A Structural Reevaluation of the Collapse of World Trade Center 7

originally posted by: carsforkids
a reply to: neutronflux

So? To you? Building design has nothing to do with how a building reacts to a fire? Your saying an all steel structure with deficient fire insulation vs a building built with reinforced concrete columns are going to provide the same building performance?

The pic of building 7 above that large quote you posted. Shows some flames
jetting up thru the curtain wall.

You mean the buiding you kept claiming wasn't on fire?

originally posted by: neutronflux
a reply to: Gandalf77

To cut steel by pressure wave, a specific pressure must be created. That specific pressure is going to result in the same sound level regardless of explosive type cutting steel by pressure wave.

The point of using nano thermite is its more of an explosive than cutting charge. If the nano thermite is cutting steel by pressure wave, then that is going to result in the same loudness as any other explosive using a pressure wave to cut steel.

Thermite burns slow. With no guarantee columns would be cut at the same rate. Might result in cold welds when cutting columns vertically. Whit no means to misalign columns to insure a rapid collapse initiation.

1000 pounds of thermite couldn’t even finish cutting a SUV in half horizontal. Doubtful if it would be effective against vertical columns for a rapid onset of collapse.

MythBusters Destroy A Car Using 1000 Pounds Of Thermite

m.youtube.com...

With the flashing, the large amounts of smoke, and the heat, it would be obvious if thermite was cutting at the exterior columns near windows and the facade. Flashing in the windows. Large amounts of flame and smoke. Cutting and burning through the facade.

Thermite makes UV light.

AE truth said the fires were never hotter than normal office fires. Is that false? I would take it that rules out floor to floor column to column thermite fueled fires burning at 3000 degrees Fahrenheit.

There is zero evidence of pyrotechnics bringing down the WTC.

Take a look at this video and read the article on the same page:
Steel sulfidation - WTC7

- A thermitic reaction works differently than something like RDX; it's an incendiary, so the thermal heating cuts, rather than blasts. The initial explosions from a thermitic reaction wouldn't be as loud.

- In the case of WTC7, there hasn't been an adequate explanation for the presence of elemental sulfur in the melted metal samples. (NIST tried claim there wasn't evidence of that, but eyewitness accounts suggest otherwise.)
Adding sulfur to thermite creates thermate, which can burn metals at lower temps.

Anyway, the video is interesting and speaks to a number of the points we've been discussing.


ETA: There does appear to be a difference in the properties of thermate (thermite + sulfur) and nanothermite (superthermite). Thermate does the cutting at lower temps, but it sounds like nanothermite can be tailored and, according to one source, produce blast waves up to Mach 3.

a reply to: Gandalf77

You

A thermitic reaction works differently than something like RDX; it's an incendiary, so the thermal heating cuts, rather than blasts. The initial explosions from a thermitic reaction wouldn't be as loud.

You don’t say.

Maybe that’s why I posted this? And linked to a video of 1000 pounds of thermite working on a 4000 SUV?

www.abovetopsecret.com...

“Thermite burns slow. With no guarantee columns would be cut at the same rate. Might result in cold welds when cutting columns vertically. Whit no means to misalign columns to insure a rapid collapse initiation.

1000 pounds of thermite couldn’t even finish cutting a SUV in half horizontal. Doubtful if it would be effective against vertical columns for a rapid onset of collapse.

MythBusters Destroy A Car Using 1000 Pounds Of Thermite
m.youtube.com...

With the flashing, the large amounts of smoke, and the heat, it would be obvious if thermite was cutting at the exterior columns near windows and the facade. Flashing in the windows. Large amounts of flame and smoke. Cutting and burning through the facade.

Thermite makes UV light.

AE truth said the fires were never hotter than normal office fires. Is that false? I would take it that rules out floor to floor column to column thermite fueled fires burning at 3000 degrees Fahrenheit.”

You again

- In the case of WTC7, there hasn't been an adequate explanation for the presence of elemental sulfur in the melted metal samples. (NIST tried claim there wasn't evidence of that, but eyewitness accounts suggest otherwise.)
Adding sulfur to thermite creates thermate, which can burn metals at lower temps.

A specific quote by you, “Adding sulfur to thermite creates thermate, which can burn metals at lower temps.“

The above seems false

Thermate

en.m.wikipedia.org...

Because thermate burns at higher temperatures than ordinary thermite,[1] it has military applications in cutting through tank armor or other hardened military vehicles or bunkers

2nd source that must be source for Wikipedia

Thermate

www.revolvy.com...

Because thermate burns at higher temperatures than ordinary thermite,[1] it has military applications in cutting through tank armor or other hardened military vehicles or bunkers

Also from www.revolvy.com, the composition of military thermite.

www.revolvy.com...

The composition by weight of Thermate-TH3 (in military use) is 68.7% thermite, 29.0% barium nitrate, 2.0% sulfur and 0.3% binder (such as PBAN).

For every 1000 of thermate, there would be 20 pounds of sulfur. But there should be 290 pounds of barium nitrate. So any unusually high concentrations of barium?

a reply to: neutronflux

Thanks and good points. I was going by the thermate explanations of that video. I'll look at your sources and watch again. Seems like they mentioned it burns at a lower temp, but I may have misunderstood or misheard something. That lower temp could be relative to something else.

a reply to: Gandalf77

More here

Can thermate really melt tank armors?
www.quora.com...

Article doesn’t allow cut and paste.

Claims thermite burns at 2200-2500 Celsius
Claims military thermate burns at 2700-3000 Celsius.

originally posted by: neutronflux
a reply to: PublicOpinion

False argument for the towers. Scrap like cars was quickly removed to make access to the actual pile. Unlike WTC 7 steel, the twin tower columns actually had identification stamps. Much of the steel went to Fresh Kills for examination, and then shipped off.

And steel was examined at the pile too.

Then there is WTC columns on display throughout the world.

Right. That's why you keep posting 911myths and pictures in lieu of evidence for the "fire weakened steel" hypothesis. A "near-simultaneous failure of every column" due to office fires, nothing to see here!

Talking about false arguments, can we say the science is settled now? Cuz... ya know... it is? BTW... any new news from Mick West and the Metabunk-Bunch?

"All about bunk, and how to (politely) debunk it!"

Ask yourself this.


If thermite was used why not 'create the illusion' of another bombing like in 93 and not try to coordinate planes hitting them? There were also 2 other planes going to 2 other places.


If you go back and take the time to look at the buildings burning you will see them failing long before the collapsed. Simply watch the planes striking at full power. To be honest it is a miracle they did not fall into each other as was planned.

a reply to: PublicOpinion

Metabunk has nothing to do with Fresh Kills, other than Metabunk pointing out how the truth movement doesn’t like talking about the efforts at Fresh Kills that recovered remains, DNA, personal effects, and physical evidence.

a reply to: PublicOpinion

A "near-simultaneous failure of every column" due to office fires, nothing to see here!

Other than the Hulsey’s modeling is missing key collapse features seen in the collapse video WTC 7

The collapse of Hulsey’s modeling was input driven. The models were not driven by any actually modeled event.

There is no support of a mechanism in the video, audio, seismic, physical evidence that resulted in columns failing in the same instance as Hulsey forced is models.

The only thing Hulsey proved, if you magically make columns disappear with no bases in actual mechanisms, you can input a model into submission.

UAF WTC 7 Evaluation Simulation Plausibility Check (Leroy Hulsey, AE911Truth)

m.youtube.com...

a reply to: neutronflux

Other than the Hulsey’s modeling is missing key collapse features seen in the collapse video WTC 7

That's kinda funny considering the fact, that you had no qualms with the NIST simulation. Name one of those "missing key collapse features" and we would a least have a conversation?

The collapse of Hulsey’s modeling was input driven. The models were not driven by any actually modeled event.

Every model is input driven, and they modeled different events. What are you talking about?

There is no support of a mechanism in the video, audio, seismic, physical evidence that resulted in columns failing in the same instance as Hulsey forced is models.

Even if you have a point here, which you don't: none of that affects the structural analysis.

May I ask why you would expect that kind of movement, which we can see in the NIST simulation, in a construction like the WTC7? Do you guys simply ignore the design or how do you come up with labels like "inferior" and vague appeals to authority? Fascinating stuff!

More to the point :

Approach 2 Findings
Under our second approach, we used a solid element model to evaluate the validity of NIST’s collapse initiation hypothesis, introducing a number of assumptions made by NIST that we considered to be invalid or, at best, questionable (Section 3.1). These assumptions included assuming the east exterior wall to be rigid and thermally fixed, assuming shear studs on several beams were broken due to differential thermal movement, assuming no shear studs were installed on girder A2001, and assuming that the bolts fastening girder A2001 to its seats at Columns 44 and 79 were broken (Section 3.1.1). [...]

P. 15

Ask NIST to run a simulation without those assumptions?

a reply to: PublicOpinion

Let’s start with what you ignored

UAF WTC 7 Evaluation Simulation Plausibility Check (Leroy Hulsey, AE911Truth)

m.youtube.com...

Ask NIST to run a simulation without those assumptions?

What assumptions? That NIST more accurately modeled the observed traveling fire that were observed on several floors of the WTC 7. The global modeling that showed thermal stress lead to collapse. With two other studies concluding fire released collapse of WTC 7. Vs Hulsey modeling small areas of fires on only two floors? With the modeling manual drawn, with no proof of dynamic modeling, with no proof Hulsey took resistance into account.


Hulsey false assertion?

Approach 2 Findings
Under our second approach, we used a solid element model to evaluate the validity of NIST’s collapse initiation hypothesis, introducing a number of assumptions made by NIST that we considered to be invalid or, at best, questionable (Section 3.1). These assumptions included assuming the east exterior wall to be rigid and thermally fixed, assuming shear studs on several beams were broken due to differential thermal movement, assuming no shear studs were installed on girder A2001, and assuming that the bolts fastening girder A2001 to its seats at Columns 44 and 79 were broken (Section 3.1.1). [...]

Vs

By
benthamitemetric• 1y •

www.reddit.com...

NIST did not actually model the perimeter columns as fixed. Hulsey is misrepresenting what NIST did, either due to his own ignorance, or to mislead. There is an extensive discussion about this on metabunk that is summarized here with relevant links, including details on how NIST actually modeled the exterior columns.

www.metabunk.org...

a reply to: PublicOpinion

Deeper look into output vs input

By oystein
www.metabunk.org...


Post: www.metabunk.org...

So this boils down to 6 distinct features, which Hulsey thought worthy of a mention:

i) EPH descends several seconds before the rest - no details given, such as that it kinks
ii) Screenwall and WPH start descent 0.5 to 1 s prior to north wall - no further details given
iii) Collapse staight down, largely into the footprint
iv) 2.25 to 2.5 s of FFA of the north face roofline
v) minimal differential movement of the exterior, resulting in no window breakage, no cracking of the façade, and no exterior deformation
vi) no large pieces of concrete flooring or intact structural framing in the debris pile post-collapse

Hulsey notes (page 91):
While NIST’s progressive collapse simulation does show the three key features listed above, it also predicts significant differential movements in the exterior, both before and during the fall of the roofline, that were not observed in the video (see Figures 4.1a and 4.1b).
Content from external source
So...
Feature i) is covered by NIST. What's more, in the NIST analysis, this is a result (output) of the simulation of the damage accumulation, while in the Hulsey model, it is a premise (input) of the simulation: The EPH drops a few seconds before the rest because Hulsey artifically forces it to. NIST's model explains, Hulsey's doesn't
Feature ii) is covered by NIST. What's more, in the NIST analysis, this is a result (output) of the simulation of the damage accumulation, while in the Hulsey model, it is a premise (input) of the simulation: The west core drops a moment before the perimeter because Hulsey artifically forces it to. NIST's model explains, Hulsey's doesn't
Feature iii) is FALSE - as I showed in post #29, the building did NOT collapse into its own footprint, and NOT (entirely) straight down, instead it had major parts hitting buildings across two different streets. In addition, Hulsey FAILS to show that this feature is replicated by his preferred simulation (all columns removed).
Feature iv) is covered by NIST (according to Hulsey - I am not aware that NIST, or Hulsey, or anyone, ever actually analysed the acceleration of the north wall roofline in NIST's global collapse simulation). What Hulsey misses is the few tens of seconds before FFA is reached. He again forces the FFA, by artificially, and without explaining (stating a cause), removing all perimeter columns at once, thus making free fall a premise (input) of his model.
Feature v) is FALSE - there was deformation of the facade observed, there was differential movement, there was window breakage. See below.
Feature vi) is a bare assertion, not supported by a proper citation nor by own study. The only reference, Figure 1.7, actually DOES show very large pieces of still-connected structural framing. In addition, Hulsey FAILS to show that this feature is replicated by his preferred simulation (all columns removed).
In effect, we see that Hulsey replicates NO actual, real feature that NIST doesn't - none anyway that he cared to mention himself.

originally posted by: Gandalf77
I didn't mean to imply "all" of the debris; that would be next to impossible. And certainly there has been some material analysis. The main point is that FEMA's actions may have inhibited later investigative analysis/efforts. From what I've read, NYC officials had every debris truck tracked on GPS.

The removal of forensic evidence from the scene was criticized at the time. NIST said they recovered no steel from WTC7. They set themselves the task of performing a postmortem without examining a single body part. Contrary to their statement, they had access to the highly corroded piece of WTC7 steel which puzzled the FEMA study of 2002 (from which they quote) and a column (labelled Figure D17 Seat connection in fire-damaged W14 column from WTC7).

a reply to: neutronflux

That post is typical; cherry-pick one item, have an "extensive discussion" about it (lol?) and voilà - debunked!

What the... why don't you just put up the part from the NIST report if they really did so? Why waste good shopping time with a fcking discussion instead? Debunk me that, Metabunch!

there was deformation of the facade observed, there was differential movement, there was window breakage.

Maybe Mick West just didn't see all that smoke moving in front of the building, and thought he saw a deformation of the facade instead? That's why the NIST simulation is such an accurate representation?

That's fcking hilarious, to be frank. Is this really happening?

a reply to: PublicOpinion

So you ignored


And you ignored that Hulsey does have his NIST modeling mixed up.

And you ignored the quoted statements about input/output between the NIST /Hulsey models.

And you ignored the Hulsey modeling is manually drawn ignoring actual collisions

And you ignored that some of the key features of the WTC 7 collapse seen on video is in the NIST modeling. With the Hulsey model missing key elements of WTC 7’s collapse as seen on video.

Hulsey hadcto force his model to behave how he wanted.

Hulsey’s model ignored the actual witnessed existent of the WTC 7 fires.

There are at least two studies that conclude fire related collapse along with the NIST conclusions?

What was your point again?