Now for some more evidence.

Danny Jowenko, a controlled demolition expert in the Netherlands with his own firm was asked by a filmmaker to comment on a video of the collapse of WTC7 without knowing what it was. He had not realized that a third building had collapsed on 9/11.

After viewing the video, he said: "They simply blew up columns, and the rest caved in afterwards.... This is controlled demolition."

When asked if he was certain, he replied: "Absolutely, it's been imploded. This was a hired job. A team of experts did this."

When he was told that this happened on September 11, he was incredulous, repeatedly asking, "Are you sure?" When he was finally convinced, Jowenko said, "Then they worked very hard."

In 2007, Jowenko was asked whether he stood by his statement that it must have been controlled demolition. He replied "Absolutely...I looked at the drawings, the construction and it couldn't be done by fire... absolutely not."

Jowenko also explained why controlled demolition experts in the United States hve not stated this obvious fact. When the interviewer mentioned that he had phoned the US Company Controlled Demolition Inc. which said: "Oh its possible it came down from fire," Jowenko replied: "When you have to earn your money in the States as a controlled demolition company and you say "No it was a controlled demolition, your're gone."

NIST, as a political rather than scientific agency, did not report any of this expert testimony.

Easy.

The explosives to the columns started going off at 9:30 a.m.

and he could tell that from a Video!
Did he explain to the Film-Maker what is required to prepareWTC7 to be blown?
The unholy mess you create while you weaken the Columns so they can be blown?
That it is impossible to hide the Charges?
I think that Guy better gets out of Business before he hurts someone!
Oh,damn,he did!

Lol someones opinion after watching a video is not evidence.

A favorite "cut and patse" and written in laymens terms too...

How Building Implosions Work:

You can demolish a stone wall with a sledgehammer, and it's fairly easy to level a five-story building using excavators and wrecking balls. But when you need to bring down a massive structure, say a 20-story skyscraper, you have to haul out the big guns. Explosive demolition is the preferred method for safely and efficiently demolishing larger structures. When a building is surrounded by other buildings, it may be necessary to "implode" the building, that is, make it collapse down into its footprint.
In this article, we'll find out how demolition crews plan and execute these spectacular implosions. The violent blasts and billowing dust clouds may look chaotic, but a building implosion is actually one of the most precisely planned, delicately balanced engineering feats you'll ever see.
The Bigger They Come, the Harder They Fall
The basic idea of explosive demolition is quite simple: If you remove the support structure of a building at a certain point, the section of the building above that point will fall down on the part of the building below that point. If this upper section is heavy enough, it will collide with the lower part with sufficient force to cause significant damage. The explosives are just the trigger for the demolition. It's gravity that brings the building down.

The Reading Grain Facility in Philadelphia, Pa., was blasted by Controlled Demolition Group, Ltd. in the winter of 1999.
Photo courtesy ImplosionWorld.com
Demolition blasters load explosives on several different levels of the building so that the building structure falls down on itself at multiple points. When everything is planned and executed correctly, the total damage of the explosives and falling building material is sufficient to collapse the structure entirely, so cleanup crews are left with only a pile of rubble.
In order to demolish a building safely, blasters must map out each element of the implosion ahead of time. The first step is to examine architectural blueprints of the building, if they can be located, to determine how the building is put together. Next, the blaster crew tours the building (several times), jotting down notes about the support structure on each floor. Once they have gathered all the raw data they need, the blasters hammer out a plan of attack. Drawing from past experiences with similar buildings, they decide what explosives to use, where to position them in the building and how to time their detonations. In some cases, the blasters may develop 3-D computer models of the structure so they can test out their plan ahead of time in a virtual world.
The main challenge in bringing a building down is controlling which way it falls. Ideally, a blasting crew will be able to tumble the building over on one side, into a parking lot or other open area. This sort of blast is the easiest to execute, and it is generally the safest way to go. Tipping a building over is something like felling a tree. To topple the building to the north, the blasters detonate explosives on the north side of the building first, in the same way you would chop into a tree from the north side if you wanted it to fall in that direction. Blasters may also secure steel cables to support columns in the building, so that they are pulled a certain way as they crumble.

Sometimes, though, a building is surrounded by structures that must be preserved. In this case, the blasters proceed with a true implosion, demolishing the building so that it collapses straight down into its own footprint (the total area at the base of the building). This feat requires such skill that only a handful of demolition companies in the world will attempt it.
Blasters approach each project a little differently, but the basic idea is to think of the building as a collection of separate towers. The blasters set the explosives so that each "tower" falls toward the center of the building, in roughly the same way that they would set the explosives to topple a single structure to the side. When the explosives are detonated in the right order, the toppling towers crash against each other, and all of the rubble collects at the center of the building. Another option is to detonate the columns at the center of the building before the other columns so that the building's sides fall inward.

The Hayes Homes, in Newark, N.J.: The 10-story housing project was demolished in three separate phases, over the course of three years. Even though all the buildings had exactly the same design, blasters handled the implosions differently for each phase. These towers were blasted by Engineered Demolition, Inc. in the summer of 1999.
Photo courtesy ImplosionWorld.com
According to Brent Blanchard, an implosion expert with the demolition consulting firm Protec Documentation Services, virtually every building in the world is unique. And for any given building, there are any number of ways a blasting crew might bring it down. Blanchard notes the demolition of the Hayes Homes, a 10-building housing project in Newark, New Jersey, which was demolished in three separate phases over the course of three years. "A different blasting firm performed each phase," Blanchard says, "and although all of the buildings were identical, each blaster chose a slightly different type of explosive and loaded varying numbers of support columns. They even brought the buildings down in different mathematical sequences, with varying amounts of time factored in between each building's collapse."
Generally speaking, blasters will explode the major support columns on the lower floors first and then a few upper stories. In a 20-story building, for example, the blasters might blow the columns on the first and second floor, as well as the 12th and 15th floors. In most cases, blowing the support structures on the lower floors is sufficient for collapsing the building, but loading columns on upper floors helps break the building material into smaller pieces as it falls. This makes for easier cleanup following the blast.
Once the blasters have figured out how to set up an implosion, it's time to prepare the building. In the next section, we'll find out what's involved in pre-detonation prepping and see how blasters rig the explosives for a precisely timed demolition.


Detonators and Dynamite
In the last section, we saw how blasters plan out a building implosion. Once they have a clear idea of how the structure should fall, it's time to prepare the building. The first step in preparation, which often begins before the blasters have actually surveyed the site, is to clear any debris out of the building. Next, construction crews, or, more accurately, destruction crews, begin taking out non-load-bearing walls within the building. This makes for a cleaner break at each floor: If these walls were left intact, they would stiffen the building, hindering its collapse. Destruction crews may also weaken the supporting columns with sledge hammers or steel-cutters, so that they give way more easily.
Next, blasters can start loading the columns with explosives. Blasters use different explosives for different materials, and determine the amount of explosives needed based on the thickness of the material. For concrete columns, blasters use traditional dynamite or a similar explosive material. Dynamite is just absorbent stuffing soaked in a highly combustible chemical or mixture of chemicals. When the chemical is ignited, it burns quickly, producing a large volume of hot gas in a short amount of time. This gas expands rapidly, applying immense outward pressure (up to 600 tons per square inch) on whatever is around it. Blasters cram this explosive material into narrow bore holes drilled in the concrete columns. When the explosives are ignited, the sudden outward pressure sends a powerful shock wave busting through the column at supersonic speed, shattering the concrete into tiny chunks.
Demolishing steel columns is a bit more difficult, as the dense material is much stronger. For buildings with a steel support structure, blasters typically use the specialized explosive material cyclotrimethylenetrinitramine, called RDX for short. RDX-based explosive compounds expand at a very high rate of speed, up to 27,000 feet per second (8,230 meters per second). Instead of disintegrating the entire column, the concentrated, high-velocity pressure slices right through the steel, splitting it in half. Additionally, blasters may ignite dynamite on one side of the column to push it over in a particular direction.

Concrete columns (on the left) are blown apart with conventional dynamite or a similar sort of explosive. Steel columns (on the right) are sliced in half using a high-velocity explosive called RDX.
Photo courtesy ImplosionWorld.com
To ignite both RDX and dynamite, you must apply a severe shock. In building demolition, blasters accomplish this with a blasting cap, a small amount of explosive material (called the primer charge) connected to some sort of fuse. The traditional fuse design is a long cord with explosive material inside. When you ignite one end of the cord, the explosive material inside it burns at a steady pace, and the flame travels down the cord to the detonator on the other end. When it reaches this point, it sets off the primary charge.

Blasting caps are used as a catalyst to set off the explosives loaded in support columns.
Photo courtesy ImplosionWorld.com
These days, blasters often use an electrical detonator instead of a traditional fuse. An electrical detonator fuse, called a lead line, is just a long length of electrical wire. At the detonator end, the wire is surrounded by a layer of explosive material. This detonator is attached directly to the primer charge affixed to the main explosives. When you send current through the wire (by hooking it up to a battery, for example), electrical resistance causes the wire to heat up. This heat ignites the flammable substance on the detonator end, which in turn sets off the primer charge, which triggers the main explosives.

Columns are fully loaded with explosives and hooked up to blasting caps and fuses.
Photo courtesy ImplosionWorld.com
To control the explosion sequence, blasters configure the blast caps with simple delay mechanisms, sections of slow-burning material positioned between the fuse and the primer charge. By using a longer or shorter length of delay material, the blasters can adjust how long it takes each explosive to go off. The length of the fuse itself is also a factor, since it will take much longer for the charge to move down a longer fuse than a shorter one. Using these timing devices, the blasters precisely dictate the order of the explosions.
Blasters determine how much explosive material to use based largely on their own experience and the information provided by the architects and engineers who originally built the building. But most of the time, they won't rely on this data alone. To make sure they don't overload or under-load the support structure, the blasters perform a test blast on a few of the columns, which they wrap in a shield for safety. The blasters try out varying degrees of explosive material, and based on the effectiveness of each explosion, they determine the minimum explosive charge needed to demolish the columns. By using only the necessary amount of explosive material, the blasters minimize flying debris, reducing the likelihood of damaging nearby structures.

A test blast is performed on a concrete column in the RCA Victor Complex in Camden, N.J. The building was demolished in the summer of 1997.
Photo courtesy ImplosionWorld.com
To further reduce flying debris, blasters may wrap chain-link fencing and geotextile fabric around each column. The fence keeps the large chunks of concrete from flying out, and the fabric catches most of the smaller bits. Blasters may also wrap fabric around the outside of each floor that is rigged with explosives. This acts as an extra net to contain any exploding concrete that tears through the material around each individual column. Structures surrounding the building may also be covered to protect them from flying debris and the pressure of the explosions.
When everything is set up, it's time to get the show underway. In the next section, we'll find out what final steps the blasters must take to prepare for the implosion, and we'll look at the implosion itself. We'll also find out what can go wrong in explosive demolition and see how blasters evaluate the project once the smoke has cleared.

The Big Bang
In the last couple of sections, we looked at everything blasters do to prepare a building for implosion. In addition to these measures, the blasters must prepare the people in the area for the blast, assuring local authorities and neighboring businesses that the demolition won't seriously damage nearby structures. The best way blasters can calm down anxious authorities is by demonstrating the firm's success with previous implosions.

Animation courtesy ImplosionWorld.com
Two towers in the Holly Street Development in London, England, were demolished in March 2001. They were a formidable challenge for the blasting firm, Controlled Demolition Group, Ltd.. One tower had to be rigged so it would fall over on its side, away from a gas line, while the other had to collapse perfectly into its own footprint, to avoid damaging neighboring structures. The demolition went exactly as planned, with no damage whatsoever to the gas lines or the neighboring buildings.
To help the blasters work through this process, a blasting company may bring in an independent demolition consulting firm, such as Protec Documentation Services. Protec uses portable field seismographs to measure ground vibrations and air-blasts during an implosion. Brent Blanchard, an operations manager for the company, says that they also inspect surrounding structures prior to the implosion, so that they can help assess any damage claims following the blast. Additionally, Protec's staff videotapes the blast from multiple angles so that there is a record of what actually happened. Using data collected from previous blasts, the company's engineers can predict ahead of time what level of vibration a particular implosion may cause.
Once the structure has been pre-weakened and all the explosives have been loaded, it's time to make the final preparations. Blasters perform a last check of the explosives, and make sure the building and the area surrounding it are completely clear. Surprisingly, implosion enthusiasts sometimes try to sneak past barriers for a closer view of the blast, despite the obvious risks. With the level of destruction involved, it is imperative that all spectators be a good distance away. Blasters calculate this safety perimeter based on the size of the building and the amount of explosives used.
On occasion, blasters have misjudged the range of flying debris, and onlookers have been seriously injured. Blasters might also overestimate the amount of explosive power needed to break up the structure, and so produce a more powerful blast than is necessary. If they underestimate what explosive power is needed, or some of the explosives fail to ignite, the structure may not be completely demolished. In this case, the demolition crew brings in excavators and wrecking balls to finish the job. All of these mishaps are extremely rare in the demolition industry. Safety is a blaster's number-one concern, and, for the most part, they can predict very well what will happen in an implosion.

The Wolverine Hotel in Detroit, Mich., was blasted in early 1997 by Engineered Demolition, Inc.
Photo courtesy ImplosionWorld.com
Once the area is clear, the blasters retreat to the detonator controls and begin the countdown. The blasters may sound a siren at the 10-minute, five-minute and one-minute mark, to let everyone know when the building will be coming down. If they are using an electrical detonator, the blasters have a detonator controller with two buttons, one labeled "charge" and one labeled "fire." Toward the end of the countdown, a blaster presses and holds the "charge" button until an indicator light comes on. This builds up the intense electrical charge needed to activate the detonators (this is similar to charging a camera flash to build the necessary electrical energy to illuminate a scene). After the detonator-control machine is charged, and the countdown is completed, the blaster presses the "fire" button (while still holding down the charge button), releasing the charge into the wires so it can set off the blasting caps.

Two types of blasting machines, a traditional rack-bar and a modern electronic control box
Photo courtesy ImplosionWorld.com
Typically, the actual implosion only takes a few seconds. To many onlookers, the speed of destruction is the most incredible aspect of an implosion. How can a building that took months and months to build, and stood up to the elements for a hundred years or more, collapse into a pile of rubble as if it were a sand castle?
Following the blast, a cloud of dust billows out around the wreckage, enveloping nearby spectators. This cloud can be a nuisance to anyone living near the blast site, but blasters point out that it is actually less intrusive than the dust kicked up by non-explosive demolition. When workers take down buildings using sledgehammers and wrecking balls, the demolition process may take weeks or months. In this time, a significant amount of dust is being kicked up into the air every day. When the building is leveled in one moment, on the other hand, all the dust is concentrated in one cloud, which lingers for a relatively short period of time. Nearby residents with allergies can leave the area for that one day and avoid the dust entirely.

The Scudder Homes in Newark, N.J., blasted by Engineered Demolition, Inc. in the summer of 1996
Photo courtesy ImplosionWorld.com
After the cloud has cleared, the blasters survey the scene and review the tapes to see if everything went according to plan. At this stage, it is crucial to confirm that all of the explosives were detonated and to remove any explosives that did not go off. If a demolition consulting crew was on hand, the blasters review their vibration and air blast data as well. Most of the time, experienced blasters bring buildings down exactly as planned. Damage to nearby structures, even ones immediately adjacent to the blast site, is usually limited to a few broken windows. And if something doesn't work out quite right, the blasters log it in their mental catalog and make sure it doesn't happen on the next job. In this way, job by job, the science and art of implosion continues to evolve.

Hey Leigh long time no see...t6hat was quite a post...good lord

Imploding buildings is complex!

Good to see you!

Of course he can tell that from a video. He's an expert.

The thing that is actually "impossible" if you want to talk "impossible" is the idea that the building completely collapsed as it did from a fire.

That is the most unlikely hypothesis. It has NEVER HAPPENED BEFORE.

This was sort of..... oh yeh.... a miracle happened.

Anyone can cut and paste.

Anyone can post a link.

I totally agree. It has to be done by experts.

But hey, since someone discovered that a mere fire can totally take down a building, or an airplane can, then maybe these explosive experts are full of b.S. and all we have to really do to take down a building now is start a fire or crash a plane into a building.

It would certainly save a lot of time and money paying experts to do it.

These are the things that people don't think about when they talk this kind of silly stuff.

1. Logistics. To do what people are saying, explosives would need to be on the support beams of the building. On the twin towers, the majority of support beams were in the center of the building, any schematic will show you that. So that means that in a building where thousands of people work every day, the people placing explosives would need to go into the building with all their equipment and explosives, remove walls back to the beams, place explosives and then replace walls so that the people that have been working there every single day for years, wouldn't notice the repairs or the initial work which would take months.

2. Detonation. Someone would have to detonate the explosives. It's probably safe to say that the person doing that isn't going to want to be in the building, so that means they will need to be detonated remotely, that means radio freq. detonation. So that means that 100's if not 1000's of lbs of explosives will need to be put in place, and radio dets put in place for the future detonation, and HOPE that one of the millions of cellphones, shortwave radios, cb's or the laundry list of other sources of radio freqs in the area wouldn't accidentally set off those explosives prematurely and then someone would have to explain why the buildings spontaneously detonated.

3. Impact. IF there was an inside job to 'blow' the buildings after planes hit to make it look like the planes did it, it has to look legit right? There is no doubt the city, if not the world, would be watching and videoing. How would they know where the planes were to hit? If they hit at say the 30th floor, how would they explain all the floors above it detonating as well. When i was watching the towers fall, the the section above where the planes hit came down as one unit and the weight of that section pushed its way through the floors below.

If you have ever seen a building brought down with explosives within its own footprint it is almost an art form and they do things that leave nothing to chance and have to do so to assure that the building will fall within its own footprint. One of those things they do is totally gut the building of all infrastructure except the the bones of the building. It takes weeks to prep a building of decent size to fall within its own footprint on purpose. They do this because if you leave those things in place, like walls, studs and in some cases wiring, while those things in small amounts probably won't alter the path of the building as it falls, if they aren't removed, when they start stacking on top of each other in the fall, their strength builds and there is a very good chance that that increased strength of the cumulative matter will change the path of the fall not allow it to fall as planned.

was an Expert,remember,he ran his Car into tree and killed himself,or so the Story goes!
Or he's sitting somewhere in the Dutch Westindies sipping on a Planter's Punch and killing himself laughing!
Thinking of the Money he's wheedled out of people for that crazy Story he's told!

actually about 300tons for each Tower,according to estimates,without prepping the Building!

Instead of trying to figure own how it was not possible or how difficult a job it would have to had been for the buildings to have been taken down with explosives, (which is the most likely hypothesis according to the manual put out by NFPA) people continue to defend the official report about how WTC7 totally collapsed because of a fire, and how the twin towers where each totally demolished by a plane.

Which continues to be the most unlikely hypothesis.

As for the planning and planting of explosives, the security in the towers was lax. It was also a company with connections to the Bush-Cheney administration via Marvin Bush.

There were witness reports of a floor that was off limits, where strange noises were heard, and men in cover-alls were seen bringing large containers in and out of. That floor was totally off limits to anyone and it had access to freight elevators all the way to the ground floors and below. The underground garage had no security. Anyone with a large truck of explosives could have driven in there any time they wanted.

Given that the first time the WTC was attacked (Years before this one) was a result of someone using explosives, you would think that would be the FIRST THING THEY WOULD USE ON THE SECOND ATTEMPT.

What I am thinking right now is that all of the people who continue to make excuses in an effort to turn a blind eye to the evidence and the truth and the people who still insist on defending the official propaganda of the 9/11 attack are in deep physiological denial.

There are none so blind

Did you bother to read my "cut and paste"?.....Wait a minute, your post makes it obvious, you didn't....To do the kind of prep work needed, they would need to shut down the whole building, all three buildings, for a long time Jeannie....One floor off limits!!!???!!!...Give me a break!...That is too funny!!

all threehundred tons of it,all in one Floor,yet at the same time claim it was a Classical,by the Book Demolition?
Make up your minds,if all the Explosives were crammed in one Floor,how can there be a classical Demolition by Explosives?

There is strong evidence not only for the proposition that WTC7 wasf brought down by explosives but also for the conclusion that explosions began going off in this building by 9:30 in the morning.

Barry Jennings consistently testified to this effect. On 9/11, Michael Hess spoke of an early morning explosion, and his later retraction is not credible. The attempts by NIST and the BBC to undermine these men's reports are too riddled with problems to be convincing. And even engineer Matthys Levy, who supports the view that fire brought WTC7 down, said that fires had begun in this building at about 9:30.

But why, in the light of the fact that WTC7 was not brought down until 5:21 pm, would explosives have started going off by 9:30 am?

Demolitions of large buildings with many support columns normally begin with the use of explosives to take out some of the core columns, so that they do not need to be removed all at once just before the collapse. Having preliminary removals would be especially important in a surreptitious operation, in which the perpetrators hoped to disguise the fact that the building was brought down with explosives.

A preliminary removal of some of the core columns evidently occurred in the North Tower.

According to North Tower Janitor William Rodriguez a massive explosion occurred in the basement of the North Tower at 8:46 am, shortly before this building was hit by a plane. (Rodriguez's account has been corroborated by other North Tower employees.)

These facts provide a possible answer as to why there were explosions in ETC7 long before it came down. They do not, however, provide a possible explanation for why they occurred so lone -over eight hours- before the collapse. The answer to that question goes beyond the scope of the main body of this subject which is limited to a critique of NIST's report on WTC7, as linked to in this thread, showing it to be unscientific and false.

One of the reasons for calling the NIST report unscientific and false is the fact that it ignored much of the relevant evidence, and it ignored evidence especially Jenning's testimony about explosions that evidently began by 9:30 am.

The evidence for such explosions, especially the big explosion repoorted by Hess as well as Jennings, is very strong.

These explosions would be intelligible, however, if those who brought down WTC7 had originally intended to bring it down in the morning. Doing so would have certainly been more sensible than bringing it down late in the day.

That one floor gave unlimited and unseen access to the entire building from its elevators. I did not say that all the Explosives were on that floor. Use your thinking cap. geeeeze.

Of course I read it. It does not even address the current subject or point except to say how difficult it is to demolish a building.

I know that already.

That is why the expert remarked.... Then they must have worked very hard!!