The real story of the Twin Towers blown up in New York and what they really symbolized

Fifteen years ago, on September 11, 2001, the World Trade Center complex was blown up in New York. 2996 people died, over 10 thousand were injured of varying severity. Both Twin Towers ceased to exist. Another building of the complex - the Marriott Hotel - was buried under the rubble of the first tower. The frames of the other four survived, but they were deemed unrecoverable and demolished.

Idea

With the idea of ​​building a Worldwide shopping center(WTC) famous billionaire brothers performed back in the late 1950s David and the then mayor of New York Nelson Rockefellers... They were supported by the local Port Administration. Construction of the complex began in 1966 and cost, according to some estimates, $ 1.5 billion.

The WTC skyscrapers were designed by the American modernist architect Minoru Yamasaki, who is believed to have won the competition because he offered to build the towers quickly and cheaply. He worked with Antonio Brittaiochi and by Emery Roth & Sons. Before embarking on the construction of the two giants of steel, glass and concrete, Yamasaki created hundreds of models. Perhaps he felt that the most grandiose and modern building in the world at that time would become his swan song and therefore tried to express his idea in it. “The WTC should be a symbol of faith in the power of man,” the architect said more than once.

When creating the project, Yamasaki mixed his Gothic passions and the architectural and ethical ideas of the great Le Corbusier... Subsequently, some critics called the architectonics of the WTC towers limited and boring, and the paucity of form, in their opinion, served as an "indicator of internal catastrophe." Someone considered these buildings to be the personification of the social system existing in the United States.

When the first of the colossus appeared in New York, critics called him "the biggest toe in the sky." A technical history specialist Lewis Mumford regarded Twin Towers as "an example of the unintended gigantism and technological exhibitionism that is now gutting the living tissue of every major city." Many did not like the narrow (only 46 cm wide) windows office space towers. According to the judgments prevailing then, the architect made them so, because he was terribly afraid of heights.

However, there was also an opinion that the skyscrapers of the World Trade Center personified a man and a woman. As confirmation, it was pointed out that Yamasaki emphasized the male tower with an elastic antenna, and the female tower with the gateway of the observation deck. He and She were, as it were, on the move to the Hudson and all of America. The woman, as always, was half a step behind. Perhaps it was an architectural depiction of Adam and Eve leaving Paradise? The architect himself definitely did not speak on this matter.

Design

Dozens of low-rise buildings were demolished to clear space for the grandiose construction in the city's port area. 1.2 million cubic yards of earth were removed and taken out to create a 21-meter-deep foundation under the skyscrapers and the Plaza - an underground space, where then shops, restaurants, banks, airline ticket offices, tourist offices, a new metro station, workshops for servicing the twin towers were located , warehouses and an underground garage for 2 thousand cars.

The skyscrapers were built using an engineering concept pioneered in the IBM Seattle office building. In this case, the designers also applied a structural model of a rigid "hollow pipe" of closely spaced 990 mm diameter columns, with 83 cm thick floor trusses expanding towards the central part. Many steel columns inside the building and became the load-bearing part that supported the entire building. The “stiffening ribs” in this case were complex-profile steel floors. This concept made it possible to create spacious spaces inside, not cluttered with unnecessary structures.

The facade of the buildings, 64.5 m wide, was a prefabricated steel lattice with 476.25 mm wide columns. They protected the entire structure from wind and other external overturning loads. The location of the "wind struts" outside the surface of the building prevented the transfer of forces through the membrane of the floors to the center. On each of the four sides of the building, 61 steel girders ran along the entire height. Ropes were stretched between them along the entire height. They, as well as a package of cables inside the elevator shafts, provided design flexibility. In general, the towers were a combination of steel cages made of modules produced at the plant, measuring 10x3 m and weighing 22 tons. The outer columns of the buildings were finished with a silvery aluminum alloy. This gave the impression that there were no windows at all in the skyscrapers. Although there were as many as 43 thousand.

The twins were the first ultra-tall buildings to be designed without masonry. For them, a special "dry-walled" system was developed, fixed in a reinforced steel base. The floors were supported by a series of lightweight trusses on rubber panels located between the outer columns and the elevator section. Both "brothers", according to the designers, were able to withstand hurricane winds and had to withstand even in the event of a ramming by a medium-sized aircraft such as the Boeing 707.

They were built mainly from glass, steel and concrete using duralumin and durable titanium. In total, about 400 thousand cubic meters were needed for the construction. m of cement, 200 thousand tons of steel and 20 thousand square meters. m of glass.

Exploitation

The first tower was built in 1970. But the WTC in New York was officially opened only on April 4, 1973 after the second was commissioned. The complex included five more ground structures. Among them - the high-rise "Marriott Hotel", the commodity exchange and the 8-storey palace of the American Customs. 8 floors in both skyscrapers (7-8, 41-42, 75-76 and 108-109) were technical. All the rest, with a total area of ​​more than 1 million sq. m, were rented out.

The height of the WTC skyscrapers (North Tower - 110 floors, 417 m, South Tower - 104 floors, 415 m) was at that time a constant topic of jokes and anecdotes. Here is one of them. At a press conference after the opening ceremony of the WTC, Yamasaki was asked, “Why two buildings with 110 floors? Why not one in 220? " His answer: "I didn't want to lose the human scale."

In the 1990s, the World Trade Center towers housed 10% of all offices in lower Manhattan. There were offices of almost 500 companies. So, in the South Tower 25 floors for the head office were rented by the investment corporation Morgan Stanley, which manages $ 487 billion, 5 floors were occupied by the Oppenheimer fund with "modest" $ 125 billion under management. Fuji Bank was located on four floors . The New York Stock Exchange, the insurance company AON, the telecommunications company Verizon (capitalization of $ 17.5 billion), the architectural firm Manciani Duffi (recognized as the best interior designer in 2000) and the law firm Thacher, Proffit & Wood . Modestly, only 2 floors each, had a computer corporation Sun Microsystems, the New York State Department of Taxes and Finance, and the insurance agency Frenkel & Co.

On a typical day, 50,000 employees and 200,000 visitors and tourists came to work at the WTC. On the 107th floor of the North Tower there was a fashionable and expensive restaurant "Windows to the World". There, Americans loved to celebrate weddings and celebrate various significant events. In the 1990s, tens of thousands of tourists climbed to the observation deck of the South Tower every day. On a clear day, through the suicide fence, they could survey the surroundings within a radius of 78 km.

The system of 99 lifts in the skyscrapers was arranged in such a way that from below the high-speed lifts went to the beginning of the 2nd and 3rd sections of the building, starting on the 44th and 78th floors. From there, "local" elevators lifted passengers to the desired floor. Each intersection elevator could lift 55 people at a speed of about 8.5 meters per second. In total, the WTC complex had 239 elevators and 71 escalators, which were controlled by a computer center. The windows in the two towers were washed automatically 3 times a week using special machines on movable steel cables.

Destruction

A huge design advantage of the New York twins was that the steel beams of the buildings were connected to the supports located less than a meter from each other, which form the outer walls of the building. Whereas the vertical supports of most other American skyscrapers are located at a distance of up to 6 m from each other, and the main load in them is transferred to the combined diagonal struts, the damage of which, as a rule, leads to the immediate destruction of the entire building.

And the disadvantage was the lack of foam fire protection systems that could handle burning aviation fuel. Concrete is guaranteed to withstand the flame for an hour or two. But 91 thousand liters of aviation fuel, with which both planes sent by terrorists to the buildings of the World Trade Center were fueled, turned the winged machines into thermal bombs. When the combustion temperature exceeded 800 ° C, the steel supports began to melt. However, later it turned out that the main reason for the collapse of Gemini was not this.

Several years after the tragedy, experts unequivocally established that the cause of the collapse was the gradual displacement of the center of gravity as a result of the fire in the buildings. The outer columns could not withstand the extraordinary stress.

Oleg Klimov

(based on materials from foreign press)

REFERENCE: Minoru Yamasaki — American architect who combined international style with neoclassical features. Born in Seattle, USA on December 1, 1912, to a Japanese family with American citizenship.

In 1949 he founded his own company. In 1951, he received an award from the American Institute of Architecture for a residential complex in St. Louis, USA. True, already in 1972 these buildings were destroyed as "morally obsolete and socially burdensome."

Among the most famous buildings designed by Minoru Yamasaki are the US Consulate in Kobe, Japan (1955), Lambert Airport in St. Louis, USA (1956), McGregor Memorial Community Center in Detroit, USA (1958), Dhahran airport, Saudi Arabia (1961) and Eastern Province Airport in Riyadh (1985).

He built skyscrapers and at the same time was terrified of heights. Working on the WTC buildings, Minoru Yamasaki divorced his wife, married another, then divorced and married again, then again. He eventually divorced again and returned to his first wife.

Construction Thursday 25 August 1966 - Wednesday 4 April 1973 Usage Wednesday 4 April 1973 - Tuesday 11 September 2001 Height Antenna / Spire 1 WTC: 526.3 m. Roof 1 WTC: 417 m.

2 WTC: 415 m.
3 WTC: 73.7 m.
4 and 5 WTC: 36 m.
6 WTC: 32 m.
7 WTC: 186 m.

Top floor 1 WTC: 413 m.

2 WTC: 411 m.

Technical specifications Number of floors 1 and 2 WTC: 110 floors

3 WTC: 22 floors
4 and 5 WTC: 9 floors
6 WTC: 8 floors
7 WTC: 47 floors

The area inside the building 1 and 2 WTC: 400,000 m 2

4, 5, and 6 WTC: 50,000 m 2
7 WTC: 170,000 m 2

Number of lifts 239 Architect Minoru Yamasaki

Emery Roth and Sons

Owner Port Authorities of New York and New Jersey

World trade center(eng. World Trade Center), abbr. The World Trade Center is a complex of seven buildings designed by Minoru Yamasaki, an American architect of Japanese origin, and officially opened on April 4, 1973 in New York (USA). The architectural dominant feature of the complex was two towers, each with 110 floors - North (417 m high, and taking into account the antenna installed on the roof - 526.3 m) and South (415 m high). On September 11, 2001, the WTC complex was destroyed in a terrorist attack. For some time after the completion of construction, the towers were the tallest skyscrapers in the world (before that the tallest building was the Empire State Building, which, after the destruction of the WTC, again became the tallest building in New York). Sometimes these towers are called "the symbol of US world domination."

History and construction

View of the window of one of the twin towers. It can be seen that the entire outer skin is made up of huge steel rods.

Minoru Yamasaki conceived the project of the World Trade Center in 1962, in January 1964 the architect, commissioned by the Port Authority, created the blueprints for the buildings, a little later in the same year he presented a 1: 130 life-size model for discussion, and two years later (5 August 1966) powerful excavators began to dig the foundation pit.

Before the twins, skyscrapers in New York were built on natural stone foundations. Manhattan is really stone, under a layer of earth there is stone, granite, you can see this when you watch the construction of new houses: the pits are not dug out here, but are cut down, gnawed out by the steel teeth of the cut hammers.

The first problem the engineers faced was that there was no grazing stone in the place where the twins were supposed to stand. Instead, they found artificial, alluvial soil that used to "belong" to the Hudson River. This soil was a large amount of artificial soil, mixed with layers of cobblestone, sand, gravel, pebbles, even old ships came across in artificial soil. The builders were in despair: additional difficulties, additional costs, additional concrete.

This was not the only problem that lay in wait for the architect and engineers. The next problem that befell them was 164 large and small, narrow and wide buildings, most often stone, which stood on the site of the future World Trade Center and had to be demolished. It was not difficult to take them down, but the problem still remained after that. At the same time, it was much more difficult to leave intact, and then move the saturated and complex system of underground communications, a fire alarm system, multi-core telephone and electric cables, gas, heat, pneumatic and water pipes, not to touch the highway passing nearby and to save numerous pedestrian roads and transitions.

Another problem turned out to be the underground railway station, from here begins an underwater route in New Jersey, which carries hundreds of thousands of people to and from work. If the road was closed, New York and the entire United States would face imminent economic problems. The subway carried people until a new underground station was built in the lower tier of the complex.

This is not to say that the work of the builders was easy. That only cost 1.2 million cubic meters. yards of earth that had to be dug up and taken out. Instead, under the twins, the so-called Plaza was created - an underground space where numerous restaurants and banks, tourist bureaus, airline ticket offices, shops, a new New Jersey road station, much better than the old one, were created, warehouses, technical workshops for servicing the twins and an underground garage. for two thousand cars.

Faced with the difficulty of constructing a building of unprecedented height, the engineers applied a progressive structural model: a rigid "hollow tube" of closely spaced steel columns, with floor trusses extending towards the center. Along the outer surface of each of the four sides of the building, 61 steel beams were running along the entire height, between which cables were also stretched along the entire height. The columns, finished in silver aluminum alloy, were 476.25 mm wide and installed only 558.8 mm apart, which made the towers appear to have no windows at all from a distance. The load-bearing walls were assembled from pre-fabricated steel blocks, each weighing 22 tons, 36 feet high (4 stories high), 10 feet wide. The steel laid in Gemini weighed two hundred thousand tons in total.

As the twins grew, the installers laid the floor slabs of special, prefabricated corrugated steel and durable concrete slabs... The ceilings were attached to the external load-bearing walls with outside and to the internal, only steel columns in the twins with a purely useful function - they were erected to attach internal elevators.

The elevator system used in the buildings was also unique. The Twin Towers were the first ultra-tall buildings designed without masonry. Worried that the intense air pressure generated by high-speed elevators might bend standard shafts, the engineers devised a solution using a “drywall” system anchored in a reinforced steel base. Elevators with a standard configuration for serving 110 floors may have needed half of the floor space for the shafts. Otis Elevators developed a fast and compact system in which passengers had to take turns in “heavenly lobbies” on the 44th and 78th floors, which halved the number of mines. In total, the World Trade Center complex had 239 elevators and 71 escalators, which were operated by a computer center from the Port Authority. Each elevator with a lifting capacity of 4536 kilograms could lift 55 people at a lifting speed of about 8.5 meters per second.

The laying of the foundation in the dug pit began from the north tower in August 1968, including by the forces of Italian workers, who started work at 8 in the morning and worked until 15:30 with a 40-minute lunch break at the normal rate, and after half past four worked at a double rate: the foreman received $ 40 per hour or, respectively, $ 80 per hour of work in the evening, and overtime was the rule, not the exception. Construction proceeded quickly, despite recurring funding difficulties. New York City Budget 1965-1970 was $ 6 billion. In order to raise money for investment in the construction of the Shopping Center, the city issued bonds with a guarantee of their redemption. But in 1970 New York suffered a financial crisis. The maturity date for the bonds also approached. The construction site was almost frozen. To save the situation, it was necessary to introduce new, increased taxes in the field of entrepreneurship. Another source of money was found: they began to lease the future premises of Gemini for offices. And they were expected to be huge - 100 thousand square meters. m. Of all the difficulties it was finally possible to "get out". The construction of the north tower was completed in 1971, the south tower in 1973. The inauguration of the World Trade Center took place on April 4, 1973.

In cross-section, the towers were square, with a side of 65 m. Each tower had 110 floors. The foundations of the structures went 23 meters underground. 200 thousand tons of rolled steel were spent on the frames of the buildings, and the cables of electrical networks, with a total capacity of 80,000 kilowatts, stretched for 3 thousand miles - half the distance from New York to London, across the Atlantic. The structure of the buildings was simple and sensible. The facades are made in the form of steel frames and modular aluminum sections with dimensions of 3.5 × 10 m mounted on them, manufactured by stamping at the factory. This design is earthquake resistant and able to withstand very strong wind pressure at high altitudes. According to the architects, each tower of the World Trade Center could withstand collisions with several planes, but on September 11, 2001, both towers of the World Trade Center collapsed to the ground.

Fire 13 February 1975

On February 13, 1975, three fire alarms sounded on the 11th floor of the North Tower. The fire spread through the central empty pipes up to the 9th and 14th floors due to the ignition of telephone wires in a shaft located vertically between floors. Those areas where the fire penetrated through the wires was extinguished almost immediately, the fire was dealt with after a few hours. Most of the damage caused occurred on the 11th floor, where a fire started in an office filled with paper, printing fluid and other office equipment. The fire treatment of the steel against melting saved the skeleton itself and no structural damage was caused to the tower. In second place in terms of damage was the lower floors, which suffered not so much from fire as from fire foam. At that time, the World Trade Center did not have a fire extinguishing system.

Terrorist attack on February 26, 1993

Destruction in the basement

On February 26, 1993 at 12:17 pm, a truck with 680 kg of explosives driven by Ramzi Jozef drove into the territory of the World Trade Center. It exploded in the North Tower underground garage. As a result, a blast wave made a hole with a diameter of 30 m through 5 underground floors, causing the maximum damage to the B1 and B2 levels in their entire history and significant damage to the B3 level. Six people were killed (including during the stampede at the exit) and another 50,000 workers and visitors could not breathe due to lack of oxygen on the 110 floors of the towers. Many people inside the North Tower had to climb down dark staircases, some taking more than two hours.

Yusef fled to Pakistan shortly after the bombing, but was arrested in Islamabad in February 1995 and extradited to the United States for trial. Sheikh Omar Abdel Raman was charged in 1996 with involvement in the bombing and other conspiracies. Yousef and Ayd Ismoil were sentenced to life in prison in 1997 for involvement in the bombing. Four more were also sentenced for participation in the explosion in May 1994. According to the court, the purpose of the conspirators was to completely destabilize the North Tower, followed by the South Tower - that is, the complete destruction of both towers.

After the explosion, the damaged floors had to be rebuilt, especially because they carried the structural load and were pivotal. The wall of liquid cement after the explosion was in danger, and metal plates were also lost, preventing the pressure of the Hudson water from the other side. The cooling unit on the B5 sub-level, which supplied air to the entire World Trade Center complex, was disabled.

After the attack, the port authorities installed photoluminescent markers on the walls. The fire warning system had to be completely replaced due to the fact that the wiring and alarm system of the original system were out of order. In memory of the victims, a reflective reservoir was created with the names of those killed in the explosion. As a result of the September 11 terrorist attack, the memorial was destroyed. A new memorial, common to the victims of the bombing and terrorist attack, will appear in a new complex being built on the site of the former World Trade Center.

September 11, 2001 destruction

On September 11, 2001, terrorists hijacked American Airlines Flight 11 and deliberately collided it with the North Tower at 08:46 (from the north facade, between floors 93 and 99). Seventeen minutes later, a second group of terrorists crashed a similar hijacked United Airlines Flight 175 into the South Tower (floors 77-85). Due to the destruction caused by the aircraft body to the North Tower, all exits from the building above the collision site were completely blocked, as a result of which 1,344 people were trapped. The impact of the second plane, unlike the first, came closer to the corner of the skyscraper, and one stairwell remained intact. However, few people managed to descend without hindrance until the moment the structure collapsed. But still, despite the fact that the strike of the plane on the South Tower fell below, here they were blocked between floors or less than 700 people died at once - much less than in the North. At 9:59 am, the South Tower collapsed due to a fire that damaged steel structural elements already weakened by a collision with an aircraft. The North Tower collapsed at 10:28 am after a fire that lasted 102 minutes.

At 17:20 on September 11, 2001, the eastern penthouse of the seventh building of the World Trade Center (WTC-7) collapsed, and at 17:21 the entire building collapsed due to the fact that spontaneous fires irreversibly destroyed its structure. The third building of the World Trade Center, the Marriott Hotel (WTC-3), was hit by the falling Twin Towers. The three remaining buildings of the complex were severely damaged by falling debris and were eventually demolished as they were beyond repair.
The Deutsche Bank building on the other side of Liberty Street, opposite the World Trade Center complex, was later declared unsuitable for people to be in it due to the high content of toxic compounds in the premises; now this structure is dismantled. The Feiterman Hall of Manhattan Community College at 30 West Broadway is also slated for demolition due to extensive damage sustained in the attack.

After the terrorist attack, the media reported that tens of thousands of people could be injured, since over 50,000 people could be in the complex during normal working hours. As a result of the 9/11 attack, 2,752 death certificates were issued, including in the name of Felicia Dunn-Jones, whose death was recorded only in May 2007; Dunn-Jones died five months after the attack due to a terrible lung condition caused by clouds of flying dust during the collapse of the World Trade Center buildings. Two more victims were later added to the official death toll: physician Sneha Anne Philip, who was last seen the day before the attack, and Leon Hayward, who died in 2008 from lymphoma caused by inhaling dust-laden air. that rose from the collapse of the Twin Towers. Investment bank Cantor Fitzgerald L.P., located on floors 101-105 of the World Trade Center, lost 658 employees - more than any other institution, even the Marsh and McLennan Companies located directly below the bank premises on floors 93-101 (where the plane crashed terrorists) and lost 295 people. In third place in terms of human losses (175 people) - Aon Corporation (Aon Corporation). Another 343 New York City firefighters, 84 Port Authority of New York and New Jersey officers, including 37 Port Authority Police Department (PAPD) officers and 23 New York City Police Department officers, were killed. Of all those people who were in the towers at the time of their collapse, only 20 people were removed alive, including PAPD police officers Will Gimeno and John McLaughlin (eighteenth and nineteenth survivors).

Effects

As a result, all seven buildings of the complex were destroyed: the three tallest buildings (North Tower, South Tower and WTC-7) collapsed, the Marriott Hotel was almost completely destroyed by the wreckage of WTC-1 and WTC-2, the other three buildings suffered such damage that they were found unsuitable for restoration and later demolished. Also, as a result of the collapse of WTC-2, irreparable damage was caused to the 40-storey building of Deutsche Bank, which is currently being dismantled.

A memorial complex was erected on the site of the collapsed twin towers.

Buildings of the new complex

• Freedom Tower 1 )
• 200 Greenwich Street (Tower 2 )
• 175 Greenwich Street (Tower 3 )
• 150 Greenwich Street (Tower 4 )
• 130 Liberty Street (Tower 5 )
• World Trade Center Transport Hub

Notes (edit)

1. Builders: WTC Towers Collapsed Due to Pancake Effect
2. 9/11 Commission Report. The National Commission on Terrorist Attacks Upon the United States. Archived
3. Dwyer, Jim, Lipton, Eric et al .. 102 Minutes: Last Words at the Trade Center; Fighting to Live as the Towers Die, The New York Times(May 26, 2002). Archived from the original on October 10, 2008. Retrieved May 23, 2008.
4. NIST NCSTAR 1-1 (2005), p. 34; pp. 45-46
5. FEMA 403 -World Trade Center Building Performance Study, Chapter. 5, section 5.5.4 (PDF). Archived from the original on August 27, 2011. Retrieved January 30, 2011.
6. Final Report on the Collapse of World Trade Center Building 7 - Draft for Public Comment xxxii. NIST (August 2008). Archived from the original on August 27, 2011.
7. World Trade Center Building Performance Study. FEMA (May 2002). Archived
8. World Trade Center Building Performance Study - Bankers Trust Building. FEMA (May 2002). Archived from the original on August 26, 2011. Retrieved July 12, 2007.
9. The Deutsche Bank Building at 130 Liberty Street Archived from the original on August 26, 2011. Retrieved July 12, 2007.
10. Fiterman Hall - Project Updates. Lower Manhattan Construction Command Center. Archived from the original on August 26, 2011. Retrieved November 19, 2008.
11. DePalma, Anthony... For the First Time, New York Links a Death to 9/11 Dust, The New York Times(May 24, 2007).
12. Official 9/11 Death Toll Climbs By One, CBS News(July 10, 2008). Retrieved August 29, 2010.
13. Foderaro, Lisa W.... 9/11 "s Litany of Loss, Joined by Another Name (September 11, 2009). Retrieved August 29, 2010.
14. Siegel, Aaron... Industry honors fallen on 9/11 anniversary, InvestmentNews(September 11, 2007). Retrieved May 20, 2008.
15. Lung Ailments May Force 500 Firefighters Off Job, The New York Times(September 10, 2002). Retrieved May 23, 2008.
16. Post-9/11 report recommends police, fire response changes (August 19, 2002). Retrieved May 23, 2008.
17. Police back on day-to-day beat after 9/11 nightmare, CNN(July 21, 2002). Retrieved May 23, 2008.
18. Oliver Stone's film premiered in New York, Radio Liberty(August 07, 2006). Retrieved March 5, 2011.

see also

• World Trade Center Memorial
• List of world trade centers (eng. List of world trade centers )

Links

• Official site (eng.)
• Genis, Alexander... September 11: Images of Tragedy (about the book: David Friend, Watching the World Change), Radio Liberty(September 13, 2006). Retrieved March 5, 2011.
• Genis, Alexander... September 11: "Gemini Day" Radio Liberty(September 08, 2008). Retrieved March 5, 2011.
• Kopeikin, Anatoly... I keep looking somewhere in the sky, as if looking for an answer, or an amazing story, Russian thought(June 06-12, 2002). Retrieved March 5, 2011.

Ultra-tall buildings (see also the list of buildings above 100 floors)
Constructed
During construction	23 Marina 175 Greenwich Street Ahmed Abdul Rahim Al Attar Tower Al Hamra Tower Al Yaquob Tower APIIC Tower Central Market Project China 117 Tower DAMAC Heights Diamond Tower Gift D1 Tower Dubai Towers Doha Elite Residence Emirates Park Towers Faros del Panamá

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World Trade Center. New York Twin Towers - Fallen brothers

New Yorkers called the Twin Towers the skyscrapers of the World Trade Center, which were destroyed on September 11, 2001 in a terrorist attack. This event became a national tragedy for the United States. It was not in vain that the terrorists chose the Twin Towers as their target, because they were national pride country, a symbol of democracy and a symbol of the greatness of the American people. Today we are reminded of the Twins Towers by a huge memorial built on the site of the tragedy. In many pre-9/11 Hollywood films, we can see the panorama of New York City's Dream City, where the World Trade Center towers are imperative. The tourist postcards of those times also traditionally depicted gigantic "twins". And how many souvenirs associated with these towers were made! Unfortunately, now these trinkets are more likely to remind us of the sad:

However, this article was not planned as an essay in memory of the fallen colossi, but rather as a story about an architectural masterpiece that has gone into oblivion, but, nevertheless, has retained a good memory of itself. Naturally, there is no project exactly copying the WTC in the plans of American urban planners. Why strive to repeat the success? Let the Towers "live" in our hearts.

However, in addition to the memorial on the area once occupied by the WTC, it was nevertheless decided to build several high-rise buildings. Indeed, such a tidbit area of ​​Manhattan is not empty, is it? The Freedom Tower skyscraper, which will have a height of over 500 meters, is already at the construction stage. It will be roughly completed by 2013. In addition to this office building, there are 4 more projects, but so far they only exist on paper. 3 high-rise towers and one residential building have been developed. These giants will grow up next to the memorial on Greenwich Street.

Before starting the story about the Twins Towers, let's give a little explanation. The World Trade Center was actually a complex of seven buildings, which included the ill-fated North and South Towers. Each of the towers contained 110 floors, but the height varied - at the South Tower it was 415 meters, and the North - 417. Nearby was the 22-storey Marriott Hotel, which had the abbreviated name of WTC-3. Three more buildings, WTC 4-6, had 9 floors, while WTC-7, located across the street from the rest of the complex, had 47 floors.

Construction history

The idea to build a grandiose skyscraper was born in the post-war years. The US economy was actively reviving after the recession caused by the Second World War. In the 50s, most large companies had their offices in New York, specifically in Manhattan. Influential businessman David Rockefeller, using the guarantee of his brother Nelson, (who served as governor of the city), proposed to start the construction of the World Trade Center here. The project was supported by the Port Authority of New York and New Jersey. The entire project was led by the Manhattan Creative Association, of which David Rockefeller was the head. It was assumed that at the end of construction, the WTC will contain about 4% of all office real estate in the city.

For some time, the project remained only in the minds of his associates, but at the end of the 50s, the WTC was taken up in earnest. This was mainly due to the political situation in the country. In those years, the citizens of the United States noticeably lost faith in the further development of democracy and the country's prosperity. It was then that the authorities decided to implement Rockefeller's ideas, teaching the World Trade Center "under the sauce" of a national project. According to the authorities, the giant complex could rally the entire people of America around itself. Eminent architects vied with each other to offer their projects, but preference was given to the development of Minoru Yamasaki. This Japanese-American architect is the author of many beautiful backdrops, including the St. Louis Airport, the Concrete Institute, the Arts and Crafts Institute in Detroit. Architect Antonio Brittechi and Emiri Roth & Sons worked with Minoru Yamasaki on the concept of the WTC.

In 1964, by order of the Port Authority, the first drawings of the future twin towers were created with a decrease of 130 times, and on August 5, 1966, the construction of skyscrapers began.

From the very first days at the construction site, various technical problems... On the site of the future construction there was not a stone, but an artificial soil, which is a mixture of cobblestones, sand, and bare. Therefore, it took a lot to build the foundation of "Twins Tower" more concrete than originally planned, this circumstance led to a sharp increase in the cost of building the facility.

Then it was necessary to solve a difficult engineering and technical problem. On the site of the future skyscrapers, it was required to demolish about 160 buildings, but at the same time preserve all engineering communications (gas, water, sewerage, electrical cables, etc.), as well as the high-speed highway and road network passing nearby.

Another important problem was the underground railway line passing in this place. It was impossible to close it, since every day tens of thousands of people traveled by subway to work and home. The authorities decided not to lay alternative transport routes, as this would further increase the costs of building the towers. Therefore, the New York subway line functioned until a new one was launched, with a station at the lowest tier of the WTC complex.

During the construction of the "Twins Tower" more than 1.2 million cubic yards of soil had to be removed from the ground. The formed pit became not only the foundation of the twin towers, but also the Plaza was organized in it, which is a huge space that housed a parking lot for 2,000 cars, a new underground railway station, restaurants, offices of various companies, banks, warehouses, shops, etc. etc.

According to the plan proposed by Minor Yamasaki, the "Twins Tower" were supposed to become not only the tallest skyscrapers in the United States of America, but also in the world. And this meant that the Twin Towers should be given a greater height than the Empire State Building, which at that time firmly held the palm of the largest building on the planet. For this, an interesting engineering solution was invented. In fact, the towers were a very sturdy hollow metal tube constructed from columns with trusses for the floors. Along the walls of the building were 61 beams made of special steel. Each column had a diameter of 476.25 mm, they were installed tightly to each other. The distance between the beams was only 558.8 mm. The weight of each such steel block was as much as 22 tons, and the height was equal to 4 floors of the future building! In total, about 210,000 tons of heavy-duty steel were used to construct the skyscrapers. The floors between the floors were made of concrete slabs and corrugated steel, which were attached to the load-bearing elements of the entire structure. Steel columns were erected inside the buildings for future elevators.

The twin towers were the first building in the world without the use of masonry, and the engineers feared that the high pressure of the air currents could disrupt normal work elevator shafts. Therefore, a special engineering system was developed for the elevators, which was later called "dry-walled". For a standard elevator system serving a skyscraper, almost half of the entire area of ​​the lower tier would have to be used in order to accommodate the elevator shafts, which was not economically viable. Therefore, the specialists of the "Otis Elevators" company have developed a special system called "fast" and providing for the transfer of passengers on the 44th and 78th floors of the buildings. This elevator system made it possible to reduce the number of elevator shafts by half as compared to the traditional system. As a result, 239 elevators and 71 escalators were operating in the "Twins Tower" complex. Each elevator was designed for a carrying capacity of 4535 kilograms, that is, it could simultaneously lift 55 people. The speed of the elevators was 8.5 meters per second. By the way, this system of "transplants" was also used by engineers in the design of other skyscrapers, which were born much later than Gemini.

During the construction of the facility, financial difficulties arose more than once, but, despite this, the construction not only did not stop, but also proceeded rapidly. In 1965-1970, the New York authorities could not fully finance the construction, so credit bonds were issued. In 1970, a major economic crisis broke out, as a result of which the government stopped paying off the bonds. At first, the administration decided to freeze construction for several years. But then this seditious idea was abandoned, because the prestige of the United States could be greatly affected by these measures. Then economists devised another way of financing and the money was found. Taxes for entrepreneurs were increased, lease agreements for office space in the skyscrapers of the World Trade Center were concluded (with prepayment), etc.

The construction of the North Tower was completed in 1971, and the South Tower was commissioned two years later. The official opening date of the World Trade Center in New York is April 4, 1973.

Features of the WTC Towers

As a result, the twin towers became the tallest skyscrapers in the United States. Each "giant brother" had 110 floors. The height of the 1st building of the World Trade Center was 526.3 meters including the antenna. The last floor in the South Tower was 411 m from the ground, and in the North - at 413! The depth of the foundation was 23 meters underground. The length of the power supply cables exceeded 5,000 kilometers, and the total capacity of the electrical network was about 80,000 kW. Thus, the builders really managed to bring to life the "Project of the Century", which has become one of the symbols of the United States, the pride of the American people.

In the last years of the Complex's existence, about 50,000 people came to work at the WTC every day, and another 200,000 people a week visited the World Trade Center as tourists.

An Observatory was set up in the South Tower on the 107th floor. From the observation deck, a magnificent view of the city opened up. The North Tower, between the 106th and 107th floors, housed the chic "Windows to the World" restaurant, which opened in 1976 and was the world's highest-rise dining facility.

At that time, no one could have thought that these towers would one day fall. After all, the frame of the building, according to the assurances of the engineers, could withstand an impact of colossal force, for example, when rammed by an airplane. The towers were all the more not afraid of the strongest gusts of wind that raged at an altitude of 400 meters. The construction of the skyscrapers was distinguished by high strength, stability, thanks to the facades made in the form of steel frames and aluminum modular sections mounted in them. These elements were 10x3.5 meters in size. All technical tricks turned out to be in vain, since in the fall of the planes it was not the destructive force of the collision that played a decisive role, but the high temperature. As a result of the explosion of fuel tanks containing more than 5,000 liters of gasoline, steel instantly heated up to 1,000 degrees Celsius! This is what provoked the collapse.

reference

At present, on the site of the twin towers, the construction of three new skyscrapers is underway, under the working names Tower No. 2, No. 3 and No. 4 and a tower with a height of 541 meters, which received the symbolic name "Freedom Tower". All new buildings will be strikingly different from the first towers that fell in the terrorist attack. The ceremony for the start of construction of the new World Trade Center was held in July 2004, and the construction itself began on April 27, 2006. The site is being developed by Larry Silverstein, a real estate entrepreneur. According to the plan, the completion of the construction of the Freedom Tower should take place before 2013. In addition to this tower, the new World Trade Center in New York will also include a residential skyscraper, three high-rise office buildings, a museum and memorial to the victims of the September 11, 2001 tragedy, and a concert and exhibition center. Many Americans have dubbed the 540-meter skyscraper "The Tower of Fear" because during its construction, innovative technologies will be used to prevent destruction during a terrorist attack of any force. In particular, it is planned to clothe the first 52 meters of the building in concrete frame, and for exterior decoration apply glass of a prismatic shape, this is the only way to avoid the notorious visual effect of the "stone bag".

The construction of this complex was a symbol of the post-war prosperity of the United States of America. Its destruction 11 years ago became new point countdown, dividing the history of the planet into the next "before" and "after". Behind these events of gargantuan proportions, it is almost invisible that the buildings built in the early 1970s were an outstanding engineering structure of their time. The World Trade Center, which existed for only 30 years, nevertheless managed to become one of the architectural icons of New York, says blogger Darriuss.

The United States emerged from World War II as a superpower. Its largest city, New York, became the capital of world diplomacy with the establishment of the headquarters of the United Nations in 1945, and was seriously preparing to become the most influential center of international trade. However, the initial plans for the construction of the necessary infrastructure for this, which included the construction of a complex of 21 buildings with a total cost of $ 150 million in the early 1950s, were frozen in 1949.

Again to the so-called project The World Trade Center returned at the end of the next decade, tying it to the redevelopment of Lower Manhattan, spearheaded by billionaire David Rockefeller. He attracted the largest US architectural firm to create the concept of the WTC - Skidmore, Owings and Merrill of Chicago, who submitted a conceptual design in 1960 for the new complex on the east side of the island, along the East River. The World Trade Center as represented by SOM consisted of 50 - A 70-storey high-rise building in the "international style", reminiscent of the UN headquarters (office space and a hotel were to be located here), and the adjacent (275 meters long) volume of the exhibition center. 1960 version.

A year later, an option with several high-rise buildings was proposed.

In 1961, the so-called Port Authority became the developer of the project, the Port Authority of New York, an organization responsible not only for the port facilities of the metropolis, but also owning all of its coastal infrastructure (land, tunnels, roads), and not only the city of New York itself but also the state of New Jersey in its area. After consultations between the Port Authority and the US authorities, a conceptual decision is made to move the construction of the WTC from the East River to the opposite, western side of Manhattan. The original site of the World Trade Center is highlighted in orange, in red - new, where the project was eventually implemented.

This site (already on the banks of the Hudson) was much more profitable for the state of New Jersey, located on the opposite side of the river. In accordance with mutual agreements, the New York Port Authority bought from New Jersey the unprofitable high-speed underground railway Hudson and Manhattan Railroad, which connects the state with Manhattan. After - demolished its main Manhattan terminal (Hudson Terminal), without affecting the actual tunnels of the road, and deployed the construction of the WTC in its vicinity. This 1919 photo showing the city's still Art Deco skyline, Hudson Terminal - these are the two dark buildings to the left of the center of the image. The WTC is located on the site of low-rise buildings in the lower left corner.

The demolition of these quarters caused a considerable scandal at the beginning of the construction of the Center. Its skyscrapers were designed on the site of Radio Row, Manhattan's borough, home to hundreds of small shops, offices and warehouses selling radio and other electrical equipment. This is what Radio Row looked like in the 1930s; some buildings here date back even to the 1850s.

This is how the area looked from a bird's eye view. The white line marks the site, which was eventually occupied by the WTC complex.

Many shop owners in Radio Row and about a hundred people who had apartments there, as often happens, categorically refused to move anywhere, even for compensation. Pickets, demonstrations and lawsuits, however, did not have much success. This project was too important for the municipal authorities, the amount of investments being mastered was too large.

The resettlement of Radio Row began in 1965 and was largely complete by 1967.

Five years later, modern skyscrapers will grow here.

New York skyline from the opposite, New Jersey, coast of the Hudson. In the center - low-rise Radio Row, behind it - Hudson Terminal. Note that the train station looks like a symbolic predecessor to the WTC. Also two towers (1909, architect James Hollis Wells, bureau Clinton and Russell), at one time high (22 floors), almost twins, served as a business center located above the railway terminal itself hidden underground.

On September 20, 1962, having finally decided on the site and getting involved in the battle for the settlement of the site, the Port Authority chose the chief architect of the project. It was Minoru Yamasaki, an American of Japanese descent. He lived in the suburbs of Detroit, pcs. Michigan, and therefore the local New York workshop Emery Roth & Sons was assigned to provide him with technical assistance. The customer gave Yamasaki the following challenge: to place 930,000 sq. M. On a 16-acre site (65,000 sq. M). m of office space. The architect went through several dozen conceptual options: a single skyscraper, a set of smaller "skyscrapers", but in the end settled on the option of building two 110-storey twin towers surrounded by several relatively low-rise buildings. 1964 sketch.

In January 1964, a model of the project was presented to the city and the world.

So, the plan for the World Trade Center. Its main elements were two identical "skyscrapers", the so-called North and South towers (1 WTC and 2 WTC on the plan, respectively). The perimeter of the building site was completed by 4 complex buildings, numbered 3-6 and built in 1975 - 1981 years. In the center of the site, a large square was created ("plaza" in American terminology), which served for recreation and distribution of pedestrian flows into the buildings of the complex. All six buildings formed one giant "superblock", which took the place of a dozen previously existing here. Finally, in 1987, a high-rise business center (7 WTC) was added to the WTC, formally outside the original site.

The twin towers were designed to be square in plan with a side length of 63 meters. Yamasaki's fundamental innovation was his proposal to build them with a load-bearing outer frame forming a rigid "tube", which would be complemented by an inner core, standing on the rocky base of Manhattan. This design, instead of the previously widely used scheme with columns carrying loads distributed over the entire internal area of ​​the building, made it possible to obtain more office space. In addition, the latter were suitable for subsequent free planning at the request of the tenants.

Typical skyscraper floor plan. The outer frame of the building is formed by metal columns located along the perimeter (59 pieces on each side of the building, the length of the column side - 36 cm, marked on the plan with small squares). The corners of the square perimeter are chamfered. In the center is a rectangular (27 × 41 m) core, the base of which is made up of another 47 steel columns, standing right on the rocky base of Manhattan Island. The engineering infrastructure is also concentrated in the core: technical shafts, elevators, stairs, utility and auxiliary premises. The office space surrounds the core and is completely free of supporting columns.

Additional stability was given to the building frame floor slabs connecting the perimeter columns, taking part of the weight load and redistributing wind loads. Structurally, each of these floors consisted of a grid of steel trusses (main and connecting them transverse), covered with sheets of corrugated metal and poured on top with a thin layer of concrete.

Interfloor floors and the supporting outer frame of skyscrapers close-up.

In addition to the structural scheme of the building, Yamasaki also used a number of other advanced solutions at that time. For example, he faced the following problem common to all high-rise buildings. The higher the skyscraper, the more elevators are required to serve its occupants. With an increase in the number of elevators, the useful area of ​​the tower decreases in direct proportion. The architect found an elegant way out of this situation. He divided the entire office space of the WTC skyscrapers into 3 equal parts. The floors bordering between them (44th and 78th) were given over to the so-called "sky lobby". The third vestibule was the reception on the first floor of the tower, called the Concourse. The meaning of the idea was as follows. All elevators in the core of the skyscraper are divided into huge “express elevators” that can accommodate several dozen people, but move only between interchange “heavenly lobbies”, and several clusters of “local” elevators, each of which served its own set of floors of a particular segment of the tower. This scheme made it possible to evenly provide each floor of the "high-rise" with elevators, while without uncontrolled inflation of their number (we stopped at the number 99 elevators per tower). The traditional scheme would allow using only 62% of the area of ​​each floor for offices; transfer lobbies increased this figure to 75%. There were also direct "express lifts" that moved exclusively between the 1st and 107th (last inhabited) floors of the towers, which housed the restaurant and the observation deck.

The Sky lobby floors were interconnected with the technical floors, where the equipment serving the towers was located. On the facade of the "skyscrapers" these auxiliary levels are well marked.

Yamasaki's signature style, who loved tall, narrow, almost Gothic-style windows (as they say, not least because of his own fear of heights), fit perfectly into the design of skyscrapers. The frequent mesh of the load-bearing outer columns made it possible to make windows only 45 cm wide, which made the towers look like a solid steel monolith from a distance.

Upon closer examination, the monolith turned out to be not at all solid, and besides, it was not even steel. For better resistance to corrosion, the metal frame of the building is clad with aluminum alloy panels.

In March 1965, the Port Authority begins buying up real estate at the promising site of the World Trade Center. A year later, in parallel with the resettlement of the site, the demolition of its old buildings begins, which ends in 1967.

During the earthwork phase, architects, engineers and builders face a major challenge. The fact is that the repurchased site, formally being Manhattan, was actually part of the island rather conditionally. Over the centuries of its development, the original coastline has changed significantly. Faced with a shortage of land for construction, local residents were actively reclaiming new areas. In this diagram, the original Manhattan coastline is marked with blue dots, gray outlining areas, and a red circle - location of the WTC.

The future World Trade Center was located just on the reclaimed area, and for the construction of buildings it was necessary to get to the rocky base, hidden by 20 meters of alluvial soil.

Already at the end of 1966, to solve the problem, the formation of the so-called "bathtub" began. The WTC site is fenced off using the “wall in the ground” technology: roughly speaking, a rather narrow trench is dug along its perimeter, which is subsequently poured with monolithic concrete (the whole process took 14 months). After the removal of the alluvial soil, a huge pit is formed, surrounded by a concrete wall, which prevents the penetration of groundwater and the water of the Hudson River into the interior. The base of the pit, which was called the "bathtub", is the required rock. Photo of July 1968.

Left - "Wall in the ground". The WTC was one of the earliest examples of the large-scale use of this technology. On the right is the frame of the WTC.

During the formation of the "bath", a million cubic meters of alluvial soil was extracted from it, which had to be disposed of. The architects again acted extremely elegantly: 917,000 cubic meters of surplus land moved just a few tens of meters to the west and formed a new reclaimed plot, which the project developers could later also use for commercial construction. In this picture, the Hudson reclaim site is in the foreground. To the left is the former coastline with piers.

The expansion of Manhattan's area continues. Battery Park is visible in the right corner (with the stadium). In honor of him, the area, located on the squares reclaimed from the river (on the left), was named Battery Park City.

In this remarkable photo, showing that New York is also a city of contrasts, the twin towers from the Hudson side and the new alluvium are not yet obscured by anything.

Since 1980, the development of the alluvium began. Ultimately, dozens of residential, administrative and public buildings were located here, including the so-called World Financial Center, which formed a single cluster with the WTC. Towers of the WFC and eventually blocked the WTC from the Hudson.

As mentioned, the World Trade Center was being built next to the Hudson and Manhattan Railroad subway station. One of the features of the development of the territory was the presence of two railway tunnels on it. Amazingly, the construction of skyscrapers did not interfere with her work. In the process of forming the bath, the tunnels were excavated and then built into the underground levels of the complex, where a new station was later organized to replace the demolished Hudson Terminal. Pay attention to the upper right part of the image - this is a fragment of the tunnel.

In addition to the railway station, a huge shopping mall and a parking lot for 2000 cars were built in the "bath". The tunnel is in the foreground of a 1969 photograph.

And in this picture, you can see that the frame of the twin towers was going right around the tunnels.

The lower six floors of the skyscrapers formed huge lobbies. Here, the supporting columns were more powerful, but they were less frequent, which provided better natural lighting for the foyer and reception area. At the level of the sixth floor, the columns were arranged, forming a kind of tridents, the trademark artistic technique of Minoru Yamasaki.

The supporting columns of the outer perimeter were made of steel at third-party enterprises and delivered to the construction site in already partially assembled blocks, which made it possible to significantly intensify the construction process. Each such element weighed 22 tons. On average, one floor of the tower was erected in 5 days, and the assembly of the entire 110-storey high-rise took only a year and a half.

Special self-expanding Kangaroo cranes purchased in Australia were used for the construction.

The structural diagram of the towers is clearly visible: an internal rectangular core and an external supporting frame.

The "twins" looked especially impressive at sunset, when the sun shone through them.

The northern tower was built from August 1968 to December 1970, the southern tower from January 1969 to July 1971. The entire complex cost the developer $ 900 million in 1971 prices, although it was originally estimated at $ 350 million. Total weight The amount of steel consumed for the construction of the complex was about 200,000 tons.

The color photographs clearly show the characteristic rusty color of the metal structures of the frame. Subsequently, it was treated with special anti-corrosion and fire-fighting compounds, but instead of painting it was lined with aluminum panels.

The process of construction (above), processing (behind the yellow screens) and cladding (below) of the skyscrapers went in parallel.

The construction of the North Tower was completed in 1971, and the South Tower was commissioned two years later. The official opening date of the World Trade Center in New York is April 4, 1973.
Characteristics of the WTC Towers:
As a result, the twin towers became the tallest skyscrapers in the United States. Each "giant brother" had 110 floors. The height of the 1st building of the World Trade Center was 526.3 meters including the antenna. The last floor in the South Tower was 411 meters above the ground, and in the North - at 413! The depth of the foundation was 23 meters underground. The length of the power supply cables exceeded 5,000 kilometers, and the total capacity of the electrical network was about 80,000 kW. Thus, the builders really managed to bring to life the "Project of the Century", which has become one of the symbols of the United States, the pride of the American people. In the last years of the Complex's existence, about 50,000 people came to work at the WTC every day, and another 200,000 people a week visited the World Trade Center as tourists. An Observatory was set up in the South Tower on the 107th floor. From the observation deck, a magnificent view of the city opened up. The North Tower, between the 106th and 107th floors, housed the chic Windows to the World restaurant, which opened in 1976 and was the world's highest-rise dining facility. At that time, no one could have thought that these towers would one day fall. After all, the frame of the building, according to the assurances of the engineers, could withstand an impact of colossal force, for example, when rammed by an airplane. The towers were all the more not afraid of the strongest gusts of wind that raged at an altitude of 400 meters. The construction of the skyscrapers was distinguished by high strength, stability, thanks to the facades made in the form of steel frames and aluminum modular sections mounted in them. These elements were 10x3.5 meters in size. All technical tricks turned out to be in vain, since in the fall of the planes it was not the destructive force of the collision that played a decisive role, but the high temperature. As a result of the explosion of fuel tanks containing more than 5,000 liters of gasoline, steel instantly heated up to 1,000 degrees Celsius! This is what provoked the collapse.

Destruction of the World Trade Center.

Evidence of explosives in the Twin Towers.

Millions of people around the world watched the events around the WTC live on CNN on September 11, 2001 and could hardly believe their eyes. They saw huge puffs of smoke over Manhattan and saw the towers collapse ... in a strange way. They didn't fall apart; they "LOOKED" in such a way, as many have seen during CONTROLLED DEMOLITION: the building does not collapse chaotically, scattering debris over a wide area; rather, it comes crashing down on itself. This is how the WTC towers collapsed.
That the destruction of the towers was controlled was immediately noticed by some astute observers:
Well, is it just me, or did someone else realize that the WTC was not destroyed by aircraft attacks? For me personally, this is the most frightening moment of this morning. ...
If you look at the timing, you will see that everything happened as follows:
- The plane crashes into the 1st tower, making a breach at the very top. Next, the expected things happen:
- The tower remains standing. The reinforced concrete building is * extremely * robust. The terrorists have already detonated a large bomb * inside * the same building without much damage. ...

The second plane crashes into the second tower, lower and at a higher speed. He punches a larger hole in it, debris pours into the streets, but the building nevertheless stands and looks quite solid.
- The second building starts to burn, also up from the collision site.
- About half an hour later, the fire in the first building * goes out *. It is still smoldering and black smoke is coming out, but there is no flame. ...
- The fire in the second building is extinguished.
- The second building suddenly crumbles into dust, as if a smooth wave ran from the top of the building (above the place of burning) down through all the floors at the same speed. The debris mostly falls inward. Individual solid pieces do not fall off the building and do not collapse onto the surrounding houses. ... The destruction started from the top (above the collision point). It happens evenly. All structural elements are destroyed in sequence, so that no supporting skeleton remains. The destruction is uniform, symmetrical and absolute.
To summarize: it all looks like demolition - because that's what it is.
- The first tower collapses as a result of a similar "wave".
There is no doubt that the planes hitting the towers caused serious damage. But look at the pictures - these buildings were just * razed to the ground *. Demolishing a building does not require a lot of explosives, but it needs to be placed in the right places (in direct contact with structural elements) and detonated in an even, synchronized sequence. ...
This message appeared on the Internet on September 11th, a few hours after the destruction of the Twin Towers. From the very beginning, some people were not deceived.

At first, the explosives theory had a problem: there was no media report that anyone heard the explosions just before the collapse of the WTC. But for Last year such messages appeared, there is even a video footage in the public domain, demonstrating that there were actually explosions inside the Twin Towers before their collapse.
Viewers watching the terrible events of September 11th saw the explosions before the towers collapsed. Television images show what appears to be a violent explosion close to ground level near the 47-story Salomon Brothers building, known as WTC-7, before the first tower collapsed.
... One witness, based near the World Trade Center, told AFP that he was standing in a crowd on Church Street, about two and a half blocks from the South Tower, when he saw "a series of short flashes emanating from inside the building between 10 and 15 floors. " He saw about 6 of these short flashes, followed by a "crash" before the tower collapsed. Each tower had six bearing columns.
One of the first firefighters in the second tower to be attacked, Louie Cacchioli, 51, told People Weekly on September 24th: “I took the firemen in an elevator to the 24th floor to evacuate employees. bombs were planted in the building. "
Kim White, 32, an employee from the 80th floor, also reported hearing an explosion. “All of a sudden the whole building shook, then it started to sway. We didn't know what was going on,” she told People. "We gathered all the people from the floor to the stairwells ... at the time we all thought it was a fire ... We went down to the 74th floor ... then another explosion was heard."
(Many eyewitness accounts insist on the presence of bombs when the WTC collapsed.)
The Danish site offers 4 hours of video footage containing evidence of what happened on September 11th and what was silenced or ignored by the mainstream media:
Falling Towers video clips were often edited in such a way that it was impossible for TV viewers to get the "Full picture" of the entire collapse of the towers. ... During my 1000 hours of video investigation, I found very few "long distance full-length images" that showed the entire towers (top to bottom). Most of the September 11 video clips we saw (and over the coming weeks) are edited versions ... [which] do not show at all the numerous "clouds" from EXPLODING bombs "erupting from the windows" of the WTC façade well below the impact site. ... Someone in the "editorial" didn't want to show us the "Full picture"!
But some of the most important BOMB video evidence remains! In my video, I will show you 5 significant "DUST CLUBS" from devastating bombs exploding INSIDE the WTC Towers. These "bomb clouds" were approximately 20 and 40 levels BELOW the collision level of the falling towers. ... They provide complete proof of Destruction Bombs detonated MUCH BELOW "point of impact".
("Bombs Inside the World Trade Center").
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The WebFairy 911 Memorial site has some very interesting videos. Particularly interesting is the clear evidence of the explosions that occurred during the fall of the North Tower.
On the left is a controlled demolition footage: note what WebFairy calls "demolition firecrackers," clouds of debris and dust that are thrown horizontally by exploding charges placed on multiple levels in the building to be demolished.
Now look at the image on the right: this is a footage of the collapse of the North Tower. Two horizontal explosions are clearly visible before debris reaches the bottom of the frame.
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But not only the Twin Towers were deliberately destroyed, but also the building known as WTC 7.
"Not quoted by the monopolized press, some firefighters who survived Black Tuesday insist that there were explosions in the buildings, in parts of the Twin Towers of the World Trade Center, separately and away from the impact of the aircraft crashing into the buildings. ... Was the explosive inside the buildings detonated. remotely to demolish towers, as is done with old buildings? And there is good reason to believe that the explosives inside caused the mysterious collapse, already on Black Tuesday evening, of building number 7 of the World Trade Center complex. "
(Sherman H. Skolnick: "The Overthrow of the American Republic" Part 14).
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The Twin Towers collapsed in a very strange way, with almost nothing left but metal fragments of the outer wall and a huge amount of fine ash and dust, without the central steel columns of the lower sixty stories standing or falling. It is very strange. Take a look at all this dust (click on the image to enlarge it and also see the next two photos of the dust clouds). It was as if some kind of high-energy destruction beam was focused on the towers, spraying each concrete block into the smallest particles of ash and dust.
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But, while some types of "dark" technologies could be used to destroy the Twin Towers, we do not need to prove this, since the fall could well be explained by controlled demolition with explosives. In fact (as Christopher Bollyn first pointed out in his Open Letter), evidence of strong explosions was recorded by seismographs located 34 km from the WTC:

"A sharp peak of short duration" - this is how an underground nuclear explosion looks on a seismograph.
The seismograph that recorded this data worked at Columbia University's Lamont-Doherty Earth Observatory. The American Geophysical Union published a report in the November 20th issue of Eos, but the authors misinterpreted the data. They speculated and reported that the two largest signals were caused by the fall of the Twin Towers. But:
"During the collapse, most of the energy of the falling pieces was absorbed by the towers and surrounding structures, converting them to debris and dust, or causing other damage - but not producing significant earthquake."
(Dr Arthur Lerner-Lam, director of Columbia University's Center for Hazards and Risk Research, as cited in Earth Institute News).
Thus, if most of the energy of the falling debris was dissipated and was not the cause of the main peaks in the seismic record, then what was it? Perhaps the strongest explosions at the lowest levels (minus 7th level) of the Twin Towers foundation, near the supporting steel columns, where they rested on the rock formations of Manhattan? Maybe even small NUCLEAR explosions?
This, together with numerous small explosions at every tenth or so the level of the supporting steel columns, may explain an observation that the official version does not explain: why did the bottom of the massive steel supporting columns not remain standing after collapse? If the official version is correct that the destruction was the result of collisions and fire, which occurred only on the upper floors, and that the floors then "settled" on top of each other, one would expect that the steel columns in the core, say, 20 or 30 lower floors , had to stay standing, which did not happen. But this becomes understandable if the foundations of the steel columns were destroyed by explosions at the level of the rock. With the base destroyed and the supporting steel columns destroyed by explosions at different levels of the Twin Towers, the upper floors lost their support and collapsed to ground level in about ten seconds.
Further evidence of the presence of explosives is provided by video footage of the South Tower collapsing: approximately 30 of the upper floors tilted at the start of the collapse. If the floors "sat down" on top of each other, as the official version claims, then these upper floors would have to fall straight down. But if explosions somewhere in the area of ​​the collision level killed the steel supporting columns in the center, then it is understandable why the upper floors tilted (possibly towards the damaged corner where the plane crashed).
Explosive devices could be enclosed in a heat-resistant sheath so that they would not explode from fire. If synchronicity was important, then they could be detonated remotely (radio or microwave signal) at the right time. Even if the fire had disabled the bombs at the level of the aircraft collision, it could not have damaged the bombs below the level of the fire. There is no need for wires, processors or clockwork, you just need a way to undermine each of the devices with a unique signal. Even a synchronous sequence might not be necessary - the simultaneous detonation of all devices at ground level might be sufficient to achieve the desired result.
The time t required for an object to fall from a height h (in vacuum) is calculated by the formula t = sqrt (2h / g), where g is the acceleration due to gravity. Thus, an object falling from the top of one of the towers (take h = 1306 feet (398 meters) and g = 32.174 feet / sec 2 (9.81 meters / sec 2)) will take 9.01 seconds before falling to the ground, if we neglect air resistance and a few seconds longer if we take air resistance into account. The Twin Towers collapsed in 10-15 seconds, which is close to free fall. Immediately after the destruction began, the upper floors would have smashed the steel lintels in all 85 or so floors of the lower levels. Even if it took a second per floor, the collapse would take more than a minute. But the material from the upper stories hit the lower ones at a rate of at least six stories per second. This is only possible if all structural elements of the lower 85 floors were completely destroyed before the collapse began. Since the lower floors were not damaged in an aircraft collision and fire, the removal of structural support on these floors must have happened for another reason - and the most obvious possibility is explosives. That. the rate of collapse (not much higher than the rate of free fall) is strong evidence that the Twin Towers were destroyed during controlled demolition using explosives (or other destructive technology) at all levels.
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During the week following the collapse of the Twin Towers, there were areas under the surface that remained extremely hot.
"AVIRIS data, acquired on September 16, 2001, found a number of thermally hot spots at the site of the WTC tower collapse. Analysis of the data found temperatures above 800oF (430oC) at those sites (some over 1300oF (700oC))."
("American Geological Observations Report").
What was the source of this heat? Maybe the residual phenomena from underground nuclear explosions?

A way to prove that the supporting steel columns of the Twin Towers were destroyed by explosives would be to examine their debris for what metallurgists call "twinning". But the ruins of the WTC were cleared out as quickly as possible, and no investigative examination of the wreckage was permitted by the FBI or other government agency. Nearly all of the 300,000 tons of steel from the Twin Towers were sold to New York scrap metal dealers and exported to places such as China and Korea as quickly as the ships could be loaded, thus destroying the evidence. See Pile of Debris Begins to Shrink for Controlled Demolition Inc. (the world leader in demolition of high-rise buildings) apparently took good care of the wreckage and disposal as quickly as possible, and was able to provide a detailed plan for these activities 11 days after the destruction of the Twin Towers, which suggests that this company has detailed information on the Towers - Gemini and the entire WTC complex before 9/11.
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One could argue that there were hundreds of security guards and hundreds of surveillance cameras (possibly) at the WTC. With such a security service, it would be possible to plant a couple of bombs, but planting many of them (especially those powerful enough to destroy the bases of supporting steel columns) seems impracticable. However, the World Trade Center changed ownership 11 weeks before the attack. Larry Silverstein became the new owner. The destruction of the WTC and George W. Bush's declaration of the "War on Terrorism" proved (and could have been predicted) extremely beneficial to Israel in its brutal suppression of the Palestinian people, in its efforts to destroy the Palestinian leadership called "terrorist", and in its attempts to dominate all Arab neighbors ... The new owners of the WTC could well have been persuaded to cooperate on a plan with such obvious benefits to Israel. But if 11 weeks is considered insufficient time for planting explosives, then what about several years?

Terrorist attack or controlled bombing?
According to representatives of science, "fire (fire) could not lead to the destruction of the building's steel structures." Supporters of the official (government) version of the tragic events keep silent about this fact. Moreover, according to a report signed by the directorate of the National Institute of Standards and Technology (2005), the steel structures of the buildings collapsed, allegedly as a result of fires. At the same time, science is not aware of any such fact.
Interestingly, the towers were designed taking into account a possible air attack and were created with design strength, allowing to withstand a collision with such a colossus as the Boeing-767.
"They were designed to withstand all kinds of impacts, including tornadoes, bombings or collisions with huge airliners," says Hyman Brown, project manager for the Twin Towers (2001).
The theory of the destruction of a building by fire and melting of the supporting steel structures is also absurd. According to experts, the destruction of skyscrapers resembles a "controlled demolition", when a certain amount of explosives is placed in the supporting structures and is triggered in the desired sequence.
In the course of a controlled detonation, the destruction of a building occurs suddenly - at first there is nothing, but the next moment the structure disintegrates. Steel structure under high temperature cannot suddenly break. This happens gradually - the horizontal beams begin to bend, and then the vertical steel columns deform.
But the video recording of the destruction of the towers did not record such processes even on the floors located above the hole left by the plane. In addition, the art of a controlled demolition of a high-rise building is that the blown-up skyscraper does not fly in all directions, but "sags" in such a way that the debris remains exclusively at the construction site. This is what happened with the towers.
According to Marc Loisier, president of the largest controlled demolition company, such an explosion "must be completely planned and the explosives must be placed in a specific order." All 110 floors of the twin towers collapsed very neatly. In an unplanned explosion construction garbage would have covered the entire area, but that did not happen.
With a controlled detonation, the remains of the building descend to the surface at the speed of free fall, which does not happen in an accidental disaster. To do this, the demolitions first lay explosives under the support systems of the lower floors, so the upper ones go down, almost without encountering resistance.
According to the commission's report, the south tower collapsed in 10 seconds, which corresponds to a controlled demolition. Moreover, this technique makes it possible to "cut" the supporting steel structures into parts of a certain length, which was recorded in New York. The huge cloud of dust that formed at the site of the towers after the explosion also serves as indirect evidence of a controlled explosion. This was the conclusion reached by Colonel of the US Corps of Engineers John O "Dowd." It seemed that the air at the site of the explosion of the WTC was saturated with cement dust. "
Another proof of the planned explosion is a huge amount of molten steel at the crash site of the towers. For example, Peter Tully, head of Tully Construction, and Marc Loisier reported on "lakes of molten steel" found at the site of collapsed structures in underground elevator shafts. Meanwhile, the collision of the aircraft with the building and the subsequent ignition of aviation fuel could not lead to the formation of temperatures at which steel structures begin to melt. The mystery of the explosion of the twin towers, according to scientists, still remains unsolved. And what about the government? It is inactive, refusing to divulge information that contradicts the official theory.
Shortly after 9/11, over 500 New York City fire and ambulance personnel gave oral testimony, one way or another pointing to some inconsistencies noted during the aftermath of the terrorist attack. The City Hall of New York has done everything not to publicize or refute these facts.
Only in August 2005, The New York Times and a group of relatives of those killed as a result of a lengthy trial and a number of appeals managed to force the mayor's office to publish the said testimonies of direct witnesses to the death of the WTC.
Witnesses' words disprove government theories, proving that 9/11 is a well-planned act of intimidation.

Unfortunately, American officials do not want to conduct an independent investigation, establish the truth and punish those responsible. Why it happens? Who benefits from it and why? These questions still remain unanswered, but the public is not satisfied with the position of the Bush administration, and the S9 / 11T group does not intend to stop its activities. Soon, new details await us, revealing the essence of these tragic events and the hypocrisy of officials. If the assertions of American scientists turn out to be true, "controlled disruption" may well lead to an uncontrolled reaction of society - not only American, but also the world. And then the authors of the largest hoax in the history of mankind may not be in good luck.

Reference.
At present, on the site of the twin towers, the construction of three new skyscrapers is underway, under the working names Tower No. 2, No. 3 and No. 4 and a tower with a height of 541 meters, which received the symbolic name "Freedom Tower". All new buildings will be strikingly different from the first towers that fell in the terrorist attack. The ceremony for the start of construction of the new World Trade Center was held in July 2004, and the construction itself began on April 27, 2006. The site is being developed by Larry Silverstein, a real estate entrepreneur. According to the plan, the completion of the construction of the Freedom Tower should take place before 2013. In addition to this tower, the new World Trade Center in New York will also include a residential skyscraper, three high-rise office buildings, a museum and memorial to the victims of the September 11, 2001 tragedy, and a concert and exhibition center. Many Americans have dubbed the 540-meter skyscraper "The Tower of Fear" because during its construction, innovative technologies will be used to prevent destruction during a terrorist attack of any force. In particular, it is planned to clothe the first 52 meters of the building in a concrete frame, and use prismatic glass for the exterior decoration, this is the only way to avoid the notorious visual effect of the "stone bag".