Brief Summary of NIST Report in Debate
Hi all,
This is the straight 5-minute summary of the Building 7 NIST Report 2008 Richard and I agreed on for our debate. It was read by Tom Kiely, our moderator and a host on Rule of Law Radio. This will stay as is unless there is something grossly wrong with it, because it's just a platform we both used for our debating of Building 7.
Chris Mohr
5 minutes of facts we agree on about collapse of Building 7
SLIDE OF BUILDING 7 NEAR TOWERS STANDING
In 2008, NIST issued its final report on Building 7. There are both differences and similarities between Building 7 and the two towers. Some differences:
A.) No plane hit bld 7 .
B.) Towers fires spread horizontally; bldg 7 fires spread vertically up and down the south face and then inside the building.
D.) The Towers suffered structural damage from the plane crash; Building Seven had very little structural damage.
E.) NIST Quote: “The collapse of WTC 7 is the first known instance of a tall building brought down primarily by uncontrolled fires.”
F.). The Towers burned for under two hours each before going down; Building 7 got hit with burning debris at 10:28 am and collapsed at 5:20 pm after almost 7 hours of fires.
SLIDE OF BUILDING DESIGN WITH COLUMN 79: NIST: Column 79 helped support the east penthouse of the building.
VIDEO OF TRUSSES
Building 7 had a large open atrium in the lobby and was held up by columns and three complex truss systems.
SLIDE OF TRUSSES PLUS COLUMN 79
SLIDE OF RICHARD’S PHOTO: Here is a photo of Column 79 and the nearby structure.
So now I will just paraphrase the NIST Report so we know what they claim:
that fire was the main reason for the collapse, along with lack of water to fight the fire. Fires burned all afternoon esp. on the lower floors.
SLIDE OF DRAWING OF DAMAGE
Separate fires in WTC 7 broke out on different floors, most notably on Floors 7 to 9 and 11 to 13.
SLIDE OF DEBRIS HITTING BUILDING 7
Firefighters reported large gashes and fires in the south face of Building Seven but NIST says there was not much structural damage.
SLIDE OF FIRST FLOOR LOBBY.
Building 7 collapsed because heat expanded the floor beams and girders; and their unusual length magnified that effect. Also, connections between structural elements that could not resist the heated loads; and a structure not designed to prevent fire-induced progressive collapse.
SLIDE OF MINOR FIRES ON NORTH PERIMETER
The north perimeter showed fires on only a few floors, but
SLIDE OF FIRE DAMAGE DRAWING NIST claims the fires were more extensive on the south side which was hit with burning debris.
SLIDE OF LOWER BUCKLING FLOORS
NEW NIST: a girder on Floor 13 lost its connection to a critical column, Column 79, that provided support for the long floor spans on the east side of the building. The displaced girder caused Floor 13 to collapse, floor failures cascaded to the 5th floor. This collapse weakened Column 79 over nine stories.
Column 79 then buckled and triggered an upward progression of floor system failures that reached the building's east penthouse.
SLIDE DRAWING OF EAST PENTHOUSE COLLAPSE
Failure first occurred all the way to the roof line-involving all three interior columns on the easternmost side of the building (79, 80, 81).
SLIDE DRAWING OF EAST PENTHOUSE COLLAPSE
Then, all of the columns east to west failed in the core of the building (58 through 78).
DETAIL SLIDE OF EAST PENTHOUSE COLLAPSE that reached the building's east penthouse.
Finally, the entire façade collapsed.
VIDEO SLIDE OF COLLAPSE OF NORTH FACE
That series of structural failures was mostly invisible, with east penthouses seen collapsing first, then around seven seconds of nothing visible on the north face.
SLIDE OF WINDOWS WITH SUNLIGHT THROUGH THEM
As evidence of the complete collapse of the penthouse and the structure during those seven seconds, NIST shows this picture of light shining through the windows right after the east penthouse disappeared from view.
FREE FALL COLLAPSE Diagram
IMPORTANT: NIST said the building's exterior facade fell slowly at first, then at approximately free fall acceleration for 2.25 seconds through a distance of approximately 8 stories (32 meters, or 105 feet).[62] The entire facade collapsed downward as a single unit.
SLIDE OF EXPLOSIVES SIMULATION
NIST also did a computer simulation of what an explosive demolition would have looked like. These diagrams of the damage they say it would have caused many more broken windows, much louder sounds, and a different pattern of destruction.
There are several other scientists who have proposed variations on the NIST Theory for Building 7: Arthur Scheuerman, and Ryan Mackey both focus on the long-span beams expanding, sagging and then contracting when the fire moved away and the long beams cooled; NIST focuses more on the building connections. The Council on Tall Buildings and Urban Habitat, the University of Edinburg, and Arup have also issued their own scientific criticism of details of the NIST report.
NCSTAR1A (read it here:
http://www.ctbuh.org/Publications/T...ISTWTC7/tabid/739/language/en-GB/Default.aspx)