Re: Why the planes did not crumple

First, thanks for being civil and putting forward a good argument.
Your position is well thought out, but I don't think I'm going to
convince you (nor do I think you will convince me). This part of the
thread has been much more civil than the rest of this thread and I do
enjoy the debate.

I'll continue to respond here as I have time, but I have an astronomy
newsletter I need to get out in the next week so that will need to
take priority. My replies are inline.



are the TAIL WINGS not higher than the big-wings, i.e. their tip should
create
separate holes?

the vertical stabilizor,

should it not leave its own imprint?

For the horizontal stabilizors, almost certainly no. Even though the
energy of the aircraft is easily enough to punch through the shell, it
is not going to leave a nice "cookie cutter" hole. That's just not
the way metal fails unless you get so much energy that you cause the
metal to fail in brittle overload. You didn't have anywhere near that
much energy here. Instead, the metal bends as it breaks (I kind of
like thin plastic or rubber bends as you break through it.

So, the wing and fuselage structure are going to create holes much
larger than the actual aircraft structure. This would be enough
larger that there is practically no chance that the horizontal
stabilizors will impact building structure (you would need an
astounding pitch rate to accomplish that).

As for the vertical stabilizor, yes, it almost certainly impacted the
building structure. However, it would not create a "hole" that would
be identifiable as coming specifically from the vertical stab. It
would create what would appear to be an oblong extension of the
fuselage hole. This would be further obscured but the subsequent
explosion and the smoke.

Going back to your pictures and video clips (and thank you very much
for some of those links), it does appear that you can see an oblong
extension of the fuselage hole perpendicular to the wing hole. In
other words, the fuselage hole looks egg shaped up. You can't see it
for long because the smoke and debris coming from the building
obscures overall outline pretty quidkly.




So, how does this lighter (although still beefy with a significant
leading edge spar) structure penetrate the building?

yes!?

started. The tail is hitting massively weakened structure to begin
with.

weakend, but it resisted? (there is no impact hole:

http://www.questionsquestions.net/WTC/WTC767images/fema_767_engine_fit2.jpg


We'll have to agree to disagree here I think. By the figure you
posted, the fuselage doesn't even fit. If you look at the actual
photographs of the building (this site had probably the best
collection http://www.physics911.ca/ ), you can see a defnite
elongation in the aircraft "up" position where the fuselage hit..
There is a hole where the vertical stabilizor would have passed
through. Remember, it won't look like a nice cookie cutter (they
don't even when they hit the ground near vertically).



Now, I doubt this does the entire trick if not for one more very
significant point: The tail is more or less vertical when it hits.
The major structure of the building is designed to carry vertical
loads and we have, in essence, hit a single load carrying piece of
structure that is free at the bottom.

so the vertical stabilizer indeed was smashed, and its remants bounced
off?

Re: BlackBoxes...

The very upper part probably did (as did the last 2-5 feet of
wingtip). The rest of the vertical stab penetrated. I don't know
exactly where the black boxes are in a 767, but usually they sit
either in the aft fuselage or the lower part of the vertical
stabilizor. These parts penetrated. Only the very top couple of feet
(5 at most) wouldn't have penetrated.


As an engineer, I'd love to hear all of these, but I understand
their reasons.

You are tolerant of the secrecy of a government department created to
serve the people?

Not necessarily. CVR data should not, IMO, be released in it's raw
format. It is disrepectful to the families. Edited transcripts are
fine with me so long as the FDR data are released. That being said, I
do think that some CVR data has been misinterpreted in other cases
(after reading the Egyptair report, I think that the US investigators
came to an incorrect conclusion based on a translation). Still, that
is just my opinion and I wasn't involved in the actual investigation.

Some secrecy is necessary and I do think the CVR should be treated as
confidential. I'd like to see a transcript if it exists. As for the
FDR, I'd like to see that data if it exists as well, but it shouldn't
show much more than an airspeed and velocity and some controls input
and then nothing as the power is cut.


Still, I'm with you and would like to know if they every found the
boxes and /or got anything useful out of them.

You maybe in a good position to find out. Please coem back to us,
and share what transpired, thanks!

I'll ask around, but if these items were found, I doubt they went into
the normal investigative channels.




Then the INCREDIBLE collapse!!
...
Can you address why the vertical center core columns vanished?

Well, they didn't really vanish, the simply collapsed with the rest of
the building.
.....
breaking like popsicle sticks.

structural steel with over-engineered strength?

and then ALL 200 meters of it?

Sure. Why is this surprising? It wasn't meant to be freestanding
without the shell to help support it. With the rest of the bulding
collapsing around it and the top part giving way and falling, the
center section never had a chance to stand.

Remember, buildings are designed to carry loads in certain directions.
Change the direction from vertical to even slightly horizontal and the
structure is very weak. With tons of building collapsing, the load
paths int he building went completely to heck.




I fully expected the upper structure to
"topple" onto nearby buildings and take out half of Manhattan.

me too.

http://www.propagandamatrix.com/collapse.html
shows a nice photo of the top-section leaning over...

Yeah. They got really lucky. As you watch the video, you can clearly
see that one side of the shell holds longer than the other side. The
core has given way and one side of the shell has given way. The only
thing that prevents that top section from tipping all the way over is
that as the front (down) corner of the intact upper section starts to
encounter intact structure below it, it slows.

how long do you thing was the hold-up? 300 milliseconds?

It doesn't need to stop it, just slow it down and that's all it
appears to do. As the "down side" is encountering resistance, the
back side is starting to free fall. Like I said, they got lucky, but
what happened doesn't seem to violate the laws of physics (at least to
me).


Where there any other holdups? adding up to a second or two?

Probably not. A second or two would have resulted in a tip the other
direction. You just need to slow it a bit to arrest the tip.
Essentially the friction on the "down" side was greater than that on
the "up" side.


When I now tell you that the total-collapse time was near free-fall,
would you now adjust your argument to fit the fact?

Nope. The key is "near" free fall. It is like building implosions.
Once it starts falling, it keeps falling. It is hard to measure the
exact time it takes the building to fully collapse becuase of the dust
and the fact that the collapse continued below ground level.


Had that back structure held just a little longer, that would have
been a whol lot uglier!

isn't it amazing how everything became very small rubble, just as if
explosives were used?

Not really. If you read how they bring buildings down, the explosives
do nothing to create the rubble. All the explosives do is blow out
supports so that the building implodes in an orderly manner. The
energy released by the falling building is massive.

Look at it this way. You used a LOT of energy to put all that steel
and concrete in the air. It is going to release that energy coming
back down. I don't know how much each floor weighed, but the total
structure of each building was estimated at about 500,000 tons and it
was about 110 stories. Call it a bit under 5,000 tons a story. The
top floor was over 1,000 feet up. Drop 5,000 tons 1,000 feet and you
are going to release a MASSIVE amount of energy. This is far more
than any explosives that would have been used to cut the supports.


Wouldn't a collapse originating from a single-location in the building
have a good chance of leaving some big structural pieces intact?

like this:
http://0301.netclime.net/1_5/C/H/F/114610794237462.jpg
or:
http://0301.netclime.net/1_5/5/D/K/1146107942766527.jpg

For a relatively small building, perhaps. In this case, you took,
say, the top 20 stories (or about 100,000 tons) and dropped it 4
stories (about 40 feet or so) onto the rest of the structure.
Everything below the upper section is going to be pulverized. As for
the top floors, you just dropped it 800 feet. I wouldn't necessarily
expect large structure to survive. As you said, the upper 100,000
tons hit the ground at near free fall speed. I wouldn't expect much
to survive.

Still, this kind of structure isn't my area of expertise. I wouldn't
expect it to survive, but I'd listen to any expert that said that it
should. They'd have to show me the numbers to convince me though.


The world-trade center was designed for demolition by explosives?

Not neccessarily by explosives, but yes, when they put these buildings
up, they have to consider that they might need to come down some day.

What evidence do you have for this?

Talk to any Civil Engineer. In the old days, they didn't consider
this and the buildings came down as messes. Now adays, there are many
reasons that a building may need to be taken down (fire, earthquake,
urban renewal) and in the middle of a big city, they need to consider
how this might be done ahead of time. Obviously, every engineer hopes
his structures will last as long as the pyramids, but they have to
plan for how you'd bring it down and make sure it is well behaved.

For example, in San Francisco or Tokyo, you don't want buildings to
"tip over" in an earthquake and create a domino effect. You WANT
them to come straight down when they fail. That is good design in a
dense urban environment.


Remember that this wasn't the first time they tried to bring down
these towers. The first time was with a van loaded with explosives
that was supposed to be parked right next to one of the major corner
supports. Fortunately, the idiot driving the van couldn't find a
parking place in the right area so he parked elsewhere (instead of
just double parking and running!). As you may recall, these were the
same geniuses who later tried to claim insurance on the rented van
claiming it was stolen!

and they were guided by a ex-egyptian military intelligence officer,
working
as an agent-provocateur for the FBI. He recorded his conversations with
his FBI handlers (probably as a life-insurance, it worked so far)...

Never heard of that and I have NO idea why the FBI would be involved
in anything like this. The CIA or NSA maybe, but the FBI should not
be involved in foriegn intelligence.

If you can provide links, I'll at least read (but I won't guarantee
I'll believe).


http://www.saunalahti.fi/wtc2001/soldier5.htm
What I meant was the spread of the explosion plumes.
http://911research.wtc7.net/materials/contrib/911_physics_v9a.htm
http://www.911hoax.com/Morgan_Reynolds_911_Hoax.html

Interesting sites. This is turning into another Grassy Knoll
conspiracy theory.

YES!! thats what I am worried about. I know it is generally accepted
that Oswald was alone and fired 4 bullets. Yet there are so many
doubters.
They claim the real events that day were different from what the
highly-powered Warren Commission stated.

I won't go there because it is way off topic.


Both sites make a very fundamental error at the beginning.

I know. They are not useful as evidence, only for inspiration.
In physics every theory needs to be bomb-proof, (to coin a phrase)
every and any provable counter-argument invalidates the theory in todo.

Fair enough.

The pancake theory isn't quite correct. Only a couple of floors
collapsed in this way. When the concrete slabs collapsed, they pulled
the walls in and the core out. This dropped the top part of the
buildings onto the intact lower part and the rest was crushed.

So the core was not strongly enough braced?

The core was only designed to carry about 50% of the load in the
building. The steel shell structure carried the other half. Neither
the core nore the shell was sturdy enough to be free standing. They
needed the floors to hold them together and create the stiffness that
allowed the building to stand.

Look at a traditional building as it is being build. You see
internally braced truss structure everywhere. The WTC didn't have
that. It had essentially two very tall, very thin rods that were
connected to each other every 10 feet. The two worked together to
stand. Without one, the other couldn't stand alone for more than
40-50 feet max.

So, the answer was that the core worked exactly as designed. It
simply wasn't designed to do what I think you are expecting it to do
(hold the building structure intact by itself).


The metal structure in the areas of concern tell the story. They were
exposed to high heat and they did ductilely deform.

So the burning office furniture was able to generate the required heat?

No. But 150,000 pounds of burning aircraft fuel would. It is amazing
what you see melted after an aircraft crash (including engine
components that are SUPPOSED to stand up to high temperatures). The
thin steel in teh structure simply could't dissipate the heat rapidly
enough.


Actually, the best picture in both the websites (and they do have a
lot of fact correct, it is how they try to link them together that
causes their arguments to fall apart) is the chimney being broght down
at the end of the first website. All I can say is "Bingo!" That is
exactly what happened. The only difference is that instead of
explosives, you used aircraft and fire to bring the buildings down.
The rest of the collapse was exactly like an implosion.

Including the free-fall-speed like no-resistance collapse?

Sure. Watch an implosion. They come down at near free-fall speed.



They have a social system that allows for more worry-free
think-well-time ;-)
(paid parental leave lets you sleep a lot better..)

I think it is because it is so cold in the winter that they don't have
anything better to do (I REALLY hope none of my Canadian friends read
this).


I have trouble too. Too many points. I am happy to encounter
them in a willy-nilly fashion... there is no shortage.

And I'll admit I don't have anwers to everything. I can't figure out
if you believe all this stuff or you are just playing Devils Advocate.
Either way, I'm enjoying the discussion.


use the RMVB version... 51megs and still eminently viewable.

Hey! I pay for a high speed internet connection and I'm going to use
it!


Yes, well, its the right of the citizen.


And I apologize. I was getting tired when I got to this last section
and I was less polite than I should have been.


Nothing in here changes my mind. In fact, many of the facts don't
even support the argument that the video is trying to present.

what did the pre-collapse melting-metal flying sparks come from?
Burning electrical fires?

Aluminum fires, burning toxic waste (ever seen what a computer does
when you burn it), to be honest, I don't know exactly where all the
crud coming out of the building came from. I wouldn't buy electrical
fires though. The circuit breakers should have cut off the power.

NOTE: Added after watching a new video: I think I found what you are
referring to (a video shot from a great distance appears to show
burning liquid coming from the corner of the building seconds before
collapse). I don't know what the substance is, but from that
distance, it doesn't HAVE to be metal. It doesn't seem to flow like
running metal, although I've never seen metal fall from that kind of
distance (my father worked in a steel mill for years so I have seen
various types of liquid metal flowing). One note is that if what you
are seeing were really steel, where is it coming from? It isn't from
the shell (1/4 to 5/8 inch thick) because you would see large holes
appearing in the building. If it is from the core, it needs to flow
all the way across the floor to get to the outer edge of the building.
Instead, I'd expect it to flow down the center.

No, I don't know what it is. No. I don't think it is molten metal.


BTW, most of the structural engineers I know aren't at all surprised
that WTC7 came down. They were more surpirsed that the others did
not.

Wow, I haven't heard that before..

I saw in interview with one of the chief engineers of the original
project. He said as soon as he saw the damage, he started calling
people and telling them that the towers were at high risk for collapse
and if they came down, they would damage all of the deep foundation
and all of the other buildings on that foundation were at high risk as
well.



Well, thank god no earthquake has yet destroyed a skyscraper.

Not a modern one at least. I've seen several building collapses and
the cities most at risk for earthquake expend truckloads of $$
engineering their buildings with all kinds of arcane protective
devices. I don't pretend to understand them all, but they seem to
work.

To be honest, I think it is only a matter of time before we have major
building collapses due to a major earthquake. I don't think all the
engineers in the world can keep a building standing when you take the
two haves and move them 30 feet in opposite directions.


Did it surprise me that they didn't immediately tip over? Yep. Did
it surprise any of the Civil Engineers I know? Nope. And after it
was explained to me, it didn't suprise me any more either.

You seem confident.

Confident may be the wrong term. Lets say I understand the basic
principles now and it sounds reasonable. My CE friends ask me about
aircraft crashes all the time. They respect my judement and analysis.
I extend them the same courtesy. I don't pretend to understand the
details, but I can see the broad strokes now and the explainations
they offered were enough to show me that my basic premise for my
belief was incorrect.



I'd love to hear what his evidence of thermite being used. I hope it
is more than he found these metals at the scene. The WTC was rotten
with all 3 of them. Oh, and your typical building starts to corrode
before it is even complete! There should have been rusy steel beams
all over the place.

Yep.. ok, we'll see what he comes up with.

Here is a recent interview.. so you can hear him speak and
make a sanity-check. (The interviewer Alex Jones is certifyable,
though!)

http://prisonplanet.tv/audio/070606jones.mp3

Wow. This is long. Looked up Jones and he has a decent resume.

OK. Interesting, but I definitely need a lot more. Nothing this guy
says really changes my mind. First of all, he states that he found
Sulphur and that was the key. Well, he needs to talk to a
metallurgical engineer. ALL Steel contains Sulphur! He claims that
the presence of sulphur is evidence of Thermite. Well, common steel
plate is about .03% sulphur. and common steel bar is up to .054%
sulphur! I've been unable to find the exact chemical composition of
Thermate (therminte contains NO sulphur), but the one number I found
was .002% by weight. Note that this is MUCH less than the amount
found in the base steel!

I read the paper as well (well, skimmed it. I'll read it in detail if
I can find the time). His evidence for Thermate is sketchy at best.
The elements he found were all present in the building structure
itself (we didn't even need the aircraft) and the quantities found are
such that they are withing measuring error of common structural steel.
Having tried to identify a LOT of materials forensically after
aircraft crashes, I can tell you the hardest part is trying to
eliminate contaminants. The professor made no attempt to either
eliminate contaminants or to match them to phase transitions of the
steel itself as it heated or ot other materials commonly present in
office buildings (metal conduit, plumbing, light fixtures, etc.).

BTW, I agree that the host is pretty rabid, but it was interesting to
listen to the professor. I don't discount what he is saying. I am
saying that he is talking outside his area of expertise (he's a
physicist) and he doesn't seem to have been as rigorous as he should
have been.

COULD it have been Thermate? Well the chemical composition is I've
been able to track down CAN fit Thermate. Does it HAVE to be
Thermate? No. Materials already present in the building have the
same chemical properties.


The MOVIE (above rmvb) at least tries to give an answer and provides
evidence for it in the unprecendented (?) power-down in the WTC on
the weekend before the lethal Tuesday.

Yeah, but unprecedented simply means "hasn't happened before". It
could be sinister, or it could be that the needed to shut down for
some reason.


It would take you months just to get all the explosives into place!

Really? What if money was no object?

Well, let's look at what you need. First of all, you need access to
an entire floor. It should be a simple matter to identify the
approximate floor where the collapse started and find the tenents. Oh,
yeah. you need this for both buildings. Next, you need to get the
thermate up there. Next, as has been noted, you need to cut the
structure diagonally so you need access to the entire diameter of the
structure you are trying to cut which means major demolition. This
isn't something you are going to do in a weekend unnoticed.

Finally, in order to get the towers to topple as they did, you are
going to need to set your explosives to go off in a rather specifc
order.

I don't buy it with the evidence presented.
.

Relevant Pages

  • Re: Why the planes did not crumple
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  • Re: Portland Oregon metal supplier?
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