NOVA | Building On Ground Zero | PBS

[greyl]

Airs Sept 5, 8 PM.

Following up its Emmy Award-winning documentary, "Why the Towers Fell," NOVA probes the conclusions of the government's engineering investigation into the World Trade Center's collapse on 9/11, with updated analysis of the devastating attack and how subsequent knowledge gained will shape skyscrapers of the future. Yet is it practical or even possible to construct invincible buildings?

"Building on Ground Zero" features candid interviews with leading construction and safety experts, investigators, architects, and engineers—including Leslie Robertson, lead structural engineer of the original World Trade Center and Shanghai's new World Financial Center, and Jake Pauls, occupants advocate and evacuation specialist. From the hallways of the newly erected World Trade Center 7 in New York, to China, where the world's tallest building is midway to completion, NOVA explores the complex challenges of building tall buildings in the wake of 9/11.

Previously, it was natural threats to the safety of tall buildings—earthquakes, hurricanes, and the relentless force of the wind—that had driven structural engineering codes. But with the threat of terrorism, determined attackers have targeted even the most secure structures, forcing engineers and architects to consider what was once unimaginable.

In the months after 9/11, NOVA followed a team of engineers tasked by FEMA to study the Twin Towers' collapse. Preliminary conclusions originally reported in "Why the Towers Fell" determined that the floors of the buildings may have "pancaked" down upon one another as their trusses failed. Now, with the benefit of years of additional investigation, the National Institute of Standards and Technology (NIST) has revealed that no structural element was to blame for the buildings' collapse.
http://www.pbs.org/wgbh/nova/wtc/

Preview: http://www.pbs.org/wgbh/nova/preview/i_3311.html

Transcript will be here: www.pbs.org/wgbh/nova/transcripts/3311_wtc.html

[petgoat]

1. Following up. Right. Last time I checked, that meant expunging

Thomas Eagar's zipper theory from the website, and removing those
lying animations of the trusses peeling off.

[greyl]

2. So, it has improved according to newfound knowledge? nt

[hack89]

4. You can't move beyond Eagar's theories, can you?

One guy forwards a theory that is over taken by later research and studies - what's the big deal?

[petgoat]

5. The big deal is that it was an entirely speculative fantasy,

concocted by a guy who was not an engineer and who may never even
have seen the blueprints, and yet it stood as conventional wisdom
for three years, unchallened by the structrual engineering community.

The point is that NOVA presented this theory with blatantly dishonest
animations and diagrams, and nobody but that tinfoil-hatter Jim Hoffman
raised any objections.

The point is that NIST completely overturned the Eagar theories,
absolutely reversing the collapse mechanism, and not one person who
endorsed Eagar's theory before NIST came along will now defend it,
not even Eagar himself. And the structural engineering community
still has no comment.

"Government business, stay out of it." This is what fascism looks
like.

[hack89]

6. What does all that have to do with the current understanding

on how the towers fell? And perhaps the "structural engineering community
still has no comment" simply because they don't attach the same significance to it that you do. It certainly wouldn't be the first time the CT community has taken an obscure factoid and distorted beyond recognition to prove some CT.

[petgoat]

7. It has to do with the context of the current understanding

Lies and fantasies were accepted without criticism as conventional
wisdom, and the experts said nothing.

There's no reason to think it's any different today.

Many experts went on record soon after 9/11, spreading the notion that
the jet fuel "melted" the steel. No one of any stature slapped this
nonsense down, and none of the "experts" who spread this nonsense have
apologized.

[hack89]

8. Accepted by who ?

there were a lot of speculative theories at the start - it looks like the vast majority of the professional engineers simply waited without comment until NIST did their studies. Note that many organizations did comment on the draft reports.

You make too much of this - why should the engineering community give a rats ass about everyone with some crack pot idea? Notice that they are not wasting a lot of time with Dr Jones and his merry band?

[petgoat]

9. "why should the engineering community give a rats ass"

They should give a rat's ass when experts are going around telling us
the jet fuel melted the steel, and they know it isn't possible.

The conventional wisdom for three years was an unjustifiable fantasy
that was crazy on its face. If the clips were so flimsy on the perimeter
side that they unzipped, why were they so strong on the core side that
collapsing floors tore the core down?

And yet only the tinfoilers criticized it.

[greyl]

10. Great show, huh? nt

[zforce]

11. In my opinion, just as good as the first version.n/t

[greyl]

12. You think it will win an emmy as well? nt

[zforce]

13. Lets hope so. n/t

[mhatrw]

20. For most convincing situational comedy. n/t

[petgoat]

17. That's not much of an endorsement. nt

[AZCat]

14. There's a whole lot of stuff...

with higher priority than this that the engineering community is worried about.

If (and hopefully when) we start tackling junk science, there are lots of areas that need attention before we get to this.

[petgoat]

16. Right, the enginering community prudently waited until the FEMA

study came out. And while they were waiting, the steel was
destroyed. FEMA's answer was the Eagar zipper fantasy. But
nobody but tinfoilers criticized it, because how do you know
when you can't see the blueprints?

And now it's old news, ho hum. The government dynamites
office towers with people inside, who cares.

[AZCat]

27. You don't like engineers, do you?

Have you had a bad experience with one? I can relate - there are some real idiots out there. But you consistently slander the entire community without any real evidence to back your claims. If you were willing to prove that you have been a regular reader of engineering publications in the various branches since September 11th, 2001, then I would concede that you have a basis for your claim, but you have not done so.

Why do you do this?

[mhatrw]

19. But now that NIST has produced its own speculative study,

the silence of the vast majority of the professional engineers means something completely different -- namely, their full tacit approval of NIST's study.

Weird.

First, a bunch of flawed, crazy theories came out and the silence of the vast majority of the professional engineers signaled their patient circumspection and hestitation to involve themselves in a battle with flawed speculation.

Then, NIST's study came out and the silence of the vast majority of the professional engineers signals their tacit approval of science at its finest.

Funny how the exact same response is interpreted two completely different ways depending on the "conventional wisdom" about the WTC collapses du jour.

[greyl]

22. Did you see the program?

From your comments, I don't think you did.
Here's the transcript if you'd care to deal with any of the substance of the show.

[mhatrw]

24. OK.

Why, as other countries build soaring skyscrapers with vastly improved safety features, does America still lacks national guidelines five long years after 9/11?

Interesting that the same guy, Eugene Corley, who covered up what happened at the Oklahoma City attack was chosen as the lead investigator for the initial ASCE "investigation."

From the transcript:

EUGENE CORLEY: Once the transfer girder fails, there's no longer any support over most of its length, and almost half of the building collapses immediately. Whether McVeigh knew what he was doing or whether it was luck, he parked it in the place that it would do the most damage to the building.

Oh, those crazy terrorists. Always getting so lucky!

Why were no structural engineering codes changed in response to the Oklahoma City bombing?

NARRATOR: In truth, Corley was given scant time and resources to come up with anything but a preliminary conclusion, and a tragedy of this magnitude certainly warranted more than that.

Why?

NARRATOR: So, in 2002, Congress charged the National Institute of Standards and Technology to conduct the most detailed building analysis ever undertaken.

Why wasn't NIST's study started until most of the WTC-1 & WTC-2 and all of the WTC-7 evidence was destroyed?

SHYAM SUNDER: For most investigations, you usually have a building to investigate.

Exactly. Why not for the WTC tower investigations? Why was NIST forced to rely on video and photographic evidence instead of the physical rubble?

NARRATOR: Another suspect was the fireproofing that covered the trusses and other steel members. It was clearly blown off by the airplane impacts, leaving the steel exposed to the fires.

How much was fireproofing was "clearly blown off by the airplane impacts"? What is the scientific basis for that statement?

NARRATOR: In the areas of direct impact, the planes severely damaged the interior cores, destroying emergency stairs, elevators and sprinkler systems. With the stairs and elevators gone, those above the impact zones were trapped in a mounting inferno that would reach 1800 degrees.

What is the scientific basis for this statement? What does the actual forensic evidence say about this?

NARRATOR: Above the impact zone, in the south tower, one damaged staircase remained passable. Brian Clark and a few colleagues somehow managed to find it.

BRIAN CLARK: So we started down that stairway, and we only went three floors. There was a group of seven of us, myself and six others. We met two people that had come up from the 80th floor, a heavy-set woman and a, by comparison, a rather frail male. She said, "You've got to go, you've got to go up. You can't go down, there's too much smoke and flame below."

How did these guys manage to save themselves by climbing through fires that supposedly reached 1800 degrees?

NARRATOR: Designing big buildings so everyone can exit at the same time will increase building costs. More and wider stairwells, better fireproofing to protect against collapse, and specially-designed elevators for firemen or evacuees will not come cheap. And many experts believe these recommendations are an expensive over-reaction to one very bad day.

Yes, of course. One very bad day. Why worry about changing our codes over one bad day? Why worry about performing a first class forensic investigation of the physical evidence over one bad day? Sure, 9/11 changes everything geopolitically and in terms of our domestic civil rights, but it was just one bad day! Right?

JONATHAN BARNETT (Fire Safety Engineer): Prior to 9/11, we've never had a collapse of a protected steel building.

Exactly. But we had out first three failures in history on "one bad day."

NARRATOR: In every case before 9/11, the building remained standing, and virtually everyone got out alive.

Exactly. Why worry about changing our codes over one bad day? Why worry about performing first class forensic investigation over one bad day? Sure, 9/11 changes everything geopolitically and in terms of our domestic civil rights, but it was just one bad day! Right?

WILLIAM CONNOLLY: Terrorists, who know what they're doing, and many of them are engineers, could deliberately knock out a sprinkler riser before starting a fire, or put a chemical agent into the air handling system of the building.

Many terrorists are engineers? So that explains the NIST's 9/11 study!

NARRATOR: So how safe is safe enough? Certain buildings, because of their size or iconic status, will always require greater safety considerations. A case in point is the Freedom Tower, currently planned to rise from the footprint of the World Trade Center and fill the empty skyline of lower Manhattan.

Freedom Tower? To commemorate Operation Iraqi Freedom?

[greyl]

29. reply

-Why, as other countries build soaring skyscrapers with vastly improved safety features, does America still lacks national guidelines five long years after 9/11?

I agree - that bothers me too. However, based on other posts of yours, it would seem you'd rather the authorities in charge spent time investigating every conspiratorial wild goose chase in order to put there unanswered questions to rest.

-Interesting that the same guy, Eugene Corley, who covered up what happened at the Oklahoma City attack was chosen as the lead investigator for the initial ASCE "investigation."

I don't believe there was a cover up there other than of what pissed off mcveigh to begin with.

EUGENE CORLEY: Once the transfer girder fails, there's no longer any support over most of its length, and almost half of the building collapses immediately. Whether McVeigh knew what he was doing or whether it was luck, he parked it in the place that it would do the most damage to the building.

-Oh, those crazy terrorists. Always getting so lucky!

I think that's just a silly comment. If you were trying to do the most damage to a building, wouldn't you think of taking out the support structures? It wasn't like it was some needle in a haystack.

Why were no structural engineering codes changed in response to the Oklahoma City bombing?

I couldn't tell you for sure, but it seems like the Risk V Benefit equation was offered as a real world consideration. Btw, Corley's team recommended changes as a result of their investigation:

"In the wake of the 1995 disaster, Corley's team recommended that back-up systems to prevent progressive collapse become mandatory. But the codes were never changed.

On to 9/11 and the WTC:

NARRATOR: In truth, Corley was given scant time and resources to come up with anything but a preliminary conclusion, and a tragedy of this magnitude certainly warranted more than that.

-Why?

Stupidity, incompetence, boneheaded priorities, or covering up for the people who designed and/or built the Towers maybe? I'm not sure.

NARRATOR: So, in 2002, Congress charged the National Institute of Standards and Technology to conduct the most detailed building analysis ever undertaken.

-Why wasn't NIST's study started until most of the WTC-1 & WTC-2 and all of the WTC-7 evidence was destroyed?

Our government bureaucracy sucks and is not infallable? Plus, maybe my possible answers from above. It's clear that NIST would have liked to have had more physical evidence to study, because:

SHYAM SUNDER: For most investigations, you usually have a building to investigate. So we had to recreate, in great detail, what happened on 9/11, and that's why the need for a painstaking reconstruction of the entire process.

-Exactly. Why not for the WTC tower investigations? Why was NIST forced to rely on video and photographic evidence instead of the physical rubble?

The buildings had suffered a total collapse. Unlike the Murrah building, for example, no structure(extremely little) was standing. Even if the NIST was called in on 9/11, they wouldn't have had buildings to investigate.
The NIST was called in after ASCE because of empassioned calls from the victims families to ensure the safety of buildings and to find out who they should lay blame with for the buildings' collapses.

NARRATOR: Another suspect was the fireproofing that covered the trusses and other steel members. It was clearly blown off by the airplane impacts, leaving the steel exposed to the fires.

-How much was fireproofing was "clearly blown off by the airplane impacts"? What is the scientific basis for that statement?

It didn't say "how much", but knowing the bonding characteristics of that kind of sprayed on fireproofing, one could easily calculate a conservative estimate. It was the kind that could be rubbed off if maintenance workers brushed against it, not the best kind available today as a result of NIST recommendations. I'd imagine some of the pre-collapse video showed where some fireproofing had been blown off.
Unless you can show that the fireproofing couldn't be expected to get blown off by the plane impacts, I don't think you've got reason to doubt this point.

NARRATOR: Above the impact zone, in the south tower, one damaged staircase remained passable. Brian Clark and a few colleagues somehow managed to find it.

BRIAN CLARK: So we started down that stairway, and we only went three floors. There was a group of seven of us, myself and six others. We met two people that had come up from the 80th floor, a heavy-set woman and a, by comparison, a rather frail male. She said, "You've got to go, you've got to go up. You can't go down, there's too much smoke and flame below."

-How did these guys manage to save themselves by climbing through fires that supposedly reached 1800 degrees?

Straw argument. They didn't. One staircase was passable because the entire floor was not engaged with fire. However, the people that continued up the stairwell may very well have died as a direct result of fire.

NARRATOR: Designing big buildings so everyone can exit at the same time will increase building costs. More and wider stairwells, better fireproofing to protect against collapse, and specially-designed elevators for firemen or evacuees will not come cheap. And many experts believe these recommendations are an expensive over-reaction to one very bad day.

-Yes, of course. One very bad day. Why worry about changing our codes over one bad day? Why worry about performing a first class forensic investigation of the physical evidence over one bad day? Sure, 9/11 changes everything geopolitically and in terms of our domestic civil rights, but it was just one bad day! Right?

Your comment is a bit tangential. The NARRATOR said "many experts" and it was in response to a quote by SHYAM SUNDER of NIST of all people:

SHYAM SUNDER: Based on these findings, we also have made recommendations for a tall building to be able to evacuate fully in an emergency.

Anyway, I wish you would have seen the show. Maybe you can catch a repeat and benefit from the visuals.

[mhatrw]

15. Good point.

And these are the same experts we are supposed to defer to because they haven't publicly criticized the new NIST theory du jour en masse.

[greyl]

3. k nt

[greyl]

18. I see there is a dearth of pertinent commentary about the program

from the CTists. I won't act like it's a mystery why.

[mhatrw]

21. Well, I watched the first one.

The theories espoused (and graphically illustrated so clearly) were ridiculous and are now widely discredited by everyone in the structural engineering "community" including those that proposed them at the time.

And it won an Emmy!

No doubt the updated version will sweep all award ceremonies. How could it not?

[petgoat]

23. I forgot to watch. Wanted to.

Did they mention that the steel was destroyed before it could be
examined and analyzed?

Did they mention the conflicting stories of the firemen, FEMA/ASCE,
and NIST with respect to WTC7?

Did they mention that the blueprints are secret?

Do you think a program that didn't bring these points up could be
considered honest?

[AZCat]

25. Why wouldn't the blueprints be a secret?

Building plans are not public information - they are protected documents under copyright law. It is up to the owners of the documents to release them.

More importantly, what would you do with such information if it was available? Are you going to produce your own model and simulation of the WTC towers? I'd love to see you try, but I'm confident that neither you nor anyone else that posts or lurks here is capable of producing anything that approaches the level of complexity of the NIST model, flawed as it is. This isn't comparing videos of controlled demolitions with videos of the WTC collapses - it's nasty voodoo crap that can stump even professionals.

[petgoat]

26. The Port Authority is a public agency. I don't believe Mr.

Silverstein's lease gave him ownership of the blueprints, especially
after the buildings no longer existed. Those drawings belong to the
public.

Qualified engineers are not going to comment on the collapses until
they've seen the blueprints. Keeping the drawings secret keeps the
engineers silent.

The complexity of the NIST model is not to be admired. It is a snow
job designed to intimidate and impress and credulous and distract from
NIST's failure to ask basic questions.

[AZCat]

28. The Port Authority doesn't own the blueprints.

The individual who stamped the drawings does - they're copyrighted under his/her seal.

How would you have any idea what "qualified engineers" would do, and what do you consider necessary for qualification?

Until you can understand the NIST model, perhaps you should refrain from criticism. I'd be happy to point you in the direction of some illuminating texts if you wish.

[petgoat]

30. I can understand the NIST model fine.

They assumed that collapse initiation equals total
progressive collapse, and failed to model the
collapse of the structure below the impact zone--
because after all, it collapsed, didn't it, so
why do you need to model it?

Their model failed to collapse, and they had to
make ever-more unrealistic assumptions before
they could get it to collapse.

They failed to express regret that the steel had
been destroyed.

If a medical examiner failed to comment on the
fact that a corpse's head was missing, I might
think that his declaration of death by cerebral
stroke lacked just a bit of credibility.

They make unsubstantiated unfootednoted claims.