WTC7 and the girder walk-off between column 79 and 44

[Oystein]

1. He believes that to be true.
2. Yes. I think it was a combination of nano-thermite and nano-thermite mixed other types of explosives.
3. No
4. A nano-thermite device would do most of the cutting with 4500 degree molten iron as in Jon Cole's backyard experiment.
5. A nano-thermite demo device would make a lot less noise.

1-3: Cool. So we are talking about explosive demolition of steel.
4: Evasion. I am not asking about melting action. I am asking about explosives. So please try another, fitting answer to: What property of explosions is it, by the way, that severs structural steel? The heat, the volume increase, or the shockwave? You know that heat is the WRONG answer.

5. Will revisit that after you corrected your answer to 4.

There were over 100 first responder reports of explosions and dozens of videos of survivors and reporters telling of explosions.

How many of these could possibly have been steel cutting charges? A rough estimate in % will do
How many of these could possibly have been something other than steel cutting charges? A rough estimate in % will do

(My replies: 0-5%; 100%)

Don't repeat the denial canard about "could have been something else"

Why? Could they NOT have been something else? You know how "explosions" are routinely heard and reported in many building fires?

unless you are willing to admit that the explosions could have been explosives.

The vast majority could not, for the many many reasons trotted out here again and again and again and again and again and again and again and again and again and again and again and again and again and again and again and again and again and again and again and again and again and again and again and again and again and again and again and again and again and again and again.

I have no problem admitting that "explosives" are a logical possibility with non-zero probability for an unspecified small number of these reports.

So are midgets with saws.

The explosions that brought down the lobby on these firemen could only be explosives as building codes would not allow something that could cause such and explosions.

http://www.youtube.com/watch?v=IO1ps1mzU8o

You are aware that these men are interpreting sounds that they witnessed earlier while being under a LOT of stress? How big is the chance that the interpretation "explosives" is simply mistaken? (Answer: Substantial; your claim "could only be explosives", i.e. "0% chance of mistake" is obviously FALSE)

 

[Oystein]

You persist in showing how vacant and trite you are by making a big deal out of semantics. You even use baby talk in your childish insults. Grow up.

AE911Twoof makes a big deal out of a subjective appreciation of "aesthetically pleasing proportionality and balance", and pushes that as engineering evidence for a technical claim. You are cool with that, right?

Don't you feel silly you are defending such silly nonsense?


ETA: I wonder why you edited the following out your quote of my post:

The other meaning of "symmetry" is "an imprecise sense of harmonious or aesthetically pleasing proportionality and balance" - that is the subjective, non-engineering, non-science, non-rational semantics.

It has no place in forensic evidence.​

Cuts too close to the bone, eh? Reminds you too strongly that AE911Twoof has no engineering evidence, right?

 

[Oystein]

...
The explosions that brought down the lobby ...

Oh anyway: "The explosions that brought down the lobby" has nothing at all to do with the building collapse. As David Chandler has shown (tee hee ), the twin tower collapses progressed from the impact zones downward. They arrived at the lobby level last.

So there is an example of reported "explosions" that very obviously were NOT demolition charges.

This is reinforced by the fact that these firemen can still HEAR. If they had been in a room with high explosive demolition charges capable of cutting structural steel members of the dimensions found on the WTC lobby levels, they would most likely be dead, but at the very least be deaf.

Thanks for providing us with this very good example to show why reports of explosions generally do NOT imply presence of high explosives!

 

[LSSBB]

So tell us how the 90 some cement floors got pulverized into dust, one at a time, in 20 seconds?

Tell us how the crushed bodies became chopped into tiny pieces bodies?

How many floors were in WTC7?

 

[MarkLindeman]

Symmetrical is subjective.

Watch out there: you may be teetering on the brink of awareness.

I look forward to your authoritative technical definition of "pyroclastic-like."

 

[Christopher7]

There were over 100 first responder reports of explosions and dozens of videos of survivors and reporters telling of explosions.

Don't repeat the denial canard about "could have been something else" unless you are willing to admit that the explosions could have been explosives.

I have no problem admitting that "explosives" are a logical possibility with non-zero probability for an unspecified small number of these reports.

That is a double speak non answer.

The explosions that brought down the lobby on these firemen could only be explosives as building codes would not allow something that could cause such and explosions.

http://www.youtube.com/watch?v=IO1ps1mzU8o

You are aware that these men are interpreting sounds that they witnessed earlier while being under a LOT of stress? How big is the chance that the interpretation "explosives" is simply mistaken? (Answer: Substantial; your claim "could only be explosives", i.e. "0% chance of mistake" is obviously FALSE)

You . . . . . There is no ambiguity here. The firefighter was very clear that there were 3 explosions as they were waiting to go up. "It was definitely a secondary explosion." The lobby collapsed, trapping people. That could only be explosives. The other firefighter had a bloody nose from the event. He said "There could be more. Any one of these building could blow up." He was talking about bombs and you know it but you will lie and double talk around it.

You will continue to deny explosives no matter what.

 

[Gamolon]

You are showing the building when it is more than halfway into its fall. I obviously was talking about the initial portion of the collapse, where it certainly does come down even with the Horizon.

Anyone lurking here can verify the symmetry at the beginning of the collapse

here from the north http://www.youtube.com/watch?v=bllvfjHYsoE

and here from the west http://www.youtube.com/watch?v=972ETepp4GI&feature=related

and then ask yourself why this guy Triforcharity is trying to say it wasn't symmetric and only showing it when it does lean about halfway into the collapse.

Why are you focusing on only that part of the collapse and ignoring everything else? When the symmetrical part of the collapse is added in with everything else that happened structurally, it becomes insignificant.

You folks only do this type of thing to create an air of mystery and awe.

That's why Gage shows a video of just the facade and then claims that WTC7 COMPLETELY collapsed in 6 seconds. Because if he told the WHOLE story, it wouldn't be as mysterious.

 

[ozeco41]

..."It was definitely a secondary explosion."...

Out of the mouths of babes....and you actually said it C7.

We are well aware of your quaint version of language where your usage of words such as "lies" or "fraud' and their derivatives bears zero resemblance to English language.

glad to see you support "...definitely a secondary explosion". Now go and work out what it means.

...You will continue to deny explosives no matter what.

Only till someone shows that there were explosives used at WTC on 9/11. And explosives defined as materials which can cut steel - to protect slightly against your habit of changing word meanings. Since there was no use of explosives at WTC on 9/11 anyone trying to prove that there was is in for a hard time. Unless they lie.

 

[LSSBB]

Out of the mouths of babes....and you actually said it C7.

We are well aware of your quaint version of language where your usage of words such as "lies" or "fraud' and their derivatives bears zero resemblance to English language.

glad to see you support "...definitely a secondary explosion". Now go and work out what it means.

Only till someone shows that there were explosives used at WTC on 9/11. And explosives defined as materials which can cut steel - to protect slightly against your habit of changing word meanings. Since there was no use of explosives at WTC on 9/11 anyone trying to prove that there was is in for a hard time. Unless they lie.

I feel like I'm watching some amazing contortionist at work here. He shows a non-explosive cutting torch to prove his conjecture. Now he insists explosions (in a burning building no less) MUST MEAN EXPLOSIVES.

 

[alienentity]

I hesitate to call C7's antics 'mental gymnastics' because that would imply they're skillful and graceful - I think it's more apt to characterize them as 'spastic flailing'.

C7 seems to be unable to make a coherent statement which has any bearing on the context of the collapses. An explosion in a tower lobby, for example, is related not to the eventual failure of the steel far above, but instead to the plane crashes and jet fuel. It's not just some random event to be used as 'evidence of explosives', devoid of any other context.

Similarly, C7 oddly demands to know how bodies and concrete could be pulverized, apparently completely unaware that giant buildings were disintegrating in collapse. I don't know if such stunning ignorance of context is an acquired avoidance skill or a simple mental deficit, but it's on display here and quite apparent.

I once again will point out that 9/11 Truthers of the no-plane variety also exhibit this characteristic, strongly and very obviously. They simply cannot or will not place evidence in context. That's the core of their misapprehension of reality.

 

[Ape of Good Hope]

There is no ambiguity here. The firefighter was very clear that there were 3 explosions as they were waiting to go up. "It was definitely a secondary explosion." The lobby collapsed, trapping people. That could only be explosives. The other firefighter had a bloody nose from the event. He said "There could be more. Any one of these building could blow up." He was talking about bombs and you know it but you will lie and double talk around it.

You will continue to deny explosives no matter what.

Hi Chris, couple of quick questions from a newbie:

Which lobby are you referring to in the quote above?

What makes you so sure the firefighters in the video are talking about bombs?

 

[Sword_Of_Truth]

I have refuted this BS many times but JREFers keep bringing it up.
One guy 8 blocks away thought WTC 7 was leaning.
None of the firefighters at the scene said it was leaning.
NIST never mentioned WTC 7was leaning.
WTC 7 was not leaning.

Keep lying, Christopher. You can lay down next to Tony with his magic hush-a-boom and symmetrical-except-when-it's-not nonsense.

The gentleman in the video is a firefighter, that blows away your claims. That the lean was visible from 8 blocks away means that it was quite severe.

And the firefighter in the video wasn't the only one who saw it:

Yeah. There was enough there and we were marking off. There were a lot of damaged apparatus there that were covered. We tried to get searches in those areas. By now, this is going on into the afternoon, and we were concerned about additional collapse, not only of the Marriott, because there was a good portion of the Marriott still standing, but also we were pretty sure that 7 World Trade Center would collapse. Early on, we saw a bulge in the southwest corner between floors 10 and 13, and we had put a transit on that and we were pretty sure she was going to collapse. You actually could see there was a visible bulge, it ran up about three floors. It came down about 5 o’clock in the afternoon, but by about 2 o’clock in the afternoon we realized this thing was going to collapse.

-FDNY Deputy Chief Peter Hayden​

A "transit", per wikipedia:

Transit refers to a specialized type of theodolite developed in the early 19th century. It featured a telescope that could "flip over" ("transit the scope") to allow easy back-sighting and doubling of angles for error reduction. Some transit instruments were capable of reading angles directly to thirty seconds. In the middle of the 20th century, "transit" came to refer to a simple form of theodolite with less precision, lacking features such as scale magnification and micrometers. Although precise electronic theodolites have become widespread tools, the transit still finds use as a lightweight tool on construction sites. Furthermore, the Brunton Pocket Transit, commonly employed for field measurements by geologists and archaeologists, has been in continuous use since 1894. Some types of transits do not measure vertical angles.​

So the building was visibly leaning from 8 blocks away. The FDNY used surveyors instruments to measure the lean and other pre-collapse structural deformations. Since this all happened before the collapse, the collapse itself was at no time ever symmetrical.

 

[Oystein]

... "It was definitely a secondary explosion." The lobby collapsed, trapping people. That could only be explosives.

Christopher7 - Do "bombs" or "demolition cutting charges" cause secondary explosions?

Wouldn't these be primary? As in "deliberately implemented and set off"?

Please meditate a few minutes over the term "secondary explosion". Wjhat could these be secondary to? How does would that relate to claims of explosive demolition?

The other firefighter had a bloody nose from the event.

Exactly! That means he was subjected to some low-force, low pressure event. Not the detonation of a high explosive designed to cut through inches of structural steel. Thanks for pointing out the subtle evidence that destroys your claims!

He said "There could be more. Any one of these building could blow up." He was talking about bombs and you know it but you will lie and double talk around it.

No, he wasn't. He didn't say "bombs", for starters.

You will continue to deny explosives no matter what.

It's not denial if that which I reject does not exist.

 

[Oystein]

... the collapse itself was at no time ever symmetrical.

Awww but that is subjective! Don't you agree that it fell in a harmonious, balanced, aethetically pleasing way, i.o.w. symmetrically (subjective meaning of the word)?

 

[erwinl]

One, maybe not so, simple question.
How loud would an explosion be in decibel?
Say a kilo of TNT from 1 meter distance. Is that even possible to calculate?

 

[Oystein]

One, maybe not so, simple question.
How loud would an explosion be in decibel?
Say a kilo of TNT from 1 meter distance. Is that even possible to calculate?

One figure, often quoted from NIST's WTC7 FAQ, is (if I recall correctly) "9 pounds of TNT half a mile away: 130db". That figure of 9 pounds represents the minimum necessary to cut column 79 at the point where it presumably failed to initiate progressive collapse.

db are on a logarithmic scale. That means, "twice as loud" would not be twice the db value, but a constant linear increase. If I recall correctly, that which we would subjectively classify as "twice as loud" is an increase of 6db. "loudness" is proportional do the inverse of distance squared. So half the distance is four times as loud, or +12db.

(At this point someone who knows this stuff should step in and correct my numbers; I am sure I am getting some wrong. Just giving you an idea)

half a mile is about 800 meters. Divide that by 2 5 times, or by 32, and loudness increases by +60db at 25m. We are now at 190db. I don't think that such a value can reasonably be compared to anything. It totally destroys your ears, and not just these.

 

[newton3376]

db are on a logarithmic scale. That means, "twice as loud" would not be twice the db value, but a constant linear increase. If I recall correctly, that which we would subjectively classify as "twice as loud" is an increase of 6db. "loudness" is proportional do the inverse of distance squared. So half the distance is four times as loud, or +12db.

(At this point someone who knows this stuff should step in and correct my numbers; I am sure I am getting some wrong. Just giving you an idea)

The "twice as loud" is closer to 10dB, but that is because of how things are defined when it comes to sound.....its a bit different than voltage or power because there is a "perception" of loudness that is not exactly the same as the "sound pressure level"...

I dont typically even bother posting stuff like this because such things don't really add to the 911 discussion.....lol Im not sure why I bothered to do so in this case.......

 

[alienentity]

One, maybe not so, simple question.
How loud would an explosion be in decibel?
Say a kilo of TNT from 1 meter distance. Is that even possible to calculate?

From NIST NCSTAR 1-9, Appendix D, p. 706 'If propagation
were unobstructed, as would be the case for a person standing on a street with a direct view of any WTC 7 face with open windows, the sound level from all building perimeter openings at 1 km would be approximately 130 to 140 dB. Adjacent buildings and their effect on the sound propagation was not
considered in this analysis.'

From the summary, p. 709 'In Phase III, an acoustic analysis was performed to assess the distance from the building that the blast would have been audible. Analyses were performed for both layout scenarios, using the pressure history and window failure location predictions generated during Phase II. For all scenarios and charge sizes, significant audible sound was predicted from all building faces. For locations where sound propagation
was unobstructed, the sound level from all building perimeter openings at 1km would have been approximately 130 dB to140 dB. '

To Oystein's point 'Hamby (2004) lists 190.6 dB for 2 lb of TNT at a close standoff. Further, 1 lb of TNT is listed as generating 194.1 dB at 6 ft,
186.1 dB at 10 ft and 180.0 dB at 15 ft standoff (Kinney 1985)' NIST
NCSTAR 1-9 p 706

Chart of relative SPL's
http://www.gcaudio.com/resources/howtos/loudness.html

 

[BasqueArch]

<snip>
It is interesting that newly released show the beam NIST says buckled first (the one closest to the north wall) had three beam stubs supporting it from the wall at equal intervals. NIST did not include these in their model. Buckling load is related exponentially to unsupported length. The real beam (not the one shown by NIST) would have had an unsupported length that was one third that of the full length unsupported beam they show. C7 could add this to the girder bearing seat width fib and the girder stiffener ommission on his list of things NIST ommitted or changed to suit their explanation. I did a finite element analysis leaving the beam stubs off of that northmost beam and it does buckle since it is closest to the trapped girder side at column 44. However, the key to the problem is to see and tell what happens to the other four beams. They did not buckle.

(I couldn’t find my E12/13 copy of the drawing)

This is wrong. Those horizontal " beam stubs" were not added to support this beam. They were braces added to stiffen the 26 foot long unbraced span perimeter girder/beam for wind at 3 of these typical locations on the building. 2 at the north perimeter walls, 1 at the south wall.

1) This beam had a contributing floor width area of ~ 6 feet, the other typical interior beams of ~ 9'-7", in order to reduce its load and help with the lateral bracing for the long span perimeter beam/girder. Shear studs on both beam and girder fixed it to the slab.

2) This beam size was W21x44, the other typical interior beams were W24x55. Had the engineers needed extra support for this beam they would have sized it larger as the others. You don't best vertically support a beam with lateral bracing, you increase its size.

3) The TOS for these 12” braces were dropped 7 1/2", for bracing near the center of these perimeter girders. SEs can spot that this is wind bracing for the perimeter girder and not beam supports.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
On the second claim that NIST omitted or changed things to suit their explanation, it’s wrong also.

NIST didn’t consider the vertical failure of the seat and its model included a seat stiffener at Col 79 not shown in the plans.

“Since vertical failure of the seat was not considered (Section 11.2.5), the connections at Columns 79 and 81 were both modeled as stiffened seats.” (NCSTAR 1-9 p.558) See “Figure 12-25 Seat connection in global model Column 79”. (p. 559)

Column 79 did not have a seat stiffener, but NIST included it in their modeling. This is the seat that failed under the girder. Had they modeled it without the stiffener, they may have discovered the seat bent and the girder slid off.

 

[Sword_Of_Truth]

From NIST NCSTAR 1-9, Appendix D, p. 706 'If propagation
were unobstructed, as would be the case for a person standing on a street with a direct view of any WTC 7 face with open windows, the sound level from all building perimeter openings at 1 km would be approximately 130 to 140 dB. Adjacent buildings and their effect on the sound propagation was not
considered in this analysis.'

For the purposes of context, this is what was heard from WTC7 at the time of its collapse: