09-08-2013, 06:52 PM
Tony Szamboti Wrote:Let's see if Jeffrey's notions of the floors collapsing first and instigating the collapse of the North Tower can hold up to scrutiny when combined with observation and how things actually work.
1. In order for the floors to instigate the collapse they would have needed to collapse at least three floors before leaving the columns unsupported enough for buckling of the columns to even be possible.
2. If the three floors had collapsed before the columns buckled we would have seen huge amounts of smoke and dust coming out of the windows before the roofline fell. We don't and three stories if 36 feet of height so this would not have been something easy to miss. So the floors did not instigate the collapse.
So Jeffrey's floors first theory does not hold up to scrutiny and it is no different than saying the moon is made of green cheese.
What actually happened is the core went down first and pulled the perimeter columns inward causing them to buckle and fail and smoke and dust came out of one story 9the 98th) across the building as the roofline started going down.
Don't misrepresent my position. Let's try again:
Planes did substantial mechanical damage to the core and the facade. Loads were redistributed driving down FOS in the aggregate and likely pushing SOME columns periously close to failure. There were damaged or dented columns as well clearly not able to perform at capacity
Fire proofing was blasted off many columns by the plane impact and debris flying the the structure... a jumbo jet would be very disruptive to the interiors including the fire protection. It also severed and shorted electrical risers causing electrical explosions and fires on 108 and in the sub basement where sub stations and switch gear was located.
The heat eroded the strength of the frame. Several large section of floors were destroyed by the plane and sections becan to collapse. The supports for the slabs were rather few steel angle seats... debris shows many bent over and riped from the belt girder and the facade panels. Perimeter core columns lost bracing and unbraced length increased weakened those still in place.
Fires advanced through several floors in the core which was tenant space as the shafts mostly ended on flr 78 sky lobby. These floors supported the spread of the fires and pooled fuel that entered with the plane... not all fuel ignited outside... most likely burned inside the tower and flowed in some cases down the vertical riser shafts adjacent to the core columns.
Bracing splices began to fail from the heat weakening... columns continued to weaken from multiple assaults. Weaker column splice joints were 4' above the floor slabs and subject to intense heat from the flames. Steel warped and twists and columns moved out of alignment.
The center core columns were the weakest one and now were seeing the displace loads from the destroyed stronger columns. The failed and this led to the 360 ton antenna to plunge down into the core area of the 3 top floors. At this point the entire interior including the core was coming apart... the facade was incapable of carrying the floor loads without the core side support fully functioning... it began to buckle and as the FOS dropped to one and all reserve strength was gone... the 30,000 tons plunged down through the building setting off the ROOSD... the facade without lateral support broke apart and came down in sheets of varying sides. The collapse or the top inside the tower caused a huge flashover shooting smoke and flames and debris outward and ROOSD began.
It was something similar to what is depicted in the attached cartoon.
perhaps