World Trade Center 7 Explosion and Controlled Collaspe Caught on Tape.

a reply to: ForteanOrg

First of all WHAT concrete core

When a hijacked airplane struck the north tower of the World Trade Center, six men, including Polish immigrant window washer Jan Demczur, found themselves trapped in an express elevator at the 50th floor. Thinking quickly, Demczur and the others pried open the elevator doors and used this squeegee handle to cut their way through the drywall of the elevator shaft. They squeezed through the hole in the wall, fleeing from the building just minutes before the tower fell.

Now I will refer you to this again.

Seismic design relies on modelling, risk analysis and changes to the structural stiffness. Wind design relies on additional structural members and wind tunnel tests. Current fire design relies on very simple, single element tests and adding insulating material to the frame. Thermal induced forces are not calculated or designed for

Lets see if you are willing to now try this as YOUR fellow posters seem to avoid it

Have a go at working out the amount of force that can be generated by a falling mass, you might be shocked!

For example if I dropped a 10kg mass the height of a Twin Tower floor 3.6 mtr and that mass was brought to a halt over 100mm distance have you any idea of the avg force of the impact ?

Here click and have a go Energy of a Falling Object

Your answer is given in Newtons divide by 9.81 for KG

Now imagine if you had held your arms locked straight to catch that!!!

Now imagine a 700,000+ KG floor slab in the Twin Towers dropping

Now lets see if YOU come up with an answer

originally posted by: ForteanOrg

originally posted by: Xcathdra
a reply to: ForteanOrg

Sure however my question still stands.

Buildings are not made where only one type of metal is present and in use. Different metals have different temperatures at which point they can become damage / destroyed / warped / etc.

Thank you for participating in the discussion without attacking anybody, refreshing

I know that buildings are made of many types of materials and yes they differ wildly w/regard to melting point, structure etc. However, that is also known to the engineers that design these buildings. They specifically construct buildings in such ways that the resulting mix of materials is sufficiently capable of supporting the building within its design criteria. In this case, the building was designed such that it should have been capable of withstanding the impact of the plane without collapsing. Yet, the building magically collapsed. Either the engineers are quite incapable, or they lied when they said they designed these buildings to withstand the impact of a fully loaded 707.

As the nist report says they couldn't find the methodology or calculations involved in the design (from the 1960s) regards plane impact. However. Are all impacts the same? Are all 707s travelling at the same speed or altitude or fuel load or angle? How would you design for that. What if it came in at 30° to the vertical? What if it hit 5m to the left? What if it was doing 375kts as opposed to 450kts? Hoe do you want to work out these calculations? You're asking designers using slide rules and pencils to do what these days involves some serious structures programs.

originally posted by: wmd_2008
to cut their way through the drywall of the elevator shaft.

Yes, the elevator shafts were made of drywall. But these shafts ran inside the core. The CORE was made of concrete and reinforced steel. The concrete was necessary to give the core more rigidity; this was a very tall building and steel warps and bends too much to give such buildings sufficient rigidity. Hence a concrete perimeter wall was added. Yamasaki's design for this torsion resistant core structure - steel reinforced cast concrete - won a competition in strength with several others.

So, indeed, it was an engineering wonder. And it consisted of significant amounts of REINFORCED CONCRETE.

Now I will refer you to this again.

Seismic design relies on modelling, risk analysis and changes to the structural stiffness. Wind design relies on additional structural members and wind tunnel tests. Current fire design relies on very simple, single element tests and adding insulating material to the frame. Thermal induced forces are not calculated or designed for

Lets see if you are willing to now try this as YOUR fellow posters seem to avoid it

Sigh. I'm not part of some competition, so please don't make it sound like that. I'm defending my alien ray theory, like you defend your boxcutters field day theory. In the process we exchange data, that's all.

Have a go at working out the amount of force that can be generated by a falling mass, you might be shocked!

Have a go of studying the action = reaction paradigm. You might be shocked.

Formally stated, Newton's third law is:

For every action, there is an equal and opposite reaction.

The statement means that in every interaction, there is a pair of forces acting on the two interacting objects. The size of the forces on the first object equals the size of the force on the second object. The direction of the force on the first object is opposite to the direction of the force on the second object

Now imagine if you had held your arms locked straight to catch that!!!

Yeah. imagine. But - that were not my arms, as the buildings would still be there, of course . No, it were just a measly 70+ floors, resting on trusses, resting on rubber pads, bolted to both the inner and outer tube of the Towers. Even if the floors pancaked down like that they would have had to overcome the inertia and upward force of the next floor, so the falling speed should have been much less. Especially when large parts of the kinetic energy were needed to rip the core apart, as you suggest.

Now imagine a 700,000+ KG floor slab in the Twin Towers dropping

Now lets see if YOU come up with an answer

To which question?

Even if, for the sake of the argument we assume that the structure was somehow weakened by the 'raging fires' (you know, the ones in which poor Erna stood waving). Raging fires that did not rage in the lower 70 or so floors, raging fires that according to reports of the FDNY only required one line to put them out. Those raging fires.

But lets assume that indeed the steel structure of the mesh was weakened - the truss hat would have ensured that the load shifted to the other three undamaged meshes. But say even that did not work. Say you are right, and the structure was weakened. Then I'd expect the mesh to sag, perhaps a floor collapse, but not like it did. It is highly improbable that the floor bolts would all break simultaneously. Some bolts hold on longer than the others and so I would expect much slower progress, and a far less regular demolition. Sagging, toppling, slowly starting to fall, the falling mass being stopped by the next floor, the mesh would remain standing one one or more sides. And of corse, that reinforced core should still be there.

But no, the entire building simply collapses at full speed, the entire concrete core simply pulverises and the outer skeleton is reduced to pieces too. And all that energy supposedly was already IN the building?

Nah. Alien ray.

a reply to: ForteanOrg


There was NO repeat NO concrete around the core steel, the only concrete was in the floor slab 4.5 inches thick



Core columns NO CONCRETE.

a reply to: wmd_2008

Then, pretty please, can you explain how it was that Yamasaki solved the problem of flex and twist of steel columns?

originally posted by: ForteanOrg
a reply to: wmd_2008

Then, pretty please, can you explain how it was that Yamasaki solved the problem of flex and twist of steel columns?

The picture above gives some clues look at the horizontal beam the floor trusses connect to at the core, the building was a system the core took the bulk of the gravity load, the walls the bulk of the wind load the floor slab tied the two together. If you look at the column trees of the outer walls the joints were staggered which you see in the impact holes the joint failed in the impact.

The South tower although hit second FELL FIRST, greater load above the impact point it was also hit off center and you can see in the collapse video or this image it did not fall straight down at first.



As for you comments re Newtons Laws you have tens of thousands of tons dropping on the floor below only the connection holding that floor can try to resit the load.

So if I hit you with a 10 ton mass do you think you would cause it any problems

Buy the way the ten kg mass would generate an average of 350+ kg if slowed over 100mm so imagine many 700 ton floor slabs falling !

The buildings ripped themselves apart.

originally posted by: wmd_2008
There was NO repeat NO concrete around the core steel, the only concrete was in the floor slab 4.5 inches thick

It is almost as if truthers had no clue at all how the WTC was constructed! (Or much of a clue about physics, or building demolition, or explosives, or aircraft etc. etc.!)

a reply to: ForteanOrg

The problem though is the "theory" that it could withstand a hit from an aircraft views the impact collision with the mindset the pilot of the aircraft is trying to avoid impact.

It does not take into account an act of terrorism where the plane is being deliberately aimed and flying at full power with absolutely no intention of trying to avoid the collision.

Secondly we must remember that back in the day a company claimed its newest ocean liner, with state of the art compartmentalized sections that could control flooding by isolating sections, hit an iceberg and sank.

Those building schematics and theory also stated the ship could not be sunk.

Humans are not perfect and things we make are prone to failure, even when the engineers think they have accounted for all possibilities. There will always be scenarios the engineers didn't anticipate. Even more so is the fact engineers don't always consider a deranged person in the equation. They will concentrate with the mindset of accidents and not intentional acts.

originally posted by: ForteanOrg
a reply to: wmd_2008

Then, pretty please, can you explain how it was that Yamasaki solved the problem of flex and twist of steel columns?

Simple answer: Spandrel Plates

No Vertical concrete reinforcement. All the core columns were however sprayed with fire proofing. This is what you see coming off of them as they fall.

originally posted by: Xcathdra
a reply to: ForteanOrg

The problem though is the "theory" that it could withstand a hit from an aircraft views the impact collision with the mindset the pilot of the aircraft is trying to avoid impact.

It does not take into account an act of terrorism where the plane is being deliberately aimed and flying at full power with absolutely no intention of trying to avoid the collision.

Secondly we must remember that back in the day a company claimed its newest ocean liner, with state of the art compartmentalized sections that could control flooding by isolating sections, hit an iceberg and sank.

Those building schematics and theory also stated the ship could not be sunk.

Humans are not perfect and things we make are prone to failure, even when the engineers think they have accounted for all possibilities. There will always be scenarios the engineers didn't anticipate. Even more so is the fact engineers don't always consider a deranged person in the equation. They will concentrate with the mindset of accidents and not intentional acts.

Engineers calculated that would take a lateral force of 17 million foot-pound to push the building over

A jet airliner crashing into the building would generate 13 million foot-pounds

SO - while building would survive the impact it was the secondary effects, the impact damage to the load bearing
columns and fires started by the jet fuel doomed the buildings......

a reply to: firerescue

the foot pounds estimate does not take into account a deliberate impact and high speeds. Its based on an accidental impact where the plane is flying within flight tolerances and speeds for the controlled airspace above New York.

Even if, for the sake of the argument we assume that the structure was somehow weakened by the 'raging fires' (you know, the ones in which poor Erna stood waving). Raging fires that did not rage in the lower 70 or so floors, raging fires that according to reports of the FDNY only required one line to put them out. Those raging fires.

a reply to: ForteanOrg


That was one floor in the South Tower 78th floor sky lobby

That floor was hit by wing tip of United 175. As a sky lobby most of the floor was occupied by elevator machinery and floors lined with tile and marble. It lacked the flammable materials found in most modern offices - everything from
carpets to desks and computer systems (most built with plastics)

Bulk of fires were on floors above them

a reply to: FlyingFox


The reason people are talking about the melting point of steel is because red hot liquid molten steel was found at the site days after the building had came down.

originally posted by: Xcathdra
a reply to: firerescue

the foot pounds estimate does not take into account a deliberate impact and high speeds. Its based on an accidental impact where the plane is flying within flight tolerances and speeds for the controlled airspace above New York.

Buildings did not fall over...........

Supposedly did do set of calculations showing the WTC would not collapse in high impact collosion with aircraft

I have no idea why you all are discussing this about WTC7, it has been proved it was a classic demolition by Architects and Engineers years ago. For those who don't know should go to their website.

originally posted by: JamesCarrot
because red hot liquid molten steel was found at the site days after the building had came down.

Got a valid source for that claim?

originally posted by: JamesCarrot
a reply to: FlyingFox


The reason people are talking about the melting point of steel is because red hot liquid molten steel was found at the site days after the building had came down.

www.youtube.com...

FDNY Fire Chief talking about red hot steel being uncovered from the debris pile

Steel was heated up by underground fires burning in the debris pile left by the collapse

originally posted by: Informer1958
it has been proved it was a classic demolition by Architects and Engineers years ago.

Care to show us that "proof"? Unless....

This is the quality of the research done by their leader!

originally posted by: firerescue

Buildings did not fall over...........

Supposedly did do set of calculations showing the WTC would not collapse in high impact collosion with aircraft

Experts and engineers also showed the titanic could not be sunk due to its construction.

Experts and engineers also state that a Boeing 737-297 has to have a completely intact airframe in order to fly. Aloha Airlines flight 243 shot that conclusion all to hell.

a reply to: hellobruce

I don't need to, the proof is in their documents, perhaps any science done that is not control by our corrupt government is what you might like.