'What about building 7'?

[Miragememories]

"As you know, the whole basis for the NIST case regarding the mysterious, sudden, high speed plummet of 7WTC, centres around the steel expansion hypothesis which they cannibalized from their WTC1 and WTC2 collapse hypotheses.

The thing is, even if they could show (which they can't), that column 79 was dislodged and buckled because of steel expansion, it would not create the form of collapse that was clearly revealed by the many video recordings.

The left side (east) would not be in such immediate agreement with the right (west).

By the time the failure on the east side was communicated as overwhelming load to the west side (we are talking about an area roughly the size of a football field), the east side would have been leading the collapse dramatically.

The roofline descent on the east side would have been much further advanced or finished before its western portion joined in the action."

"Not true, the failure mode of the towers was from thermal induced weakening leading to buckling of the core columns, the falling upper block falls into the funnel effect of the outer perimeter Columns, and off center strikes cause failure of the welds rapidly breaking the remaining welds, weld failure of the core columns being the primary failure mode."

Not true?

Says who?

The NIST presented a hypothesis about thermal expansion being the cause for the high speed collapse of 7WTC.

The NIST has never presented a proven theory to support that hypothesis.

Funnel effect? That is a new way of putting it.

You are suggesting an incredible number of events occurring in a matter of seconds.

Even if we stretch the imagination and accept that the collapse of the east penthouse was a consequence of column 79 buckling and failing.

Mere seconds later, the east side of 7WTC begins to drop and soon reaches freefall acceleration over a height of 8 storeys.

But that does not explain why the west side also drops in unison.

Your argument would require machine gun like rapidity for the overall failure mechanism.

Inside 7WTC you would have us accept, without argument, that for the length of a football field, from east to west, thermal weakening from roaming office cubicle fires, caused interconnected-steel to fail so rapidly, that not only did the west side drop in sync with the east side, but it only resulted in minor window breakage to the north and west building façades.

All that tonnage of structural steel ripping free of those façades without the occurrence of the kind of easily observable damage that was seen on the south side façade when it was struck by WTC1 debris.

No gaping holes, falling bricks, or large dimples.

Façade walls that had no outside lateral bracing were amazingly not pulled inwards when all their internal connections were supposedly being pulled downward by your "funnel effect".

Thank you Chris Mohr for rightly pointing out Crazy Chainsaw's glaring error about the 30 minutes of BBC observations.

The building was damaged on fire and leaning, tilting and fire fighters were expecting a possible collapse when the BBC mistakingly aired the report that it had collapsed.

So it was most likely redistributing energy before the collapses.

The Cameras that caught the collapse were clearly preplaced and waiting for it.

A leaning building is a good indication of the building slow progressive collapse.

You are grasping at straws.

7WTC was never shown to be leaning!

All you have is the well known story about a transit being placed on the SW corner of 7WTC hours before it collapsed.

Even the NIST never claimed that a building lean was revealed.

 

[beachnut]

Gerry, sadly I see an all too familiar pattern of responses here. ...

You spreading lies?

You offer no engineering, you offer no evidence.
You can't explain how WTC 7 was destroyed.
You can't tell me where you get your silent explosives.
You don't have anything.

If I knew WTC 7 was CD, I would now have a PhD in engineering, and would prove it was CD, but find out I was wrong. I already have my masters in engineering, and what you are doing is BS, not engineering, not science, just words. If you can't figure out 911 by now, you might want to take up something else. If you can type fast, it does not take up must time, so keep up the illusion of CD.

 

[DGM]

I see some broken windows.

Supposedly 7WTC is but a shell at this point and its interior has been gutted.

All that steel connected to the outside facades should have pulled in huge sections of building face and not just caused some minimal window breakage don't you think?

Who claims this? Certainly not the NIST. Are you making stuff up again?

 

[JSanderO]

\

It is difficult to imagine a modern 47-storey office tower with all its interconnected steel, suddenly plummeting to the earth it such a manner.

It's not hard to image this collapse in the 7WTC design

The core region collapse first... it doesn't topple it collapse down.If columns get pushed out of alignment... somehow... no columns need to be crushed and the structure above has essentially no resistance. It plummets down and it severs connections to floor beams.

This leaves the floors and the moment frame at the perimeter. The latter is supported in very unorthodox manner. 80% of the north side was on the end of cantilevers... nothing structural axially linking that the the foundations.

Both the east and west sides were braced frames - truss structures with only 4 vertical columns. The south side had a multistory lobby with no lateral support for most of the width. The braced frames apparently acted like membranes and folded in when the core collapsed and their interconnecting beams pulled them inwards.

Essentially there was a rapid progressive destruction of the structure below flr 7 ... and the relatively few columns that were there. The failures left the core destroyed and the rest came down... last to fall was the exterior moment frame which has the structure pulled out (inward) from under it.

One failure caused adjacent failures and the pace picked up very rapidly and then there was not enough capacity and it let loose.

 

[gerrycan]

You keep making stuff up.

I said that in NISTs analysis, column 79 was not unsupported from the East and West until the girder spanning C79 and C44 had "walked off".

The simple shear connection between Column 79 and the girder that spanned the distance to the north face (to Column 44) failed on Floor 13. The connection failed due to shearing of erection bolts, caused by lateral thermal expansion of floor beams supporting the northeast floor system and, to a lesser extent, by the thermal expansion of the girder connecting Columns 79 and 44. Further thermal expansion of the floor beams pushed the girder off its seat, which led to the failure of the floor system surrounding Column 79 on Floor 13. The collapse of Floor 13 onto the floors below-some of which were already weakened by fires-triggered a cascade of floor failures in the northeast region. This, in turn, led to loss of lateral support to Column 79 in the east-west direction over nine stories (between Floors 5 and 14). The increase in unsupported length led to the buckling failure of Column 79, which was the collapse initiation event.

Source: (NCSTAR 1-9) VOLUMES 1 and 2, page 611.

You're oversimplifying NIST's words to your convenience. NIST says their simulation shows the girder walked off the seat; they don't say any beam expanded by the length of the walk-off distance. You built a strawman of an argument.

Further thermal expansion of the floor beams pushed the girder off its seat.

my emphasis

Critical Column 79 became laterally unsupported between Floors 5 and 14 in the east-west and south directions as a result of the progression of floor system failures

You've been caught in multiple mistakes and misrepresentations. Try to be more rigorous if you want to argue in the technical field, please.

NIST said what they said. It's you who is lacking the rigor here. Show me where NIST say that the girder walk off at the C79 connection was preceded by a lateral shift to the East by the column.

 

[Brass]

What other buildings totally collapsed on 9/11 "from fire and falling debris"?

5 World Trade Center suffered partial collapse. Was that an inside job, too?

 

[DGM]

5 World Trade Center suffered partial collapse. Was that an inside job, too?

St. Nicholas Greek Orthodox Church and 3 WTC also collapsed.

Odd the conspiracy theorist don't mention 3 WTC. The 1993 truck bomb was actually parked under it, not the towers.

 

[Spanx]

Gerry, when you and your un-named members created your team, why did you go to youtube instead of the NIST ?

 

[gerrycan]

Gerry, when you and your un-named members created your team, why did you go to youtube instead of the NIST ?

That is exactly where we went. Straight to NIST.

 

[Spanx]

That is exactly where we went. Straight to NIST.

How did you get on ?

 

[Miragememories]

It is difficult to imagine a modern 47-storey office tower with all its interconnected steel, suddenly plummeting to the earth it such a manner.

I am not saying it could not happen because obviously it did.

What I am saying is that it did not happen for the reasons that the NIST claimed.

If it was possible for random debris damage and several floors of roaming office cubicle fires to create the high speed, virtually symmetrical collapse of 7WTC, than it stands to reason that the failure mechanism should be easy to simulate in conditions where most of the structure's collapse-resisting elements were removed, and humans were free to delegate fires, and pick away at the supports.

All I ask is that someone show how several levels of unfought fire and a similar degree of external debris damage could make a simple wooden block structure total collapse so symmetrically.

I predict that without a designed core implosion, the structure will either topple or only partially collapse.

"It's not hard to image this collapse in the 7WTC design

The core region collapse first… it doesn't topple it collapse down.

If columns get pushed out of alignment... somehow… no columns need to be crushed and the structure above has essentially no resistance.

It plummets down and it severs connections to floor beams."

A core implosion is fundamentally a "core region collapse".

You just refuse to accept that the core's destruction was a planned event.

An engineered demolition of the core is a rapid enough event that the building above will plummet down like was observed with 7WTC on 9/11.

An un-engineered core demolition, if possible as a result of unfought fires, would not be as rapid an event.

Yet you still believe the core failure was caused by fire, and occurred rapidly across the whole structural floor space, and in such a manner, that there was a balanced loss of total building support.

Fire weakening by its very nature, would be gradual and regardless of the truss inter-relationships, you have never successfully described a mechanism which would rapidly gut the lower core with such balanced precision that it would lead to both the east and west sides dropping at and close to freefall with a relatively level roofline!

 

[pgimeno]

You keep making stuff up.

I said that in NISTs analysis, column 79 was not unsupported from the East and West until the girder spanning C79 and C44 had "walked off".

The simple shear connection between Column 79 and the girder that spanned the distance to the north face (to Column 44) failed on Floor 13. The connection failed due to shearing of erection bolts, caused by lateral thermal expansion of floor beams supporting the northeast floor system and, to a lesser extent, by the thermal expansion of the girder connecting Columns 79 and 44. Further thermal expansion of the floor beams pushed the girder off its seat, which led to the failure of the floor system surrounding Column 79 on Floor 13. The collapse of Floor 13 onto the floors below-some of which were already weakened by fires-triggered a cascade of floor failures in the northeast region. This, in turn, led to loss of lateral support to Column 79 in the east-west direction over nine stories (between Floors 5 and 14). The increase in unsupported length led to the buckling failure of Column 79, which was the collapse initiation event.

Source: (NCSTAR 1-9) VOLUMES 1 and 2, page 611.

Yes, that's the loss of lateral support over nine stories that led to its failure. I'm not talking about its failure, I'm talking about displacement of the column prior to its failure, that is, prior to collapse initiation.

Further thermal expansion of the floor beams pushed the girder off its seat.

my emphasis

And indeed it did. They don't say that was the only mechanism into play in that brief summary, but it was certainly the main one.

Show me where NIST say that the girder walk off at the C79 connection was preceded by a lateral shift to the East by the column.

Do you want me to paste the same quote a third time? I already pasted it twice.

But sure, here you go again. I guess certain things take time to sink in for some people.

"The temperature of the girder between Columns 76 and 79 on Floor 13 was sufficient to displace Column 76 to the west and Column 79 to the east."​

NCSTAR 1-9 vol 2 p.527, discussion of results of ANSYS simulation for Case B temperatures.

Here's another quote:

Temperatures in [the floor 11] region were less than 100 °C on these floors. The tensile force in the connection was due to an eastward lateral displacement of Column 79, which was primarily caused by thermal expansion of the girder between Column 76 and Column 79 at Floor 13.
​

I'll let you guess the page where this is located. It's repeated several times throughout the report.

NIST said what they said. It's you who is lacking the rigor here.

I think even you can realize how ironic that sounds.

 

[JSanderO]

A core implosion is fundamentally a "core region collapse".

You just refuse to accept that the core's destruction was a planned event.

An engineered demolition of the core is a rapid enough event that the building above will plummet down like was observed with 7WTC on 9/11.

An un-engineered core demolition, if possible as a result of unfought fires, would not be as rapid an event.

Yet you still believe the core failure was caused by fire, and occurred rapidly across the whole structural floor space, and in such a manner, that there was a balanced loss of total building support.

Fire weakening by its very nature, would be gradual and regardless of the truss inter-relationships, you have never successfully described a mechanism which would rapidly gut the lower core with such balanced precision that it would lead to both the east and west sides dropping at and close to freefall with a relatively level roofline!

The core came down because it largely was load transfer structures... transfer means they move the forces laterally... this resulted in rapid progression through the core. These structures were NOT destroyed by office contents fires.

The failed when as little as one node... one bolted connection failed. When that happened the truss collapsed and involved other load tranfer structures and then down it went.

Weakening is a gradual process... but once the weakened thing has capacity below the service loads... it fails instantly and catastrophically.

It's like heating water... you apply heat and don't see much change until it reaches boils point.

 

[DGM]

You just refuse to accept that the core's destruction was a planned event.

An engineered demolition of the core is a rapid enough event that the building above will plummet down like was observed with 7WTC on 9/11.

Good, now explain the mechanism and how it's use better explains the evidence we have. All the evidence.

An un-engineered core demolition, if possible as a result of unfought fires, would not be as rapid an event.

Why? When you say "rapid", when are you starting the clock? Eight hours is a long time for unfought fires.

Yet you still believe the core failure was caused by fire, and occurred rapidly across the whole structural floor space, and in such a manner, that there was a balanced loss of total building support.

Fire weakening by its very nature, would be gradual and regardless of the truss inter-relationships, you have never successfully described a mechanism which would rapidly gut the lower core with such balanced precision that it would lead to both the east and west sides dropping at and close to freefall with a relatively level roofline!

The building was gradually weakened. Was 8 hours not enough for you?

 

[Crazy Chainsaw]

Not true?

Says who?

The NIST presented a hypothesis about thermal expansion being the cause for the high speed collapse of 7WTC.

The NIST has never presented a proven theory to support that hypothesis.

Funnel effect? That is a new way of putting it.

You are suggesting an incredible number of events occurring in a matter of seconds.

Even if we stretch the imagination and accept that the collapse of the east penthouse was a consequence of column 79 buckling and failing.

Mere seconds later, the east side of 7WTC begins to drop and soon reaches freefall acceleration over a height of 8 storeys.

But that does not explain why the west side also drops in unison.


[qimg]http://i1265.photobucket.com/albums/jj515/Miragememories/WTC7LevelCollapse-lowcontr_zps62091716.png[/qimg]

Your argument would require machine gun like rapidity for the overall failure mechanism.

Inside 7WTC you would have us accept, without argument, that for the length of a football field, from east to west, thermal weakening from roaming office cubicle fires, caused interconnected-steel to fail so rapidly, that not only did the west side drop in sync with the east side, but it only resulted in minor window breakage to the north and west building façades.

All that tonnage of structural steel ripping free of those façades without the occurrence of the kind of easily observable damage that was seen on the south side façade when it was struck by WTC1 debris.

No gaping holes, falling bricks, or large dimples.

Façade walls that had no outside lateral bracing were amazingly not pulled inwards when all their internal connections were supposedly being pulled downward by your "funnel effect".

Thank you Chris Mohr for rightly pointing out Crazy Chainsaw's glaring error about the 30 minutes of BBC observations.



You are grasping at straws.

7WTC was never shown to be leaning!

All you have is the well known story about a transit being placed on the SW corner of 7WTC hours before it collapsed.

Even the NIST never claimed that a building lean was revealed.

The funnel effect only occurred in the towers NIST proposed two radically different failure mechanisms, Thermal weakening in the towers, Thermal expansion in Building 7.

7 fire fighters are on record on 9/11 stating they believed the building was doomed hours before it collapsed.


How about the CNN collapse predictions and I believe it was Ray Mackey who stated that the firemen observed the building was leaning and likely to collapse.
I am looking for those quotes right now.

Yes there may have been some thermal weakening in building 7 that helped to prevent load redistribution after Column 79 failed.

It appears to me from your post that it was mainly a bolted structure column buckling then is not required to cause failure just bolt shearing, that allow floor failure.

If you want to determine mode of building failure, the energy redistribution pattern must first be established, I have read this entire thread and could not find one post were you even came close to an attempt.

 

[Crazy Chainsaw]

Good, now explain the mechanism and how it's use better explains the evidence we have. All the evidence.



Why? When you say "rapid", when are you starting the clock? Eight hours is a long time for unfought fires.



The building was gradually weakened. Was 8 hours not enough for you?

Heat the bolts and beam seats on the columns until enough bolts sheer in the proper pattern to control energy redistribution which will follow a predictable pattern.
No thermite needed just damage the fire proofing and light fires.
After all buildings are just simple load transfer structures.
That is assuming that the pictures posted by MM are representative of the structures involved, I always thought that the building also had welded structures, if so that could lead to the failure, but unfortunately right now I do not have time for a more in depth study of the structure.

 

[DGM]

Heat the bolts and beam seats on the columns until enough bolts sheer in the proper pattern to control energy redistribution which will follow a predictable pattern.
No thermite needed just damage the fire proofing and light fires.
After all buildings are just simple load transfer structures.
That is assuming that the pictures posted by MM are representative of the structures involved, I always thought that the building also had welded structures, if so that could lead to the failure, but unfortunately right now I do not have time for a more in depth study of the structure.

I told the story of a building I worked on (or was asked to). Good size fire, after the owner got a crew to do some clean-up at the site. Myself and the FD started looking the next day and noticed remains of broken bolts on the floor (that had been swept up). Closer inspection showed beams barely on seats and exterior walls bowed out. I couldn't get out of there fast enough. The building was soon torn down.

 

[Crazy Chainsaw]

I told the story of a building I worked on (or was asked to). Good size fire, after the owner got a crew to do some clean-up at the site. Myself and the FD started looking the next day and noticed remains of broken bolts on the floor (that had been swept up). Closer inspection showed beams barely on seats and exterior walls bowed out. I couldn't get out of there fast enough. The building was soon torn down.

I know that feeling, I was in a steel frame building a large one, during a high wind storm,
the bolts started popping they had been over torqued, I was glad when the storm ended and never went back to that store.

 

[Crazy Chainsaw]

Not leaning , what about these eye witness accounts?
"testimonies in Firehouse Magazine with Captain Boyle and Deputy Chief Hayden where
these officers give signs of structural damage (the large hole supposedly created by debris
from WTC 1, as well as creaking, leaning and bulging in WTC 7) that they say led them
to worry about the stability of the building and, in Hayden’s case, to conclude at about
2:00 p.m. that the building “was going to collapse.”[9] But many of us will not be
satisfied with this answer. Hayden, for example, was"

 

[Crazy Chainsaw]

Ops