The Spire on WTC 2

[pomeroo]

A poster on the LC forum keeps asking about the spire and why it didn't topple over. I suspect this topic has been addressed here. Can someone direct me to the thread, or briefly explain the physics of this phenomenon?


The poster wrote:

The northwest side of the WTC 2 was relieved of most of the weight it had to bear when the top section shifted, yet the perimeter columns were severed and ejected on all four sides, seemingly at the same rate. The North Tower spire dropped straight down, instead of toppling. Have you ever seen a tree just sink into the Earth like that? Solid bedrock does not just suddenly turn into thin air.

 

[gumboot]

When they say "spire" do they mean the antenna at the top, or the spire of partial building that was left standing for a time?

Only WTC1 had an antenna, and the reason it didn't topple over was because it was attached to the building.

The reason the spire of remaining building fell straight down is the same reason the rest of the building fell straight down. Gravity.

-Gumboot

 

[T.A.M.]

and to add....if you watch the collapse of the tower, you will see that part of the columns left up, do fall to the side for a time, then they go down, thanks to gravity.

TAM

 

[Horatius]

A poster on the LC forum keeps asking about the spire and why it didn't topple over. I suspect this topic has been addressed here. Can someone direct me to the thread, or briefly explain the physics of this phenomenon?

Again, it's their refusal to understand that the core columns weren't single, solid pieces like tree trunks, and that the dimensions were also very different from your average tree trunk.

When the column is perfectly vertical, the forces all act downwards, in line with the center of mass (CoM) of the column. But, as soon as it begins to tilt, there is a separation between the line of action of the force, and the CoM. This produces a torque. Some of the force still acts to accelerate the mass downwards, but some acts to rotate the mass about some pivot point. This torque will tend to cause the column to fail at its weakest point, which would be the joins between the segments out of which the columns were constructed. Of course, there are a lot of these joints, and they all get loaded virtually simultaneously, so a large percentage fail within a very short time.

At that point, you don't have one single column toppling over, you have a bunch of shorter segments all falling pretty much straight down, in a jumble.

 

[Mancman]

Only WTC1 had an antenna, and the reason it didn't topple over was because it was attached to the building.

It did actually topple off and to the south. It's only visible from a couple of angles.

Regards, the 'spire'. The simple answer is that it didn't fall straight down.

It's certainly leaning noticeably as it drops. Doesn't go straight down, may even have toppled right over. Hard to tell.

 

[gumboot]

It did actually topple off and to the south. It's only visible from a couple of angles.

Regards, the 'spire'. The simple answer is that it didn't fall straight down.
[qimg]http://i1.tinypic.com/4umz1qx.gif[/qimg]

It's certainly leaning noticeably as it drops. Doesn't go straight down, may even have toppled right over. Hard to tell.

Sorry, I was using the "Truther" definition of "straight down" which seems to be "in a generally downward direction, rather than levitating upwards or leaping sideways".

(By the way, in the bit you quoted I was talking about the Antenna, not the spire... )

-Gumboot

 

[Horatius]

 

[Mancman]

Sorry, I was using the "Truther" definition of "straight down" which seems to be "in a generally downward direction, rather than levitating upwards or leaping sideways".

(By the way, in the bit you quoted I was talking about the Antenna, not the spire... )

-Gumboot

I quoted the bit about the antenna on purpose, I was talking about the antenna. From the second sentence onwards I am on about the spire. The antenna toppled over. The spire might have.

*Head asplodes*

 

[gumboot]

I quoted the bit about the antenna on purpose, I was talking about the antenna. From the second sentence onwards I am on about the spire. The antenna toppled over. The spire might have.

*Head asplodes*

Oh, right. When did the antenna topple off?

-Gumboot

 

[Gravy]

The "spire" refers to the north tower, WTC 1, btw. A large portion of the south tower's core also stood briefly, but not long enough for it to stand out from the dust and smoke like the north tower's did.

 

[Monza]

Horatius' illustration is excellent.

In engineering classes they usually use the example of grain silos being toppled over to demonstrate these bending moments . Silos will break in half (or in several sections) before hitting the ground, exactly as Horatius describes. They will not simply land on their side. This is true for any tall/thin (i.e. large L/D ratio) object with sufficient mass.

I used to see this as a kid building objects with Lego bricks. If I built something tall enough, grabbed the base firmly and slowly rotated it horizontal, at some point it would break.

Now picture something like the WTC. If you could have tilted the WTC in a similar manner to my Lego example, you would not have to tip very far before it came crashing down. In other words, it would not have fallen on its side. The building pretty much couldn't have fallen any other way than down.

Gumboot's answer of "gravity" sums it up pretty well .

 

[gumboot]

The "spire" refers to the north tower, WTC 1, btw. A large portion of the south tower's core also stood briefly, but not long enough for it to stand out from the dust and smoke like the north tower's did.

It was my understanding that the "spire" refers to an exterior wall section of WTC1, which stood for quite some time after the building had collapsed (possibly hours?).

-Gumboot

 

[Foolmewunz]

It was my understanding that the "spire" refers to an exterior wall section of WTC1, which stood for quite some time after the building had collapsed (possibly hours?).

-Gumboot

I think that was actually the concrete core. I was talking to a guy in California and he said he has all kinds of proof. I'll ask him to join the forum.

 

[capracus]

It's obvious that the spire turns to dust. I saw the same thing happen to that guy in the new Spider-Man movie. Spider-Man lives in New York City, so there must be a connection. The same corporation that dustified the guy in Spider-Man, must have done it to the towers too.

 

[njslim]

I beleive it was the antenna falling from the top of WTC 1 which slashed open
the south side of WTC 7 and caused much of the structural damage that
caused the building to collapse from the fires.

 

[Monza]

It's obvious that the spire turns to dust. I saw the same thing happen to that guy in the new Spider-Man movie. Spider-Man lives in New York City, so there must be a connection. The same corporation that dustified the guy in Spider-Man, must have done it to the towers too.

Remember the "banned" trailer for the first Spiderman movie in 2001? The scenes of the WTC were removed. It is all starting to make sense now.

 

[Travis]

It was my understanding that the "spire" refers to an exterior wall section of WTC1, which stood for quite some time after the building had collapsed (possibly hours?).

-Gumboot

If memory serves me there are three things that could be referenced as "The Spire" in regards to the WTC collapse. But, interestingly, in reference to the OP all of them involve WTC1 not WTC2.

The first, most obviously would be the antenna on top of WTC1. It's lack of movement in relation to the movement of the outer skin at the instant when the collapse began is an important bit of supporting evidence for the NIST scenario that is usually "conveniently" ignored by Truthers.

The second is the some 60 storey tall shard of the core that stood briefly after the outer tube of WTC1 had already plummeted to earth. Mancman's animated gif is of this shard. Note that the way it finally collapses is exactly as Horatius' diagram indicates it should.

The third would be the 20-30 meter tall base of the northern face of WTC1 left over after the collapse. It can be seen in numerous photos I have that I won't post owing to the fact that I'm unsure of their copyright status. But they are numerous and a short web search would turn them up.

-Travis*

*Shamelessly imitating Gumboot.

 

[I Am He]

I have this Site that I saved about 9-11 and it has some pics of the top of the tower when it started to fall. I don't know but maybe you people have seen them before. You have to scroll down a little to see them. But I must warn you that there are some pretty graphic pics in there also. I hope the link still works.

http://www.jeffhead.com/attack/

 

[William Rea]

I am intruiged by this mode of failure as proposed in the cartoon in post #7. This looks like the way a stack of building blocks in a nursery would fail but I don't recall ever seeing a silo or other discrete structure fail like this...

http://www.powderandbulk.com/videos...a6f606eb525ffdc5&page=1&viewtype=&category=tf

The classic demolition sequence would be more like that shown in the attached cartoon. Does anyone have any pictures, footage etc showing this building block collapse happening?

 

[Foolmewunz]

I am intruiged by this mode of failure as proposed in the cartoon in post #7. This looks like the way a stack of building blocks in a nursery would fail but I don't recall ever seeing a silo or other discrete structure fail like this...

http://www.powderandbulk.com/videos...a6f606eb525ffdc5&page=1&viewtype=&category=tf

The classic demolition sequence would be more like that shown in the attached cartoon. Does anyone have any pictures, footage etc showing this building block collapse happening?

William, are you shooting for the Ace Baker Intentionally Obtuse Award? That's a video of grain silos being pulled down by cables on earthmoving machinery. There are no explosives. In the final pull you can see that they've cut through the aluminum all 'round.

Further, the cartoon animation shows you you would set the charges if you wanted a silo to fall in a certain direction. Farms and grainaries commonly have free space and you can allow objects to fall to one side if you wish.

CD within a crowded urban area is a completely different thing. If you fall NSEW, you can damage someone else's property, so you cut the structure, then place the charges so that the structure falls in on itself, rather than outwards.