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WTC7 and the girder walk-off between column 79 and 44

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There's one thing truthers are missing.

Each floor (i.e. slabs and beams, in this case a truss system) is designed to support the weight of just a single floor, that includes the weight of the structure, furniture, equipaments, people, etc.

In other words, a single floor is not able to suport neither the weight of multiple floors nor the weight of a single floor plus the weight of debris from multiple floors.

Columns are designed to suport the weight of multiple floors.
 
DGM said:
Actually your own data shows there actually was. It just wasn't as much as you expected to see.

Wouldn't that be a more honest statement, Tony?

:rolleyes:
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Actually you are not correct here. Velocity from distance measurements over time is not determined based on one data point and its difference from the point before. It requires a differencing algorithm which needs the difference between the points before and after a specific point and the time elapsed between the before and after points. That is what we did in the Missing Jolt paper and it shows no velocity loss or deceleration. This was the same methodology as that used by NIST and David Chandler in their measurements of WTC 7. Chandler also measured the North Tower and found no deceleration.

In their WTC 7 measurements both Chandler and NIST had a data point here or there in the overall data, which if measured strictly from the preceding point would indicate greater than or less than freefall during that time. Do you propose that the NIST and Chandler measurements of WTC 7 do not show it was in freefall for the 2.25 seconds they show it was? Or that it was speeding up or slowing down during that time frame?
 
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Carlos said:
There's one thing truthers are missing.

Each floor (i.e. slabs and beams, in this case a truss system) is designed to support the weight of just a single floor, that includes the weight of the structure, furniture, equipaments, people, etc.

In other words, a single floor is not able to suport neither the weight of multiple floors nor the weight of a single floor plus the weight of debris from multiple floors.

Columns are designed to suport the weight of multiple floors.
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You are simply and unambiguously wrong here.

Each floor in the towers was built with a factor of safety which enabled it to support the load of multiple floors. If I remember correctly it was something like the static load of 12 floors that could be handled by one floor.
 
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Grizzly Bear said:
Acceleration is the change in velocity over change in time. A net acceleration refers to the sum of all the acceleration values in a system, like a net force is the sum of all the forces in a given system. If you have acceleration in one direction considered "positive", and another acceleration value going the opposite direction "negative" your "net" acceleration is the sum of the two values. If A1=9.81 m/s/s and A2= 3 m/s/s then A1+A2 = 9.81-3 = a net acceleration of 6.81 m/s/s and both the resulting change in velocity and the resulting changes in potential energy remain positive. It is still "accelerating."

I kind of expect not to have to explain this when I assume your experience grants you knowledge about something this rudimentary.

So to your point I reiterate:
"The load does not change when something is continually accelerating"

Do you consider the significance of net values in a statement like this? From what I'm reading you don't.
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I understand net values and they would apply if an item was being acted on by two separate forces from different directions. The item would then accelerate in the direction of the net force. They don't apply here as the force is in the downward vertical direction.

Three points need to be made here.

One is that when a piece of loose rubble is decelerating it has little to no effect on the other pieces of loose rubble around it. When a part of a rigidly joined structure decelerates it transmits this to the rest of the structure and affects how it behaves.

Two, the fact remains that in order to deliver a dynamic load an impacting object must decelerate. The equation for the dynamic load can be stated as
F = m(g) + m(deceleration). Where the second term is the amplification.

Three, if a structure is acted on by a force, dynamic or static, that it can sustain in the elastic range, then it won't be damaged. Each piece of loose rubble can only apply a dynamic load proportional to its own mass and since these loads take place at different times the force applied by the overall mass of loose rubble is either static or slightly above, which we call quasi-static. It is not a dynamic load of the overall mass and can never reach those values.

An example of what I am saying would be if you had a beam that would fail with a 100 lb. static load and you dropped five 10 lb. weights on it at different times where each developed a dynamic load of 20 lbs. on impact. The actual load for each hit would be 20 lbs., but since the beam is being hit at different times it never experiences the dynamic load of all of the items togather. The maximum resultant load would be 40 lbs. for the first four weights plus the 20 lb. dynamic load of the last weight or 60 lbs. The beam will not fail under this loading. However, if you took a 50 lb. weight and it developed a 100 lb. dynamic load when dropped on the beam the beam would fail.
 
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Tony, how many people with relevant training and knowledge would you require to say you're wrong before you'd start questioning your beliefs?
 
Tony Szamboti said:
Actually you are not correct here. Velocity from distance measurements over time is not determined based on one data point and its difference from the point before. It requires a differencing algorithm which needs the difference between the points before and after a specific point and the time elapsed between the before and after points. That is what we did in the Missing Jolt paper and it shows no velocity loss or deceleration. This was the same methodology as that used by NIST and David Chandler in their measurements of WTC 7. Chandler also measured the North Tower and found no deceleration.
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This is not true. Your data does show a loss in acceleration, just not as much as you expected. You have been shown this and you ignore it.


Tony Szamboti said:
In their WTC 7 measurements both Chandler and NIST had a data point here or there in the overall data, which if measured strictly from the preceding point would indicate greater than or less than freefall during that time. Do you propose that the NIST and Chandler measurements of WTC 7 do not show it was in freefall for the 2.25 seconds they show it was? Or that it was speeding up or slowing down during that time frame?
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Personally I think this is all pointless. Why exactly should we care how fast this building fell? I bet you can't show how it supports your (yet to be defined ) theory.
 
twinstead said:
Tony, how many people with relevant training and knowledge would you require to say you're wrong before you'd start questioning your beliefs?
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Apparently, the problem for you is I am not wrong and it doesn't matter what some of the obtuse individuals who don't understand that here think.
 
DGM said:
This is not true. Your data does show a loss in acceleration, just not as much as you expected. You have been shown this and you ignore it.
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The data does not show a loss in acceleration. There is one data point which shows a flat velocity and that is not deceleration.

If you persist in this you then need to show how any of that would be relevant to a dynamic load that could overcome the resistance of the lower structure.

Peanut gallery type comments are not acceptable.
 
Tony Szamboti said:
You are simply and unambiguously wrong here.

Each floor in the towers was built with a factor of safety which enabled it to support the load of multiple floors. If I remember correctly it was something like the static load of 12 floors that could be handled by one floor.
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Makes sense

I thought I read once that the weight of the paper stored in the towers rivaled the weight of the steel used in their construction.

Unfortunately, the loads we're talking about were quite dynamic and obviously dwarfed that figure.
 
Tony Szamboti said:
Apparently, the problem for you is I am not wrong and it doesn't matter what some of the obtuse individuals who don't understand that here think.
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All those people at the NIST, all those that made comments (that still agreed FIRE not BOMBS took down the Trade Center buildings), and now, officially, the AIA are all obtuse individuals?????


You need to open your eyes brother.
 
Tony Szamboti said:
You are simply and unambiguously wrong here.


Each floor in the towers was built with a factor of safety which enabled it to support the load of multiple floors. If I remember correctly it was something like the static load of 12 floors that could be handled by one floor.
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Sorry Tony…simply not true…the floor framing system is designed to support one floor only. Usually, using a 1.4 safely factor for dead load (DL) and a 1.7 factor for live load (LL). Columns, of course, are designed to support all the floors above them.

Nobody is going to design a single floor system to support 12 floors. High rise buildings would become be too expensive to build. :cool:
 
MileHighMadness said:
Sorry Tony…simply not true…the floor framing system is designed to support one floor only. Usually, using a 1.4 safely factor for dead load (DL) and a 1.7 factor for live load (LL). Columns, of course, are designed to support all the floors above them.

Nobody is going to design a single floor system to support 12 floors. High rise buildings would become be too expensive to build. :cool:
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The connection capacities of the trusses were very high and the double trusses were deep for floor loading. However, you don't need to take my word for it.
You need to argue with NIST about the number of additional floors a single floor in the twin towers could hold, as that is where I got the information. See Question 1 of this NIST FAQ http://www.nist.gov/public_affairs/factsheet/faqs12007.cfm and come back and respond.
 
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MileHighMadness said:
Design Load vs. Capacity
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I was talking about static failure loads in the post you initially responded to. You don't seem to want to admit that the NIST FAQ proved I was right. The floors could take a static load of 12 floors before failing. This is why I say there would have had to be about eight to nine stories of rubble before quasi-static failures could take place with the floors.
 
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Tony Szamboti said:
You are simply and unambiguously wrong here.

Each floor in the towers was built with a factor of safety which enabled it to support the load of multiple floors. If I remember correctly it was something like the static load of 12 floors that could be handled by one floor.
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Safety Factor = 12?

Source?
 
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