NIST's New Mechanical and Metallurgical Analysis of Structural Steel (WTC)

[stickdog]

Highlights:

1) No WTC-7 steel was recovered or analyzed.

2) No unprocessed, intact floor trusses were recovered or analyzed.

3) No testing for explosives (or sulfidation or other residue of any kind) was performed.

4) Only 12 total core columns were recovered from WTC-1 & WTC-2 combined.

5) Of the recovered core pieces, none showed exposure to temperatures in excess of 250 C.

6) Of 170 examined areas on the perimeter column panels, only three showed exposure to temperatures in excess of 250 C and for one of these three forensic evidence indicated that the high temperature exposure occurred AFTER the collapse.

7) No recovered steel showed any evidence of exposure to temperatures above 600 C for any significant time.


http://wtc.nist.gov/pubs/NISTNCSTAR1-3Draft.pdf

A total of 236 recovered pieces of WTC steel were cataloged; the great majority belonging to the towers, WTC 1 and WTC 2. These samples represented a quarter to half a percent of the 200,000 tons of structural steel used in the construction of the two towers. The NIST inventory included pieces from the impact and fire regions, perimeter columns, core columns, floor trusses, and other pieces such as truss seats and wind dampers.

The collection of steel from the WTC towers was sufficient for determining the quality of the steel and, in combination with published literature, for determining mechanical properties as input to models of building performance.

...

Of the 31 core floor truss connectors (core seats) recovered, about 90 percent were still intact, although many were extensively damaged. Only two were completely torn from the channel.

...

A coating on the SFRM prevented the loss of the SFRM in some locations on the perimeter columns. This coating appeared as a band of white features on the SFRM wherever two aluminum panels met on the exterior columns of the buildings, becoming visible when the panels were dislodged. This may be a coating applied to protect the SFRM from moisture infiltration at the aluminum panel joints, acting to preserve the SFRM even when the SFRM was knocked off both above and below those locations.

...

The pre-collapse photographic analysis showed that 16 recovered exterior panels were exposed to fire prior to collapse of WTC 1. None of the nine recovered panels from within the fire floors of WTC 2 were observed to have been directly exposed.

NIST developed a method to characterize maximum temperatures experienced by steel members using observations of paint cracking due to thermal expansion. The method can only probe the temperature reached; it cannot distinguish between pre- and post-collapse exposure. More than 170 areas were examined on the perimeter column panels ...

Only three locations had evidence that the steel reached temperatures above 250 °C.

These areas were:

• WTC 1, east face, floor 98, column 210, inner web,
• WTC 1, east face, floor 92, column 236, inner web,
• WTC 1, north face, floor 98, column 143, floor truss connector

Other forensic evidence indicates that the last example probably occurred in the debris pile after collapse. Annealing studies on recovered steels established the set of time and temperature conditions necessary to alter the steel microstructure. Based on the pre-collapse photographic evidence, the microstructures of steels known to have been exposed to fire were characterized. These microstructures show no evidence of exposure to temperatures above 600 °C for any significant time.

Similar results, i.e., limited exposure if any above 250 °C, were found for two core columns from the fire-affected floors of the towers.

...

No steel was recovered from WTC 7!

...

From the observations made of the spandrel connections on recovered panels, there was no difference in failure mode whether or not the panels were exposed to pre-collapse fires.

...

Table 6–2 lists the 12 identified core columns, including as-built locations and possible conditions to which they may have been exposed prior to the collapse of the buildings. Due to the small number of samples, statistical data analysis of the damage features and failure modes would be of little use. Therefore, in-depth descriptions of the four significant pieces (C-80, C-88a, C-88b, and HH) that were located within the fire zone floors are provided below. For reference, Fig. 6–29 displays the position of the columns within the core and with respect to the perimeter panel damage.

...

Core columns C-88a and C-88b, from WTC 2, were unique among the recovered core elements in that the columns were still connected at the welded column splice. ... There was no visible necking of the plate in the area of failure, with the remaining portion of the plate having been flame cut during the recovery effort. ... The fracture surfaces were too corroded for analysis.

Aside from the three columns discussed above, only one other core column was recovered from within the fire region.

...

All floor truss samples received at NIST were either small sections (less than 3 ft to 4 ft in length) of chord and rod material (Fig. 6–35a) or large, entangled masses ... According to Structural Engineers Association of New York (SEAoNY) volunteer members involved in the recovery effort, it was necessary to “ball up” any truss pieces of significant size to facilitate removal from the WTC site and subsequent handling in the recovery yards. This was necessary since the primary and bridging trusses for a given floor were welded together into huge grids. During the collapse, these lightweight floor sections were severely damaged and could not be easily removed. Thus, it is unknown when specific damage features occurred. Further, it is likely that sections of multiple trusses were “balled” together and labeled as a single unit rather than that NIST labeled samples consisting of just one pre-fabricated truss unit.

Attempts were made to identify the as-built location of the truss material, but unlike the other major structural elements, identifying marks could not be found on the trusses. Difficulty was also encountered in trying to measure the length of the truss members to determine if they were of the 35 ft or 60 ft variety. It appears that no whole length sections were recovered. A large majority of the compressive resistance welds between the chords and rods were observed to have failed. This was evident from the large amount of chord material recovered without rods attached and vice versa. It is unknown when these failures occurred or what caused them.

...

The spandrel steels identified as having been exposed to fire prior to the collapse of the building showed no microstructural evidence of change. Similar results indicated that three of the four seats observed to be exposed to severe pre-collapse fire conditions did not experience significant microstructural changes as a result of the exposure. However, the seat with the melted binder (Fig. 6–38) did show signs of microstructural alteration as a result of elevated temperature exposure, though it was unknown when this exposure occurred. Finally, in the several columns with known pre-collapse fire exposure, metallographic analysis provided no conclusive evidence that the steel exceeded 625 °C, based on calibrations in furnace exposure studies of WTC steel reported in NIST NCSTAR 1-3E.

...

Based on microstructural analysis of the recovered structural steel, there was no evidence indicating that the pre-collapse fires were severe enough to affect the steel microstructure of these pieces. Based upon this evidence, it is believed that no steel was recovered which experienced temperature excursions above 600 °C for any significant length of time as a result of the pre-collapse fires.

...

Because NIST recovered no steel from WTC 7, it is not possible to make any statements about its quality. The recommended values for the stress-strain behavior were estimated using the same methodology that was used for the WTC 1 and WTC 2 steels (NIST NCSTAR 1-3D). The static yield strengths were estimated from historical averages and corrected for testing rate effects.

Because, prior to collapse, WTC 7 did not suffer any high-strain rate events, NIST made no effort to estimate high-strain-rate or impact properties of the steel.

No metallography could be carried out because no steel was recovered from WTC 7.

...

Discernible changes to the microstructure of furnace exposed WTC steel were observed when exposed to a temperature of 625 °C for as little as 0.25 h. At or below 500 °C, no microstructural change was apparent using light optical microscopy. The hardness of these samples varied for a given temperature and material type, but correlated well with microstructural observations.

...

Of the 31 core floor truss connectors (core seats) recovered, about 90 percent were still intact though extensive damage may have occurred. Only two were observed to have been completely torn from the channel.

...

The pre-collapse photographic analysis showed that 16 of the 33 exterior panels recovered from WTC 1 were exposed to fire prior to building collapse. None of the nine recovered panels from within the fire floors of WTC 2 were observed to have been directly exposed.

It is difficult or impossible to determine if high-temperature exposure occurred prior to or after the collapse. Of the more than 170 areas examined on 21 exterior panels, only three locations had mudcracking of the paint, indicating that the steel may have reached temperatures in excess of 250 °C.

Annealing studies on recovered steels established the set of time and temperature conditions necessary to alter the steel microstructure. Based on the pre-collapse photographic evidence, the microstructures of steels known to have been exposed to fire were characterized. These microstructures show no evidence of exposure to temperatures above 600 °C for any significant time for the recovered pieces.

Two of the core columns with as-built locations in the fire-affected floors were examined for paint cracking. The few areas with sufficient paint for analysis did not show mud cracking patterns, indicating the columns did not exceed 250 °C.

[RPM]

1. mihop - n/t

[crizzo5137]

2. woah... Lotsa big words there...

Can ya explain it to me in a simple sentence like I was Bush?

[Goldmund]

5. Or better yet, you can exert yourself a little bit?

[Oversea Visitor]

3. Woah they did manage to save some samples after all

Oh the rest was sold to China. Damn fast move.

[Goldmund]

4. Thanks for posting this

When was it published?

[oblivious]

7. It says Sept 2005.

[niyad]

8. it said sept, 2005 on about the third page--weird, I know

[BrewerJohn]

11. It's a draft, evidently scheduled for release in Sept

Title page reads, "For Public Comment".

This definitely calls for careful study. If it's ever allowed to be released in final form, it could be a bombshell.

[oblivious]

6. Can't wait to hear the spin.

If only they'd let NIST make an engineering conclusion. I'd love to hear what they really think of this.

[Goldmund]

10. Spin won't be the prefered method.

They'll ignore it.

[oblivious]

14. I mean the spin on the discussion boards.

"My father's an engineer and he says 250 degree heat can melt steal and my dog, who has a degree in metallurgy agrees with him, and even though there was no fire at the base of the building, my disinformation notes told me to write that it is perfectly normal for steel to melt for no reason, blah blah..."

[stickdog]

12. Here's FEMA's take on its own Limited WTC Metallurgical Analysis

The FEMA report titled World Trade Center Building Performance Study, Appendix C "Limited Metallurgical Examination," shows evidence of explosives used, by way of photographs, microscopic, and chemical examination.

From: http://www.fema.gov/pdf/library/fema403_apc.pdf

"Evidence of a severe high temperature corrosion attack on the steel, including oxidation and sulfidation with subsequent intergranular melting, was readily visible in the near-surface microstructure."

...

"The thinning of the steel occurred by high temperature corrosion due to a combination of oxidation and sulfidation."

...

"The unusual thinning of the member is most likely due to an attack of the steel by grain boundary penetration of sulfur forming sulfides that contain both iron and copper."

...

"A liquid eutectic mixture containing primarily iron, oxygen, and sulfur formed during this hot corrosion attack on the steel."

...

"The severe corrosion and subsequent erosion of Samples 1 and 2 are a very unusual event. No clear explanation for the source of the sulfur has been identified. The rate of corrosion is also unknown. It is possible that this is the result of long-term heating in the ground following the collapse of the buildings. It is also possible that the phenomenon started prior to collapse and accelerated the weakening of the steel structure. A detailed study into the mechanisms of this phenomenon is needed to determine what risk, if any, is presented to existing steel structures exposed to severe and long-burning fires."

[oblivious]

15. Wow! Thanks.

[DoYouEverWonder]

113. 'It is also possible that the phenomenon started prior to collapse'

I don't think 'phenomenon' is what I would call what happened to the steel, if it was prior to the collapse.

[Name removed]

9. Deleted message

Message removed by moderator. Click here to review the message board rules.

[drdtroit]

13. Look for it under "fiction". n/t

[Frederik]

18. You think NIST writes fiction?

http://www.nist.gov/

[Dancing_Dave]

35. During the Bush Administration, FEMA, EPA, NIST etc.

Have been under instructions from the Bush Administration to write fiction, so sure, they do it to keep their jobs!

[Endangered Specie]

38. Id like to see these "instructions"

People really need to take the time to read the NIST findings (ive spent 3 hours doing so).

[rman]

60. NIST writes a lot of irrelevant things

in their 9-11 report.

The bulk of the report deals with simulations of aspects of the event which are not under dispute: the crashing of the planes and the subsequent fires.
They spend like 1 page on the collapse, and simply assume that "global collapse" is inevitable once collapse has been initiated. Also they disagree with FEMA on the details of the "collapse initiation mechanism".
They ignore WTC7 completely.

[number6]

17. you like the official Bu$hevik story ....eh

:tinfoilhat: :eyes:

[number6]

16. good points .....

:thumbsup:

1) No WTC-7 steel was recovered or analyzed.

2) No unprocessed, intact floor trusses were recovered or analyzed.

3) No testing for explosives (or sulfidation or other residue of any kind) was performed.

4) Only 12 total core columns were recovered from WTC-1 & WTC-2 combined.

5) Of the recovered core pieces, .........


yes, the official government fairy tale

[DoYouEverWonder]

114. It sounds like they took a randon sampling

rather then looking for the most bent and fire damaged pieces.

This isn't how they handled the 'crime scene' at the WTC in 1993. That time they took forever and recovered everything possible.

[Bismillah]

19. "No testing for explosives was performed." (What?)

Is this really true? If so, how on earth can they justify it? How can NIST possibly justify an "investigation" that doesn't even consider one of the likeliest explanations for the buildings' collapse?

It's beyond satire.

[ROH]

20. Very important points

Thank you for detailing the points you mentioned.

[JackRiddler]

21. I notice the OCT crowd is staying away from this one!

OCT = Official Conspiracy Theory.

[stickdog]

22. So I'm not the only one who noticed that.

When it comes to actual hard evidence (as opposed to pseudo-scientific speculation), the official conspiracy theory (Osama's planes alone) of the three WTC collapses is woefully lacking.

The two pieces of metal that were studied most intensively (by FEMA and not NIST, btw) demonstrated clear signs of intense, high temperature sulfidation of "unknown origin." Meanwhile, no recovered core piece and only 2% of the recovered perimeter column panels were ever exposed to any temperatures greater than 250 C for more than a few seconds.

Furthermore, in NIST's most recent study, the ONLY recovered steel pieces that were even examined for high temperature exposure OR microstructure alterations were the recovered perimeter column panels (plus just 4 core pieces) whose markings identified them as coming from floors that photographic evidence showed were exposed to fires.

Considering the fact that the initial test for exposure to temps in excess of 250 C was no more than a visual inspection for a certain pattern of "mud cracks" in the steels' primer coating, why wasn't each and every recovered piece -- regardless of its putative location vis a vis the photographic evidence of fire -- examined for over 250 C exposure?

[Bismillah]

23. It beggars belief that they did "no testing for explosives"

What does that tell us? It amounts to an open admission that they will not even consider any hypothesis that might undermine the Official Conspiracy Theory.

[spooked911]

24. I assume they did not want to know the answer.

[LARED]

25. Let's try item 4

4. Only 12 total core columns were recovered from WTC-1 & WTC-2 combined.

That would be true of it stated 'only 12 total identified core columns were recovered from WTC-1 & WTC-2 combined.

From the link http://wtc.nist.gov/pubs/NISTNCSTAR1-3Draft.pdf

The volunteers searched through enormous unsorted piles of steel and other debris for pieces from the WTC buildings, specifically searching for (McAllister 2002):

• Exterior column panels and interior core columns from WTC 1 and WTC 2 that were exposed to fire and/or impacted by the aircraft,
• Exterior column panels and interior core columns from WTC 1 and WTC 2 directly above and below the impact zones,
• Badly burned pieces from WTC 7,
• Connections from WTC 1, 2, and 7 (e.g., seat connections, single shear plates, and column splices),
• Bolts in all conditions,
• Floor trusses including stiffeners, seats, and other components,
• Any pieces that in the engineers’ professional opinion might be useful.

Once selected for recovery, the samples were marked as “SAVE” and given an alphanumeric code that identified the recovery yard where they were located and an accession number. Some pieces were not
saved in their entirety, but instead, small portions were removed, hereafter called coupons and held at Gilsanz Murray Steficek, LLP (GMS). Coupons were also removed in the field for WTC 5 and held at
GMS (all coupons were later sent to NIST).

So what is being characterized as only 12 core columns being recovered is really 12 core column of the collected steel have been identified for locations and possible conditions to which they may have been exposed prior to the collapse of the buildings. Itis plain to see the investigators had an enormus pile of steel to select whatever they wanted.

[stickdog]

26. What's your point? They ANALYZED only 13 core pieces in total.

From page 35 of http://wtc.nist.gov/pubs/NISTNCSTAR1-3Draft.pdf :

Table 5–2 lists the 12 core columns that have been positively identified. An additional sample, C-83, is also listed in this group. Though no markings were found on the piece, the shape and dimensions of this sample conform to the design drawings for core columns and have a similar appearance to core column C-90.

Of these 13, they were able to positionally identify 12. Furthermore, they only analyzed FOUR of these 13 core columns for temperature exposure and NONE of these four were from WTC-2's supposed "fire exposure zone"!

While the investigators definitely had access to "an enormous pile of steel" that does NOT imply that they had access to all or even a large portion of the WTC steel rubble.

Why didn't they recover any WTC-7 steel? What you posted specifically says they were looking for "badly burned pieces from WTC 7," so why couldn't they find any?

Why were they unable to recover any impacted exterior panels from WTC-2 despite looking for them specifically? Why were they unable to recover any core panels from WTC-2's fire exposure zone despite looking for them specifically?

Finally, why did NIST limit even their most basic temperature exposure analysis (a simple visual inspection of the steel's primer coating) to ONLY the recovered pieces that they positionally determined to come from fire exposure zones using photographic evidence? What kind of metallurgist looks at photos of a fire to determine what happened when he's got the metal right in front of him?

[LARED]

28. My point is simple

4) Only 12 total core columns were recovered from WTC-1 & WTC-2 combined.

does not represent the facts.

[stickdog]

30. I'd be happy to correct that small oversight.

That is if you can tell me, how many core columns from WTC-1 & WTC-2 were actually recovered in total and what relevant analyses were made of them?

[StrafingMoose]

31. Yea, well

Still, the analysis made by unbiased agencies (duh, GOVERNEMENTAL agencies) don't corroborate THEIR story and doesn't answer to any questions in a favorable way, for THEM.

"This is what we picked up, this is what we found".

From what you posted, as far as I understood, they picked up badly damaged parts, and parts exposed to aircraft hit. Are you saying that the study is invalid since they haven't analysed intact columns?

For my part, I don't think the NIST is part of a conspiracy fueling cabal...

[JackRiddler]

32. you're missing the point

NIST does not have to be part of a cabal.

Lucky for NIST, the physical evidence was destroyed (i.e., Ground Zero steel was scrapped and shipped to Asia) long before they were assigned to do a report.

This is what Stickdog is making clear, quoting NIST on how few physical parts they have.

They also need not be part of a cabal because they can be open about all the tests they're not performing and all the hypotheses they're not considering.

Their most important hypothesis -- airplane crash knocked insulation off the core beams, which exposed them to weakening by fire -- is not subject to falsification, since there are almost no core beams left to examine to figure out whether this was indeed the case.

Again, the asses of all the NIST engineers are fully covered, long as they do not stray from their easy, softball mandate.

They need not be part of a cabal to end up helping the cover-up.

[StrafingMoose]

34. Hmm..replied to the wrong one I think..

What I meant is that NIST didn't put up this study (or were ordered to) to undermine the official 9/11 story. Sorry I think I replied to the wrong argument, bare with me I'm new :P

[stickdog]

37. Exactly. This latest round of NIST studies contains all sorts of computer

models (reverse engineered to arrive at the predetermined result) and photographic analysis, but exactly NOTHING in the way of even a shred of physical evidence that unambiguously supports their tenuous predetermined models.

And it's not because the scientists who did the studies were "in on it" per se. They merely did the work they were commissioned to do. It's like when a corporate boss hires a big consulting team to "help" his department arrive to a predetermined business solution through "teamwork." Nobody has to be "in on it" to figure out where their bread gets buttered.

[Ka hrnt]

76. Facts?

"does not represent the facts. "

Obviously you've forgotten where you're posting; there is no room in this forum for facts. ;-)

[John Q. Citizen]

111. Your point is? n/t

[stickdog]

27. If NIST metallurgists had access to any WTC steel they wanted,

why would they be satisfied with analyzing just FOUR core columns in the either WTC-1's or WTC-2's impact/fire zones -- NONE from WTC-2's fire zone and just one WTC-1's fire zone and one from WTC-1's impact zone?

http://wtc.nist.gov/pubs/NISTNCSTAR1-3CchapsDraft.pdf

In the two buildings (stickdog's note: WTC 1 and WTC 2), there were 329 core columns, each three stories tall, traversing floors involved in the impact and pre-collapse fires. NIST has portions of four of these columns, which represents about 1 percent of all core columns intersecting floors with damage from the impact or fires. Thus, while these pieces allow for some assessment of damage, the following forensic analysis does not, and cannot, give a full and accurate picture of the type and amount of damage sustained by the vast majority of core columns.

...

4.1.3 Other Identified Core Columns
As none of the remaining columns were within the impact or fire floors, no further analysis (stickdog's note: further analysis? so what was the initial analysis, again?) was conducted as damage was assumed to be a result of the collapse and subsequent handling during the recovery.

4.1.4 Unidentified Core Columns
Due to the unknown location of these columns, and the small overall population of the core columns, no further analysis (stickdog's note: further analysis? so what was the initial analysis, again?) was conducted.

[JackRiddler]

29. a sweet and easy cover-up

Destroy and dispose of the evidence as quickly as possible. One hundred percent of it, in the case of WTC 7.

Screw anyone who objects. Arrest anyone who tries even to photograph Ground Zero.

Have the wrong agency - FEMA - do a "preliminary" report. For this, they hire a few engineers part-time on the weekends! These guys receive extremely limited access to the actual steel, under supervision at all times.

Two years later, the right agency - NIST - can safely be put on the job. There is so little evidence left from the impact zone (and none from 7) and their mandate is so predetermined (find out how impact and fire caused this structural collapse) that they really need not make up anything for the cover-up - they only need to be literalists, and come up with a hypothesis.

An unprovable one, in this case: the plane impact loosened the fireproofing, allowing the fire to weaken the core columns. This hypothesis necessary because the actual NIST test conducted by UL at Chicago found that even more intense fires would not have weakened the core columns. And convenient because there's no way to show whether the impacts knocked off the fireproofing and thank god, the evidence has been destoryed.

So the NIST guys don't need to lie; they only need to play the hand that's been given to them: almost no actual physical evidence to complicate things, and a hypothesis that can't be disproven.

Just make sure not to test anything for explosive residue. And try not to notice all the signs of sulfidation (as even the FEMA report revealed).

And here's a typical line: "NIST has seen no evidence of controlled demolition, explosions or missiles." (With regard to 7.)

What the hell does that mean? Every videotape of the 7 collapse is evidence of a controlled demolition, which is why everyone's first reaction is to compare it to a CD.

Now, scientists may determine that this evidence is overcome by the total evidence, i.e. that the evidence against CD is even greater than the visual evidence for one.

But to say "we have seen no evidence" is simply dishonest, since the external view in the videos corresponds to a CD.

Lazy, convenient. Did you expect a group of government civil engineers to risk their livelihoods and be labeled insane by the media and OCTers by entertaining the technically possible demolitions hypothesis? Ha.

Hell, they're not even going to entertain the hypothesis that the there might have been an actionable design flaw, or a specific part that was actually the culprit for the collapse. No fucking way is anyone going to be found liable!

[screembloodymurder]

63. Right on.

I know someone who was thrown offsite for releasing information that was meant to protect the cleanup workers. The Bush administration did not allow anyone that exposed the truth to remain onsite. All information had to pass through their hands and was 100% censored.

[we can do it]

56. A Little Slow On the Response Today?

[DoYouEverWonder]

65. Recovered and analyzed

are two different things.

BTW: What happened to this pile of 'recovered' items? Is it still around or have they finished melting it all already?

[Dancing_Dave]

33. Federal Agencies involved in WTC Cover-up:

Let them be remembered in infamy:

1.FEMA supervised illegal destruction of crime scene evidence. They also came out with a report on the "collapses" which Fire Engineering magazine accurately characterized as a "half-baked farce."

2.EPA falsely told New Yorkers that the air in lower Manhattan was safe to breathe. A later audit showed they told this lie under direct orders from the Bush Administration.

3.NIST did this silly "investigation" where no thorough study of the explosions in the WTC on 9/11/2001 was done, and no explosive experts were involved conducting forensic analysis. And as this post indicates, they had pathetically inadequate physical evidence, insufficient for any kind of forensic investigation of the crime.

Enough of the official Federal cover-ups. We have to figure this one out for ourselves.

[Christophera]

54. Right On! "We have to figure this one out for ourselves."

and spending a lot of time analysing subterfuge designed to be a waste of time (credibly disguised in authority) won't help.

[pox americana]

36. I'm almost certain explosives were used to bring down WTC1 and 2

based on what I saw on 9/11, for 2 reasons. 1) When the first tower came down, it started tipping from the middle, like the top half was going to fall across the street, kind of like a tree that had been chopped. But then it started collapsing from the bottom.

2) I distincly remember little smoking pellets of debris flying from the burning floors as the towers came down.

But it wasn't black smoke. It was grayish white, like burning sulfur or fireworks. So there were explosives on the planes at the very least, but that still doesn't explain why the buildings pancaked from the bottom, and didn't just lose the floors above the planes.

[Endangered Specie]

39. Read this...

http://wtc.nist.gov/pubs/reports_june05.htm
(the main full report explains in detail how and why the towers collapsed as they did).

But, to quickly summarize it:
1) A tower isnt a 'tree' it 'tipped' as you say because the plane did not cause uniform damage to the impacted floors (it was heavily concentrated on the side of impact, naturally). Incidentally, this tipping rotating of the top portion during collapse is good evidence AGAINST demolition (as any good demolition team would not let that happen, but would actually strive to cause uniform, completly vertical, pancaking). It collapsed at the "bottom" of the impact site since that was where the most damage was done (weakest point always fails first).
The reason why the bottom floors pancaked is because of gravity which slammed the top rack of 20/30 floors on to the bottom, causing immediate structural failure.

2)First, go back and 'reexamine' where you saw it, the human brain is faulty, and making those kinds of conclusion from memory of a video, even of a demolitoins expert/engineer, is not reliable in any way. But, it certainly could have been either paper, concrete, drywall, gypsium (sp) or any number of furnishings.

[stickdog]

41. No commentary on the complete lack of physical evidence for your

and NIST's favorite theory?

[JackRiddler]

42. your latest fallacy...

endangered specie says:

"Incidentally, this tipping rotating of the top portion during collapse is good evidence AGAINST demolition (as any good demolition team would not let that happen, but would actually strive to cause uniform, completly vertical, pancaking)."

The strawman assumption here is that those who theorize the Towers were blown up also think this means they were wired by a "good demolition team" to "cause uniform, completly (sic) vertical pancaking."

No, actually: most of those who theorize demolition think the Towers were rigged in advance, but programmed after the plane crash to blow up in a sequence that would mimic a possible spontaneous collapse.

Clearly, if the Towers were blown up, this was not a "controlled demolition"; it was an intentional destruction using enough explosives to pulverize most of the concrete and create huge clouds of debris, with little regard for human life.

The burden is on either side in this argument to demonstrate why their hypothesis is superior. So far, from the pro-collapse side, I do not so much hear reasons why physics dictates that demolition is impossible, but rather psychological excuses ("it would be hard to wire the buildings and not be noticed, too many people would be involved," etc. etc.)

You are right about one thing:

"The human brain is faulty."

This doesn't just apply to an individual's recall of sudden unexpected events.

It also applies to the human desire for reassuring narratives. (Example: A guy in a turban did that terrible thing, it had nothing to do with you or your government, now we will go get him and everything will be better.)

It also applies to many individuals' sense of morality. There are psychopaths out there, and most of those who hold power in the world are obviously among them.

[DoYouEverWonder]

66. That's right, this was not a "controlled demolition"

The buildings were blown up. Gravity took care of the rest. There is only so far out heavy material will fly before gravity takes over. Plus the perimeter buildings acted has a barrier and took the brunt of the collapse.

Steel and concrete skyscrapers do not explode into a volcanic reaction without a huge energy source. A few fuel bombs in the elevators probably would do the trick. A few cutter charges on the big columns in the corners maybe. Definitely had to be an inside job, whatever they used to do it.

[John Q. Citizen]

75. I refer to it as a planned demolition. It was planned to bring it

basically downward and to not tip it over, but it was far from a "controlled" demolition.

[undeterred]

40. Welcome to DU pox americana

So you were in the area of the WTC on 9/11?

This link has a lot of the arguments for explosives being used.
http://algoxy.com/psych/9-11scenario.html#anchor1209645

[pox americana]

43. thanks undeterred

I wasn't downtown, so I can't claim to be an eyewitness, and most of what I saw I saw on live TV.

[philb]

44. Comprehensive Evidence supporting controlled demolition at WTC

Evidence of Controlled Demolition of WTC Buildings
http://911research.wtc7.net/wtc/analysis/index.html
http://911research.wtc7.net/wtc/analysis/collapses/index.html
http://911research.wtc7.net/wtc/analysis/towers.html
http://911research.wtc7.net/wtc/evidence/surviving.html
http://911research.wtc7.net/wtc/analysis/proofs/index.html

Fires in the WTC Rubble That Persisted for Months
http://911research.wtc7.net/wtc/evidence/rubblefires.html

Reports from Firefighters at the Impact Zone Inside the South Tower- small controllable fires in South Tower http://911research.wtc7.net/wtc/evidence/audiotape.html

Implausible Pancake Theories not supported by the evidence
http://911research.wtc7.net/wtc/analysis/official/index.html

[stickdog]

45. Don't you find it strange that none of our great advocates of the official

"Osama's planes did it all by themselves while we were sleeping" conspiracy theory feel inclined to discuss the complete and utter absence of any physical evidence in favor of their (and NIST's) favorite theory?

[stickdog]

46. kick

[stickdog]

47. EXTRA, EXTRA, READ ALL ABOUT IT!!!!

NIST Finds No Physical Evidence for the "Osama & His Planes Did It By Themselves" Theory Favored by Official Tinfoilers

See the original post on this thread!

[IChing]

48. Unfrickin believable, no steel analysis on Building 7-thanks stickdog

Which was the command computer center for the controlled explosions on buildings 1&2,
and that area( Was it the 15th floor?) had it's own independent power and air system
separate from the building 7 and the city.


Then since building 7 was fine and especially the command center,
they could leave and set the computer timer for that building,
destroying all evidence of the command center.

They knew the steel would not be analyzed.

[petgoat]

49. It's **worse** than no steel analysis.

The FEMA Appendix C report analyzed a piece of WTC7 steel, and ended with a call for
further investigation of its bizarre sulfidative erosion which reduced an I-beam to
scrolls of foil.

Not only was further investigation not done, NIST pretended this steel did not
even exist.

http://www.wpi.edu/News/Transformations/2002Spring/steel.html



http://911research.wtc7.net/wtc/evidence/metallurgy/WTC_apndxC.htm

[rman]

50. Metallurgical Examination of WTC Steel Suggests Explosives - pictures

Forensic Metallurgy
Metallurgical Examination of WTC Steel Suggests Explosives
http://911research.wtc7.net/wtc/evidence/metallurgy/index.html

FEMA's volunteer investigators did manage to perform “limited metallurgical examination” of some of the steel before it was recycled. Their observations, including numerous micrographs, are recorded in Appendix C of the WTC Building Performance Study. Prior to the release of FEMA's report, a fire protection engineer and two science professors published a brief report in JOM disclosing some of this evidence. 1

The results of the examination are striking. They reveal a phenomenon never before observed in building fires: eutectic reactions, which caused "intergranular melting capable of turning a solid steel girder into Swiss cheese." The New York Times described this as "perhaps the deepest mystery uncovered in the investigation." 2 WPI provides a graphic summary of the phenomenon.

A one-inch column has been reduced to half-inch thickness. Its edges--which are curled like a paper scroll--have been thinned to almost razor sharpness. Gaping holes--some larger than a silver dollar--let light shine through a formerly solid steel flange. This Swiss cheese appearance shocked all of the fire-wise professors, who expected to see distortion and bending--but not holes.

FEMA's investigators inferred that a "liquid eutectic mixture containing primarily iron, oxygen, and sulfur" formed during a "hot corrosion attack on the steel." The eutectic mixture (having the elements in such proportion as to have the lowest possible melting point) penetrated the steel down grain boundaries, making it "susceptible to erosion."

“The thinning of the steel occurred by high temperature corrosion due to a combination of oxidation and sulfidation.”...“The unusual thinning of the member is most likely due to an attack of the steel by grain boundary penetration of sulfur forming sulfides that contain both iron and copper.”...“A liquid eutectic mixture containing primarily iron, oxygen, and sulfur formed during this hot corrosion attack on the steel.”

[hack89]

51. How does this suggest explosives?

As posted many time in this forum, modern high explosives are not sulfur based. There are, however, other sources for sulfur ranging from acid rain to gypsum in the sheet rock.

Did you also catch the part where it states that this liquid eutectic mixture is direct evidence of temperatures of at least 1000C - at least you have clear up the issue of the intensity of the fires.

[stickdog]

52. Well, with such "great" evidence like this one has to wonder

why NIST & FEMA did exactly ZERO additional metallurigical examination of any WTC metal beyond unaided visual inspection.

Furthermore, consider that sulfur is used a fuel/filler material in a wide variety of high explosive mixtures.

http://www.mii.org/Minerals/photosul.html

Sulfur: Used in the manufacture of sulfuric acid, fertilizers, chemicals, explosives, dyestuffs, petroleum refining, vulcanization of rubber, fungicides.

http://www.globalsecurity.org/military/systems/munitions/explosives-compositions.htm

Dynamite was originally a mixture of nitroglycerin and diato-mite, a porous, inert silica. Today, straight nitroglycerin dynamite consists of nitroglycerin, with sodium nitrate, antacid, carbonaceous fuel, and sometimes sulfur in place of the inert filler. It is most commonly manufactured in weight strengths of 20 to 60 percent. Because of the tendency of nitroglycerin to freeze at low working temperature, another explosive oil usually replaces part of the nitroglycerin in a straight dynamite.

Straight gelatin is a dense, plastic explosive consisting of nitroglycerin or other explosive oil gelatinized with. nitrocellulose, an antacid, sodium nitrate, carbonaceous fuel, and sometimes sulfur. Since the gelatin tends to coat the other ingredients, straight gelatin is water-proof. Straight gelatin is the equivalent of straight dynamite in the dynamite category and is manufactured in weight strengths of 20 to 90 percent with corresponding cartridge strengths of 30 to 80 percent. The cartridge strength or the weight strength may be referred to by the manufacturer as the “grade” of the gelatin, a term which is confusing. Straight gelatin has been used in very hard rock or as a bottom charge in a column of explosives. It has been replaced in most applications by a more economical substitute such as ammonia gelatin, brit higher grades are still used in underwater blasting and in deep well shooting.

Slurries, sometimes called water gels, contain ammonium nitrate partly in aqueous solution. Depending on the remainder of the ingredients, slurries can be classified as either blasting agents or explosives. Slurry blasting agents contain nonexplosive sensitizers or fuels such as carbon, sulfur, or aluminum, and are not cap sensitive; whereas slurry explosives contain cap- sensitive ingredients such as TNT and the mixture itself may be cap sensitive. Slurries are thickened and gelled with a gum, such as guar gum, to give considerable water resistance.

[JackieO]

53. nice work, stickdog

kick

[NecessaryOnslaught]

55. Some info on the scrapping of the steel

and a Kick:hi:

http://www.sourcewatch.org/index.php?title=Destruction_of_Evidence_from_Ground_Zero_at_the_World_Trade_Center

[stickdog]

57. Kick for today's crew of "skeptics" fearlessly standing up for our

nation's "trained experts."

[stickdog]

58. Another kick for our resident knights who say "NIST." (nt)

[mirandapriestly]

59. You're a hero, thanks

I've read the FEMA, but not the NIST. I wonder if just the severed edge of the steel were heated for cutting, it would have showed up as being subjected to extreme heat. But then, much of it was too CORRODED to tell. Hmmm..

[dailykoff]

61. Lest it be forgot.

:dem:

[screembloodymurder]

62. Incredible!

This is criminal negligence on NIST's part.

[zforce]

64. Representative/Adequate sample..Forensic testing..Umm we mean

...."representative/adequate steel sample in determining the quality of steel".

P3 Mechanical Analysis..
Paint study

• Paint condition used to map upper limits to

temperature exposure on 21 perimeter panels

�� Most perimeter panels (157 of 160 locations mapped)

saw no temperature T > 250 °C,

Findings – Forensic assessment

• Of the more than 170 areas examined on the exterior panels, only three locations had a positive result indicating that the steel may have reached temperatures in excess of 250 ºC.

despite pre-collapse exposure to fire on 13 panels


The NIST found themselves to be in quite a pickle after the above Metallurgical Results had attested to temps of less than 250c in Oct of 2004. These findings had explicitly contradicted their long held theory which stated the fires had heated the WTC members to temps of 550c and above thus causing the affected steel to lose half of its strentgh ultimately leading to failure (*Even if that were the case that wouldn't explain the collpase, for the steel was prorated, thus even if the steel had lost half its strength it would still be able to bear its load)

So what did the NIST do?

Magic.

They, with a slight of hand, had changed their "adequate steel sample" from being adequate for the investigation (whole), to it only being adequate in determining the quality of the steel (final report).

The NIST did this even though in June 2004, before the "Steel temperature results" the NIST had clearly stipulated..

http://wtc.nist.gov/progress_report_june04/chapter2.pdf

---------The collection of steel from the WTC towers is adequate for purposes of NIST’s investigation (i.e., chemical, metallurgical, and mechanical property analyses as well as a substantial damage assessment and failure mode examination) to examine why and how WTC 1 and WTC 2 collapsed following the impact of the aircraft and ensuing fires.---------


As you can clearly see above, the NIST clearly states, the collection of steel was adequate for the needs of the investigation (whole) - Chemical, Metallurgical,and Mechanical property analyses as well as a substantial damage assessment and failure mode examination.

Moreover, the NIST details exactly what the Metallurgical Investigation consists of in other papers describing their investigation..

http://www.nist.gov/testimony/2002/wtcplan.html

----------Collection and Analysis of Forensic Evidence: structural steel, material specimens and other forensic evidence to the extent they have been collected or are otherwise available; metallurgical and mechanical analysis of steel to evaluate quality and estimate maximum temperatures; analysis of fire and elevator control panels.-----------

------Hence, "The collection of steel is considered adequate for the needs of the investigation above"-------

Just in case more evidence is needed..

http://www.aws.org/conferences/abstracts/2004/papers/2A.pdf


----------NIST is implementing its technical plan to address these issues (see http://wtc.nist.gov/). A primary objective of the investigation is to determine why and how the towers collapsed after the initial impact of the aircraft. As part of this investigation, the Materials Reliability and Metallurgy Divisions in MSEL are studying more than 200 structural steel pieces from the WTC site. Progress in this study is outlined here..............

.......Task 3: Property data to support studies of structure performance and airplane impact modeling. Fourteen grades of steel were specified in the design of the WTC towers. All grades have been characterized for room-temperature mechanical properties, and initial high-temperature test results are complete. Testing at high strain rate is underway to determine the effects of strain rate on the mechanical properties of the outer columns, the inner columns and the spandrels. Chemical composition and metallographic examinations have been completed on the majority of the steels. Creep, or time-temperature-dependent behavior of some steels will be studied after the high temperature properties are developed.........

Task 5: Metallographic analysis of steel to estimate temperature extremes. Microscopic, macroscopic and metallographic analyses are under way to determine the maximum temperature excursions seen by the steel. --------------

Hence as was stated before regarding task's 3 and 5...

---The collection of steel is considered adequate for the needs of the investigation (above)

So, as you can clearly see, the Metallurgical aspect of the investigation which the steel was adequate for, had clearly consisted in determining the quality of steel, and determining the steel temperatures.

Last but not least, lets turn to the NAIL in the coffin.
The "Nail in the coffin" is evidence of the fact that the NIST had actually discussed changing their initial findings from the steel being adequate for the investigation to it being adequate to only part of the investigation (determining quality).

Note, the following discussion takes place on the very same day the results of the steel being less than 250c were to be presented - Oct 19th 2004.

http://www.nist.gov/public_affairs/ncstmin_oct19-20.htm

------------C: As John Barsom said, the statement is not accurate. The validity of the model question from yesterday speaks to this issue. I do not believe that we have enough forensic evidence. It may be okay to establish steel quality. There was no effort by the Building Performance Study team to systematically look at the steel.

C: The use of the term “adequate” needs to be revisited. There is no core column test to support the hypothesis. The floors came down, the slabs were pulverized. This was unprecedented. Exterior columns and core remained. The floors group will attack this finding---------------


"The use of the term "adequate" needs to be revisted", Science? I don't think so...

In summary, the NIST had only focused on one, and only one hypothesis/theory throughout its entire investigation, and that one hypo/theory being the assumption that fires were the cause of the two buildings(Three buildings-WTC 7) collapsing.

Focusing on a such a theory(blinders) was the sole reason the NIST had ignored the metallurgical analysis results of the WTC structural steel . Over and over again, the wtc steel indicated temps of less than 250c, which inturn naturally indicated fires not being the cause of the collapses, yet the NIST kept on with their assumptions and computer generated simulations via their assumptions that the steel had attained temps of 550c, even though there was not one piece of metallurgical evidence in support thereof..

In comparison, the general public are really no different than the NIST, they have also concluded before sifting through the evidence that fires were indeed the cause for the buildings collapsing, even though, no steel structure in history has ever collapsed because of a fire.

Zel..

PS...

See Nist Appendix D

Comparing the results from the two analyses, some discrepancies exist where the visual observations made by WJE were in opposition to that of the results of the paint mapping technique utilized by NIST. As most of the observations of sooting and paint damage made by WJE were corroborated by the fire exposure-time sequence maps, it may be that a degradation mechanism exists where the primer paint exposed to the pre-collapse fires was damaged (resulting in the visual patterns) without increasing the local temperature of the steel above 250 °C.

Z: The above statement is explaining the discrepency with regard to what the WJE had observed (soot and paint damage) and what the NIST had mapped..In other words, the NIST had mapped an area that the WJE had observed to be damaged, as an area where there shouldn't of been steel temps of above 250c. Hence the nist goes onto explain that maybe there is a "degrading mechanism" that can damage the paint faster and keep the steel temps from increasing above 250c.

From there, we move onto another discrepency, and in all actuality, quite opposite of the preceding one...

Additional to the discrepancy between the visual observations of WJE and the paint mapping technique of NIST, there were seven panels where precollapse fires were observable, yet neither analysis technique indicated the exposure on the recovered panel. One example of this was from piece M-2 where images show fires/external flaming for over 16 continuous minutes on the 98th floor (Sec. 2.3.1).


Fires for 16 minutes on 7 panels, yet no evidence of exposure over 250c?

In all reality, just one panel of steel should/could be representative of all the steel in the Fire Area, since all the steel was primarily afftected in the same way by the fires, that is to say..Fires for almost the same amount of time(give or take a few mins (16 to 20 minutes).

[wildbilln864]

67. kick!

lest we forget!
911 was an inside job!
Lock em up!

[greyl]

68. stickdog was a wanker nt

[frylock]

100. most insightful, as usual..

you never fail to disappointment.

[mhatrw]

69. Bookmarked. Like many others have commented here,

what stands out most for me about this thread is how few official narrative defenders have deigned to make any substantive comments of any kind.

If I did not know better, I would have to conclude that they consider this NIST report just as problematic as all the rest of us.

[Jazz2006]

97. Did you not notice the date on this thread?

It's an old one (almost a year and half old) that someone just kicked after many months - but its subject matter has been the matter of vigorous debate on various other, much more recent threads.

[BootinUp]

70. A comment or two

Disclosure: I am not a structural engineer.

Why shouldn't we believe the NIST report?

Conspiracy you say? Then why did they leave you anything to question at all. They could have fudged it plenty if they could fudge it at all. Why the half assed effort?

The real answer is that there are unknowns no matter how many millions you want to spend on it. What would it take to get you to accept the conclusion?

There have been analysis published by qualified engineers that say it was primarily the fire. Some have said it would have collapsed with no fire. NIST after millions spent on computer simulations and small scale fire tests says it was both but the fire and damage to insulation was key. Obviously it is conceivable to experts that any one of those three scenarios is reasonable.

What is your qualification for disputing them? This study was not a coverup nor a poor piece of work. Its a shame there is an internet campaign to discredit it based on non scientific pulling things out of your ass observations.

/rant

[mhatrw]

71. What?

Nobody is disputing NIST's report that no recovered WTC metal showed any exposure to any temperatures in excess of 600C and that less than 1% of the examined pieces even showed pre-collapse exposure to temperature in excess of 250C.

This thread is simply pointing out that the hard, physical evidence that NIST examined in no way supports the assumptions of its unscientific collapse hypothesis. In the face of these facts, all NIST and its supporters can fall back on is the NIST's chosen lack of rigor in terms of any examination of the actual physical evidence.

It's as if I designed an industrial process that promised that a significant percentage of widgets I produced would be hardened by exposure to temperatures above 600C. Then my Quality Assurance department examines a sample of 250 or so of my widgets -- in a sampling specifically selected to demonstrate the promised high temperature exposure. Then when not a single selected widget demonstrates the promised high temperature exposure, I respond by shutting down my QA department rather than changing my process.

[BootinUp]

72. Apples and Oranges

Sampling a process does not guarantee you find a defective part. It allows you to estimate the probability of defective parts, but only if the sampling is representative of the process or population.

The problem with taking a representative sample is often overlooked. In the case of the WTC pile of rubble, if they were not able to determine the position of the steel in the original structure it was nigh impossible to be sure which samples came from the fire involved floors, and a small sampling of any kind would not guarantee finding the heated steel. The floor trusses were not so identified. So they could have sampled many many more pieces, which if I read correctly these trusses were broken into multiple pieces.

But the real question is why don't you believe the steel got hot per the simulations and lab tests? Thats the only mystery. If you put metal in a furnace or fire it will heat up.

[mhatrw]

73. I'm sorry, but I'm inclined to believe the actual physical evidence

rather than your rhetoric or NIST's speculative models.

[John Q. Citizen]

74. Jim4Wes is trying to spin. he's smart enough to see the writing on the

wall. And the writing says, the steel samples NIST collected didn't experience temperatures great enough to cause the failure. NIST says so.

They didn't even recover any evidence at building #7.

So now they have a hypothesis with zero evidence to support that hypothesis.

That should cause the hypothesis to collapse, shouldn't it?

[mhatrw]

78. Yes. Zero actual physical evidence.

No wonder so few espousing the official line have seen fit to address this thread.

[Carefulplease]

79. The issues have been and are being discussed in other threads. n/t

[John Q. Citizen]

80. Thanks for making that clear. Zero evidence for pancakes theory. But lots

of really cool speculation.

[John Q. Citizen]

77. Kicking cause this is important.

[mirandapriestly]

81. I have a restored 1930 O'Keefe Merritt Gas Range

It's made mostly out of steel. I can't believe it has lasted 76 years without melting!

[petgoat]

82. You don't understand. It's jet fuel. That's high tech. Just like

Tim McVeigh's racing fuel fertilizer bomb did the OK City
building. Right?

I miss stickdog. I had a lot of respect, and wonder why he or she got banned.

[Carefulplease]

83. The jet fuel isn't the reason why the WTC fires were hot.

Edit: grammar

The fires were just as hot as any other residential or office fires usually are. The jet fuel just spread them and contributed initially to a fraction of the combustible load.

[petgoat]

84. That's the technical view. The political view is that "jet fuel"

plays very well in Peoria. And without it, the collapses
would be implausible.

[mirandapriestly]

85. It must have been all that office paper, except it wasn't burned

it is all white in the pictures. Okay, then maybe that plastic and metal furniture then, I heard that stuff bursts into flames like dry kindling! and the carpets, I'm sure they put flammable carpets in the wtc, right?

[Carefulplease]

88. The unburnt paper sheets that have rained on Manhattan...

Those could have come from some of the 100+ floors in each tower that were not affected by the fires.

[John Q. Citizen]

87. Now if only the people in charge of collecting the evidence could

produce some steel that shows exposure to sufficient heat to cause the collapse, that "pancake" hypothisis might fly.

Unfortunatly for that hypothisis, there is no physical evidence to support it. Unless you believe that NIST is hiding the physical evidence to support their dubious conclusions, Carefulplease?

[Carefulplease]

89. I dont think NIST is hiding evidence supporting their conclusions.

However, the "pancake hypothesis" can refer either to early speculations that the sequential failure of whole floor diaphragms initiated the collapse. It can also refer to the progressive collapse that follows the initiation phase (failure of the column on one floor). I do not know many qualified professionals who have ever doubted the inevitability of pancaking in the second sense.

Judy Wood and Gordon Ross have questioned this possibility (or the possibility of the short duration of the collapse) but their arguments are flawed. This has been discussed here and on the PhysOrg forum.

[mhatrw]

90. So initial failure always leads to global failure?

In that case, don't you find it strange that building demolitions teams don't just take out a single floor and let the inevitable proceed?

[BootinUp]

92. Isn't that pretty much the way it works? n/t

[mhatrw]

93. So you think that it would take just minutes to set enough

explosives to knock down a skyscraper?

[Carefulplease]

96. A minute amount of explosives...

The kinetic energy released from the aicrafts impacts was equivalent to the energy released by the explosion of 2000 pounds of TNT. Released in a more efficient manner, a somewhat lesser ammount would have been sufficient to initiate the collapse immediately, I would think.

On the other hand, many controlled-demolition theorists much overstimate the amount of explosives needed. This is because they believe that the collapse, once initiated, can not proceed fast, or can not proceed at all. Thus they suppose that the columns of the lower floors must be weakened or cut in advance of the arrival of the collapse front.

[mhatrw]

98. Why isn't this the typical practice, then?

Sorry, but that makes no sense.

Are you saying that controlled demolition practices should be changed because of what "we learned" on 9/11?

[Carefulplease]

99. There is no such thing as typical practice...

Edited to fix reference and add link

There is no such thing as typical practice concerning the explosive demolition of 110 story high skyscrapers. For more about the role of gravity in typical explosive demolitions see the recent paper by Blanchard on the implosionworld.com website.

http://www.implosionworld.com/WTC%20COLLAPSE%20STUDY%20BBlanchard%208-8-06.pdf

[mhatrw]

101. What you seem to be see saying is that you can cause skyscrapers

to collapse by simply blowing out one of their upper floors. So why don't demo experts save time & money by doing it that way in the real world?

[Carefulplease]

102. Demolition experts do not blow up skyscrapers...

Demolition experts do not blow up skyscrapers, so there isn't much money to save there. The tallest building to be brought down through explosive demolition was the J.L. Hudson Department Store in Detroit. Discounting the thin 6-storey tower on top, it comprised 23 above grade levels. Its construction had little in common with either WTC1, WTC2 or WTC7.

http://www.controlled-demolition.com/default.asp?reqLocId=7&reqItemId=20030225133807

Have a look at the video also. Notice how the ejections of dust and debris are a consequence of the energetic gravity driven collapse and are produced seconds after the explosions are over.

[mhatrw]

106. Yes, the old "never before happened in history, so anything's possible"

excuse.

It seems to be something of a mantra.

[Carefulplease]

107. Your own mantra is misplaced here...

You rather badly missed the point. You suggested that skyscrapers are normally blown up one particular expensive way (destroying structural supports on many levels) rather than another more economical way (destroying supports on just one level.) Skyscrapers aren't brought down using explosive demolition period. Your point is moot.

[mhatrw]

108. How are skyscrapers brought down?

Other than on 9/11, of course.

[Carefulplease]

109. They are dismantled from the top down one piece at a time...

This is how it was done with One Bankers Trust Plaza and the Singer Building in NYC for instance. Can you cite just one building worldwide that was even nearly as tall as the 29-storey J.L. Hudson Department Store in Detroit and that was brought down explosively?

[mhatrw]

110. That sounds very expensive.

Blowing them up would certainly save a lot of time an money -- at least for the buildings' owners. Wouldn't you agree?

Of course, you would have the problem of deadly pollution, but if you could just somehow blame it on someone else ...

[Make7]

103. Maybe....

... they call it controlled demolition for a reason. Very tall buildings collapsing from the top down do not appear to be very controlled as they fall.

- Make7

[John Q. Citizen]

91. If you believe NIST isn't hiding the evidence that supports their

hypothesis, and since they had access to the evidence of the condition of the steel, then one can only surmise that they were unable to find any physical evidence that supports their hypothesis IE there wasn't any.

That puts the pancake hypothesis in the circular bin, IMHO.

Do you know many qualified professionals who continue to cling to a hypothesis which lacks any physical evidence? Particularly when the have exclusive and extraordinary access to that evidence?

Back to the drawing board.

PS

On the "smoking gun" thread you made a claim that their were "new calculations" on the seismic evidence. I asked you for a link and days later i have no reply. Do you not have verification for your statement?

Sorry to ask you here, but your silence on the other thread is making me wonder how you came to the conclusion that there were "new calculations" from LDEO. Thanks.

[Carefulplease]

94. About the LDEO revised times for the WTC impacts...

I don't see that you asked me this. Rather, it appears you asked Make7. But he already gave the bibliographical information for the new report. I supposed you could contact LDEO or Dr. Kim to get a copy.

The results from the new LDEO analysis are reported in the NIST report.

http://wtc.nist.gov/NISTNCSTAR1-5A_chap_1-8.pdf
p.23 and the table p.22.

[Carefulplease]

95. The evidence from the steel samples...

I am discussing this in another thread and I dont fell like repeating it all here. So, meet you over there, if you will.

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=125&topic_id=110375&mesg_id=110375

[JackRiddler]

104. kick

[Name removed]

86. Deleted message

Message removed by moderator. Click here to review the message board rules.

[leftofthedial]

105. if all you conspiracy wack jobs don't just shut the hell up . . .

the terrursts win!

:sarcasm:


MIHOP
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[mhatrw]

112. Kicking for our newest shift of "debunkers." n/t

[Lithos]

115. Locking

Year and a half old thread.

Lithos
DU Moderator