about controlled demolition

so one said

One bugaboo I have with the forbidden “conspiracy theory” diaries is that the landlord of WTC7 – one of those subjects forbidden as conspiracy theory – flat out said on a documentary that they “decided to pull it.”  No ifs ands or buts, he said the NYC fire department decided to perform controlled demolition.

One of the degrees I ended up forfeiting was architecture, but I did tool around Boston Architecture Center in classes, plus a lot of autodidactic reading, enough to understand that it takes months to prepare a building for a controlled demolition which will allow a building to “fall in its footprint.”  I saw this done to a Boston building, and also read on the primary family who does this procedure as to their techniques.  People don’t realize what an art there is to making this happen.

WTC7 fell in around six and a half seconds into its footprint.  42 stories tall, that is just about exactly the amount of time it would take a dropped object from the top of the building to hit the ground.

Like Silverstein said – it was brought down by controlled demolition.  He admitted it for crying out loud.  The only thing is that most of the public don’t know enough about controlled demolition to realize that it would take MONTHS (not days, not weeks) to properly prepare for such a successful controlled demolition.  That, and as you say, it was not hit by a plane.  No dispute exists on that question.

Another problem is that there are no extant orders on record for the fire department to do that work.  Which either means they did it in secret – for months – or someone else did the work.

This is not to advance any theory of who did what or why – only to say that 1) we have not heard the full proper story of what happened, ever, and 2) no technical investigation of any of the demolition was ever performed.  Period.

It is very counterintuitive of the public to just accept the MSM account of things without question.  We should demand a technical investigation.  

and another said:

give the blueprints to an elite military demolition specialist. Give him 2 days to prepare the gear. Building comes down in less than 45 mintues from the time you let him drive the truck into the basement garage.

to which the first answered:  

because I spent quite a bit of time reading about the work of the Loizeaux family, and it did take roughly a couple months to prepare larger buildings, as with the one I observed while studying architecture in Boston.  It was not a quick job, although as you say it can be done with a basement detonation – but basement detonations will not cause a building to neatly “fall in its footprint.”  In exceptionally tall buildings work is done on multiple floors, not just from a basement.  That is why the sloppy basement demolition did not work on the first WTC attack in 93, which btw I barely escaped (and I used to work in the north tower, never could contact old friends from my temp agency which had gone under by 2001.  (link  http://www.controlled-demoliti…

Also it was the report in the controversy about the twin towers, that workers sealed off various floors from access for several months preceding the attacks – workers unknown to the usual personnel of the towers.  Elevators would forbid access to various floors for periods of time, which went on for months.  The plumes of smoke were evident in photos issuing from corners of about every 6 stories, as I recall, which of course are disputed by skeptics as manipulated photos.  So it goes.  But what was rendered in private photography/videos of the towers was consistent with the techniques employed by experts such as the Loizeaux family.

And first later added:

With the press of a button at 5:47 PM on October 24, 1998, Detroit Mayor Dennis Archer dropped the J.L. Hudson Department Store from his city’s skyline and into the history books and record books.

Hudson’s was the tallest department store in the country and was second in square footage only to Macy’s anchor Store in New York. It dominated the retail market in the city through the 1970’s before closing its doors in 1983.

The store was built in 12 separate stages, the first in 1911 and the last in 1946. The complex had two retail basements and 23 above grade retail floors, including mezzanines. Two additional basements and six upper stories in a tower, provided storage and mechanical support for the 2.2 million square foot building. In all there were 33 levels in the structure.

In the fall of 1997, the Downtown Development Authority of Detroit (DDA), retained a joint venture of Walbridge Aldinger and Jenkins Construction of Detroit to manage the project. Walbridge/Jenkins took bids for asbestos abatement of the structure and the contract, which took three months to complete, was performed by Loyalty Environmental of Chicago.

The demolition contract went to a joint venture between Detroit based Homrich, Inc. and Boston based North American Site Development. They, in turn, retained Controlled Demolition, Inc. (CDI) and the Loizeaux Family of Phoenix, Maryland to design and perform the tricky implosion of the Detroit landmark.

No structural drawings of the facility were available, making structural analysis and implosion design a considerable task for CDI. The interdependency of the 12 different construction stages, with differing construction and variable column flange directions and bay widths created what CDI calls differential natural failure modes in each section of the structure which CDI’s demolition program had to cope with. These factors created an implosion design, preparation and dynamic control challenge for the 2nd and 3rd generation of a family recognized as the international founders of the commercial implosion industry (see ENR cover story October 1972).

Hudson’s was bordered on four sides by streets filled with critical infrastructure and flanked on 3 sides by poorly maintained, turn-of-the-century structures with huge sand-cast glass windows that occasionally broke in high winds. Lastly, Detroit’s elevated “People Mover” paralleled the east face of the 439 ft. tall structure just 15 ft away.

Mark Loizeaux, President of CDI, called Hudson’s the greatest dynamic structural control challenge the company had ever faced. CDI had to sever the steel in the columns and create a delay system which could simultaneously control the failure of the building’s 12 different structural configurations, while trying to keep the hundreds of thousands of tons of debris within the 420 ft by 220 ft footprint of the structure.CDI needed structural data to complete its design.  Under CDI direction, Homrich/NASDI’s 21 man crew needed three months to investigate the complex and four months to complete preparations for CDI’s implosion design. During that period, the lower two basements of the structure were filled with engineered fill and the perimeter basement walls bermed to 1st basement level with soil to support perimeter walls which would surely have failed under soil and hydrostatic loads once the horizontal support of the Hudson’s internal structure was removed by the implosion.

Double column rows installed in the structure between vertical construction phases, internal brick shear walls, x-bracing, 70 elevators and 10 stairwells created an extremely stiff frame. Columns weighing over 500 lb/ft, having up to 7.25 inch thick laminated steel flanges and 6 inch thick webs, defied commercially available shaped charge technology. CDI analyzed each column, determined the actual load it carried and then used cutting torches to scarf-off steel plates in order to use smaller shaped charges to cut the remaining steel. CDI wanted to keep the charges as small as possible to reduce air over pressure that could break windows in adjacent properties.

CDI’s 12 person loading crew took twenty four days to place 4,118 separate charges in 1,100 locations on columns on nine levels of the complex. Over 36,000 ft of detonating cord and 4,512 non-electric delay elements were installed in CDI’s implosion initiation system, some to create the 36 primary implosion sequence and another 216 micro-delays to keep down the detonation overpressure from the 2,728 lb of explosives which would be detonated during the demolition.

Even with all the precautions to control overpressure, the age, existing cracks, and poor condition of glazing windows in vacant structures on the north, east and west sides of the J.L. Hudson complex, window breakage was a concern. CDI had seven glass company crews on standby to handle any problems. Although Homrich/NASDI has placed over 2,000 yards of soil over utilities in the four adjacent streets, emergency utility crews were also standby “just in case.”

When the button was pressed at 5:47 PM, assembled officials, contractors, former Hudson patrons and an estimated crowd of 20,000 watched the store begin to pivot at its southwest corner. The controlled collapse moved north and east through the structure, folding the walls inward.  ( http://www.controlled-demoliti… )

Repeat, for the sake of public awareness  

three months to investigate the complex and four months to complete preparations for CDI’s implosion design

The demise of building seven is almost unknown to the US public

Which may be related to some text, somewhere on some blog, which reads:

It is forbidden to write diaries that:

…refer to claims that the airplanes that crashed into the WTC and Pentagon were not the cause of the damage to those buildings or their subsequent collapse.

Authoring or recommending these diaries may result in banning…

elsewhere:

Diaries advancing ‘Conspiracy Theories’ are subject to ridicule and derision from the community at the very least. Repeat offenders can and will be banned. Yes, this does include ‘controlled demolition’ of WTC 7.