10. The claim that the core of each of the Twin Towers was "a hollow steel shaft" — a claim that denied the existence of the 47 massive steel columns that in reality constituted the core of each tower and that, given the "pancake theory" of the collapses, should have still been sticking up many hundreds of feet in the air (27-28).
The 9/11 Commission Report does not discuss the design of the towers in the body of the text, however in the footnotes to Chapter Nine:
Quote:
In addition, the outside of each tower was covered by a frame of 14-inch-wide steel columns; the centers of the steel columns were 40 inches apart. These exterior walls bore most of the weight of the building. The interior core of the buildings was a hollow steel shaft, in which elevators and stairwells were grouped. (pg.541)
There are a number of inherent claims in this allegation:
Quote:
The claim inherent in the allegation is that 47 massive steel columns in reality constituted the core of each tower.
The claim inherent in the allegation is that, given the “pancake theory” of the collapses, [the core columns] should have still been sticking up many hundreds of feet in the air.
As with previous discussions about the World Trade Center towers, the appropriate official document to refer to is the NIST report, not the 9/11 Commission Report.
Quote:
A second structural subsystem was located in a central service area, or core (Figure 1-5), approximately 135 ft by 87 ft, that extended virtually the full height of the building. The long axis of the core in WTC 1 was orientated in the east-west direction, while the long axis of the core in WTC 2 was orientated in the north-south direction (Figure 1-3). The 47 columns in this rectangular space were fabricated using primarily 36 ksi and 42 ksi steels and also decreased in size at the higher stories. The four massive corner columns bore nearly one-fifth of the total gravity load on the core columns. The core columns were interconnected by a grid of conventional steel beams to support the core floors.
NIST NCSTAR1 – Final Report on the Collapse of the World Trade Center Towers, pg.8
The description of the building core as a “hollow steel tube” does not necessarily deny the existence of the core columns. For example, NIST describes the exterior columns as a tube:
Quote:
The first, the exterior structural subsystem, was a vertical square tube that consisted of 236 narrow columns, 59 on each face from the 10th floor to the 107th floor (Figure 1-3).
NIST NCSTAR1 – Final Report on the Collapse of the World Trade Center Towers, pg.6
The WTC tower design has, since its creation, been commonly referred to as a "tube-within-a-tube design", as demonstrated by C P Wang, one of the key architects of the Taipei 101 tower:
Quote:
C. P. Wang: So we had an emergency meeting with the owner we tried to simulate what if the similar incident would happen to this building? We know the WTC in NY is basically a tube in a tube design with very thin exterior wall. It is a very smart and genius design to me but in Taipei with the earthquake and typhoon we are not able to do that. We need a very strong building and we have very big steel columns.
Innovation: Life, Inspired - Episode One: Building to Extremes, aired February 10, 2004
Thirteen/WNET
Episode Transcript A January 2002 article at
Graduating Engineer uses the same phrase:
Quote:
The strength and redundancy of the structure itself, however, was the direct result of careful planning by the engineers who designed the buildings. The WTC towers utilized tube in tube construction, which provided primary support to the structures from external sheathing.
Source Although the 47 core columns were large, they accounted for a fraction of the total floor space of the core of the towers. Each core was 26m by 41m, totalling 1066m
2 in area. In contrast, at their largest dimensions in the base of the towers the core columns measured 0.3m by 1.3m, giving a footprint of 0.39m
2, with a total footprint area of 18.3m
2 for all of the core columns – about 1.7% of the total core area.
In Dr Griffin’s book
Omissions and Distortions he states:
Quote:
One of the major problems with the official account is why, even if the fire could have somehow caused the floors of the building to “pancake” (as the generally accepted explanation has it), the resulting pile of rubble was only a few stories high. Why were these massive steel columns not still sticking up hundreds of feet in the air?
Griffin, D.R.; The 9/11 Commission Report: Omissions and Distortions, pg.27-28
There are many problems with this statement by Dr Griffin, the first of which is the “pancake collapse” contention. This is addressed by NIST, who undertook the official investigation of the collapses:
Quote:
NIST’s findings do not support the “pancake theory” of collapse, which is premised on a progressive failure of the floor systems in the WTC towers (the composite floor system—that connected the core columns and the perimeter columns—consisted of a grid of steel “trusses” integrated with a concrete slab; see diagram below). Instead, the NIST investigation showed conclusively that the failure of the inwardly bowed perimeter columns initiated collapse and that the occurrence of this inward bowing required the sagging floors to remain connected to the columns and pull the columns inwards. Thus, the floors did not fail progressively to cause a pancaking phenomenon.
NIST FAQ Another problem with Dr Griffin’s statement is that, as we have seen previously, the core of each tower did remain “sticking up hundreds of feet in the air” for some time after the initial collapse.
These core sections did not remain standing for very long, for the simple reason that they were incapable of remaining standing. The core of the towers were never designed to stand on their own. With the majority of the structure gone, the cores were subjected to forces that greatly exceeded their structural limits.
A final problem with Dr Griffin’s assertion is his claim that the debris pile at ground zero was “only a few stories high”.
In previous parts of this document I have provided links to numerous ground zero photographs, and more are included at the following links:
http://www.zombietime.com/wtc_9-13-2001/http://www.parrhesia.com/wtc/wtc-photos.htmThe inherent claim that 47 massive steel columns in reality constituted the core of each tower is accepted.
The inherent claim that, given the “pancake theory” of the collapses, [the core columns] should have still been sticking up many hundreds of feet in the air is rejected.
The buildings did not suffer “pancake” collapses, video evidence reveals the core of each tower
did remain standing for some time, and it is entirely expected that, bereft of the support of the rest of the structure, these core sections quickly collapsed.
