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 17 2012, 04:54 AM
Joined: 23-December 09
Member No.: 4,814
There are absence of photos of the sub station means nothing. There are many things at the site which have no photos that day. People were not going around the site with the cameras taking pics of everything. No photos of any of the mech floors of the twin twin towers... no photos of the sub basement refrigeration plant. And so on. No photos doesn't mean X didn't take place.
kawika... your theory is that someone set off bombs to take the various feeders off line just as the plane struck? And what would be the purpose of that?
WTC 7 was certainly part of the complex.
Jennings and the FDNY I believe stated there were sounds of explosions in the bottom of WTC 7 early in the morning.
I offered an explanation as to what Rodriguez heard. I can't know for sure, but it makes sense and needs to be considered and looked into perhaps.
1. He was in one of the sub basements when the plane struck. He couldn't see it but if he heard it as he claims, it would have taken 1. 3 seconds for the sound of the plane strike to reach him.
2. He claims to have heard a large explosion just before he heard the plane strike coming from below him in sub basement which house transformers for the electrical system... the same system that had exploded in 1992.
3. Transformers can and do explode from voltage spikes and electricity travels at speed of light and so a voltage spike caused by the plane severing main electric risers to the sub station on the 108th flr would cause a short, a voltage spike with could explode equipment in the sub basement at the instant of the plane strike. It also exploded transformers on flr 108 at the moment of the plane strike. Look at the video.
4. the sub station in bldg 7 supplies power to the sub station in tower 1 and 2 and the rest of the complex and other areas in downtown Manhattan. There are several transformers in it. Con Edison has the ability to re route power if sub stations go offline... up to 2 of them.
5. The fact that they were supplying power TO the sub station for re routing does not mean that the sub station was OK. In fact, it likely means that it wasn't. And at 4:15 when the FDNY had concluded that the building was a goner they cut the power going in
6. Jennings and Hess claimed that when the reached floor 6 /7 they experienced a massive explosion below them... which could only be IN THE Con Edison sub station. This was BEFORE tower 1 fell. This means that explosives were planted inside the sub station or that the sub station was experiencing explosions from voltage spikes and shorts.
7. Regardless of the cause of those pre tower 1 collapse... they caused massive damage and certainly could have stated fires on floors 6 & & where there were diesel day tanks. If the blast was as powerful as Hess claimed... this is a distinct possibility. CD buffs will claim these were from placed explosives. I am suggesting the explosions were from equipment failures and caused by voltage spikes which came from tower 1. Kawika do you understand how electricity works?
8. I have provided examples of exploding transformers. There were 2 in tower 1's sub basement in 92. These transformers are oil cooled, but the oil is flammable and explosive. It's certainly likely that it did explode.
9. No you couldn't see the fires or the equipment within the sub station because there were no windows! In fact, have you seen any photos of that sub station?
I offered a coherent theory consistent with observations of the collapse of the tower and the witness reports... and the Con Edison report of lost feeders that morning beginning at 8:46. Even AE911T claims the tower collapsed. The difference is I have identified where the collapse was initiated and what was a possible and I believe likely cause.
Of course AE911T (Gage) goes on about 81 columns being destroyed simultaneously over 8 floors to explain the free fall observation of 100 feet.
I offer the more plausible explanation supported by the evidence of movement of the tower for 60 seconds BEFORE any collapse of the transfer trusses and cantilever girders failing and then then core dropping right through the building. The East penhouse sat 41 stories above and was supported by one of those transfer trusses. LOOK AT THE PLANS. The East penthouse came down before the facade/curtain wall did. it can be seen to descend all the way down through the building before the facade/curtain wall begins to descend. Then the West penthouse which was over the other 2 transfer trusses descends. THEN the facade curtain wall comes down.
The was a massive ejections of smoke from the NW corner of the mech at 6&7 floors just before descent
The north facade/curtain wall shows pronounced inward bowing as it is descending. This can ONLY mean that the curtain wall had nothing behind it to hold it in a fixed plane. The floors and spandrels and structure behind the facade/curtain wall was gone by the time you see it descending.
The north facade/curtain wall was supported a row of columns and spandrel beams bearing on the cantilever girders in floors 6&7 41 floors below. A good hypothesis of the inward bowing is that those columns and spandrels were gone by the time that the north facade / curtain wall is dropping.
The clocked free fall descent was over a period of about 100' or 8 stories. This is the elevation of the top of the transfer trusses and cantilever girders which were within floors 6&7 mech floors. There were few columns below because the sub station was 5 stories tall. If the transfer trusses and the cantilever trusses failed it would leave an 8 story high unsupported core.
If the structure on 7&7 failed and collapsed down through the sub station... it would certainly could pull the perimeter columns and spandrels inward separating it from the facade/curtain wall. Why?
The facade curtain wall was attached to and rested on angle clips bolted to the spandrels which spanned from perimeter column to perimeter column. The spandrel to column connection was obviously much stronger than the facade /curtain wall to spandrel connections. Curtain walls are named appropriately. They are light weight and non structural and literally "hang" off the framed providing a weather barrier. It's conceivable that the facade /curtain wall connections failed at floors 6&7 as the structure on those floors plunged down through the sub station. In so doing the structure took with it the facade/curtain wall up to floor 8 with it at it collapsed inward... leaving nothing below the facade/curtain wall from floor 8 up... no resistance to slow it's fall.
It's possible that some of the columns on the east and west and perhaps the south perimeter and the spandrels were still connected to the facade curtain wall... but that only the north row went down with the core because of the cantilever girders having failed on floors 6&7. If this was the case it would leave the facade/curtain wall unsupported on the north side and it would be able to bow inward as seen.
Whatever the cause of the collapse... the explanation must match the observables. CD is not an observation. CD is a means to cause a collapse by failing key structural members and then the rest of the structure drops driven by gravity after a progression of failures consumes all the safety factor or reserve strength of the structure and no alternate load paths exist for load redistribution to the foundations. The theory of the failure of the key structural elements - transfer trusses and cantilever girders on the mech floors 6&7 is entire consistent which such a collapse and the observables on that day.
What's your theory?
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