Wtc 7 And Sandero, NIST v speculation
Mar 5 2012, 12:25 PM
Group: Valued Member
Joined: 30-January 09
Member No.: 4,095
I've seen a lot of threads on the towers being discussed by SanderO on this forum. Lately WTC7 has been discussed. I'm not attacking this person, just his arguments.
First, what exactly did the NIST Report claim regarding WTC7? This is crucial as the NIST Report is the official report on what did and didn't happen to this building. End of story.
Any theorizing or speculation which isn't addressed in what the NIST Report contains is irrelevant.
Any speculation which may exaggerated claims made in the NIST Report is actually a defense of this arrogant rag.
Any other approach to this report is no different to the Stutt/Legge approach to the Pentagon. None of what they claim (apart from being proven erroneous on many levels) has ever benn verified nor is it part of the official narrative. It is irrelevant.
Let's see what the NIST FAQ page claims in light of many questions raised by the report and compare what SanderO claims.
SanderO claims that fire was a factor. NIST says
The heat from the uncontrolled fires caused steel floor beams and girders to thermally expand, leading to a chain of events that caused a key structural column to fail. The failure of this structural column then initiated a fire-induced progressive collapse of the entire building.
According to the report's probable collapse sequence, heat from the uncontrolled fires caused thermal expansion of the steel beams on the lower floors of the east side of WTC 7, damaging the floor framing on multiple floors.
Eventually, 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 (see Diagram 1). The displaced girder and other local fire-induced damage caused Floor 13 to collapse, beginning a cascade of floor failures down to the 5th floor. Many of these floors had already been at least partially weakened by the fires in the vicinity of Column 79. This collapse of floors left Column 79 insufficiently supported in the east-west direction over nine stories.
The unsupported Column 79 then buckled and triggered an upward progression of floor system failures that reached the building's east penthouse. What followed in rapid succession was a series of structural failures. 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). Then, progressing from east to west across WTC 7, all of the columns failed in the core of the building (58 through 78). Finally, the entire fašade collapsed.
Due to the effectiveness of the spray-applied fire-resistive material (SFRM) or fireproofing, the highest steel column temperatures in WTC 7 only reached an estimated 300 degrees C (570 degrees F), and only on the east side of the building did the steel floor beams exceed 600 degrees C (1,100 degrees F). However, fire-induced buckling of floor beams and damage to connections-that caused buckling of a critical column initiating collapse-occurred at temperatures below approximately 400 degrees C where thermal expansion dominates. Above 600 degrees C (1,100 degrees F), there is significant loss of steel strength and stiffness. In the WTC 7 collapse, the loss of steel strength or stiffness was not as important as the thermal expansion of steel structures caused by heat.
These two videos address NIST's exaggeration and dishonesty regarding these claims (among others)
From NIST again, differentiating between the collapses of the towers and WTC7 (again emphasizing that fire was the cause of collapse.
WTC 7 was unlike the WTC towers in many respects. WTC 7 was a more typical tall building in the design of its structural system. It was not struck by an aircraft. The collapse of WTC 7 was caused by a single initiating event-the failure of a northeast building column brought on by fire-induced damage to the adjacent flooring system and connections-which stands in contrast to the WTC 1 and WTC 2 failures, which were brought on by multiple factors, including structural damage caused by the aircraft impact, extensive dislodgement of the sprayed fire-resistive materials or fireproofing in the impacted region, and a weakening of the steel structures created by the fires.
The fires in WTC 7 were quite different from the fires in the WTC towers. Since WTC 7 was not doused with thousands of gallons of jet fuel, large areas of any floor were not ignited simultaneously as they were in the WTC towers. Instead, separate fires in WTC 7 broke out on different floors, most notably on Floors 7 to 9 and 11 to 13. The WTC 7 fires were similar to building contents fires that have occurred in several tall buildings where the automatic sprinklers did not function or were not present.
Why did WTC 7 collapse, while no other known building in history has collapsed due to fires alone?
Factors contributing to WTC 7's collapse included: the thermal expansion of building elements such as floor beams and girders, which occurred at temperatures hundreds of degrees below those typically considered in current practice for fire-resistance ratings; significant magnification of thermal expansion effects due to the long-span floors in the building; connections between structural elements that were designed to resist the vertical forces of gravity, not the thermally induced horizontal or lateral loads; and an overall structural system not designed to prevent fire-induced progressive collapse.
Getting the hint yet?
NIST WTC 7 Investigation Finds Building Fires Caused Collapse, 08 21 08
SanderO claims that "fuel oil systems" contributed (exaggeratedly) to the heat and fires in the building...
Did fuel oil systems in WTC 7 contribute to its collapse?
No. The building had three separate emergency power systems, all of which ran on diesel fuel. The worst-case scenarios associated with fires being fed by ruptured fuel lines-or from fuel stored in day tanks on the lower floors-could not have been sustained long enough, could not have generated sufficient heat to weaken critical interior columns, and/or would have produced large amounts of visible smoke from the lower floors, which were not observed.
As background information, the three systems contained two 12,000 gallon fuel tanks, and two 6,000 gallon tanks beneath the building's loading docks, and a single 6,000 gallon tank on the 1st floor. In addition one system used a 275 gallon tank on the 5th floor, a 275 gallon tank on the 8th floor, and a 50 gallon tank on the 9th floor. Another system used a 275 gallon day tank on the 7th floor.
Several months after the WTC 7 collapse, a contractor recovered an estimated 23,000 gallons of fuel from these tanks. NIST estimated that the unaccounted fuel totaled 1,000 ▒1,000 gallons of fuel (in other words, somewhere between 0 and 2,000 gallons, with 1,000 gallons the most likely figure). The fate of the fuel in the day tanks was unknown, so NIST assumed the worst-case scenario, namely that they were full on Sept. 11, 2001. The fate of the fuel of two 6,000 gallon tanks was also unknown. Therefore, NIST also assumed the worst-case scenario for these tanks, namely that all of the fuel would have been available to feed fires either at ground level or on the 5th floor.
SanderO claims that "structural damage" was a factor along with the fires...
Did debris from the collapse of WTC 1 cause damage to WTC 7's structure in a way that contributed to the building's collapse?
The debris caused structural damage to the southwest region of the building-severing seven exterior columns-but this structural damage did not initiate the collapse. The fires initiated by the debris, rather than the structural damage that resulted from the impacts, initiated the building's collapse after the fires grew and spread to the northeast region after several hours. The debris impact caused no damage to the spray-applied fire resistive material that was applied to the steel columns, girders, and beams except in the immediate vicinity of the severed columns. The debris impact damage did play a secondary role in the last stages of the collapse sequence, where the exterior fašade buckled at the lower floors where the impact damage was located. A separate analysis showed that even without the structural damage due to debris impact, WTC 7 would have collapsed in fires similar to those that occurred on Sept. 11, 2001. None of the large pieces of debris from WTC 2 (the south tower) hit WTC 7 because of the large distance between the two buildings.
Would WTC 7 have collapsed even if there had been no structural damage induced by the collapse of the WTC towers?
Yes. Even without the structural damage, WTC 7 would have collapsed from the fires that the debris initiated. The growth and spread of the lower-floor fires due to the loss of water supply to the sprinklers from the city mains was enough to initiate the collapse of the entire building due to buckling of a critical column in the northeast region of the building.
SanderO claims that the WTC7 substations explained the explosions heard, explained the damage seen by Barry Jennings and Hess and may also have contributed (immensely) to the fires and also the explosion filmed in the lower floors just before collapse.
Did the electrical substation next to WTC 7 play a role in the fires or collapse?
No. There is no evidence that the electric substation contributed to the fires in WTC 7. The electrical substation continued working until 4:33 p.m. on Sept. 11, 2001. Alarms at the substation were monitored, and there were no signals except for one event early in the day. No smoke was observed emanating from the substation.
Special elements of the building's construction-namely trusses, girders, and cantilever overhangs, which were used to transfer loads from the building superstructure to the columns of the electric substation (over which WTC 7 was constructed) and foundation below-also did not play a significant role in the collapse.
WTC7 on 9/11 - Strange Occurrence Within the Last 20 Minutes - 03:20 mark
Explosion heard just before collapse
NIST explanation of Jennings/Hess accounts:
The sound levels reported by all witnesses do not match the sound level of an explosion that would have been required to cause the collapse of the building. If the two loud booms were due to explosions that were responsible for the collapse of WTC 7, the emergency responder-located somewhere between the 6th and 8th floors in WTC 7-would not have been able to survive the near immediate collapse and provide this witness account.
In other words, they're liars.
Barry Jennings' account of WTC 7 explosions
Michael Hess, WTC7 explosion witness
Finally, there is no physical proof that heat caused the collapse nor were any steel samples checked for explosive/exotic explosive residue.
Why didn't the investigators look at actual steel samples from WTC 7?
Steel samples were removed from the site before the NIST investigation began. In the immediate aftermath of Sept. 11, debris was removed rapidly from the site to aid in recovery efforts and facilitate emergency responders' efforts to work around the site. Once it was removed from the scene, the steel from WTC 7 could not be clearly identified. Unlike the pieces of steel from WTC 1 and WTC 2, which were painted red and contained distinguishing markings, WTC 7 steel did not contain such identifying characteristics.
So the question is SanderO, if NIST has been reduced to claiming that office fires were responsible for bringing down WTC7, why would you be making exaggerated claims that actually reinforce the report in the same vein as the Legge/Stutt OCT Mark 2 approach to the Pentagon?
If your arguments and speculation are nowhere to be seen in this report they are irrelevant.
This post has been edited by onesliceshort: Mar 5 2012, 12:31 PM
Apr 15 2012, 07:03 PM
Joined: 23-December 09
Member No.: 4,814
Are you supporting NIST's report and claims about WTC 7?
I do not find the column 79 failure they describe as plausible .. caused by failure of shear studs and the thermal expansion of a girder which walked off the beam seat leaving the column unbraced. Ha?? Rubbish I say.
Heat DOES weaken steel.
The theory about the collapse of bldg 7 is speculation. But it is based on features of the design and the observations of the actually collapse.
1. The core from flr 8 was supported by 3 transfer trusses which were on floors 6 & 7
2. The row of columns at the north facade were supported by cantilever girders, again on floor 6.
3. The core columns above floor and the row of columns inside the north facade did not have a direct axial load path to the foundations because the Con Edison sub station was *in the way*
4. WTC 7 was NOT in the least bit a conventional high rise frame. That is a false statement by NIST. It was similar in a sense to the twin towers in that it had long span column free floors... though they were not supported by light weight trusses. a *conventional* high rise frame has a grid of columns usually about 25'x25'
5. Heat will affect the strength of steel making it weaker, which is why steel has fire protection applied to it... to provide a period of time to fight the fires and for occupants to escape.
6. The con ed sub station at the bottom of WTC 7 went off line at 8:46 am the precise moment of the plane strike in tower 1. Here is the Con Ed Report:
There were two substations in WTC 7 building, serving the twin towers, and one
substation by the South Street Seaport. A total of eight 13 kW feeders were located at the
Timeline on 911112001:
08:46 a.m. Two WTC open/auto (O/A) 13 kW feeders went off
09:02 a.m. Two additional WTC open/auto (O/A) 13 kW went off
09:52 a.m. Four additional open/auto (O/A) 13 kW feeders went off
10:28 a.m. Status: '
Cortlandt 8 of 15 feeders were off
Battery Park City 6 of 8 feeders were off
Bowling Green 6 of 16 feeders were off
Park Place 1 of 12 feeders were off
Con Ed can lose any 2 feeders, and not lose a network grid. It is very expensive to make this investment and have such a robust system. The NYSE was located in the Bowling Green network. Since all 8 feeders were lost prior to WTC South tower falling, it was possible the lights had gone out before. However, the Port Authority controlled the
equipment in the towers and Con Ed did not know exactly what happened inside the towers. They did have maps of the towers and were prepared to help the Port Authority in the event they were needed."
When the sub station went down, it was likely due to high voltage spikes which cause explosions in the transformers
Exploding sub station:
"Transformer and oil-filled high voltage equipment may give rise to very strong explosions. A severe electrical fault inside the transformer may well generate pressure that the transformer casing cannot withstand, such that it ruptures. Due to the high temperature and energy released from the arc, the insulating oil will decompose and highly explosive gas mixtures will result (mainly Hydrogen and Acetylene). Upon transformer rupture, gas and oil mist will be ejected to the surrounding area, mix with air and a secondary explosion may occur. If transformers are located indoors or in subterranean stations the pressure loads can amount to more than a bar overpressure. In subterranean stations pressure waves may propagate through tunnels and corridors without weakening and pressure loads can become substantial in areas located far away from the actual explosion."
7. The mech floors above the sub station contained the aforementioned transfer trusses, cantilever girders as well as emergency generators powered by diesel from day tanks on those floors replenished from the 20,000 gallon tanks in the basement. No diesel was recovered from the 20,000 gallon tank. it leaked or burned and likely burned as it was pumped up to floors 6 & 7 where is possibly spilled and was burning as a result of the fires from the transformer explosions below in the sub station. The fires on floors 6 & 7 burned for 7 hrs... way more than the typical 2 hrs fire rating of sprayed on fire protection even if it wasn't dislodged.
8. Barry Jennings went up to the EMC on for 23 to find it empty. He and Hess then decided to abandon it as it was unmanned and they assumed that there had been a decision to leave it. The power was off as of 8:46 am. They then decided to leave but the elevators were not working and took the stairs. When they reached just above floor 8 they witnessed explosions below them. The emergency stairs were located within the core. These were likely explosions from the Con Ed substation or on the mech floors 6 & 7 just below their location. This was BEFORE tower 1 collapsed at about 10:15.
9. Whatever fires there were, were un fought all day, as the water mains were destroyed at 8:46 and the sprinkler system could not pump water up into the building's pressurized system.
10. The east penthouse was the first visible sign (to the naked eye) that the tower was coming down. It can be seen to descend right down through the entire visible part of the tower (east part of the core) by the pressure pulse observed in the windows right down the tower.
11. The FDNY and the DOB most likely advised evacuation as they were aware of the fires on floors 6 and 7 which were well supplied by massive air intake grilles on the north side... burning all day cooking the transfer trusses and girders. When a building is likely to collapse they evacuate the area. They did. The tower collapsed. Good call.
10. Immediately after the east penthouse disappears, the West penthouse dropped through the building. It was above the West side of the core.
11. Before the facade descended there is evidence that the core was no longer there (9 and 10 above).
12. Observations of the curtain wall's descent.. the famous 100 feet (8 stories) at free fall show an pronounced inward bowing of the north facade (curtain wall). This was not a dipping of the center.. or the center of the curtain wall collapsing ahead of the east and west sides as that would have caused the window frames to distort and shatter the glass. The glass does not break and so the facade was bowing inward at the frame to frame connections. Inward bowing is only possible if there was noting behind the center of the facade. And it is therefore likely that the collapsing core had pulled the perimeter columns inward along with the spandrel beams and broke the relatively weak bolts and clips which held the light weight curtain wall to the frame.
13. It likely that what we see coming down (at FF for 100') was JUST the curtain wall. It likely that the curtain wall below floor 8 along with the structure below floor 8 had collapsed into the largely open Con Ed sub station... when the transfer trusses gave way and the core above dropped right on the sub station and to the ground. The curtain wall then dropped with no resistance for 100 feet... 8 stories at FF until it hit the ground and decelerated.
The above is a speculative theory.
What is the significance of this and why did NIST not come up with this explanation (assuming it was true)? I suspect it was because the design was *insane*... innovative... and in retrospect vulnerable to a global collapse if the sub station exploded... from any cause. Therefore this theory would open up the developers, the engineers, architects and builders and the DOB to a negligence lawsuit (similar for the design of the twins). High rise buildings are not supposed to collapse like a house of cards and with Bldg 7 all the money was on the integrity of the 3 transfer trusses and the 8 cantilever girders. That's kinda like putting all your eggs in one basket. It wasn't a column failure, or shear studs... it was a failure of those transfer trusses and girders. And there was nothing *typical* about them in any high rise building. In fact, this was equivalent to building a 40 story high rise on a bridge span.
NIST engaged in a cover up of the facts about the design and the likely cause of collapse to protect the designers and engineers and to bolster the fire caused by the hijacked plane damage of tower 1. The fire damage from the collapse of tower 1's falling debris had nothing to do with the collapse of building 7. The voltage spike caused by the plane strike did. But that would expose the hair brained design of the WTC.
William Rodriguez experience an explosion an instant before the plane strike below him in the sub basement of tower 1. This was also caused by the plane and the voltage spike travels at the speed of light and the sound from the plane impact took slightly over 1 second to reach him as it travels at 1180 ft/sec through air. He heard the plane a second after it struck... but the explosion at the moment of impact! There were 8 sub stations in each tower... including in the sub basement.
Plans of WTC 7 can be seen here:
This theory matched the observations and the structural information. If you find a problem with it. Please identify it.
This post has been edited by SanderO: Apr 15 2012, 07:04 PM
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