What was that part of the building standing over 60 stories tall when the rest of the building fell?
Editors note: This essay was written in March, 2007. It was written not to be some final statement on the WTC1
spire.but to encourage closer examination of it. We are providing ideas which other researchers are free to build upon or refute altogether.
In the “progressive collapse” of both the North and South Towers, there were sections of each building seen standing at least 50 stories high after the rest of the building clearly fell.
We believe that enough of a photographic record was captured of the collapse to identify the column sections that survived the initial collapse.
In the case of WTC1, this analysis tries to show that the portion of the core seen intact after the rest of the building fell was an interconnected group of core columns, all of which were from column rows 700 and 800 only.
To locate these column rows, please refer to the following diagram which places and labels each core column.
The North Tower "Spire"
There are good quality photos of the North Tower “spire” taken from at least 5 different angles.
All of the pictures and graphics in this essay can be seen in the photo album “spire”.
I’ll start by introducing 5 different pictures of this “spire” from 5 different views.
View 1
View 2
View 3
View 4
View 5
From what angles were these pictures taken?
In order to compare these pictures with the blueprints and a 3-D model of the North Tower, we will need to know from about what angle each of these pictures were taken.
The following view of the WTC complex can help us find these angles.
Birds-Eye View
we can extract some information from this picture about how the buildings were positioned relative to each other.
Each of the 5 pictures of the North Tower "spire" shown before contains a landmark by which we can know from what angle the picture was taken.
First, we'll trace the bases of all the important buildings that we will use in our analysis and then we'll get rid of the less important details.
In the picture above, I place each of the 5 views with a blue arrow.
How do I know that the angles of these blue lines are correct?
I use a landmark from each of the 5 pictures.
I will justify each of these blue lines, one at a time, when I analyze in detail each picture in the sections to follow.
I've also added some basic coordinate systems for easy reference.
Within a safe few degree margin of error we can see the following relations.
But we are only interested in the viewing angles, so we can further simplify the diagram.
Here we have a simplified illustration of the 5 view angles relative to the North Tower orientation.
This is a very basic method of estimating these angles, and we know our results are correct only within a lenient margin of error. But we only need to know the angles within a margin of error of a few degrees to obtain very useful results.
We examine each view in more detail.
Analysis of View 1
View 1 is shown above.
If we call the width of the dome on the building to the left "W", then we can note that the direct view passes through a point that is the length "W" from the dome's right edge.
If you refer to my original derivation of angle 1, you will see that I place my blue arrow going through this very point.
That is how we know that this photo was taken at about 41 degrees relative to the orientation of the North Tower.
Analysis using weld planes
This picture is a close-up.
I give each column a generic number so we can discuss each one separately.
Those red lines are called weld planes.
Basically, they are where each 36 to 40 foot core column solid section is welded to the sections above and below.
They are important to understand for anyone who looks for evidence within the hundreds of photos of the resulting debris.
In the analysis to follow I assume the reader knows what they are and the typical geometrical characteristics found in all core box column sections.
The top of each visible column was severed in exactly 3 floor increments. These red lines are separated by 3 floors, or (most commonly) 36 feet. You know the flooring level by the cross-brace support, or "bulges" along the columns.
Columns 2 and 6 were severed at exactly the same elevations. Column 5 was severed 3 floors lower.
There is also another column, mostly hidden from view, just behind column 2. You will see it in the other photos to be analyzed. It is severed at the exact same elevation as column 5.
Exactly 3 floors lower column 7 is severed. And 3 floors below that the column pair 3 and 4 are severed.
You will be able to see that the tops of each column are separated by 3 floor increments (or multiples of 3: 6, 9.....) in each of the 5 views.
Next we will outline the columns to see them more clearly and extract the graphics.
Columns 1 and 2 obviously form a pair because the direct cross bracing is visible between them, like columns 3 and 4.
What we would like to know is the distance labelled "b".
We know that a = 12 feet because most all the floors in the building were separated by 12 feet.
The reader may astutely ask:
What if the floor with the dimension labelled "a" was one of the few floors which wasn't 12 feet between floors?
I answer that I know it isn't because if you look at the the close-up of the original picture, you will see that the lateral braces and "bulges" are consistently separated, and if you refer to the known floor height dimensions, you will notice that this consistent separation must be 12 feet.
Notice that from the viewers point of view, b is the same or slightly larger than a. But we must remember that this picture was taken at about 41 degrees relative to what we have defined as the "x-plane", or 49 degrees from the "y-plane" and looking slightly up.
Core Column Spacing and Dimensions
We need to know the on-center dimensions and relative spacing of the core columns to understand what we are looking at.
The dimensions shown above should be sufficient to properly label some of these columns.
Identifying the columns using an AutoCAD projection
AutoCAD is a program which will allow us to see what different combinations of core columns would look like when seen from different angles.
For our AutoCAD analysis we will use the picture shown above, which is of the core column layout and spacing with dimensions extracted from the blueprints, and increase or decrease the heights of different columns, all cut along their welds, until we find a pretty good match of the actual spire pictures.
We project AutoCAD renditions of different combinations of core columns using the proper angle and column dimensions over the photo.
Analysis of View 2
This is the best photo from which to analyze the closest pair of core columns.
The angle from which it was taken can be known by using the top corner of the building in the foreground, WFC 2. If the reader refers to the series of graphics I used to determine the angles, they will see that my blue line crosses over just this very corner of the WFC 2 building.
Notice that the angle of this photo could be determined with incredible precision by noting that the edge of the dome aligns pretty much exactly with a distant steeple in the background. But our simple method gives us all the information we require.
We find that the angle is about 28 degrees fron the "x-axis", or 62 degrees from the "y-axis".
In this picture we can clearly see the horizontal cross-bracing, and since we know that the WFC2 building is about 38 stories tall, not including the dome, we can safely guess that the visible region is between 38 and 50 stories tall.
Next we will outline the columns and extract the graphics.
Notice how the 700 and 800 columns line up with the photo.
We compare the remaining photographs of the spire to projections of the core at the link below.
The Spires, Demystified, Part 2
Created on 06/24/2007 12:24 PM by admin
Updated on 05/02/2009 05:50 PM by admin
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