- NYPD Police Museum exhibit "9/11 Remembered" - photo source lost, but similar photos found here and hereimage wrote:GLASS SHARDS: Glass was a rare find at Ground Zero, where these shards were recovered. The collapse and fires pulverized and melted most of the glass from the Twin Towers' 43,600 windows.
- FDNY Engine 285 firefighter in "Collateral Damages" (2006, Turn of the Century Pictures, Inc.)wrote:You didn't find a shard of glass-- anything that looked like it would be used by a person, you just didn't see it. It was just concrete, steel, that was it-- and dust.
- Chief Daniel Nigro (FDNY Chief of Department 2001-2) in "Conspiracy Files – 9/11: The Third Tower," BBC TV 2008 — watchwrote:It was like the surface of another planet. All there was, was powdered debris and metal. It was a – a very strange scene.
- FDNY Engine 7's Joe Casaliggi in the Naudet documentary "9/11" at vrt 1:25:20 in TV version at http://www.911conspiracy.tv/mainstream_ ... aries.htmlwrote:You have two 110-story office buildings. You don't find a desk. You don't find a chair. You don't find a telephone, a computer. The biggest piece of a telephone I found was half of the keypad, and it was about this big. The building collapsed to dust. How are we supposed to find anybody in this that there's nothing left of the building?
ABC News report Sept. 13: 600,000 square feet of glass in the towers. Dr. Stephen Levin mentions "fine glass powder" at vrt 1:53.
43,600 windows were a rare find in the debris pile. Let's ask why.
ABOUT THE WINDOWS
- Angus Gillespie, Twin Towers: The Life of New York City's World Trade Center, Rutgers University Press, New Brunswick, NJ, 1999, p. 81.wrote: Powerful gusts can shatter windows, so for the sake of safety tempered glass eight times stronger than needed was specified. Planners designed the towers to withstand prolonged winds of 150 miles per hour.
- Gillespie, p. 108 (The glass itself was eighteen and a half inches wide. The 107th floor of the North Tower had 30-inch wide windows, for the Windows on the World restaurant. Likewise, "extra-wide windows" were needed for the observation deck of the South Tower.[p. 216])wrote:The twenty-two-inch spaces between the columns are for the windows, which are recessed ten inches in order to shade them from all but direct sunlight. The architect specified a bronze-tinted, heat-reflective glass for the 43,600 windows.
"The columns are twelve inches deep from the outer skin of the aluminum to the glass...." [ p. 167] (bonus detail)
The windows spanned from floor to ceiling. Gillespie estimates the surface area of the towers to be about 30% glass (p. 165), as opposed to the predominant style of modern architecture known as the "International Style," which uses on average about 60% glass.
-p. 215wrote:Each tower has fifty-eight vertical columns of windows per side, and each column is numbered. The [window washing] machine does about twelve columns of windows per day, so it takes five working days, or one week, to do one side of the building. There is a turntable at each of the four corners on the roof, so at the end of the week, the machine turns the corner to deal with another side. It takes four weeks, or one month, to do the whole building.
MOSTLY GONE WITH THE WIND
OK, there was a lot of glass! Where did it go, if not into the clouds of dust?
http://pubs.usgs.gov/of/2001/ofr-01-042 ... iveSummarywrote:The dusts released from the WTC building collapse are largely composed of particles of glass fibers, gypsum, concrete, paper, and other miscellaneous materials commonly used in building construction.
More specifically, glass fiber made up 40 percent of all the samples collected and studied by Paul J. Lioy, et. al. (http://ehp.niehs.nih.gov/members/2002/1 ... -full.html):
It is important to know that the windows weren't the only form of glass in the place. Not only were there light fixtures, TVs and monitors, but also there was fiberglass insulation. "These three [dust] samples were composed primarily of construction materials, soot, paint (leaded and unleaded), and glass fibers (mineral wool and fiberglass) ." (Lioy, et. al.)
- Lioy, et. al.wrote:The Cortlandt Street sample was mainly composed of construction debris [including vermiculite, plaster, synthetic foam, glass fragments, paint particles, glass fibers, lead (Figure 3), calcite grains, and paper fragments], quartz grains, low-temperature combustion material (including charred woody fragments), and glass shards. Chrysotile asbestos fibers were estimated to comprise < 1% of the sample by volume....
Figure 4. "Glass fiber detected in the Market Street sample."
The http://pubs.usgs.gov/of/2001/ofr-01-042 ... html Spectroscopy Lab provides an important detail:Lioy wrote:Approximately 35% of the volume of the sample was in the form of loosely consolidated clumps of fibrous lint, of which the greatest portion was glass fibers. An example of the typical form of the glass fibers is shown in Figure 4. In many cases the width was approximately or equal to 1 µm (to > 10 µm), and the length ranged from 5 to 100 µm. The fiber shown in Figure 4 is not a "clean" glass fiber; other materials are agglomerated along the rod. This is typical of features noted for many different types of particles in each sample. The SEM analysis of the fraction < 75 µm in diameter revealed many glass fibers and cement particles, some in a fibrous form containing calcium, silicon, and sulfur, and some particles were composed of calcium carbonate....
However, this may be misleading because the first sentence in the paragraph read: "SEM energy dispersive analysis indicates fibrous glass with elemental composition closely matched by slag wool in all dust samples analyzed by this method." This still does not rule out the presence of glass SHARDS.wrote:Use of slag wool, a type of mineral wool insulation, was widespread in the WTC towers (Hyman Brown, personal communication) as part of fireproof coatings on steel girders and the undersides of floors, thermal insulation around glass windows, and possibly in ceiling tiles. The apparent widespread use of slag wool and its brittle nature may explain its presence in all of the dust samples as a volumetrically significant component.
- Maoxin Wu, et. al., "Case Report: Lung Disease in World Trade Center Responders Exposed to Dust and Smoke: Carbon Nanotubes Found in the Lungs of World Trade Center Patients and Dust Samples" (emphasis added)wrote:Small shards of glass containing mostly silica and magnesium were also found.
This cloud comprised a complex mix of pollutants, among them the products of combustion of 91,000 L jet fuel, pulverized building materials, cement dust, asbestos, microscopic shards of glass, silica, heavy metals, and numerous organic compounds....
Another dust study gives us this:
source: http://pubs.usgs.gov/of/2001/ofr-01-042 ... index.html
It's important to consider that Silicon is the 8th most abundant element in the universe (according to http://en.wikipedia.org/wiki/Silicon ), so it's a large part of concrete also. BUT, more important, Silicon makes up about 70% of most glass. SiO2 is mixed with other materials to lower the melting point to about 1500 °C (2700 °F) -- see http://en.wikipedia.org/wiki/Glass -- so if the NYPD Museum is correct and the glass did melt, there were some really freaking hot temperatures going on! AND THERE WERE. (See "Molten Steel & Extreme Temperatures at WTC")
Could a building collapse have pulverized the bulk of the extra-strong glass into such a huge quantity of microscopic shards? I think not.
* UPDATE *
One professional source claims there were large quantities of glass recovered. Their number is hilarious. Either they were counting the omnipresent, vitreous dust... or they were including the 600,000 square feet of glass once a part of the towers, assumed to be there in the debris pile.
- Phillips & Jordan, Inc., "Anatomy: World Trade Center/Staten Island Landfill Recoverywrote:The initial debris estimate included 125,000 tons of glass, 250,000 tons of steel, 450,000 cubic yards of concrete, 12,000 miles of electrical cable, and 198 miles of ductwork.
Operation," Phillips & Jordan, Inc., p. 2. Document originally at the Disaster Recovery Group web site (dead link) but cached at 911depository.info/PDFs/Other%20Reports/Phillip...
There also we can read: "Phillips and Jordan, Inc. (P&J) was called to New York by the U.S. Army Corps of Engineers. P&J was tasked by the Corps as their Advanced Contracting Initiative (ACI) Disaster Debris Management Contractor to serve in a strategic planning and monitoring role." These people were not on the pile in the bucket lines, digging in those first hours. They only know there SHOULD HAVE BEEN tons of glass.
* UPDATE 2 *
Please scan through the published work of Steven E. Jones, Jeffrey Farrer, Gregory S. Jenkins, Frank Legge, James Gourley, Kevin Ryan, Daniel Farnsworth, and Crockett Grabbe, "Extremely high temperatures during the World Trade Center destruction." In addition to elemental composition analysis using a scanning electron microscope, you will find this micrograph, or optical microscope image of WTC dust plainly showing dried molten metal and silicate, or glass:
** UPDATE 3 **
Engineer Mark Basile discusses his personal examination of the WTC dust in this video presentation, and at this specific spot describes once-molten silicate spheres -- with magnetic properties.