THE FALL OF THE TWO WORLD TRADE TOWERS IN 9/11
Most people will NOT take the time to even read how these two
towers were built. They will simply believe some conspiracy talk
that says they were brought down by an im-plosion, and think "Oh,
okay, so there was something done by the Government" and they run
off with a "conspiracy" plan in their mind, not a conspiracy of
evil fanatical Islam guys, but a conspiracy plan by the USA
Government to kill thousands of people, so they could go to war
on Iraq, for the other conspiracy of "oil."
Well I hope you reading this will continue to read ALL of it, as
I produce it for you from Wikipedia, the free encyclopedia (they
give numbered references - links I think to where they get their
information - I have not produced those - you can go on the
Internet as I did, for their written information and links).
Quote
Planning and construction
Main article: Construction of the World Trade Center
The idea of establishing a World Trade Center in New York
City was first proposed in 1946. The New York State Legislature
passed a bill authorizing New York Governor Thomas E. Dewey to
begin developing plans for the project but the plans were put on
hold in 1949. During the late 1940s and 1950s, economic growth in
New York City was concentrated in Midtown Manhattan, while Lower
Manhattan was left out. To help stimulate urban renewal, David
Rockefeller suggested that the Port Authority build a World Trade
Center in Lower Manhattan.
Initial plans, made public in 1961, identified a site along
the East River for the World Trade Center. As a bi-state agency,
the Port Authority required approval from both the governors of
New York and New Jersey in order to undertake new projects. New
Jersey Governor Robert B. Meyner objected to New York getting a
$335 million project. Toward the end of 1961, negotiations with
outgoing New Jersey Governor Meyner reached a stalemate.
At the time, ridership on New Jersey's Hudson and Manhattan
Railroad (H&M;) had declined substantially from a high of 113
million riders in 1927 to 26 million in 1958 after new automobile
tunnels and bridges had opened across the Hudson River. In a
December 1961 meeting between Port Authority director Austin J.
Tobin and newly elected New Jersey Governor Richard J. Hughes,
the Port Authority offered to take over the Hudson & Manhattan
Railroad to have it become the Port Authority Trans-Hudson
(PATH). The Port Authority also decided to move the World Trade
Center project to the Hudson Terminal building site on the west
side of Lower Manhattan, a more convenient location for New
Jersey commuters arriving via PATH. With the new location and
Port Authority acquisition of the H&M; Railroad, New Jersey agreed
to support the World Trade Center project.
Approval was also needed from New York City Mayor John
Lindsay and the New York City Council. Disagreements with the
city centered on tax issues. On August 3, 1966, an agreement was
reached that the Port Authority would make annual payments to the
City in lieu of taxes for the portion of the World Trade Center
leased to private tenants. In subsequent years, the payments
would rise as the real estate tax rate increased.
Architectural design
On September 20, 1962, the Port Authority announced the
selection of Minoru Yamasaki as lead architect and Emery Roth &
Sons as associate architects. Yamasaki devised the plan to
incorporate twin towers; Yamasaki's original plan called for the
towers to be 80 stories tall. In order to meet the Port
Authority's requirement to build 10 million square feet (930,000
m2) of office space, the buildings would each need to be 110
stories tall.
A major limiting factor in building height is the issue of
elevators; the taller the building, the more elevators are needed
to service the building, requiring more space-consuming elevator
banks. Yamasaki and the engineers decided to use a new system
with sky lobbies; floors where people could switch from a
large-capacity express elevator which serves the sky lobbies, to
a local elevator that goes to each floor in a section. This
allowed the local elevators to be stacked within the same
elevator shaft. Located on the 44th and 78th floors of each
tower, the sky lobbies enabled the elevators to be used
efficiently, increasing the amount of usable space on each floor
from 62 to 75 percent by reducing the number of required elevator
shafts. Altogether, the World Trade Center had 95 express and
local elevators. This system was inspired by the New York City
Subway system whose lines include local stations where local
trains stop and express stations where all trains stop.
(Ah, read this section about the elevators again! Make note of
it. It's somewhat like a folding tube inside itself - many
"sections" within a larger section - Keith Hunt)
Yamasaki's design for the World Trade Center, unveiled to
the public on January 18, 1964, called for a square plan
approximately 207 feet (63 m) in dimension on each side. The
buildings were designed with narrow office windows 18 inches (46
cm) wide, which reflected Yamasaki's fear of heights as well as
his desire to make building occupants feel secure. Yamasaki's
design included building facades sheathed in aluminum-alloy. The
World Trade Center was one of the most striking American
implementations of the architectural ethic of Le Corbusier and it
was the seminal expression of Yamasaki's gothic modernist
tendencies.
In addition to the twin towers, the plan for the World Trade
Center complex included four other low-rise buildings which were
built in the early 1970s. The 47-story 7 World Trade Center
building was added in the 1980s to the north of the main complex.
Altogether, the main World Trade Center complex occupied a
16 acres (65,000 m2).
Structural design
The structural engineering firm Worthington, Skilling, Helle
& Jackson worked to implement Yamasaki's design, developing the
tube-frame structural system used in the twin towers. The Port
Authority's Engineering Department served as foundation
engineers, Joseph R. Loring & Associates as electrical engineers,
and Jaros, Baum & Bolles as mechanical engineers. Tishman Realty
& Construction Company was the general contractor on the World
Trade Center project. Guy F. Tozzoli, director of the World Trade
Department at the Port Authority, and Rino M. Montii, the Port
Authority's Chief Engineer, oversaw the project. As an interstate
agency, the Port Authority was not subject to local laws and
regulations of the City of New York including building codes.
Nonetheless, the structural engineers of the World Trade Center
ended up following draft versions of the new 1968 building codes.
The tube-frame design, earlier introduced by Fazlur Khan, was a
new approach which allowed open floor plans rather than columns
distributed throughout the interior to support building loads as
had traditionally been done.
(Ah, did you see that? Read the last sentance again - open floor
plans with no columns distributed throughout the interior to
support building loads. Ah, is it clicking into place in your
mind? Are you thinking ahead? - Keith Hunt)
The World Trade Center towers utilized high-strength,
load-bearing perimeter steel columns called Vierendeel trusses
that were spaced closely together to form a strong, rigid wall
structure, supporting virtually all lateral loads such as wind
loads, and sharing the gravity load with the core columns. The
perimeter structure containing 59 columns per side was
constructed with extensive use of prefabricated modular pieces
each consisting of three columns, three stories tall, connected
by spandrel plates. The spandrel plates were welded to the
columns to create the modular pieces off-site at the fabrication
shop. Adjacent modules were bolted together with the splices
occurring at mid-span of the columns and spandrels. The spandrel
plates were located at each floor, transmitting shear stress
between columns, allowing them to work together in resisting
lateral loads. The joints between modules were staggered
vertically so the column splices between adjacent modules were
not at the same floor.
(Did you get it? It was of course "section by section" joined
together to make a whole high building - Keith Hunt)
The core of the towers housed the elevator and utility
shafts, restrooms, three stairwells, and other support spaces.
(Of course you had "shafts" and stairwells, all over the place in
these two towers - Keith Hunt)
The core - a combined steel and concrete structure - of each
tower was a rectangular area 87 by 135 feet (27 by 41 m) and
contained 47 steel columns running from the bedrock to the top of
the tower. The large, column-free space between the perimeter and
core was bridged by prefabricated floor trusses. The floors
supported their own weight as well as live loads, providing
lateral stability to the exterior walls and distributing wind
loads among the exterior walls. The floors consisted of 4 inches
(10 cm) thick lightweight concrete slabs laid on a fluted steel
deck. A grid of lightweight bridging trusses and main trusses
supported the floors.
(Notice .... "lightweight" concrete - lightweight bridging
trusses - maybe fine under "normal" conditions, but 9/11 was far
from normal - Keith Hunt)
The trusses connected to the perimeter at alternate columns
and were on 6 foot 8 inch (2.03 m) centers. The top chords of the
trusses were bolted to seats welded to the spandrels on the
exterior side and a channel welded to the core columns on the
interior side. The floors were connected to the perimeter
spandrel plates with viscoelastic dampers which helped reduce the
amount of sway felt by building occupants. The trusses supported
a 4-inch (100 mm) thick lightweight concrete floor slab with
shear connections for composite action.
(Yes built to sway and move in the wind - lightweight word used
again - Keith Hunt)
Hat trusses (or "outrigger truss") located from the 107th
floor to the top of the buildings were designed to support a tall
communication antenna on top of each building. Only 1 WTC (north
tower) actually had an antenna fitted; it was added in 1978. The
truss system consisted of six trusses along the long axis of the
core and four along the short axis. This truss system allowed
some load redistribution between the perimeter and core columns
and supported the transmission tower.
The tube frame design using steel core and perimeter columns
protected with sprayed-on fire resistant material created a
relatively lightweight structure that would sway more in response
to the wind compared to traditional structures such as the Empire
State Building that have thick, heavy masonry for fireproofing of
steel structural elements.
(There we are again - the "lightweight" word as opposed to the
heavy construction of the Empire State Building - Keith Hunt)
During the design process, wind tunnel tests were done to
establish design wind pressures that the World Trade Center
towers could be subjected to and structural response to those
forces. Experiments also were done to evaluate how much sway
occupants could comfortably tolerate, however, many subjects
experienced dizziness and other ill effects. One of the chief
engineers Leslie Robertson worked with Canadian engineer Alan G.
Davenport to develop viscoelastic dampers to absorb some of the
sway. These viscoelastic dampers, used throughout the structures
at the joints between floor trusses and perimeter columns along
with some other structural modifications, reduced the building
sway to an acceptable level.
Construction
In March 1965, the Port Authority began acquiring property
at the World Trade Center site. Demolition work began on March
21, 1966 to clear thirteen square blocks of low rise buildings in
Radio Row for construction of the World Trade Center.
Groundbreaking for the construction of the World Trade
Center took place on August 5, 1966.
The site of the World Trade Center was located on landfill
with the bedrock located 65 feet (20 m) below. In order to
construct the World Trade Center, it was necessary to build the
"bathtub" with a slurry wall around the West Street side of the
site, serving to keep water from the Hudson River out. The slurry
method selected by Port Authority's chief engineer, John M. Kyle,
Jr., involved digging a trench, and as excavation proceeded,
filling the space with a "slung" mixture composed of bentonite
and water which plugged holes and kept groundwater out. When the
trench was dug out, a steel cage was inserted and concrete was
poured in, forcing the "slurry" out. It took fourteen months for
the slurry wall to be completed; it was necessary before
excavation of material from the interior of the site could begin.
The 1.2 million cubic yards (917,000 m3) of material excavated
were used to expand the Manhattan shoreline across
West Street to form Battery Park City (along with other fill and
dredge material.)
In January 1967, the Port Authority awarded $74 million in
contracts to various steel suppliers, and Karl Koch was hired to
erect the steel. Tishman Realty & Construction was hired in
February 1967 to oversee construction of the project.
Construction work began on the North Tower in August 1968;
construction on the South Tower was underway by January 1969. The
original Hudson Tubes, carrying PATH trains into Hudson Terminal,
remained in service as elevated tunnels during the construction
process until 1971 when a new PATH station opened.
The topping out ceremony of I WTC (North Tower) took place
on December 23, 1970, while 2 WTC's ceremony (South Tower)
occurred later on July 19, 1971. The first tenants moved into the
North Tower in December 1970; the South Tower accepted tenants in
January 1972. When the World Trade Center twin towers were
completed, the total costs to the Port Authority had reached $900
million. The ribbon cutting ceremony was on April 4,1973.
Criticism
Plans to build the World Trade Center were controversial.
The site for the World Trade Center was the location of Radio
Row, home to hundreds of commercial and industrial tenants,
property owners, small businesses, and approximately 100
residents, many of whom fiercely resisted forced relocation. A
group of small businesses affected filed an injunction
challenging the Port Authority's power of eminent domain. The
case made its way through the court system to the United States
Supreme Court; the Court refused to accept the case....
"subsidized" office space going on the open market, competing
with the private sector when there was already a glut of
vacancies. Others questioned whether the Port Authority really
ought to take on a project described by some as a "mistaken
social priority".
The World Trade Center design brought criticism of its
aesthetics from the American Institute of Architects and other
groups. Lewis Mumford, author of The City in History and other
works on urban planning, criticized the project and described it
and other new skyscrapers as "just glass-and-metal filing
cabinets" The twin towers' narrow office windows, only 18 inches
(46 cm) wide, were disliked by many for impairing the view from
the buildings.
The trade center's "superblock", replacing a more
traditional, dense neighborhood, was regarded by some critics as
an inhospitable environment that disrupted the complicated
traffic network typical of Manhattan. For example, in his book
"The Pentagon of Power," Lewis Mumford denounced the center as an
"example of the purposeless giantism and technological
exhibitionism that are now eviscerating the living tissue of
every great city. On the other hand, Yamasaki saw the expanse as
a focal point of serenity amidst the chaos of the city.
For many years, the immense Austin J. Tobin Plaza was often
beset by brisk winds at ground level. In 1999, the outdoor plaza
reopened after undergoing $12 million renovations which involved
replacing marble pavers with gray and pink granite stones, adding
new benches, planters, new restaurants, food kiosks and outdoor
dining areas.
Complex
North and South towers
With the construction of 7 World Trade Center in the 1980s,
the World Trade Center had a total of seven buildings, but the
most notable were the main two towers, which each were 110
stories tall, stood over 1,350 feet (410 m) high, and occupied
about one acre (43,560 square feet) of the total 16 acres (65,000
m2) of the site's land. During a press conference in 1973,
Yamasaki was asked, "Why two 110-story buildings? Why not one
220-story building?" His response was: "I didn't want to lose the
human scale".
When completed in 1972, 1 World Trade Center (the North
Tower) became the tallest building in the world for two years,
surpassing the Empire State Building after a 40-year reign. The
North Tower stood 1,368 feet (417 m) tall and featured a
telecommunications antenna or mast that was added at the top of
the roof in 1978 and stood 360 feet (110 m) tall. With the
360-foot-tall antenna/mast, the highest point of the North Tower
reached 1,728 ft (527 m). 2 World Trade Center (the South Tower)
became the second tallest building in the world when completed in
1973. The South Tower's rooftop observation deck was 1377 ft (420
m) high and its indoor observation deck was 1310 ft (400 m) high.
The World Trade Center towers held the height record only
briefly: Chicago's Sears Tower, finished in May 1973, reached
1,450 feet (440 m) at the rooftop.
Of the 110 stories, eight were set aside for technical
services in mechanical floors Level B5/B6, which are four
two-floor areas evenly spaced up the building. All the remaining
floors were free for open-plan offices.
(Note that "open-plan" office again mentioned - open plan, no
support beams in the open plan office - all was "open" plan -
Keith Hunt)
Each floor of the towers had 40,000 square feet (3,700 m2)
of space for occupancy. Each tower had 3.8 million square feet
(350,000 m2) of office space. Altogether the entire complex of
seven buildings had 11.2 million square feet (1.04 km2) of space.
Initially conceived as a complex dedicated to companies and
organizations directly taking part in "world trade," they at
first failed to attract the expected clientele. During the early
years, various governmental organizations became key tenants of
the World Trade Center including the State of New York. It was
not until the 1980s that the city's perilous financial state
eased, after which an increasing number of private companies -
mostly financial firms tied to Wall Street - became tenants.
During the 1990s, approximately 500 companies had offices in the
complex including many financial companies such as Morgan
Stanley, Aon Corporation, Salomon Brothers and the Port Authority
itself. The basement concourse of the World Trade Center included
The Mall at the World Trade Center along with a PATH
station. The North Tower became the home of the corporate
headquarters of Cantor Fitzgerald, and it also became the
headquarters of the Port Authority of New York and New Jersey.
Electrical service to the towers was supplied by
Consolidated Edison (ConEd) at 13,800 volts. This service passed
through the World Trade Center Primary Distribution Center (PDC)
and sent up through the core of the building to electrical
substations located on the mechanical floors. The substations
"stepped" the 13,800 primary voltage down to 480/277 volt
secondary power and further to 12/208 volt general power and
lighting service. The complex also was served by emergency
generators located in the sublevels of the towers and on the roof
of 5 WTC.
(Ah, notice again, as logic would have it, you had electrical
substations on the mechanical "floorS" with an "s" - more than
one mechanical floor. Are you getting the picture? Is your mind
moving ahead with some common logic? - Keith Hunt)
The 110th floor of 1 World Trade Center (the North Tower)
housed radio and television transmission equipment. The roof of I
WTC contained a vast array of transmission antennas including the
360 ft (approx 110 m) center antenna mast, rebuilt in 1999 by
Dielectric Inc. to accommodate DTV. The center mast contained the
television signals for almost all NYC television broadcasters:
WCBS-TV 2, WNBC-TV 4, WNYW 5, WABC-TV 7, WWOR-TV 9 Secaucus, WPIX
11, WNEF 13 Newark, WPXN-TV 31 and WNJU 47 Linden. It also had
four NYC FM broadcasters: WPAT-FM 93.1, WNYC 93.9, WKCR 89.9, and
WKTU 103.5. Access to the roof was controlled from the WTC
Operations Control Center (OCC) located in the B1 level of 2 WTC.
Top of the World observation deck
Main article: Top of the World Trade Center Observatories
Although most of the space in the World Trade Center complex
was off-limits to the public, the South Tower featured a public
observation area called Top of the World Trade Center
Observatories on its 107th floor. When visiting the observation
deck, visitors would first pass through security checks added
after the 1993 World Trade Center bombing, then were whisked to
the 107th floor indoor observatory at a height of 1,310 feet (400
m). The Port Authority renovated the observatory in 1995, then
leased it to Ogden Entertainment to operate. Attractions added to
the observation deck included a simulated helicopter ride around
the city. The food court was designed with a subway car theme.
Weather permitting, visitors could take two short escalator rides
up from the 107th floor to an outdoor viewing platform at a
height of 1,337 ft (408 m). On a clear day, visitors could see up
to 50 miles (80 km) in any given direction. An anti-suicide fence
was placed on the roof itself, with the viewing platform set back
and elevated above it, requiring only an ordinary railing and
leaving the view unobstructed, unlike the observation deck of the
Empire State Building.
Windows on the World restaurant
Main article: Windows on the World
The North Tower had a restaurant on its 106th and 107th
floors called "Windows on the World," which opened in April 1976.
The restaurant was developed by Joe Baum at a cost of more than
$17 million. Aside from the main restaurant, two offshoots were
located at the top of the North Tower: "Hors d'Oeuvrerie"
(offered a Danish smorgasbord during the day and sushi in the
evening) and "Cellar in the Sky" (a small wine bar). Windows on
the World also had a wine school program run by Kevin Zraly.
Windows on the World was closed following the 1993 World Trade
Center bombing. Upon reopening in 1996, Hors d'Oeuvrerie and
Cellar in the Sky were replaced with the "Greatest Bar on Earth"
and "Wild Blue." In 2000, its last full year of operation,
Windows on the World reported revenues of $37 million, making it
the highest-grossing restaurant in the United States.
(Ah, did you get it? There were "restaurants" in the building. Is
your mind moving along - restaurants have power - mighty power
for all their cooking etc. and that power comes from somewhere in
the building, it does not come from the sky, out of no where -
Keith Hunt)
.......................
OKAY! Now with all this background on these two towers, let's
forget about the "science lab" and some tech guy wanting to just
stick with the "textbook" (surely you have seen in your lifetime,
that the text book does not always work in the world of
practicality - I could give you examples, but surely you have
your own) and cannot, will not, or does not, use any common
sense. Sorry to say, but it is true, some people, some tech
people are "egg-heads" and cannot tell their bum from their head.
You have HUGE planes going 250 or 350 miles an hour SMASHING
into these two towers, with a MASSIVE FIREBALL EXPLOSION! The
guys who say there was an explosion from the building before the
plane hit ... well I've watched the video many times, and such
people need to get new glasses or have their eyes tested. Such
talk is gibididoish.
The planes hit - explosions immediately - the centertube of the
buildings are smashed open, along with the elevator shafts, along
with a breaking and smashing of the electrical power lines, along
with any gas lines, if the restaurants were using gas cooking.
Well ... imagine, all the power lines of whatever to make that
whole building from bottom to top WORK and function for humans,
suddenly break, with fire explosions (the hundreds of gallons of
fuel those planes were carrying in their wings) like ... well you
see it all when you view the videos. Bits of everything from the
planes to everything in those offices on the floors the planes
hit, were burning and flying all over the place. AND SOME OF THIS
BURNING STUFF WOULD HAVE GONE DOWN THE CENTER COLUMN AND DOWN THE
ELEVATOR SHAFTS TO OTHER FLOORS, AND SOME WOULD HAVE GONE DOWN
THE CENTER SHAFT TO THE BOTTOM.
NO WONDER PEOPLE SAID THERE WERE EXPLOSIONS FROM DOWN BELOW, AND
THEY COULD HEAR EXPLOSIONS FROM TIME TO TIME BEFORE THE BUILDINGS
FELL. I GUESS SO! YOU HAD ELECTRICAL WIRES ON FIRE, FLASHING
DOWN OR UP TO OTHER WIRES AND ELECTRICAL ROOMS HERE AND THERE IN
THE ENTIRE BUILDING!! I MEAN WHERE HAS COMMON LOGIC SENSE GONE
TO? SOME PEOPLE HAVE LOST IT, IF THEY EVER HAD IT IN THE FIRST
PLACE!
THESE ARE LIVE BUILDINGS SO TO SPEAK - YOU GET TWO HUGE PLANES
SMASHING INTO THEM AND YOU HAVE FIREBALLS AND EXPLOSIONS ALL OVER
THE PLACE, FROM TOP TO BOTTOM, ELECTRICAL WIRES GO FROM TOP TO
BOTTOM IN SUCH BUILDINGS, I REMIND YOU. THERE IS THIS INFERNO
GOING ON FOR AN HOUR OR SO, ELEVATOR SHAFTS CHANNELLING FIRE,
BURNING THIS AND THAT, THEN THIS ELECTRICAL SERVICE FLOOR HERE
BLOWING UP, AND SENDING OFF MORE ELECTRICAL FIRES AND EXPLOSIONS
IN ANOTHER PART OF THE BUILDING. THE WHOLE BUILDING WAS BECOMING
AN INTERNAL MESS. SOME FIRE-FIGHTERS WERE FORCED BACK. MOST
PEOPLE ONLY HAD THE STAIRWELLS TO ESCAPE DOWN, ELEVATOR SHAFTS
WERE GETTING BLOWN APART.
When you look at the videos of the fall of these buildings IT IS
NOTHING LIKE the man made im-plosions you may have seen. I lived
once in a town where the old hospital was going to be im-
plosioned. I was there to see it happen. The bombs are placed at
important points, most at ground level. When they blow, the
building shakes from the ground up, you can see the movement of
the ground level walls and foundation and it falls within itself.
When you see the two towers come down it is as clear as day, they
are coming down from the TOP down. Just as plain as the nose on
your face, but some eyes don't seem to be able to see what is
clearly in front of them. The towers fell from the top down, you
can see the massiveness of the floors finally giving way ABOVE
where the planes hit. Crashing down with such power and force,
upon a structure that had "open office plan" and of course build
section by section. You can see it falling section by section
like a ripple, but a steady ripple, and as you see it, like a
mushroom head falling down. There is no movement of the floors
way below the mushroom head, until the mushroom head is upon
them.
After it was all over some of the structure at ground level was
still standing, which is what will happen when a building falls
from the top down and not from the bottom out.
The idea that all was turned to a cement powder is also not true,
for many slabs of concrete were among the ruins. The now famous
story of the two firemen rescued in the ground zero rubble proves
there were much slabs of concrete mingled together, forming
patches of living space for some, like those two firemen that
lived through it all.
One Youtube gives the voice of a man at ground zero and the clean
up that took months, saying that what he found amazing was that
they never found one intact (or mostly intact) chair, office
desk, computer, they found nothing larger that something the size
of your hand. I think he said part of a telephone, well whatever,
it was only the size of your hand.
The POWER and the MIGHT and the FORCE and the DESTRUCTION of the
weight of those buildings coming down on top after top after top,
as the mushroom head came down .... well it was so MASSIVE that I
do not recall them finding hardly ANY remains of the people that
were killed in that downfall. It CRUSHED all people and office
equipment to powder, just about nothing inside those buildings of
concrete and steel were left to any degree of saying "Well here's
part of a desk, or chair, stove from the restaurant." You can be
sure if there was, it would be put on display as memorabilia from
an horrific part of USA history.
Those two towers came down from exactly what brought them down -
two huge planes that started a chain-reaction that would not stop
until those buildings crashed to the ground from top to bottom.
There are more arguments to answer from the "conspiracy" people.
Those arguments for another time.
............................
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