Another unnecessary investigation would cost far more than "a couple of drones." Why don't
you pony up?
Large parts of WTC 1-2 fell on it. It burned out of control for hours. You understand how steel weakens and softens. And yet you're worried over what particular
flange gave first?
Large parts of WTC towers fell on Bankers Trust, AmEx , ATT and they did not experience much in the way of collapse... or fires for that matter. I am not disputing the notion that fires weakens steel, nor that there were uncontrolled fires. I wonder how NIST determined the extent of fire damage, and where it did the main mischief. It seems to me this is more speculation / theory than fact.
I believe there were multiple factors which facilitated the collapse of each tower... and that a KEY factor was the actual engineering design. I am suggesting that the uniqueness of these designs was a larger factor that NIST or anyone for that matter seems to consider.
You have these factors to consider:
uncontrolled fires
atypical accelerants (such as stored diesel)
loss of fire protection on steel
inoperative sprinkler system
electrical equipment exploding
mechanical damage - plane and or falling debris
age of structure and connections
engineering features such as framing design, FOS, design and service loads
siting 7 wtc over con ed sub station
fabrication issues
All of the above were contributory factors. None of these factors appears to be sufficient on its own. It was a joint effort of factors.
Does it matter WHICH factors dominated the collection of factors? Perhaps.
On the face , since we experience a complete structural collapse the structure design itself needs to be high on the list of contributory factors. And if the engineering turns out to be VERY high or the key factor then NIST is missing something.
Accordingly I've suggested that we examine the importance of the engineering / design of these towers. The OP attempts to determine if a single column failure can lead to collapse.
In the twin towers there were multiple instant column failures, yet NIST did not think this was a factor in the collapse of the twin towers. They opted for sagging trusses which pulled the facade out of column. This turns out to be completely the wrong explanation for the collapse initiation.
Ozzie says, details don't matter all that much. I say they do if engineering/design turns out to be the key factor for total collapse.
ROOSD seems to correctly characterize the collapse phase of the twin towers. ROOSD is a process which had engineering / design as a key factor.
When someone says.. fire did it move on... they are as incurious and irrational and unscientific as the truth movement in its broad and unsupported claims.
The implication of engineering / design being THE key factor would be huge I would think. If true this means that the engineers', designers', planners' and agency's which approved the designs for construction work would make them culpable in some measure. But even if this legal basis for tort is not established, if the engineering design decisions were a KEY factor then there a lessons to be learned for structures in the future. And I suspect the lesson is not simple more robust fire codes rigorously applied. And that seems to be the general thrust of the NIST conclusion.
One might think that it was cold that caused the challenger to explode... or a hurricane that cause Fukushima to melt down into the mess it did.
Get it?
