How buildings collapse, with reference to 9/11

[Wokeman]

I've had an e-mail from a neighbour I sometimes have a drink with in the local pub. However, we have always differed over what (or whom) was the cause of the collapse of the twin towers in New York on the 11th September 2001, and the attack on the Pentagon. He maintains that it was all a conspiracy theory, carried out by 19 Arab terrorists, led by a rich man, whose family are friendly with George W. Bush, and the occupant of the White House, but whom insists upon living in a cave in Afghanistan. Recently, the subject has come up again, (I am sure we have discussed it before) but this time it was about the how the twin towers collapsed. I quote (about what demoltion contractors do to prepare the building before collapse):

"Actually, quite often they did set fire to them to weaken their
structures before collapse.
As for putting bombs at different levels, I do not believe that this is
the case. The building is gutted as far as possible and explosives are
placed at the base to take away its support. Explosives above ground
level would just risk sending debris far and wide"

Does anyone have any specialist building or demoltion knowledge to confirm or deny this belief. This is from someone with an Oxford degree in physics, and I simply cannot believe that they first set light to it and then place bombs in the base of the building and hope for the best, especially within the confined area of an inner city.

[Andrew Johnson]

Most of these issues are argued in a Physics thread I started:

http://forum.physorg.com/index.php?s=7d8698c09f4f88bb5e80cecc4a3bc21d& showtopic=3108&st=0

Morgan Reynolds, Professor Emeritus and Texas A & M Univ. also thinks explosives were used to demolish the towers.

http://www.lewrockwell.com/reynolds/reynolds12.html

Hear his synopsis:


http://checktheevidence.com/audio/911/9-11%20Morgan%20Reynolds%20-%20C oast%20to%20Coast%20-%20Jun%2016%202005.mp3


Give your friend a DVD - mail me if you want one: ad.johnson@ntlworld.com

[Belinda]

This, the collapse of the 3 Towers, along with the Pentagon pin-prick is the crucial issue of 911, it's important a) to get it right in our minds and even master the physics (see Andrew's excellent tutorial on this) b) to keep plugging it, over and over. Stay off planes and hi-jackers!! Keep going on and on about how SCIENTISTS HAVE PROVED THE 3 TOWERS WERE DEMOLISHED and show exactly how this happened.

Even without the physics (although use that) there are standard demolition techniques that were applied here. Explosives in the basement of the building get rid of the concrete foundations and create a soft 'cup' for the building to fall into. Then, charges are put up inside the building at regular intervals all the way to the top, as close as possible to or actually inside the central core columns. You can see this clearly in the way WTC7 collapsed, it imploded first around its central core to cause a neat, slightly inward-pointing vertical collapse.

In the case of the 2 Towers the core columns being central as well as spaced out from each other, it would actually be possible for an aircraft to hit the building and local fires to break out without critically damaging all the core columns at once and triggering the demolition sequence, as happened here. It has always been interesting to me that the 2 aircraft performed incredible feats of manoeuvring to hit the Towers but struck the 'edges' of the buildings rather going straight into the core, presumably to allow a decent 'delay' before the buildings were pulled and ensure maximum dramatic effect.

A diagram of the cross-section of each Tower would show exactly where the aircraft entered and what part of the core if any they damaged on impact, does anyone know where to find such a diagram?

The question is, when were the buildings wired up for demolition, I know this has been done automatically to all new city centre buildings as of the 90s but was it already the norm in the early 70s? Or even earlier than that in a place like NY? We need to verify this fact and if it is the case that high-rise city centre buildings are wired up for demolition at the time of construction (to make them easier to pull down neatly in a crowded area when their useful life is over) then it's interesting that the Commission report makes no mention of this.

Perhaps someone can supply answers to this question?

[Pikey]

Hi Wokeman,

Either your professor of Physics is taking the p*** or he was p***** when he e mailed you.

I am not a structural engineer but I am a time served professional team player in the construction industry with the majority of my experience in the pre contract design phase. Part of my degree course consisted of studying structural mechanics in building design and also the construction technology of buildings.

Using fires as a means of bringing down high rise building structures! The only person to use this technique was steeplejack, Fred Dibnah who was commissioned to bring down most of the brick built chimney stacks for the cotton mills in Lancashire. The stacks came down in a line equivalent to their height and Freds skill was in getting the stack to collapse along the line required; i.e the nature of the collapse was NOT IMPLOSION!

With demolition of buildings, its horses for courses and its dependent on the structural design and materials specified in the building.

The superstructure of the twin towers was a steel frame and its design was state of art. At the time the towers were the tallest in the world when they were completed. To comply with building regulations, means of escape the design has to incorporate a certain level of integrity so that the structure remains stable to enable evacuation of the building occupants. With steel framed buildings such as the twin towers I would have expected the fire protection required would have been at least an hour but it is highly probable more. An Architect who has knowledge of designing high rise buildings should be able to verify this. I would expect the building regulations in the US to mirror those in this country or possibly be of higher standard.

In addition to the fire protection of the building there are also installed systems to fight against the incidence of fire:- sprinkler systems, etc.

I am not aware which method of fire protection was used for the steel frame on the twin towers:- encasement in concrete, clad in fire resistant boarding, or an intumescent coating on the steel are the options. I suspect that a fire resistant cladding was utilised. When the towers were being built asbestos was the commonly used material for fire resistant boarding . I seem to remember reading somewhere that they were in the process of replacing the asbestos (health & safety) before the towers fell! If that is true then its interesting because this would have given them the opportunity to position the explosives when they did this work.

The integrity of steel framed buildings in fires is excellent, historical evidence substantiates that…………no high rise steel frame buildings had ever collapsed prior to the twin towers.

The weak points in a steel frame superstructure are at the connection joints between the members. The connections are either bolted or the other option is welded connections. If explosives were positioned they would have been located at all the key connection joints to facilitate an implosive demo result.

This operation would have taken months of planning and analysis of the structural drawing blueprints of the towers. It would have been a high tech/state of the art operation, certainly not a Fred Dibnah job!

IMO it is likely that whoever did the clean up operations afterwards probably did the controlled demolition. The company which did this was US company CDI, Controlled Demolition Inc.

It is a pity that Jimmy Walter did not have the foresight to commission a professional INDEPENDENT design team to do an academic research and investigation into the collapse of WTC 1-2 and 7 rather than spending huge sums of money on advertising. Maybe there are some wealthy individuals, lightworkers, who are prepared to fund such an investigation. Any ideas who we could approach guys and gals?

At the UK 911 national conference at London on Sunday, there was a Structural Engineer who introduced himself. Does anyone have his details?

We need to form a working group to research this aspect of 911 as I feel that it is likely to provide a very compelling case for us to substantiate that 911 was an inside job. Any volunteers. (architects, engineers, demolition contractors, building contractors with high rise experience). Canary Wharfe in London was a relatively recent high rise state of the art project so perhaps anyone out there involved at a high level in the design team of this project could assist our research.

Regarding Belinda’s point that since 1990 high rise buildings in city centres are installed with a demolition installation, is interesting as well as disturbing. That’s certainly news to me. I hope the terrorists do not know about it!

We have an architect, on board the campaign and a registered member of this website who submitted a superb article to the UK professional magazine "Building Design" about the collapse of the tower. They never published it. Perhaps he would post it on this thread?

[Snowygrouch]

Hi all,
Just got back from the Library at Oxford Brookes uni with a couple of pamphlets on demolition.

One has a couple of interesting points: "Demolition by M.A.Browne BSc Hons." 1975, paper by the Institute of Building; Ascot.

Page 42: "A revolutionary approach could be to introduce an in built mode of demolition within the framework itself,

For example, explosives places strategically within the structure possibly attached to or cast into appropriate beams or columns, these charges could be set up electronically to explode from a central demolition mechanism"

"The setting of permanent explosives within the structure is a doubtful proposition due to the security needed and the..working life of the explosives.."

"to minimise security measures, the framework could be designed to accomodate the placing of such charges....another technique could be to design structural units...whereby a progressive collapse could be initated when they were removed"

I think it is logically possible to prove WT7 was pre-rigged providing you have the testimony of a professional demolition engineer to prove the length of time required to rig a large building.

Since we have larry silverstein admitting to pulling WTC7:

1: If they pulled the building "on the day" they had just hours to rig the charges and carry out a building analysis (IF it happend as he suggests as the fire damage rendered the building uneconomic or dengerous)

2: If its impossible to rig a building like that in the time available logically its only possible that if it was pulled it was pre rigged.

3: It the owner of the WTC complex admits to an event which MUST have entailed him pre rigging WT7 how much of stretch is it to say why not WT1 and 2.

I dont have time right now but I have a complete schematic of the sprinker systems in WTC1 and 2 together with list of all fire suppression systems installed. I`ll post another link for this, its VERY interesting!

Calum