10 story hole in WTC 7

[tsig]

Tell us, O engineering guru, what does it mean when there's a 3-story bulge in a skyscraper?

Eh?

Skyscrapers often bulge when they eat too much of other skyscrapers.

It may have been pregnant

 

[Newtons Bit]

It may have been pregnant

Do these girders make me look fat?

 

[Christopher7]

Ah.
I see. The loading of 5000 lb of fertilizer into the 1/2 ton pickup truck, plus the addition of the driver and a tank of gas did not cause the axle failure. The intiating event was the tiny piece of paper the cop handed the driver for being overweight.
only the strawm that broke the camel's back is significant. All the others are just window dressing?
I see.
woo

The problem is, the 5,000 lbs of fertilizer was in the bed of the pickup truck but the front axel broke.

woo

 

[Gravy]

The problem is, the 5,000 lbs of fertilizer was in the bed of the pickup truck but the front axel broke.

That once happened to my 1/2 ton pickup, although the load was less than 1/2 ton. So there you go.

 

[Unfit4Command]

What was used to demolish WTC 7 in your opinion, Chris? Bombs/explosives, thermite? What do you believe it was? Just curious.

If you already answered these questions in this thread, I apologize, I haven't been keeping up with all of the posts since its creation.

 

[Christopher7]

Normal structures (in the US) were not required by code to resist the effects of the loss of even a single column before 9/11. Alot of designers went ahead and used some crude methods to make sure there wouldn't be a collapse if there was a loss of a single column, but this doesn't mean they designed it right or looked at every single column. WTC1&2 were obviously designed to resist the loss of a single column, but they didn't design it that way because of terrorism or blast concerns, but more likely redundancy based on how little knowledge of engineering they had at the time.

For example, compare the 13th edition of the AISC Manual of Steel Construction to the 7th edition (published in the sixties). It's barbaric what was in the 7th edition. Likewise compare the reinforced concrete codes, ACI 318-05 to one from the 60's. The 60's had little tiny pamphlet compared to the book that the 05 version is.

This doesn't mean they were BAD engineers, many of them are probably better engineers than I currently am right now, however they are no were close to as knowledgeable as the senior engineers I work with. They simply didn't have the same tools and expierence that we have today.

Interesting point

A lot of redundancy was built into WTC 7 to allow for remodeling.

Loss of a column may or may not have been considered but planning for office fires no doubt was.

This is one area where the 80 boxes of documents may shed more light on the possibility of office fires causing the collapse of WTC 7.

It's the 1 column pulling 5 columns sideways that i find bloody ridiculous, but that's above my pay grade. [as they say]

Bottom line, i don't think that fires burned long enough in any area to cause a major failure nor do i believe any fire induced failure could cause WTC 7 to implode the way it did.

 

[Christopher7]

That once happened to my 1/2 ton pickup, although the load was less than 1/2 ton. So there you go.

 

[Christopher7]

What was used to demolish WTC 7 in your opinion, Chris? Bombs/explosives, thermite? What do you believe it was? Just curious.

If you already answered these questions in this thread, I apologize, I haven't been keeping up with all of the posts since its creation.

I haven't answered that question on this thread.

The "Christopher7 --- C7 & C4" thread is for debate on CD.

http://www.internationalskeptics.com/forums/showthread.php?postid=2498320#post2498320

 

[Newtons Bit]

Current International Building Code regulates fire-protection to have a rating of at the most 4 hours on structural systems. This basically means that the structural element has to perform it's normal duty for 4 hours before collapsing. That's supposed to give enough time for firefighters to get into the building and put out whatever fires may be raging. After those 4 hours, the buildings aren't rated to survive and the likelihood of someone doing a model to see what the effects of that fire would be (in the 60's and 70's!) is absurd. Due to these collapses, most engineering codes are going to include provisions that require engineers to model structures for actual fire-resistance, rather than just saying "For this type of element you need to have a 2hr rated passive fire-protection system".

 

[rwguinn]

The problem is, the 5,000 lbs of fertilizer was in the bed of the pickup truck but the front axel broke.

woo

I bow to your superior knowledge of load paths.
The fact that at least 1/2 the bed is forward of the rear axle doesn't seem to have crossed your mind--or has been deemed irrelevant...
as are the driver and the little piece of paper the cop handed him.

 

[Belz...]

Adding something is misstating.

You obviously have problems reading my posts. I didn't QUOTE you. I said FIRES, and added "diesel or otherwise" to make my point clear. That you don't understand that doesn't change anything.

You really should read post #1884 before making incorrect, uninformed statements like the one above.

I've read it, many times already. And nothing in it shows what I've been asking from you.

2) What part of;

"Analysis of the global structure indicates that the structure redistributed the loads around the severed and damaged areas."

don't you understand?

This is a no brainer, yet you just can't grasp the concept.

Which is basically 2). I guess you're in agreement with it, then.

3) Yes, except for the word 'further'.
There was NO debris damage to the area of the initiating event.

Irrelevant because of 2).

4) False. The loads were transferred to the surrounding columns, NOT to the other end of the building!

Oh ? I wasn't aware that load transfer had to stop somewhere specific. Or do you think "around" means "right next" ?

Fair enough. I will read them and respond.

<Giggle.>

 

[aggle-rithm]

I think aggle was referring to the fire fighting infrastructure, primarily the water mains, in that response. Maybe a poor choice of words since the fire fighters were present but had no water to fight the fires. In any case, if aggle meant the building I would presume he would have wrote "structure" not infrastructure.

Exactly right.

It's assumed in designing a building to withstand fire that it will be possible for emergency crews to fight the fire.

 

[aggle-rithm]

The problem is, the 5,000 lbs of fertilizer was in the bed of the pickup truck but the front axel broke.

woo

Quite possible, if the front axle is substantially less able to handle a load than the rear axle (as it often is). Damage like this follows the path of least resistance. It is oblivious to human credulity about what SHOULD happen.

 

[rwguinn]

Quite possible, if the front axle is substantially less able to handle a load than the rear axle (as it often is). Damage like this follows the path of least resistance. It is oblivious to human credulity about what SHOULD happen.

And you, sir, Liberal or conservative, twoofer or OCT'er, engineer or not, recieve my first sporadic "Sees beyond his own nose award"*.
Well done!



* These awards willbe made arbitrarily and capricously whenever I feel someone has actually seen past his own immediate concern and graspec the point being made.
Someday, I may even win the award myself--not a likely event, but anything is possible.

 

[aggle-rithm]

And you, sir, Liberal or conservative, twoofer or OCT'er, engineer or not, recieve my first sporadic "Sees beyond his own nose award"*.
Well done!

For the record, I'm a Liberal/Conservative neo-Nazi with Communist leanings who does not believe 9/11 was an inside job, but believes that Dustin Hoffman dreamed up the Holocaust in 1986 and that the Moon landings were filmed in my uncle's back yard.

 

[rwguinn]

For the record, I'm a Liberal/Conservative neo-Nazi with Communist leanings who does not believe 9/11 was an inside job, but believes that Dustin Hoffman dreamed up the Holocaust in 1986 and that the Moon landings were filmed in my uncle's back yard.

Ah--great minds think alike and all that. I am no longer alone in my ideology...

 

[Christopher7]

Current International Building Code regulates fire-protection to have a rating of at the most 4 hours on structural systems. This basically means that the structural element has to perform it's normal duty for 4 hours before collapsing. That's supposed to give enough time for firefighters to get into the building and put out whatever fires may be raging. After those 4 hours, the buildings aren't rated to survive and the likelihood of someone doing a model to see what the effects of that fire would be (in the 60's and 70's!) is absurd. Due to these collapses, most engineering codes are going to include provisions that require engineers to model structures for actual fire-resistance, rather than just saying "For this type of element you need to have a 2hr rated passive fire-protection system".

Around 3:00 p.m., fires were observed on floors 7 and 12 along the north face.

By 4:45, the fire on floor 12 had burned out.

The office fires burned less than 2 hours is any particular area.

 

[aggle-rithm]

Around 3:00 p.m., fires were observed on floors 7 and 12 along the north face.

By 4:45, the fire on floor 12 had burned out.

The office fires burned less than 2 hours is any particular area.

Do fires only burn when they are observed?

 

[Christopher7]

I bow to your superior knowledge of load paths.
The fact that at least 1/2 the bed is forward of the rear axle doesn't seem to have crossed your mind--or has been deemed irrelevant...
as are the driver and the little piece of paper the cop handed him.

This the problem with silly similes. They do not accurately reflect the actual situation.

Some people here can't grasp the concept that gravity pulls things straight down, not sideways.

When a support column is severed, the load is transferred to the surrounding columns which support the extra weight.

Since the surrounding columns supported the extra weight, there was no additional load to columns beyond the surrounding columns.

 

[rwguinn]

This the problem with silly similes. They do not accurately reflect the actual situation.

Some people here can't grasp the concept that gravity pulls things straight down, not sideways.

When a support column is severed, the load is transferred to the surrounding columns which support the extra weight.

Since the surrounding columns supported the extra weight, there was no additional load to columns beyond the surrounding columns.

oooohhh-kay. Sure.
Do me a favor, will ya.
Please let us know the location of every deck, music stand, building of any type, vehicle of any type, desk, and printer stand you have had a hand in designing/building is.
That way, at least we can avoid getting hurt. Your knowledge of statics is really, really bad.
IF it were engraved on the head of a pin, there would be room for the bible on there too. Both Testaments. This, you have demonstrated. It is a fact. This is not a personal attack. You simply lack the knowledge required to discuss the situation. That is a curable situation. Go take some classes. Then we can talk