasted 89 minutes. The sprayed fire protection should have prevented steelwork from distorting for at least two hours.
At a seminar in London on Monday Construction Technology Laboratories senior vice president Gene Corley produced a series of photographs of the WTC wreckage.
They showed that only traces of sprayed on fire protection remained on structural steel at the site of the collapsed towers. In some cases the original white chalk identity markings are clearly visible on the steel. The aircraft impact exposed fire protection, exposing steelwork. 'The obvious conclusion is that the impact caused the fire protection to shatter, ' said Corley.
'That cloud of white smoke on the videos of the disaster is made up of concrete, gypsum and asbestos fire protection.'
One of Corley's images apparently shows a fire-damaged floor truss to perimeter column connection, again with little evidence of fire protection. Corley confirmed that progressive collapse occurred as a result of the fire and was not triggered by the initial impact.
He added: 'We're currently concentrating our studies on the areas where the planes hit and the structure above them. And we've started finding parts of the structure that were actually hit in the initial impact.
'It now seems that both planes were banking at around 30degrees when they hit. This would maximise the spread of the fuel through the building, and could suggest that those responsible had studied the World Trade Center in some detail beforehand.'
INFOPLUS www. nceplus. co. uk