The complete collapse of the Twin Towers has more to do with the construction than anything else. Yes, it was the loss of fireproofing and subsequent fires that collapsed the building but if it were not for the construction, a total collapse may not have occurred. Ironically, the construction also saved many lives by letting the towers stand as long as they did. This site goes into much more detail:
http://www.debunking911.com/index.html
"Tube in a Tube"
The designers coined the term "Tube in a Tube" to describe the buildings’ construction. The design was an innovation of its day. Thick steel columns ran up the middle of the building. This housed the elevators, stairwell, electrical conduits, water, sewer and other services which ran up and down the length of the buildings.
For you to understand the collapse, you will have to remember four main elements.
- Core columns
- Perimeter columns
- Floor Trusses
- Fire proofing
The columns of the building normally found evenly spaced out on a given floor became the outer wall of the building. This left large open areas for renting. A good explanation of this can be found here:
http://www.pbs.org/wgbh/nova/minutes/q_2907.html
This is an 87 second video from NOVA. Basically what the video says is that WTC used what was considered to be an innovative design, much different than the typical skyscraper. Instead of using evenly spaced support columns as do traditional skyscrapers, the WTC moved most of the support columns to the outer wall. Steel trusses were used to connect the outer wall to the main inner core. However, i nstead of encasing each column in heavy concrete, (normal fire proofing) the designers relied on 'sprayed on' fire proofing with a 2 hour rating to protect the load bearing columns and trusses from fire. Please note: 2 hours.
Each WTC tower was essentially bolted together like an erector set. Each average floor had 376 5/8" bolts, 188 Truss seats, 120 ViscoElastic pieces and 120 gusset plates. There was a 3 to 4 inch layer of concrete on the average floor. There were reinforced concrete floors in the core as well. Contrary to what some conspiracy theorists say, the core walls were NOT concrete reinforced.
So let's look at this for a moment. A building constructed so that most of its support lies on the outer steel columns, and uses steel trusses with sprayed on asbestos is hit by a 767 traveling 500 mph with nearly a full load of fuel, that then blasts off the fire retardant across multiple floors.
The NOVA video has an excellent video showing how those steel trusses weakened, and bent, but did not vaporize. Nor did they turn into molten steel. They bent and they were weakened.
Realize the tremendous amount of weight those broken columns and weakend trusses were supporting, under temperaturs approaching 1,000 degrees. Frankly I'm amazed those buildings held up as long as they did.
No hidden bombs. Simple physics, mathematics and gravity did the trick. You saw it with your own eyes.
You guys remind me of that old Richard Pryor routine -- "My girlfriend caught me in bed with another woman. I jumped out of bed and told her 'Who you gonna believe, ME or your lyin' eyes!"
Who you gonna believe? I think I already know the answer.
Chris
