by Scott Creighton (archived reposted from Aug 9th 2009)
(Here is a link to the archived version)
(Here is a link to the archived version)
***UPDATE*** note the updated truss count. My original estimate of 23,000 trusses was based on the idea that they used single trusses in between the section breaks when in fact they did not, they used double trusses everywhere on each floor. My first count was based on doing a layout of the truss structure and then simply counting and multiplying that number by the number of floors which used these trusses. Turns out, the number of missing trusses is actually double my original number… about 43,000 – 46,000. With that one exception, I believe the research in this article still stands.
***UPDATE*** Please check out the companion article, The 6,000.
According to the official explanation of the collapse of the Twin Towers on Sept. 11th, 2001… the initial plane crashes damaged the core structure of the towers enough so that when the resulting fires “weakened” the floor trusses, the result was that the remaining floors above the areas of the plane crash and fires crashed down on the undamaged parts of the buildings, and “pulverized” them in a gravity driven demolition of sorts.
This “official” explanation, which if left unchallenged, stands as the basis for the endless “War on Terror”, the war in Iraq, the war in Afghanistan, the attacks on the general population of Pakistan, the Patriot Act, the Military Commissions Act, warrentless and illegal surveillance of U.S. citizens, and various other assaults on our democratic freedoms… is basically a lie.
It is impossible.
Sometimes in an investigation, what you don’t find at the crime scene is just as important as what you do find. Provided you know what to look for and you understand why it is or isn’t there.
With that in mind, I offer for your consideration, the great mystery of the missing Trusses and Floor-Pans of the World Trade Center towers 1 and 2… and the (estimated) 10 tons of “iron-rich” spheres found in the dust at Ground Zero by every single investigative agency that has bothered to look.
First: What exactly were the floor trusses and how were they used?
The floor trusses were used to span the distance between the 47 core columns and connecting beams of the “core” of the Twin Towers (the heart of the strength of the design) and the 200+ exterior columns that made up the distinctive look of the outside of the buildings.
The drawing is mine and it is just a rough sketch designed to give the readers here a basic understanding of how the trusses were used. The source material for this comes from the actual construction drawings of the towers themselves and the FEMA report and NIST report details pages. Here is one of them.
As you can see, my representation is rather accurate in the depiction of the truss and how it is used relative to the construction of the towers themselves.
You can see that there 12′ height from floor to floor, but with the depth of the trusses and the dropped ceiling, the finished ceiling height was around 8′. This is also evidenced by the NIST report as well as from this photograph of a typical WTC North Tower office layout.
To give you a still better understanding of how the floor trusses were used in the design of the Twin Towers, again I refer to the FEMA report.
The trusses and floor-pans (“Metal Deck”) were fabricated off site in very large sections and transported to the construction site where they were hoisted via cranes into position and welded and bolted in place.
The steel construction of the floor system sections was mainly A-36 structural steel, commonly used in high rise buildings, with a melting temp of around 2750 degs.
Carbon steels which can successfully undergo heat-treatment have a carbon content in the range of 0.30–1.70% by weight. Trace impurities of various other elements can have a significant effect on the quality of the resulting steel. Trace amounts of sulfur in particular make the steel red-short. Low alloy carbon steel, such as A36 grade, contains about 0.05% sulfur and melts around 1426–1538 °C (2600–2800 °F). Wiki
(I am deliberately using FEMA and NIST diagrams for two reasons: 1. that you understand that my information at this point is supported by the documents of the “official story” itself so that you don’t think this is some “crack pot” obscure reference… and 2. so that you will come to understand my question later about how does NIST and FEMA both spend so much time explaining the presence of the trusses in the construction of the towers.. and so little time wondering just what could have happened to them.)
Second: Relative size and overall numbers of the trusses themselves.
In order to give you a better understanding of the relative size of the trusses, I created a few 3d models that accurately represent them. The first is an isometric view coupled with an elevation of just one truss along side a 6′ tall figure of a man.
As you can see, the trusses themselves are quite long, the longest of the standard trusses was about 59′ and the shortest of them was 35′. The transverse trusses that spanned through the trusses and locked them all together were even longer on average.
Now that you have an idea of what the trusses looked like and what they did, lets take a minute to see how many of them there were, per floor. The following is from the architectural design drawing of the world trade center as well as from the FEMA report.
[note: that number should be revised to 200+]
What you see here is the truss layout in plan view. The light blue colored lines are the trusses themselves and the magenta would be the transverse trusses or what the FEMA diagram calls the “Bridging Trusses”.
The truss count on this drawing that I did is an estimate based on the drawings that I found. There were some trusses that were doubled up as “girder” trusses to carry the live load of other trusses, so the count I have up there is a bit low. But basically, it is pretty accurate; about 106 trusses per floor.
Now look back up at the isometric view of the truss. There were 106 of those large, structural steel elements, per floor.
 The towers themselves were 110 floors. Do the math. 212 trusses x 110 floors = 23,320 trusses per tower
 But wait… there were TWO Twin Towers felled that day and when you look at the photos of the aftermath of the “collapse” of the buildings, the debris is mixed together at Ground Zero… so what you are really looking for is the 46,000+ structural steel trusses (and connected floor pans) of the Twin Towers.
That’s a lot of 60′ and 35′ long trusses that could NOT have been “pulverized” like the concrete floors or the desks. They were structural steel.
These two images will give you an idea of how they were used and the shear volume of the trusses compared to the rest of the material of the buildings.
First we have an isometric view of only 2 (two) floors of the towers, again drawn to scale based on the construction drawings and the NIST and FEMA reports collectively.
The trusses are drawn in the light blue color and you can see how they span the distance between the core of the towers and the exterior columns. For a better understanding of the shear volume of the trusses I have dropped out the columns for this next image. Remember it is just two floors.
We are talking about a MASSIVE amount of floor trusses.
Third: What you don’t see is the key.
According to the official explanation of what happened to those towers, the upper section of the buildings came crashing down on the lower floors and “pulverized” the concrete floors while crushing the structure of the buildings themselves.
There have been many scientists and engineers who have attempted to prove that there just isn’t the energy in the falling upper section of the building to do what the “official explanation” says happened. In my opinion, they are correct.
However, let’s pretend for a moment that the official explanation is correct, taken at face value. What does that mean for the trusses and the floor pans?
The steel trusses and floor pans would not “pulverize”. In fact, they would probably shift one way or the other, connected together as they were, and lay pretty much flat, just dominoed as it were, together.
Even if they were somehow separated from one another, the tell-tale signs of the trusses would be everywhere: the zig-zaged tension and compression rod running through the trusses. Remember, there were over 23,000 of them over 35′ long.
You couldn’t POSSIBLY miss them. They should be scattered all over Ground Zero.
Yet, strangely, they are not.
The following images come from a group of high resolution photos I have found depicting the debris in the aftermath at Ground Zero. You will see lots of exterior columns and interior columns… you will see the pulverized concrete dust by the tons… and you will see the aluminum cladding that made of the exterior surface of the buildings and lots of steel rebar that had been inside the concrete floors…
What I dare you to find is ONE… just ONE truss. Just ONE of the 23,000+ steel trusses that fell to the ground that day and COULDN’T have been pulverized by the falling debris. The photos are all high res so I invite you to click on them and explore to your hearts content.
Now remember what the webbing (tension and compression) from the trusses look like. They have the tight angles, in a repeating pattern, over a long span. Don’t be confused by the rebar that was in the concrete floors. What you see to the right of Mr. Sonnenfeld is rebar.
I have personally been over and over these photos and many others. I have yet to find one single truss. Not one.
23,000 trusses in the Ground Zero debris, and NOT ONE is visible in the photos? Does that seem odd to anyone else?
Of course it does.
But just because they aren’t visible, doesn’t mean they aren’t THERE.
Forth and final part: What are the “Tons” of “iron rich spheres“
Ever since the beginning of the investigation into the events of 911 almost every single ‘official” and unofficial report has mentioned the discovery of the “iron rich spheres” found in the dust collected from Ground Zero.
The RJ Lee report and the FEMA report as well as the investigative work of Steven Jones and others all make mention of these mysterious metal spheres mixed in with the pulverized concrete dust. This is what they look like.
The important thing here is the language they use to describe these “spheres’ found in in the dust.
“Iron rich” implys that they are iron, but they are also made up of other metals and alloys, and of course… carbon.
Why is this important? Because “steel” is made up of mainly IRON mixed in with small amounts of carbon and, depending on the type of steel, other elements. Steel itself is “iron rich”. The structural steel of the trusses… is itself “iron rich”.
The thermite that others have been considering as the source of these spheres creates molten iron… not molten iron and carbon. Plus the shear volume of the spheres found in the dust (at one time suggested by Jones to be about 10 tons) suggests that they must have come from a structural element of the towers themselves.
At the moment of detonation, a high explosive, strong enough to pulverize the concrete floors, would also have to burn hot enough to instantly melt the trusses themselves thus creating the microscopic “iron rich” spheres found by FEMA, RJ Lee, and Steven Jones. But also it would explain the “molten metal” that burned in the debris pile for weeks after 9/11.
There is only ONE high explosive used in the demolition industry capable of that kind of combined result: PETN.
Curiously, each and every single investigation that has been done on the “collapse” of the Twin Towers, RJ Lee, FEMA, NIST, and even the Jones/Harrit paper, has gone out of their way to make the statement that they DID NOT test for residual trace elements of conventional explosives in the debris from Ground Zero.
Conclusion: The official explanation for the collapse of the towers cannot be accurate.
There is no amount of pressure that could possibly have been present in the collapse of the Twin Towers that would explain the pulverization of the trusses into the steel micro-spheres found in the dust at Ground Zero.
At the moment of collapse, those trusses were in the buildings and judging from the visual evidence of the photos afterward, they were not after the buildings came down.
If the pulverization of the floors couldn’t have rendered the trusses into micro-spheres of “iron rich” droplets, what in fact did do it?
As is often the case, the simplest explanation is often the most accurate.
Test the remaining evidence from Ground Zero for trace elements of explosive materials commonly used in the demolition industry with special attention given to PETN and RDX.
The photographs don’t lie. They are a living record of the crime of 911. And from them we can and will finally prove, beyond any reasonable doubt, that the official story of what happened that day cannot be accurate.
Sometimes what isn’t visible at a crime scene is just as important as what is.