The plausibility of demolishing WTC7 with explosives on 9/11

[BombDr]

So what size explosives would've been needed to create enough structural damage to a floor to knock off the fire proofing and create an office fire that could cause total collapse. What's always intrigued me about the towers is most people talk about controlled demolition when taking down a building, but we saw for the first time in 3 seperate cases where a destroying and weakening a few floors actually caused total collapse. So can a big enough bomb cause the same outcome? And if so, isn't it cheaper and less time consuming for demolition companies to use this method in the future instead of wiring and cutting the entire bldg.

I did a load of really rough calculations last year on this thread and came up with about 16 metric tonnes per floor, and that is after considerable preparation of several weeks. The towers collapse was hardly clean and destroyed or damaged several other buildings in the vicinity, so i would not suggest it is a viable method.

Danny Jowenko, a demolition expert, didn't think that made sense because he didn't think explosives could survive the fires.

He is right, but DJ was duped by A&E into making a call out of context and he contradicts himself afterwards as a result. The explosives themselves are flammable.

 

[BombDr]

Research Verinage Demolition in youtube. Amazing: demolition companies collapsing only one floor (no explosives) and bringing down buildings.
http://www.youtube.com/results?search_query=verinage demolition

They are impressive, but these are smaller buildings than WTC 1&2 and of completely different construction. What is obvious from the videos is the extent of the preparation work required prior to collapse.

Here is the late great Fred Dibnah doing the same thing essentially:

 

[Pete Tar]

If the weight of the floors above the collapse point is sufficient, then yes it does.

It doesn't really matter how you weaken the building - explosives, verinage hydraulics, or crashing an aircraft into them - it is "simply" a matter of physics - the structure can support a given static or dynamic (moving) load - if the load is greater then you get collapse.

And a moving load has more force than the same mass that is not moving - try resting a small weight gently on an egg...and then try dropping it from 10 feet - same weight, but movement means greater force.

The top floors of the building, once they started moving, constituted more load than the structure could support - therefore collapse was the only thing that was ever going to happen.

Are talk and calculations of what force the floors can bear or not entirely accurate when applied to the progressive stages of collapse?

As a floor was destroyed, wouldn't the floor below it have it's structural integrity compromised by failure of what connected it with the upper floor (I'm assuming buckling beams, and force transmitted through the walls into the floor below), so its rated weight capacity would actually be less than if it was structurally sound?

Only in a theoretical model is it step-by-step and floor-by-floor. Real-world it was more of a continuum not really separable into discrete steps.
Not sure it matters though, I'm probably just re-stating the obvious in a complicated way.

 

[Jason]

I did a load of really rough calculations last year on this thread and came up with about 16 metric tonnes per floor, and that is after considerable preparation of several weeks. The towers collapse was hardly clean and destroyed or damaged several other buildings in the vicinity, so i would not suggest it is a viable method.

Would it even be possible to demo the towers and have them fall into their own footprint. I doubt the most highly trained and most sophisticated hardware wouldn't have a hard time dropping 500,000 tonnes into its own footprint, otherwise the result would've been several to more stories higher of rubble. WTC 7 did fall into its own foot print and looked very simiar to the "Verinage" method above. In fact, all 3 of the bldgs initiation looked similar to the "Verinage" method. Not saying explosives were used, but I am surprised proponents of CT's never traveled down this road since it would eliminate the need for cutting steel, and placing explosives throughout the entire bldg. Now the bigger question, does anyone think the terrorist were aware of the "Verinage" method, and that they thought the planes with all of their jet fuel and explosive force upon impact would induce a collapse. If the Verinage method has been around a long time it's possible OBL knew about it and could've hope for a similar outcome.

BombDr; So you estimating 16 metric tonnes of tnt would've been needed to yield the same result as a plane crashing into the towers loaded with jet fuel. Is there an explosive material that could yield similar explosive force but be considerably less mass.

 

[Mick West]

BombDr; So you estimating 16 metric tonnes of tnt would've been needed to yield the same result as a plane crashing into the towers loaded with jet fuel. Is there an explosive material that could yield similar explosive force but be considerably less mass.

Explosives are measures in TNT equivalence (R.E, or Relative effectiveness). You could get something in about half the mass with the more exotic explosives like CL-20, although I don't think that was around in 2001 (it's still kind of experimental now)
https://en.wikipedia.org/wiki/Relative_effectiveness_factor

10 Tons of PETN is about the same as 16 tons of TNT.
https://en.wikipedia.org/wiki/Pentaerythritol_tetranitrate

 

[Jason]

Explosives are measures in TNT equivalence (R.E, or Relative effectiveness). You could get something in about half the mass with the more exotic explosives like CL-20, although I don't think that was around in 2001 (it's still kind of experimental now)
https://en.wikipedia.org/wiki/Relative_effectiveness_factor

10 Tons of PETN is about the same as 16 tons of TNT.
https://en.wikipedia.org/wiki/Pentaerythritol_tetranitrate

And the Russian FOAB (Father Of All Bombs) which is similar to the US MOAB (Mother Of All Bombs) is a bomb that weighs roughly 7.5 tons, and has a tnt equilvalency of 44 tons. So a bomb roughly 1/3 the size could yield a force equivalent to 16 tons of TNT...http://en.wikipedia.org/wiki/FOAB

Obviously, explosives weren't used on 9/11 because a bomb this size would've surely been heard miles away. But it's interesting from an engineering stance, that a bomb could bring down a sky scraper if it's place in the right place, but then again getting a device that weighs several tonnes up a sky scraper would be an engineering marvel in of itself.

 

[Keith Beachy]

Would it even be possible to demo the towers and have them fall into their own footprint. I doubt the most highly trained and most sophisticated hardware wouldn't have a hard time dropping 500,000 tonnes into its own footprint, otherwise the result would've been several to more stories higher of rubble. WTC 7 did fall into its own foot print and looked very simiar to the "Verinage" method above. In fact, all 3 of the bldgs initiation looked similar to the "Verinage" method. Not saying explosives were used, but I am surprised proponents of CT's never traveled down this road since it would eliminate the need for cutting steel, and placing explosives throughout the entire bldg. Now the bigger question, does anyone think the terrorist were aware of the "Verinage" method, and that they thought the planes with all of their jet fuel and explosive force upon impact would induce a collapse. If the Verinage method has been around a long time it's possible OBL knew about it and could've hope for a similar outcome.

BombDr; So you estimating 16 metric tonnes of tnt would've been needed to yield the same result as a plane crashing into the towers loaded with jet fuel. Is there an explosive material that could yield similar explosive force but be considerably less mass.

WTC 7 did not fall into it footprint.
UBL had no clue the buildings would fall.
Planes crashing into the towers, kinetic energy impacts, equal to 1300 and 2000 pounds of TNT (2,840,000,000 joules and 4,380,000,000 joules).
The heat energy of the jet fuel on each plane was equal in energy to 130 tons of TNT, or was it 315 tons of TNT. Who has numbers for the heat energy of all the jet fuel, is it 1,310,000,000,000 joules.
Heat energy before collapse from office fires - Estimates for WTC 1, 8,000 GJ, and 3,000 GJ for WTC 2 - jet fuel 1,300 GJ. Office fires win.
WTC 7 had no boom of explosives, and no steel showed blast effects - the only steel which showed something unique were two samples which corroded in fire, and 911 truth uses them as melted steel; but the steel was only exposed up to 1000C, to low to melt. The study of the steel talks of intergranular melting, and eutectics, which 911 truth quotes mine erroneously for melted steel.

 

[SR1419]

I agree, I'm not saying 911 was caused by explosives, Im merely trying to understand if explosives on one floor could've yielded the same results. And if they could, and it's a matter of simple physics, why don't demo companies just wire one floor with explosives instead of wiring the entire bldg and cutting the beams for up to 6 months in preperation.

At least in regards to the Towers, the use of explosives would have to had to have been on the same floor as the plane impact, since we know the collapse initiated in the impact zone. Not sure how the they could have coordinated that perfectly or the explosives survive the impact and fire.

 

[MikeC]

That's exactly what happened Mike. Each successive floor below couldn't support the loads from above once the top portion of the tower started to fall. I get that, and honestly its the only plausible explanation. But, we could've also yielded the same results by using explosives, if we took out the columns responsible for holding the up the bldg above it. By doing so, the top of the bldg would begin to fall (gravity) and we would have the same process repeat itself until we hit the foundation. So why do demo companies employ so much tactics ahead of a demo. If most bldg's are 95% air, have no other direction to fall by straight down as did WTC 1,2,and 7. Isn't it safe to assume, taking out one floor at the right place could always yield similar results to a demolition.

Yep - but demo companies often also have to ensure a particular distribution of wreckage (as I understand it) - and AFAIK you limit the spread of wreckage by cutting out floors at regular intervals.

Let's say you take out every 10th floor - in that case the bottom 10 floors are crushed by floors 11-20 and so on - floors all hit the "bottom" before they start disintegrating - the top 10 floors, for example, fall straight down more-or-less intact, and then are crushed by their own weight when they hit the pile at the bottom.

The wreckage spreads less because the destruction all happens at low altitude.

On 9/11 the destruction started on the 70th floors when those above hit them - every floor under the impact point was crushed in turn at whatever height above ground it was. And as a result some wreckage travelled quite a long distance.

 

[MikeC]

So why do companies spend so much money on using demolition companies. If it's simple physics involved, and the buildings had no where else to fall but straight down, could demolition companies in the future just wire one floor with explosives and be done...

sure - if the building is small enough and/or there is no problem with the spread of debris, and the calculations of het building strength are such that taking out 1 floor is enough.

There are lots of demo videos where only 1 floor appears to have explosions - so looks like the experts are already onto this

eg

 

[BombDr]

Would it even be possible to demo the towers and have them fall into their own footprint. I doubt the most highly trained and most sophisticated hardware wouldn't have a hard time dropping 500,000 tonnes into its own footprint, otherwise the result would've been several to more stories higher of rubble. WTC 7 did fall into its own foot print and looked very simiar to the "Verinage" method above. In fact, all 3 of the bldgs initiation looked similar to the "Verinage" method. Not saying explosives were used, but I am surprised proponents of CT's never traveled down this road since it would eliminate the need for cutting steel, and placing explosives throughout the entire bldg. Now the bigger question, does anyone think the terrorist were aware of the "Verinage" method, and that they thought the planes with all of their jet fuel and explosive force upon impact would induce a collapse. If the Verinage method has been around a long time it's possible OBL knew about it and could've hope for a similar outcome.

BombDr; So you estimating 16 metric tonnes of tnt would've been needed to yield the same result as a plane crashing into the towers loaded with jet fuel. Is there an explosive material that could yield similar explosive force but be considerably less mass.

Firstly, regarding the calculation, it was just something that was quick and dirty that I did last year in Afghanistan, and at that time it was just to refute the suggestion that it would be 'easy' to do by some ninja black ops types masquerading as elevator maintenance men or cleaners or something. The point I was trying to make also was that considerable preparation work would be required and a lot of material would have to be hidden for it to work. I suppose I could update the calculation now that I'm back in the UK, but not sure it adds much difference to it being 'a lot'.

The Verinage method is also a case in point: Yes, the method is simply reducing to the bare minimum the supports required to hold the structural integrity of the upper floors, then removing that integrity and using the mass of the upper floors to destroy the lower floors. But certain criteria have to be met, and you will firstly observe that a considerable amount of the building has already been removed - unlikely in WTC without someone noticing their entire office walls have disappeared one morning - and secondly the buildings that I have seen appear to be more of a concrete construction rather than steel (though I could be wrong)

With all demolitions, consistency is what is required, and adding a plane to a planned demolition with no guarantee the accuracy of the impact point and effect makes planning such a task difficult.

 

[Efftup]

I think this is where the "no plane" theory came in.
Having already accepted the dogma that the collapse "looked funny and was therefore defo the govt that did it as a false flag attack", when it is pointed out to them the problem sof ensuring that a plane hit the exact floor where the explosives were planted and without destroying the explosives or setting them off early, the CT'ers either had to a) accept they might be wrong, b) ignore that and call those "naysayers" shills or c) invent a NEW theory that there were no planes and that special new compositing techniques could splice an aircraft into a live video feed (or even a 10 second delay one) in real time and no, those eyewitnesses on the ground didn't have the image composited directly into their eyeballs, all those witnesses were shills and part of the conspiracy too, along with the NYPD and NYFD and etc etc etc.

Most CTers went for B, but a few went all out.

 

[Pete Tar]

No plane, or, computer-guided plane to hit the correct spot.

 

[Efftup]

that's the baby. Except THEN they had to invent a whole NEW conspiracy to account for the missing planes and passengers.
Either those passengers never existed and all those relatives and loved ones are in on the conspiracy as well OR they actually did hijack some planes, but then had to land at another airport and take the passengers off and kill them and dispose of the corpses, and the plane, ALL without anyone spotting any of this.

It would really have been simpler to fly the planes into the buildings.

 

[Bruno D.]

Would it even be possible to demo the towers and have them fall into their own footprint. I doubt the most highly trained and most sophisticated hardware wouldn't have a hard time dropping 500,000 tonnes into its own footprint, otherwise the result would've been several to more stories higher of rubble. WTC 7 did fall into its own foot print and looked very simiar to the "Verinage" method above. In fact, all 3 of the bldgs initiation looked similar to the "Verinage" method. Not saying explosives were used, but I am surprised proponents of CT's never traveled down this road since it would eliminate the need for cutting steel, and placing explosives throughout the entire bldg. Now the bigger question, does anyone think the terrorist were aware of the "Verinage" method, and that they thought the planes with all of their jet fuel and explosive force upon impact would induce a collapse. If the Verinage method has been around a long time it's possible OBL knew about it and could've hope for a similar outcome.

WTC 7 did not fall into it footprint.
UBL had no clue the buildings would fall.

They are impressive, but these are smaller buildings than WTC 1&2 and of completely different construction. What is obvious from the videos is the extent of the preparation work required prior to collapse.

The point about verinage for the CTs is that they keep saying that WTC 1 &2 looks exactly like standard demolition, when a simple 10min research shows that they look anything but standard demolition. Verinage is not standard. WTC 1 & 2 look like verinage because several floors in the middle of the buildings collapsed, bringing everything down. That's all: perception and interpretation.

WTC 7 looks like standard demolition. The conspirators would have to have decided that they wanted the 3 building to be demolished in different manners, and I have no clue why they would decided to use 2 different strategies to accomplish the same objective, increasing the risk of conspiracy plan failure. By doing that they would have to double the size of the demolition team for them to have the different needed expertise.

None of the 3 buildings fell into their own footprint. This concept is based onto bad observation of Youtube videos, and not facts. WTC 1 & 2 destroyed part of WTC 7, ie. not its own footprint. WTC 7 damaged basically all buildings in the surrounding area, also not its own footprint. Please research this forum for the "footprint" keyword or any other researches on that to find more about that.

Finally, not even the most optimistic terrorist would have imagined that they would hit 2 buildings and destroy 7. They probably thought that as soon as the buildings were hit, they would break in half and the top part would fell and destroy more things below. Unfortunately for the rest of us, it was much worse than that.

 

[SR1419]

Please research this forum for the "footprint" keyword or any other researches on that to find more about that..

https://www.metabunk.org/threads/debunked-wtc-towers-fell-in-their-own-footprints.1226/

 

[jaydeehess]

Jason asks

So why do demo companies employ so much tactics ahead of a demo. If most bldg's are 95% air, have no other direction to fall by straight down as did WTC 1,2,and 7. Isn't it safe to assume, taking out one floor at the right place could always yield similar results to a demolition.

In the case of a regular post and beam construction, failure of part of a floor will stop at the close columns. However in both the towers and WTC 7 the floors were designed to be column-less over large expanses. Moreover the floors ringed the building with no columns between perimeter and core. Failure of one part of a floor pan would pull down on adjacent floor area. The floor area is huge. This makes the vertical progression of floor collapse more likely to continue AND affect more, or all, of the floor on any given level.

This type of structure failure would also be very difficult to control. Demolitions rely on the expert's ability to design the progression of collapse rather than just start a progressive collapse and let the bricks fall where they may.

 

[Aemilius]

So this is interesting, I'm sure you guys have discussed this a million times, but I still question the whole free fall thing that happened with WTC 7. The NIST says it came down at free fall for 2.25 seconds, over a hundred feet. How can a building collapse at free fall acceleration?

 

[WeedWhacker]

I'm sure you guys have discussed this a million times, but I still question the whole free fall thing that happened with WTC 7.

It didn't actually "free-fall".

 

[Pete Tar]

Probably this thread has some discussion about it if you feel like wading through it all -
https://www.metabunk.org/threads/how-could-wtc7-possible-have-fallen-like-it-did.2138/

and some posts here -

https://www.metabunk.org/threads/us...-for-investigating-9-11-collapses.3828/page-8

 

[Pete Tar]

Short answer, the 'building' didn't collapse at freefall, a portion of the facade did - and a building can fall at freefall if its support offers no resistance or is suddenly removed.

 

[Aemilius]

Right, I see the other thread is really more to the point, I'll take a look at that. Hey.... How do I work the "Quote" feature? I don't see the icon.

 

[Jason]

Right, I see the other thread is really more to the point, I'll take a look at that. Hey.... How do I work the "Quote" feature? I don't see the icon.

If you highlight someone's opinion with your mouse a tab will pop up saying: "Quote Me". Click on it and scroll down to where you were typing your opinion and you will see it there. If you wish to quote an external link from wiki or another site. Make sure to include the hyperlink for the site as well, and use the tab above with the quotes around the 'x'.

 

[Aemilius]

Ahh, I see.... thanks. I'll go scan the other topic headings suggested and maybe comment there.

 

[Jason]

Ahh, I see.... thanks. I'll go scan the other topic headings suggested and maybe comment there.

If you comment on an older topic, it will still show up for everyone to view in the news feed. On the forums page if you look below your avatar to the right you will see the news feeds (Recent Threads). It list the current topics being discussed there as well. Good luck

 

[Aemilius]

Right.... I don't really see where I could post in the other ones. One's locked, the other looks like it's in progress and this one is really a different question.... maybe I'll start another thread.

 

[WeedWhacker]

[ quote ] text [ /quote ]

(Remove spaces inside the brackets....those are examples).

 

[alienrocketscientist]

So much time wasted on details meant to prove one's intelligence is distracting. An outsider using simple logic can plainly see natural physics had to do with the fall of the towers. There is a simple SIMPLE observation to disprove the human theory regarding explosive charges, but I doubt the conspiracy theorists will accept this reality: to plant explosives where would the best place to out it? They would put the charges in the lower levels as evidenced by the past attempt. And second, the structures started disintegrating right exactly at the points of impact, and those planting ANY explosive or incindiary device would have had to predicted the future and know exactly where the planes were going to impact the structures. The science of chemicals and devices makes no difference to this simple logic, regardless of how plausible any complex theory might be. So as well as the initial collapse location not being where explosives WOULD be planted, they would have had to tell the future and know where the planes would hit.

It is hard to see the forest for the trees.

 

[alienrocketscientist]

Regarding "free fall", if mass's attraction to the forces of gravity is greater than the ability of a supporting structure, it will move towards the center of the earth. Think real long and hard about all the potential energy created by lifting all the WTC materials up in the air over time, and then to condense all that energy in the seven or eight seconds during each towers' collapse. Once all the engineered angles and forces changed, then the house of cards fell, as the forces no longer followed the designed directions intended. Horizontal structural devices connected to and pulling on vertical structures engineered to oppose only the force of gravity created forces the framework was not designed to withstand... For example.

 

[Jazzy]

Think real long and hard about all the potential energy

Absolutely. And I agree with you. But it has been mentioned before here (somewhere!) and perhaps you should find the topic and read it through.
We'd all agree that you would be better spent covering something new, or maybe as yet unobserved, than merely duplicating what has been written before. (Scuttles off, leaving smiley )

 

[hgfbob]

Absolutely. And I agree with you.

too bad you are WRONG!!!

in order to have the dynamics, you need the LOAD BEARING VERTICAL SUPPORT to fail to ALLOW this dynamic process.......we are NOT here for the dynamics that FOLLOW the WTC steel CONTINUOUS vertical support failing .....

from....???????

the claim is the fires present........and NO supporting evidence this occurred....from the FIRES PRESENT.


lol....using the collapse to explain the collapse does nothing for ya at all when proving the cause OF the collapse.....and the initial 2005 NIST scientific investigation found it did not occur from the minimal localized initial damage and the FIRES PRESENT!

 

[hgfbob]

Regarding "free fall", if mass's attraction to the forces of gravity is greater than the ability of a supporting structure, it will move towards the center of the earth.

too bad we are not talking about 'free fall'.....we are talking about CONSTANT acceleration equal to the acceleration of gravity......to which EXCEPT on 9-11, requires a 'CLEAR PATH in which to proceed.

a natural gravitational collapse USES the building destruction to FURTHER it's collapse...

structural mass CONSTANTLY accelerating equal to the acceleration of gravity ALREADY has that resistance removed BEFORE collapse in order to CONSTANTLY accelerate.

 

[Jazzy]

you need the LOAD BEARING VERTICAL SUPPORT to fail

Which it did, by buckling because it had lost its lateral support.

NO supporting evidence this occurred....from the FIRES PRESENT.

Except that of blacksmiths everywhere who use heat to soften steel, and the fact that the fires burnt continuously and increasingly, causing floors to fall away.

we are not talking about 'free fall'.....we are talking about CONSTANT acceleration equal to the acceleration of gravity

Which is - free fall.

to which EXCEPT on 9-11, requires a 'CLEAR PATH in which to proceed.

Which buckling allowed it.

a natural gravitational collapse USES the building destruction to FURTHER it's collapse.

That's the thing about collapses.

structural mass CONSTANTLY accelerating equal to the acceleration of gravity ALREADY has that resistance removed BEFORE collapse in order to CONSTANTLY accelerate.

YES.

IT IS CALLED BUCKLING. YOU SHOULD READ UP ON IT SOMETIME.

 

[Mick West]

No shouting please chaps.

This was about the plausibility of demolishing wtc7 with explosives. If you want to discuss something else, start a new thread.

 

[NAISAIAH]

Then you shouldn't be posting here as the title is about the plausibility of demolishing WTC7 with explosives.

what kind of logic is that? noone needs to claim anything to give his or her 2 cents to a topic...imo

 

[NAISAIAH]

If it is more energetic than plain thermite it is going to be noisier than plain thermite. The video demonstrating the cutting of columns using thermite was noisy enough.

noisy enough to say it wasnt silent i would say, but it was in fron of the camera and in the open. I imagine outside a evacuated building in a safe distance noone would hear it since there was a lot noise outside the whole day.

 

[jaydeehess]

noisy enough to say it wasnt silent i would say, but it was in fron of the camera and in the open. I imagine outside a evacuated building in a safe distance noone would hear it since there was a lot noise outside the whole day.

The point is not noisy enough to be an efficient, very quick, and consistent with coordinated demolition of multiple columns at once.

That requires high explosive that severs columns in milliseconds and can reliably be timed.
High explosives generate supersonic pressure waves and an extremely loud sound.

 

[Whitebeard]

Demolition of two large bonded warehouses, Bristol UK, May 1988



I witnessed this from about half a mile away, the blast was deafening and even at that distance a blast wave could be felt.

Here's a more detailed video,



The relevant section starts at 28:05 (but anyone with an interest in industrial history may find the whole film interesting)

Note how this was at the time, the largest deliberate peacetime explosion in Europe and how preparation for the blast took eight weeks. And at the time local media reported the explosion was heard over 6 miles away

Also note these were steel framed concrete constructions, a LOT smaller that WT7

 

[Landru]

what kind of logic is that? noone needs to claim anything to give his or her 2 cents to a topic...imo

what kind of logic is that? noone needs to claim anything to give his or her 2 cents to a topic...imo

It violates posting guidelines.

 

[NAISAIAH]

The point is not noisy enough to be an efficient, very quick, and consistent with coordinated demolition of multiple columns at once.

That requires high explosive that severs columns in milliseconds and can reliably be timed.
High explosives generate supersonic pressure waves and an extremely loud sound.

Isnt it possible they ve used explosives for the concrete before while the first hours of this attack and later did the rest with thermite to the steel? in the first hours it was reportet ppl heard explosions, aswell the black guy , forgot his name, was last eyewittness in that building and said if i am correct.