Twin disaster. New world trade center in new york

Finite element model of the WTC floor, which allows evaluating the structural system of the building

The dimensions of the building in plan are 63.4 x 63.4 m, the stiffening cores are 26.8 x 42.1 m. walls or columns. This was achieved due to the fact that the outer wall of the tower, in fact, was a set of columns installed side by side, taking on the main vertical load, while the wind load fell mainly on the power columns located in the center of the tower (stiffening core). Starting from the tenth floor, each wall of the tower was composed of 59 columns, 49 power columns were installed in the center of the tower. All elevators and stairwells passed in the core of the stiffness, leaving a large free space between the core and the perimeter of the tower for office space.

The construction of the storey ceiling was 10 cm of lightweight concrete laid on a fixed formwork made of profiled decking. The corrugated board was laid on secondary (auxiliary) trusses (beams) resting on the main trusses, transferring the load to the central and peripheral columns. The main trusses had a length of 11 and 18 meters (depending on the span), and were laid in increments of 2.1 m, and were attached from the outside to the lintels connecting the peripheral columns at the level of each floor, and from the inside to the central columns. The floor was fastened through elastic dampers designed to reduce the impact of building vibrations on people working in it.

This truss system allowed an optimized load redistribution of the floor diaphragms between the perimeter and the core, with improved performance between different flexible steel and hard concrete materials allowing the moment structure to transfer the impact into compression on the core, which also mainly supported the transmission tower.

The towers also included an "outrigger (console) truss" located between the 107th and 110th floors, which consisted of six trusses along the longitudinal (long) axis of the core and four along the short (transverse) axis, which served to redistribute the load and raise the overall stability of the building, as well as to support the antenna spire, which was installed on only one of the towers. NIST determined that this design played a key role in the sequence of events leading to the towers' complete collapse.

Fire and aircraft impact resistance capabilities

Like all modern high-rise buildings, the WTC towers were designed and built to withstand normal fire. Many fire protection elements were laid down during the design and construction phase, others were added after the 1975 fire that engulfed six floors before being contained and extinguished. Tests carried out before the disaster showed that the steel structures of the towers are in line with current fire resistance requirements, or even exceed them.

Structural engineers who designed the World Trade Center considered the possibility of an aircraft colliding with the building. In July 1945, a B-25 Mitchell bomber became disoriented in fog and crashed into the 79th floor of the Empire State Building. A year later, a twin-engine C-45 Beechcraft collided with a skyscraper at 40 Wall Street, and another aircraft came close to another collision with the Empire State Building.

NIST stated that “American building standards do not contain requirements for the stability of buildings when hit by an aircraft. … and thus buildings are not designed to withstand the impact of a fully fueled commercial airliner.” However, the designers and architects of the WTC discussed this problem and recognized its importance. Leslie Robertson, one of the World Trade Center's chief engineers, recalled that the scenario was considered for a Boeing 707 jet airliner that was disorientated in fog and flying at relatively low speed in search of John F. Kennedy Airport or Newark Liberty Airport. John Skilling, another WTC engineer, said in 1993 that his subordinates were conducting an analysis that showed that the biggest problem in the event of a collision between the WTC towers and a Boeing 707 would be that all the aircraft's fuel would get inside the building and lead to a "terrible fire" and many human casualties, but the building itself will remain standing. FEMA wrote that the WTC buildings were built with a Boeing 707 jet weighing 119 tons and a speed of about 290 km / h in mind, which is much less in weight and speed than those aircraft used in the September 11 attacks.

NIST found a three-page report in the archives summarizing a study that simulated a Boeing 707 or Douglas DC-8 hitting a building at 950 km/h. The study showed that the building should not collapse as a result of such a hit. But, as the NIST experts noted, "the 1964 study did not simulate the effect of a fire caused by the spraying of aviation fuel on a building." NIST also noted that in the absence of initial calculations used to model the situation, further comment on this topic would be mostly "speculation". Another document found by NIST was a calculation of the period of oscillation of a building in the event of an aircraft hitting the 80th floor of the World Trade Center tower, but it made no assumptions about the fate of the building after the collision. In a property risk assessment report prepared for Silverstain Properties, the case of an aircraft hitting the WTC towers was considered unlikely, but possible. The authors of the report cited WTC structural engineers, who believed that the towers should have survived in the event of a collision of a large passenger aircraft, but burning fuel flowing from the aircraft to ground level would have damaged the building's skin. Part of the documents related to the analysis of the scenario of an aircraft hitting the towers was lost as a result of the destruction of WTC 1 and WTC 7, which contained documents from the Port Authority of New York and New Jersey and Silverstain Properties.

Aircraft hitting towers

The terrorists sent two Boeing 767 jets, American Airlines Flight 11 (767-200ER) and United Airlines Flight 175 (767-200) into the towers. The North Tower (1 WTC) was hit at 8:46 am by Flight 11, between the 93rd and 99th floors. Flight 175 crashed into the south tower (2 WTC) at 9:03, between floors 77 and 85.

The Boeing 767-200 airliner has a length of 48.5 m, a wingspan of 48 m, carries on board from 62 tons (-200) to 91 tons (-200ER) of aviation fuel. The planes crashed into the towers at a very high speed. Flight 11 was traveling at approximately 700 km/h when it hit the north tower; flight 175 crashed into the south at a speed of about 870 km / h. In addition to severely destroying the supporting columns, the hits caused an explosion of approximately 38 tons of aviation fuel in each tower, resulting in an almost instantaneous, massive fire spreading to multiple floors containing office furniture, paper, carpets, books, and other combustible materials. The shock wave from hitting the north tower traveled down to the first floor, along at least one high-speed elevator shaft, shattered windows on the first floor, injuring several people.

Fire

The light construction of the towers and the absence of solid walls and ceilings led to the fact that aviation fuel spread in a fairly large volume of buildings, leading to numerous fires on several floors close to the aircraft impact zones. The jet fuel itself burned out within minutes, but the combustible materials in the building itself kept the fires intense for another hour or an hour and a half. It is possible that if more traditional structures were in the way of the aircraft, then the fires would not be so centralized and intense - aircraft debris and aviation fuel could remain mainly in the peripheral area of ​​\u200b\u200bthe building, and not penetrate directly to its central part. In this case, the towers would probably have survived, or in any case, would have stood much longer.

Development of the situation

• 9:52 a.m. - Fire department helicopter radios that "Large pieces of the building may fall from the upper floors of the south tower. We are seeing large parts of the building in limbo.”

• 9:59 a.m. - Helicopter reports that south tower is falling.

Helicopters also reported on the development of the situation with the north tower of the World Trade Center.

• 10:20 a.m. - Fire department helicopter reports that the upper floors of the north tower may be unstable.

• 10:21 - It is reported that the southeast corner of the tower is warped, and that the tower is beginning to lean towards the south.

• 10:27 - It is reported that the roof of the northern tower may collapse at any moment.

• 10:28 a.m. - The fire department receives word that the north tower has collapsed.

Overloaded dispatchers and poor communication performance meant that the New York City Fire and Police Departments experienced great problems in ensuring timely communication, both with their units and with each other. As a result, the fire brigades stationed in the towers did not receive an evacuation order and 343 firefighters died in the collapse of the buildings.

The collapse of the WTC towers

At 9:59 a.m., the south tower collapsed, 56 minutes after impact. The north tower stood until 10:28, 102 minutes after the aircraft hit it. The collapsed towers created a huge cloud of dust that covered much of Manhattan. In both cases, a similar process occurred, the upper damaged part of the building collapsed on the lower floors. Both towers fell almost vertically, although there was a significant deviation from the vertical of the upper part of the southern tower. Debris and dust were also observed flying from the windows of the building below the rapidly advancing collapse zone.

Tower collapse mechanism

The NIST investigation showed that due to the fact that the planes hit the towers differently, the process of destruction of the north and south towers was also somewhat different, although it was generally the same in both cases. After being hit by aircraft, the internal force columns were seriously damaged, although the external columns were relatively lightly damaged. This caused a serious redistribution of the load between them. A significant role in this redistribution was played by the upper power structure of the towers.

Aircraft that hit the buildings stripped the refractory coating from a significant part of the steel structures, which led to the fact that they were directly exposed to fire. In the 102 minutes prior to the fall of the north tower, the temperature of the fire, although well below the melting point of metal, reached a sufficient magnitude to cause the power columns in the center of the building to weaken, which began to warp and buckle under the weight of the upper floors. The NIST report describes this situation as follows:

You can imagine the central power frame of the northern tower in the form of three sections. The lower section (below the destruction zone) was a rigid, stable, intact structure with a temperature close to normal. The upper section, above the destruction zone, was also a rigid box, which, moreover, had a large weight. The middle section between them was damaged by the impact and explosion of the aircraft, and was also weakened by the fire. The upper part of the power frame tended to fall below, but it was held by the upper truss structure, based on the peripheral columns. As a result, this design created a large load on the perimeter of the building. original text(English) At this point, the core of WTC 1 could be imagined to be in three sections. There was a bottom section below the impact floors that could be thought of as a strong, rigid box, structurally undamaged and at almost normal temperature. There was a top section above the impact and fire floors that was also a heavy, rigid box. In the middle was the third section, partially damaged by the aircraft and weakened by heat from the fires. The core of the top section tried to move downward, but was held up by the hat truss. The hat truss, in turn redistributed the load to the perimeter columns. NIST report, page 29

A similar situation was in the south tower (the internal power columns were seriously damaged). The peripheral columns and floor structures of both towers were weakened by the fire, causing the floor to subside on the damaged floors and placing a significant load on the peripheral columns towards the interior of the building.

At 09:59, 56 minutes after impact, the subsiding floor caused severe inward flexing of the outer columns on the east side of the south tower, the upper structure transferred this bending force to the central columns, causing them to collapse and the building to begin to collapse, while the top of the tower deviated towards the damaged wall. At 10:28 am, the south wall of the north tower warped, causing roughly the same sequence of events. As a result of the ensuing collapse of the upper floors, the complete destruction of the towers became inevitable, due to the enormous weight of the part of the buildings that were above the damage zone.

The reason that the north tower stood longer than the south tower was a combination of the following three factors: the zone of impact of the aircraft in the north tower was higher (and the weight of the upper part of the building, respectively, is less), the speed of the aircraft that hit the tower was lower, in addition, the aircraft hit floors, the fire protection of which was previously partially improved.

Theory of complete progressive collapse

The ruins of the South Tower (right) and North Tower (left), as well as other buildings of the World Trade Center

A huge cloud of dust covered the collapsing towers, making it impossible to determine the exact duration of the destruction based on visual evidence.

Since the NIST report deals mainly with the mechanisms of the initial collapse, it does not address the issue of the subsequent complete collapse of both WTC towers. Initial analyzes attributed the collapse to the fact that the kinetic energy of the falling upper floors was much greater than what the interfloor floors could withstand, which also collapsed, adding kinetic energy to the falling building. This scenario of events was repeated with increasing speed until the towers were completely destroyed. Although this is the most widely held view among structural engineers, it has been criticized for not taking into account the resistance of the underlying structures, which should have slowed down the collapse of the towers, or even stopped it.

7 WTC building collapse

The initial FEMA study was inconclusive, and the collapse of 7 WTC was not included in the September 2005 NIST final report. With the exception of a letter published Metallurgical Journal, which suggested that the steel frame of the building could have been melted by fire, no other studies of this issue have been published in scientific journals. The fall of 7 WTC was investigated separately from the fall of 1 WTC and 2 WTC, and in June 2004, NIST released a working report that contained several hypotheses of what happened. One hypothesis was the collapse of one of the building's critical supporting columns, caused by fire or large debris from falling towers, resulting in a "disproportionate collapse of the entire structure".

NIST diagram showing the bending of Column 79 (circled in orange) that started the progressive collapse of the building.

Destruction order of 7 WTC in a diagram from a 2004 NIST preliminary report. Column 79 is marked with a circle in the center of the red zone.

7 WTC fall model developed by NIST. In the first part of the video clip, columns 81, 80 and 79 are shown from left to right.

On November 20, 2008, NIST released its final report on the fall of 7 WTC. The NIST report cited the fire as the main cause of the destruction, along with a lack of fire fighting water for firefighters and the automatic fire suppression system. NIST reconstructs the sequence of events as follows: At 10:28 am, debris from falling WTC 1 caused damage to adjacent WTC 7. Fires also broke out, probably from burning debris from 1 WTC. By 7 WTC, firefighters immediately arrived, but at 11:30 they discovered that there was no water in the fire hydrants to fight the fire - the water came from the city's water supply system, destroyed by the fall of towers 1 WTC and 2 WTC. New York Fire Department ( English), fearing for the lives of the firefighters if 7 WTC were destroyed, at 14:30 withdrew the firefighters and stopped the fight to save the building. The fire was observed on 10 floors from the 7th to the 30th, and on floors 7-9 and 11-13 the fire got out of control. Thermal expansion of the approximately 400°C beams around Pillar 79 in the eastern part of the building in the 13th-14th floor region caused the fire-weakened floors adjacent to Pillar 79 to collapse from the 13th to the 5th floor. The destruction of the ceilings deprived column 79 of its horizontal support, and it began to bend, which was the direct cause of the complete destruction of the building after a few seconds. The bending of column 79 resulted in the transfer of load to columns 80 and 81, which also began to bend, as a result of which all the ceilings associated with these columns up to the top of the building were destroyed. Falling ceilings destroyed truss 2, causing columns 77, 78, and 76 to fall. As a result of the increased load transferred from the bent columns, falling debris from above, and the lack of horizontal support from the collapsed ceilings, all internal columns from east to west began to buckle in succession. Following this, in the area of ​​​​floors 7-14, the outer columns began to bend, on which the load was transferred from the lowered inner columns and the center, and all floors above the bent columns began to sink down as a whole, which completed the final destruction of the building at 17:20.

Some writers have criticized the city's decision to locate WTC headquarters on the 23rd floor of 7 WTC Emergency Situations Office(English) Office of Emergency Management ). It was assumed that this could be a significant factor in the destruction of the building. Particularly noteworthy was the placement in the building of large tanks with diesel fuel, which were supposed to serve to power emergency power generators. NIST concluded that diesel fuel did not play a role in the destruction of the building, but the rapid evacuation of the Office of Emergency Situations was one of the reasons for poor communication between various services and loss of control over the situation. The main cause of the building's destruction was fire, debris damage from falling 1 WTC accelerated the building's fall, but NIST calculations showed that 7 WTC would have collapsed from an uncontrolled fire alone.

Progress of investigations

First reaction

The destruction of the WTC towers came as a surprise to the construction engineers. "Before 9/11," wrote the magazine New Civil Engineer, - we quite sincerely could not imagine that a structure of this magnitude could suffer such a fate. Despite the fact that the damage from the aircraft strikes was very serious, they affected only a few floors of each building. It became a challenge for engineers to figure out how such localized damage caused the complete progressive collapse of three, some of the largest buildings in the world. In an October 2001 interview with the BBC, English architect Bob Halvorson quite aptly predicted that there would be much "debate about whether the World Trade Center could have collapsed the way it did." A full analysis should include the WTC's architectural and design plans, eyewitness testimony, video footage of the destruction, debris survey data, etc. Emphasizing the complexity of the task, Halvorson said that the destruction of the WTC towers is "far beyond the ordinary experience."

Research Authority

Immediately after the disaster, a situation of uncertainty arose as to who had sufficient authority to conduct an official investigation. Contrary to the practice in air crash investigations, there were simply no clear procedures for investigating building collapses.

Shortly after the disaster at the base Institute of Building Engineers(English) Structural Engineers Institute (SEI)) American Society of Civil Engineers(English) American Society of Civil Engineers ASCE), a working group was created, which also involved specialists American Institute of Steel Structures(English) American Institute of Steel Construction ), American Concrete Institute(English) American Concrete Institute ), the National Fire Protection Association and Communities of Fire Protection Engineers(English) Society of Fire Protection Engineers ) . ASCE also invited the Federal Emergency Management Agency (FEMA) to join this group, which was later jointly managed by ASCE-FEMA. This investigation was subsequently criticized by American engineers and lawyers, however, the authority of the aforementioned organizations was sufficient to conduct an investigation and to provide access to the crash site for the group's experts. One of the most poignant moments of the investigation was that the cleanup of the crash site actually resulted in the destruction of the remaining components of the building. Indeed, when NIST released its final report, it noted a "lack of physical evidence" that became one of the main concerns of the investigation. Only fractions of a percent of the remains of the building remained available for investigation after the completion of the clearance work, in total 236 individual steel fragments were collected.

FEMA published its report in May 2002 . Despite the fact that NIST had already declared its involvement in the investigation in August of that year, in October 2002, under increasing public pressure for a more detailed investigation, Congress passed a bill creating a new group under the leadership of NIST, which published its report in September 2005 .

FEMA's "stack of pancakes" theory

In its early investigations, FEMA developed a theory to explain the collapse of the WTC towers called the "Pancake Stack Theory". pancake theory). This theory has been defended by Thomas Iga and widely covered by PBS. According to this theory, the connection between the lintels supporting the floor and the columns of the building failed, causing the floor to collapse one floor below, placing loads on its structure that it was not designed for. Some individual publications have suggested other sets of factors that caused the collapse of the towers, but in general this theory has been accepted by the majority.

Fires remained the main key factor in this theory. Thomas Iga, professor of materials science at MIT, described the fires as "the most baffling part of the collapse of the WTC towers." Although the fires were initially thought to have "melted" the steel structures, Iga stated that "the temperature of the fires in the WTC towers was unusually high, but still definitely not enough to cause melting or severe softening of the steel." Aviation kerosene fires typically result in extensive fires, but these fires do not have very high temperatures. This led Iga, FEMA, and others to believe that there was a weak point, and this point was named as the anchoring of the floor to the building's load-bearing structures. Due to the fire, these fastenings weakened and, when they collapsed under the weight of the floor, collapse began. On the other hand, the NIST report states completely and unequivocally that these mounts were not destroyed. Moreover, it was their strength that was one of the main reasons for the collapse, since through them a force was transmitted to the peripheral columns, which bent the columns inward.

At temperatures above 400-500 °C, there is a sharp decrease in the tensile strength and ductility limit (by a factor of 3-4), at 600 °C they are close to zero and the bearing capacity of the steel is exhausted.

NIST Report

Organization of the study

As a result of mounting pressure from experts, construction industry leaders, and family members of the victims following the release of the FEMA report, National Institute of Standards and Technology(NIST) of the Department of Commerce conducted a three-year, $24 million investigation into the destruction and collapse of the World Trade Center towers. The study included a series of experiments, in addition, leading experts from many third-party organizations were involved in it:

• Structural Engineering Institute of the American Society of Civil Engineers (SEI/ASCE)
• Society of Fire Protection Engineers (SFPE)
• National Fire Protection Association (NFPA)
• American Institute of Steel Construction (AISC)
• Council on Tall Buildings and Urban Habitat (CTBUH)
• Structural Engineers Association of New York (SEANY)

Scope of study and its limitations

The scope of NIST's research was limited to studying the question of "the sequence of events from the moment an aircraft hits to the start of each tower collapse", and also included "a small analysis of the structural behavior of the tower structure after the conditions for its collapse were reached and collapse became inevitable" . Like many other engineers involved in this issue, the NIST experts focused on aircraft hitting turrets, simulating the effects of hits such as structural collapse, fire spread, etc. in a very high degree of detail. NIST has produced several very detailed models of various building components, such as lintels that support the floor, and entire buildings have been modeled, but at a lower level of detail. These models were static, or quasi-static, included modeling of deformations, but did not include modeling of the movement of structural elements after they were disconnected from each other. Thus, NIST models are useful for finding out why towers collapse, but they do not provide a way to model the collapse itself.

Parallel investigations

In 2003, three engineers from the University of Edinburgh published a report suggesting that fires alone, even without taking into account the destructive effect of aircraft strikes, were enough to completely destroy the WTC towers. In their opinion, the design of the towers made them extremely vulnerable to widespread fires that engulfed several floors at once. When the NIST report came out, Barbara Lane and the English engineering company Arup criticized its conclusion that the destruction caused by aircraft hits was a necessary factor for the start of destruction of buildings .

Criticism

Some engineers have offered their insight into the mechanism of tower collapse by developing animated collapse sequences based on dynamic computer models and comparing the results with video footage of the crash site. In October 2005 the magazine New Civil Engineer regarding the computer model created by NIST. In response, NIST enlisted Colin Bailey of the University of Manchester and Robert Planck of the University of Sheffield to create the computer visualizations needed to work on correcting tower collapse models and bringing those models fully into line with observed events.

Other buildings

Portions of the outer wall of the north tower facing the remains of WTC Building 6, which was severely damaged by the fall of the north tower. In the upper right corner are the remains of building 7 WTC.

On September 11, 2001, the entire World Trade Center complex and the small Orthodox Greek Church of St. Nicholas, which stood on Liberty Street opposite the south tower of the World Trade Center, were destroyed. In addition, many buildings surrounding the complex were damaged to one degree or another.

Effects

Clearing the crash site

The huge mountain of rubble at the site of the World Trade Center continued to burn and smolder for another three months, with attempts to control the fire failing until a significant amount of rubble and debris was removed. The clearance was a massive operation coordinated by the Construction Department (DDC). A preliminary clearance plan was prepared on September 22 by Controlled Demolition Inc. (CDI) from Phoenix. Mark Lozo, president of the CDI, particularly stressed the importance of protecting the mud wall (or "bath") that kept the WTC's foundations from being flooded by the Hudson's waters. The cleanup was carried out around the clock, involving a large number of contractors, and cost hundreds of millions of dollars. In early November, after about a third of the debris had been removed, the city government began to reduce the involvement of police and firefighters who were searching for the remains of the dead, and shifted priorities to garbage collection. This provoked objections from the firemen. As of 2007, the demolition of some of the buildings surrounding the WTC continued, amid construction of a replacement for the WTC, a memorial complex, and the Freedom Tower.

Controlled demolition versions

There is a version that the WTC towers could have been destroyed as a result of a planned controlled demolition, and not as a result of an aircraft hit. This theory was rejected by NIST, which concluded that no explosives were involved in the towers' collapse. NIST stated that it did not perform tests to search for explosive residues of any kind in the wreckage because it was not necessary:

12. Did the NIST investigation look for evidence of the WTC towers being brought down by controlled demolition? Was the steel tested for explosives or thermite residues? The combination of thermite and sulfur (called thermate) "slices through steel like a hot knife through butter."

NIST did not test for the residues of these compounds in the steel.

The responses to questions number 2, 4, 5 and 11 demonstrate why NIST concluded that there were no explosives or controlled demolition involved in the collapses of the WTC towers.

In a 2008 report, NIST also analyzed the WTC Tower 7 explosion hypothesis and concluded that the explosion could not have caused the observed effects. In particular, the smallest amount of explosives that could destroy column 79 would cause a noise of 130-140 decibels at a distance of 1 km from 7 WTC, but such noise was not noticed by either the sound recording equipment or bystanders. This theory has become a prominent part of most of all the "conspiracy theories" that arose as a result of the events of 9/11.

Notes

1. Relatives gather at ground zero to mark 9/11 , The Associated Press/MSNBC(September 9, 2007). Retrieved November 3, 2007.
2. PartIIC - WTC 7 Collapse (pdf). NIST Response to the World Trade Center Disaster. National Institute of Standards and Technology (April 5, 2005). Archived from the original on March 4, 2012. Retrieved November 1, 2006.
3. Hamburger, Ronald, et al(pdf). Federal Emergency Management Agency. Archived
4. Snell, Jack, S. Shyam Sunder NIST Response to the World Trade Center Disaster (pdf). National Institute of Standards and Technology (November 12, 2002). Archived from the original on March 4, 2012. Retrieved July 27, 2006.
5. Chapter 1 // . - NIST. -P.p. 6.
6. National Construction Safety Team Final Report on the Collapse of the World Trade Center Towers . - NIST.
7. Barrett, Devlin Steel type in WTC met standards, group says . The Boston Globe. Associated Press (2003). Retrieved May 2, 2006.
8. Glanz, James and Eric Lipton. The Height of Ambition The New York Times(8 September 2002).
9. Adam Long. PILOT LOST IN FOG; SCENE OF PLANE CRASH LAST NIGHT AIRPLANE CRASHES INTO SKYSCRAPER Ceiling Reduced by Fog , The New York Times(May 24, 1946).
10. (pdf). NIST NCSTAR 1-1 Pages 70-71 Archived
11. Leslie E. Robertson. Reflections on the World Trade Center // The Bridge. - National Academy of Engineering, 2002. - V. 32. - No. 1. Archived from the original on February 28, 2010.
12. Fahim Sadek. NIST NCSTAR 1-2. Baseline Structural Performance and Aircraft Impact Damage Analysis of the World Trade Center Towers. - NIST, September 2005. - S. 3-5, 308.
13. Nalder, Eric. (English) , The Seattle Times (27-02-1993).
14. Ronald Hamburger, et al. World Trade Center Building Performance Study. - Federal Emergency Management Agency. - S. 1-17.
15. NIST's Working Hypothesis for Collapse of the WTC Towers (Appendix Q) . NIST (June 2004). Archived from the original on March 4, 2012. Retrieved December 21, 2007.
16. NIST was informed by the Port Authority that the documents cited were destroyed in the collapse of WTC 1 and the WTC owners documents held in WTC 7 were also lost.
17. Lew, H.S.; Richard W. Bukowski and Nicholas J. Carino Design, Construction and Maintenance of Structural and Life Safety (pdf). NIST NCSTAR 1-1 Page 71. National Institutes of Standards and Technology (2006). Archived from the original on March 4, 2012. Retrieved October 15, 2007.
18. Jane's All the World's Aircraft Boeing 767. Jane "s (2001). Retrieved August 19, 2007.
19. Field, Andy A Look Inside a Radical New Theory of the WTC Collapse . Fire/Rescue News (2004). Retrieved July 28, 2006.
20. Gross, John L., Therese P. McAllister Structural Fire Response and Probable Collapse Sequence of the World Trade Center Towers (pdf). Federal Building and Fire Safety Investigation of the World Trade Center Disaster NIST NCSTAR 1-6 Archived
21. Wilkinson, Tim World Trade Center - Some Engineering Aspects (2006). Archived from the original on March 4, 2012. Retrieved July 28, 2006.
22. Lawson, J. Randall, Robert L. Vettori. NIST NCSTAR 1-8 - The Emergency Response P. 37. NIST (September 2005). Archived from the original on March 4, 2012.
23. McKinsey Report - Emergency Medical Service response . FDNY / McKinsey & Company (August 9, 2002). Archived from the original on August 26, 2011. Retrieved July 12, 2007.
24. McKinsey Report - NYPD (August 19, 2002). (unavailable link - story) Retrieved July 10, 2007.
25. NY Firefighters attack Giuliani. BBC News, July 12, 2007 http://news.bbc.co.uk/2/hi/americas/6294198.stm
26. Bažant, Zdeněk P.; Yong Zhou (2002-01-01). "Why Did the World Trade Center Collapse?-Simple Analysis". J Engrg Mech 128 (1): pp. 2-6. DOI:0.1061/(ASCE)0733-9399(2002)128:1(2) . Retrieved 2007-08-23.
27. Bažant, Zdeněk P.; Mathieu Verdure (March 2007). "Mechanics of Progressive Collapse: Learning from World Trade Center and Building Demolitions". J.Engrg. Mech. 133 (3): pp. 308-319. DOI:10.1061/(ASCE)0733-9399(2007)133:3(308) . Retrieved 2007-08-22.
28. Cherepanov, G.P. (September 2006). "Mechanics of the WTC collapse". Int J Fract(Springer Netherlands) 141 (1-2): 287-289. DOI:10.1007/s10704-006-0081-8 . Retrieved 2007-10-07.
29. Hayden, Peter WTC: This Is Their Story. Firehouse Magazine (April 2002). (unavailable link - story)
30. Observations, Findings and Recommendations (pdf). World Trade Center Building Performance Study, (Chapter 8.2.5.1). Federal Emergency Management Agency. Archived from the original on March 4, 2012. Retrieved July 28, 2006.
31. Barnett, J.R.; R.R. Biederman, R.D. Sisson Jr. An Initial Microstructural Analysis of A36 Steel from WTC Building 7 . Features: Letter. The Journal of Materials (2001). Archived from the original on March 4, 2012. Retrieved May 12, 2006.
32. Key Findings of NIST’s June 2004 Progress Report on the Federal Building and Fire Safety Investigation of the World Trade Center Disaster . Fact sheets from NIST. National Institute of Standards and Technology (2004). Archived from the original on March 4, 2012. Retrieved July 28, 2006.
33. Interim Report on WTC 7 (pdf). Appendix L. National Institute of Standards and Technology (2004). Archived from the original on March 4, 2012. Retrieved July 28, 2006.
34. NIST Releases Final WTC 7 Investigation Report. National Institute of Standards and Technology (November 20, 2008). Archived from the original on March 4, 2012. Retrieved August 28, 2009.
35. Robert MacNeill, Steven Kirkpatrick, Brian Peterson, Robert Bocchieri. Global Structural Analysis of the Response of World Trade Center Building 7 to Fires and Debris Impact Damage. - November 2008. - S. 119-120.
36. Questions and Answers about the NIST WTC 7 Investigation. National Institute of Standards and Technology (21 April 2009). Archived from the original on March 1, 2010.
37. Barrett Wayne Grand Illusion: The Untold Story of Rudy Giuliani and 9/11 . - Harper Collins. - ISBN 0-06-053660-8
38. Replying to Giuliani
39. Oliver, Anthony Lasting lessons of WTC . New Civil Engineer (June 30, 2005). (unavailable link - story) Retrieved July 28, 2006.
40. Whitehouse, David WTC collapse forces skyscraper rethink . BBC News (2001). Archived from the original on March 4, 2012. Retrieved July 28, 2006.
41. Snell, Jack. "The Proposed National Construction Safety Team Act." NIST Building and Fire Research Laboratory. 2002.
42. Experts Debate Future of the Skyscraper in Wake of Disaster, Engineering News-Record(September 24, 2001).
43. Glanz, James and Eric Lipton. Nation Challenged: The Towers; Experts Urging Broader Inquiry In Towers" Fall". New York Times December 25,
44. Dwyer, Jim. "Investigating 9/11: An Unimaginable Calamity, Still Largely Unexamined". New York Times. September 11,
45. NIST. "NIST's Responsibilities Under the National Construction Safety Team Act"
46. Thomas Eagle. The Collapse: An Engineer's Perspective. NOVA (2002). (unavailable link - story) Retrieved July 28, 2006.
47. Eagar, Thomas W.; Christopher Musso (2001). Why Did the World Trade Center Collapse? Science, Engineering, and Speculation. JOM, 53(12). The Minerals, Metals & Materials Society. Retrieved on 2006-05-02.
48. Clifton, G. Charles Collapse of the World Trade Center Towers (pdf) (2002). (unavailable link - story) Retrieved July 28, 2006.

The real story of the twin towers blown up in New York, and what they actually 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 skyscrapers (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 declared beyond repair and demolished.

Idea

The famous billionaire brothers came up with the idea to build the World Trade Center (WTC) in Manhattan back in the late 1950s. David and then mayor of New York Nelson Rockefellers. They were supported by the local Port Authority. The construction of the complex began in 1966 and cost, according to some estimates, $1.5 billion.

The WTC skyscrapers were designed by an 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 in conjunction with Antonio Brittaiochi and Emery Roth & Sons. Before embarking on the construction of 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 World Trade Center 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 predilections 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 an internal catastrophe." Someone considered these buildings the personification of the social system existing in the USA.

When the first of the colossi appeared in New York, critics dubbed it "the biggest thumb in the sky." A specialist in technical history Lewis Mumford regarded Twin Towers as "an example of the unintentional gigantism and technological exhibitionism that is now gutting the living fabric of every big city." Many also did not like the narrow (only 46 cm wide) windows of the office premises of the towers. According to the then prevailing judgments, the architect made them like that, 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 an observation platform gateway. He and She were, as it were, on the move towards the Hudson and all of America. The woman, as always, was half a step behind. Perhaps it was an architectural representation of Adam and Eve leaving Paradise? The architect himself did not specifically speak on this matter.

Design

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

When building skyscrapers, an engineering idea was used that was first applied when creating the IBM office center in Seattle. In this case, the designers also applied a rigid "hollow tube" structural model of closely spaced columns with a diameter of 990 mm, with trusses of floors 83 cm thick, expanding towards the central part. Many steel columns inside the building became the load-bearing part that held the entire building. In this case, complex-profile steel floors served as "stiffening ribs". 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 columns 476.25 mm wide. They protected the entire structure from wind and other external overturning loads. The location of the "wind props" 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 beams ran along the entire height. Cables were stretched between them along the entire height. These, as well as a package of cables inside the elevator shafts, provided design flexibility. In general, the towers were a combination of steel cages from factory-produced modules 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 the skyscrapers had no windows at all. Although there were as many as 43 thousand.

The twins were the first ultra-tall buildings 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 rubber-paneled trusses between the outer columns and the elevator section. Both "brothers", according to the designers, were able to withstand hurricane winds and should have survived even in the event of a ram 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 glass.

Exploitation

The first tower was built by 1970. But officially the World Trade Center in New York was opened only on April 4, 1973 after the commissioning of the second one. The complex included five more ground structures. Among them are the high-rise Marriott Hotel, the Commodity Exchange and the 8-story US Customs Palace. 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 square meters. m, for rent.

The height of the WTC skyscrapers (North tower - 110 floors, 417 m, South - 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 World Trade Center, Yamasaki was asked: “Why two buildings with 110 floors? Why not one in 220? His response: "I didn't want to lose the human scale."

In the 1990s, the towers of the World Trade Center housed 10% of all lower Manhattan's offices. 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 capital of $487 billion, the Oppenheimer fund with a “modest” $125 billion in management occupied 5 floors. Fuji Bank was located on four floors . 3 floors each were occupied by the New York Stock Exchange, the insurance company AON, the telecommunications company Verizon (capitalization of $ 17.5 billion), the architectural office Manciani Duffi (recognized as the best interior designer in 2000) and the law firm Thacher, Proffit & Wood . Modestly, only 2 floors each, the computer corporation Sun Microsystems, the Department of Taxes and Finance of the State of New York, and the insurance agency Frenkel & Co. had.

On a typical day, 50,000 employees and 200,000 visitors and tourists came to work at the World Trade Center. 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 the observation deck of the South Tower every day. On a clear day, through the suicide fence, they could view the surrounding area within a radius of 78 km.

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

Destruction

A huge constructive advantage of the New York twins was that the steel beams of the buildings were connected to the pillars located less than a meter apart, forming 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 racks, damage to which, as a rule, leads to the immediate destruction of the entire building.

And the disadvantage was the lack of foam fire-fighting systems that could cope with 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 the terrorists to the WTC buildings were filled, turned the winged vehicles into thermal bombs. When the combustion temperature exceeded 800 °C, the steel supports began to melt. However, it was subsequently discovered that this was not the main reason for the collapse of the Twins.

A few 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 a fire in the buildings. The outer columns could not withstand the extraordinary stress.

Oleg KLIMOV

(Based on materials from foreign press)

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

In 1949 he founded his own firm. In 1951, he received the American Institute of Architecture Award for a residential complex in St. Louis, USA. True, already in 1972, these buildings were destroyed as "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), the McGregor Memorial Community Center in Detroit, USA (1958), the airport in Dhahran, Saudi Arabia (1961) and Eastern Province Airport in Riyadh (1985).

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

The terrorist attack on the World Trade Center in New York divided the history of the United States of America into before and after. Three thousand people who died as a result of the explosion of the Twin Towers is an irreparable loss for the American people. Question: "Who blew up the towers?" remains open to many to this day. Too many logical inconsistencies in the official version of the investigation.

Mission Possible?

According to the official version, the twin towers were destroyed due to the explosions of the planes that rammed the buildings. The fire that broke out during the attack weakened the metal structures, and the building collapsed. Then the same thing happened to another skyscraper.

Ordinary people are still perplexed: how could people from Arab countries, whose names were previously known to the special services, come to the United States, undergo training in piloting passenger Boeings, carry dummies of firearms on board aircraft, capture several aircraft at the same time and with an enviable Accurately ram several buildings?

This whole operation looks incredible, but, nevertheless, it is theoretically feasible. Much more complex questions of the commission involved in the investigation are asked by experts who have obtained the results of analyzes obtained after examining the wreckage of the twin towers. At the site of the tragedy, traces of explosives and thermite were found - a substance that reaches a temperature of 1500 degrees when burned. But let's talk about everything in order. Consider the main conspiracy theories of explosions.

Analysis of the debris of buildings taken to the landfill

Less than a month after the attack, the US army invaded Afghanistan, destroying the hotbeds of terrorism, and at the same time writing off their debts, destabilizing the situation in the region and laundering multibillion-dollar investments in the military industry, in which, as it became known during the election campaign, Hillary Clinton, the Washington "hawks" have not only state, but also personal interests.

The terrorist act untied the hands of the US intelligence services, which received the right to listen to other people's conversations and read other people's letters, not only on their own territory, but in any corner of the world. Even the leaders of the G7 countries have no right to their little secrets from Washington. This was clearly shown by the phone tapping scandal. Angela Merkel.

There are many supporters of the idea that America's intelligence agencies at least knew about the preparation of terrorist attacks, and most likely played a key role in the preparation. Only with the support of "Big Brother" could Islamic radicals involved in al-Qaeda ties be able to enter the United States, receive first-class flight training, be on board aircraft with items that look like firearms, hijack aircraft and accurately direct them to predetermined goals.

Like a house of cards

Looking at the collapse of the twin towers, experts agree that it is very similar to a controlled explosion. Such explosions are used when it is required to demolish a large building in a densely populated area of ​​the city. Explosive engineers, having studied the design of the structure, calculate the power of each charge placed in the base of the supporting structures. As a result, the demolished object should fold like a house of cards, so that each wall rushes inward.

During such events, just in case, the inhabitants of nearby houses are evacuated. If there is a mistake in the calculations or some charges do not work, the building, instead of folding inward, may fall on its side, and then the destruction will be much more than planned. Looking at the video, it's hard not to be surprised at how neatly and how quickly the towers fold. It looks like real professional explosives experts worked on this.

Well, what about the planes? After all, they were seen by thousands of people, and they are captured on the set. Supporters of the controlled explosion theory are sure that the planes were needed for a beautiful picture and so that the inhabitants would not have questions: how could a bunch of terrorists bring tons of explosives into two carefully guarded buildings in the center of New York and set the charges in such a way that they collapsed fully?

As for the plane that hit the Pentagon building, it may not have been at all. The footage, taken immediately after the attack, shows the destruction, but there are no details of the Boeing. The plane could explode, but it could not dissolve. Large pieces of the fuselage and engines should be visible. In addition, the damage to the building is too minor for an incursion by a large passenger airliner. They are more reminiscent of the consequences of a cruise missile hit, and terrorists simply could not have such missiles.

Who shot down the fourth plane?

There was also a fourth hijacked airliner, which the terrorists planned to aim either at the White House, or at the Capitol. But he did not reach his goal. According to the official version, the passengers entered into a fight with the terrorists, and as a result of a fight that ensued on board the aircraft, the liner crashed to the ground. Some conspiracy theorists believe that the US military shot down the plane. This theory is supported by the fact that the debris was scattered at a great distance from each other. But several passengers managed to call their loved ones before the crash, even records of these conversations have been preserved, confirming the official version.

small atomic bomb

There are so many different opinions about the tragedy of September 11 that among them there are even completely fantastic and incredible ones. For example, in all seriousness they say that a small atomic bomb was detonated under every building. Allegedly, the New York authorities set a condition for the developers who planned to build the Shopping Center - to provide for the possibility of dismantling the building. After all, it is clear that sooner or later it will become unusable, and demolishing such a huge structure for those times, as it seemed then, will be much more difficult than building it. And for the subsequent dismantling, allegedly the builders laid a nuclear charge under each building. But this theory is easily refuted by critics. At the site of a nuclear explosion, even a small one, there should be an increased level of radiation. But he was not observed.

She's also a victim

According to the official version of the American government, the most painful thing is the question of the third tower that collapsed during the terrorist attack. This skyscraper was called the Seventh Tower of the World Trade Center. This building was not hit by a plane, however, it collapsed overnight, like two twin towers.

According to the official theory, the cause of the collapse was a fire spread from neighboring towers. Allegedly, the communications through which water was supplied to the building to automatically extinguish the fire were destroyed, the fire engulfed the building, the structures could not stand it and collapsed.

Half of the Americans surveyed several years ago did not even know that three buildings were destroyed during the events of 2001 in New York. Many of those who know do not believe that the 47-story building could have collapsed instantly in a fire. In the United States, activists have repeatedly demanded a new investigation into the case and the publication of the results of the investigation, but the authorities did not hear them or simply did not want to hear them.

A new skyscraper built on the site of the destroyed twin towers

The new World Trade Center building has opened in New York. A new skyscraper with 104 floors was built on the site of the twin towers destroyed on September 11, 2001. At 541 meters, the new building is the tallest structure in the United States.

Western media reports that tenants have already begun moving into their offices in the new WTC building, such as employees of the publishing house Conde Nast. In total, 60% of the skyscraper's area has already been commissioned. But you can visit the observation platform at the top of the building freely, numerous tourists have already reached there.

At the same time, no official ceremonies in connection with the opening of the World Trade Center have yet been held. This is because the date of the ceremonies is still being negotiated by the secretaries of the governors of New York and New Jersey.

"The New York landscape has been restored," said Patrick Foyer, executive director of the city's Port Authority, which owns the building and the 6.5 hectares of land on which the center was built.

The construction of the new WTC building cost $3.9 billion. Construction took eight years. The building is currently the tallest in the US. On the territory of a skyscraper with a height of 541 meters there is a memorial in memory of the dead and a museum that opened this year.

According to Foye, the World Trade Center "sets new standards in construction, design, prestige and integrity." Also, according to Foyer, the building is the safest office center in the entire United States.

The Twin Towers of the World Trade Center opened in 1973. During the terrorist attack on September 11, 2001, when two planes hijacked by terrorists crashed into skyscrapers, the towers were destroyed. Nearly 3,000 people were killed in the attack. After that, on the site of the destroyed towers, it was decided to build a new skyscraper.

Original taken from mgsupgs in History of the Twin Towers

Original taken from igornasa to the World Trade Center - from foundation to Ground Zero
Story WTC (World Trade Center) started in 1946.

It was the first year after the war - Europe lay in ruins, Japan was moving away from the consequences of the atomic bombing, China was in anticipation of civil war. The only country that managed with little blood, with a mighty blow, were the USA - for a very short time the world became Pax Americana.

Pax americana and sovietica

Better to be dead than red
(anti-communist slogan)
We will bury you
(N.S. Khrushchev)

The dollar was recognized as an international means of payment, the Marshall Plan began to be implemented, the International Monetary Fund, the International Bank and, of course, the UN were created.
The UN headquarters is located in cosmopolitan New York.

In 1946, the New York city fathers, anticipating the rise of international trade in the post-war world, proposed the construction of a "World Trade Center" in Lower Manhattan.

The idea turned out to be premature. The Soviet Union, having the strongest land army, acquired an atomic bomb. Over Europe, the Soviets lowered the iron curtain, while in Asia, having made friends forever with China, they unleashed the Korean War.

world out pax americana turned into Pax americana et sovietica (the American world and the Soviet world)

The Cold War was not very conducive to the flourishing of international trade - the Americans returned to the idea of ​​building the World Trade Center only in the late fifties. The word "worldwide" now referred exclusively to the capitalist world.

The center was supposed to be built in Lower Manhattan, which was in deep crisis. After 1929, not a single new skyscraper was built here, and the area itself gradually turned into a ghost town. The Rockefeller brothers, David and Nelson, managed to stop this process.

Rockefellers. "Baron", philanthropist, politician, banker

All major modern fortunes are acquired in the most dishonorable way.
"Capitalist Sharks. Biography of American Millionaires" ...
As an intelligent person, he will understand that a part is less than the whole, and will give me this part for fear of losing everything.

(Golden calf)

The brothers belonged to not the last dynasty in the capitalist world - their grandfather was the same Robber Baron (robber baron) John Rockefeller Sr., who is Standard Oil, and his father is a philanthropist John Rockefeller Jr.(Rockefeller Center).

John Rockefeller Sr.

John Rockefeller Jr. and his sons - David, Nelson, Winthrop, Lawrence and John Rockefeller III, awaiting the arrival of the coffin with the body of John Rockefeller Sr. (1937)

If the founder of the dynasty, the first "dollar" billionaire in the world, forever left the stigma of a robber baron, then his heirs became famous as philanthropists and politicians - money does not smell.
The most notable figures of the five brothers were Nelson and David.

Save Lower Manhattan!

WTC skyscrapers were going to be named "Nelson" and "David"
(New York folklore)

Nelson Rockefeller, vice president in the administration of Gerald Ford, served 14 years as Governor of New York State.
David Rockefeller since 1961 he has been president of the Chase Manhattan Bank.
It was with the construction of the 60-story skyscraper Chase Manhattan Bank that the revival of Lower Manhattan as a business center began.
In 1960, the "Downtown-Lower Manhattan Association", led by David Rockefeller, developed a plan to create World Trade Center- a complex of office buildings and hotels. With the support of New York State Governor Nelson Rockefeller, the plan began to materialize.
Such a grandiose project could only be mastered by Port Authority- a powerful organization responsible for the infrastructure inside the ring with a radius of 40 km and the center - the Statue of Liberty.

Through hardship to the stars

The construction of the World Trade Center, of course, could not do without conflicts. The interests of the two states (New York and New Jersey), the city of New York, the owners of the Empire State Building and the organization Port Authority. The parties had to compromise, make concessions and receive change.
Almost everyone was reconciled by the transfer of the WTC site from the east coast of Manhattan (East River) to the west (Hudson). At the same time, the WTC was planned to be built just above the railway tunnels connecting Manhattan with the New Jersey coast.

1 - original location for WTC, 2 - WTC

As a result, the state of New Jersey received railroad upgrades, and the state of New York and the Port Authority profited from the operation of the terminal of this road, which was planned to be built under the World Trade Center.
Contradictions were resolved in the corridors of power, only the last battle took place on the square - with the owners of small shops located on the site of the future World Trade Center. They were mostly electronics stores - that's what the place was called Radio Row(Radio series).
Businessmen, behind whom loomed the owners of the Empire State Building, who did not want the appearance of such a competitor, staged demonstrations and tried to act through the courts.

All their efforts were in vain - on March 21, 1966, the first of the red-brick buildings of Radio Row was demolished.
What did they plan to build under such a loud name - the World Center?
Back in 1962, a little-known architect from Detroit, a 49-year-old Japanese American, won a competition in which architects of the first rank participated. Minoru Yamasaki.

Quiet Japanese American

The biography of Minoru Yamasaki is a classic illustration of American success.
Born in Seattle to Japanese immigrants (his father worked in a local shoe factory and his mother was a pianist), he was exposed early to the racism then so prevalent in those parts. To earn money for his college education, he traveled to Alaska, where he worked 14-hour days on fishing boats.

Minoru Yamasaki shows the place under the World Trade Center on the layout of Lower Manhattan

two one hundred and ten

Yamasaki was given the modest task of designing a building with five times the office space of the Empire State Building. Having gone through dozens of options - a lone skyscraper with 150 floors, four skyscrapers, a complex of low buildings and others, the architect settled on two identical skyscrapers-parallelepipeds with a square section.

Italian influence is evident in the works of the American architect of Japanese origin.
The shape and arrangement of skyscrapers - like the towers of the medieval Italian city of San Gimignano

Twin towers of San Gimignano

Twin Towers of the World Trade Center

Gothic arches - like the Doge's Palace in Venice

Doge's Palace

World Trade Center Plaza

The original skyscrapers had 80 floors, making them shorter than the Empire State Building.

Guy Tozzoli, in charge of the project from the organization Port Authority, stated:
Pit, the president is going to put a man on the moon. I want our skyscrapers to be the tallest in the world

Yamasaki added 30 floors each. Now the 110-story skyscrapers have bypassed the Empire State Building... and started their second high-altitude race. As is known, first high-altitude race completed in 1931, and the winner, the Empire State Building, remained the tallest building in the world for 40 years. The second race is still going on:

World Trade Center (1973)
Sears Tower (1974)
Petronas Towers (1998)
Taipei 101 (2004)
Shanghai World Financial Center (2008)
New WTC-1 (2013, under construction)
Burj Khalifa (2010)

On August 6, 1966, twenty years after the concept of the complex was born, the construction of the World Trade Center began.

Construction of the century

We built and built and finally built

The construction of a skyscraper is an extraordinary task in itself, but the construction of the World Trade Center was unprecedented in scale and complexity.
The problems started from the foundation. The skyscraper must stand on bedrock(hard rock). It turned out to be more than 20 meters before her in the place chosen for the Center. Just digging was dangerous because of the proximity of ocean waters, so before digging began, an underground "wall" was built around the entire perimeter of the future construction site. The structure was named bathtub (trough).

Bathtub (indicated by arrows). Tunnels: 1 - in New Jersey, 2 - from New Jersey

And what was to be done with so much excavated land? New York remembered its Dutch roots - the inhabitants of the Netherlands (Lower Lands) were famous for their ability to win space from the sea. The Dutch colonists brought this know-how to the New World, and the British took advantage of their knowledge - over the centuries of colonization, the outlines of Manhattan have changed a lot.

These changes are demonstrated by a photograph from the 30s - elevated metro line runs along the border New Amsterdam

1 - a place under the World Trade Center, 2 - the area of ​​the future embankment

WTC towers and embankment under construction

Later, a residential complex was built on the embankment. Battery Park City and World Financial Center. The four squat skyscrapers of the Financial Center, similar to the Teletubbies, delight the eye with a variety of tops - an Egyptian pyramid, a Mayan pyramid, a dome and a mastaba

Blue dots - the outlines of Manhattan in the year of its "purchase" from the Indians (1626),
gray area - man-made areas.

Depths bathtub enough for seven underground floors, over which the construction of 110-story towers began.
Cranes ordered from Australia were used in the construction Kangaroo capable of self-growing

The unusual design of the WTC skyscrapers is demonstrated by a unique photograph, which, like an x-ray, shows the "skeleton" of the North Tower.

The weight of the skyscraper was carried by two groups of columns - the central and the outer.

Stairs and elevators were located in the center, and the space between the central and outer columns was intended for offices. This design gave future tenants the freedom to redevelop offices.

Typical skyscrapers of that time had facades made entirely of glass, while Twins had windows in the back, behind the columns.
At night, the windows were clearly visible.

during the day skyscrapers became blind monoliths

This is how skyscrapers looked at the end of construction, in 1970.

The last floor of the North Tower was built at the end of 1970, the South Tower - in the middle of 1971. The opening of the Center took place April 4, 1973.
The twins seemed to be the legs of a huge tuning fork upon completion of construction.

The opportunity to see them in full growth disappeared after the construction of the World Financial Center in 1988.

The cost of construction went over 1.5 billion dollars, 7.5 thousand people built the World Trade Center, 8 people died.

Perpendicular city

As is customary, the United States is divided into areas that are assigned postal codes ( zip code).

It is unusual to assign an index to a single building. In New York City, 44 skyscrapers are large enough to have their own zip code. For example, the Empire State Building zip code is 10118 , Chrysler Building - 10174 , Seagram Building - 10152 .

The WTC index was the numbers 10048 .

The World Trade Center was a real city - in the buildings of the complex on a weekday there were up to 50 thousand employees and from 50 to 100 thousand visitors. This made it the sixth most populous "city" in the state of New York.

The WTC is six buildings that fit in the Plaza (square) of 16 acres, and one building is outside the square.

1 WTC - North Tower
2 WTC - South Tower
3 WTC - Marriot Hotel
4 WTC - commodity exchange
5 WTC - Dean Witter Building
6 WTC - US Customs
7 WTC - Salomon Brothers Bank

Often the whole complex was simply called the Twins - the rest of the buildings faded next to the 110-story towers:

Height of the North Tower (without antenna) - 417 meters
The height of the South Tower is 415 meters
Antenna height - 104 meters

The delivery of people and goods was carried out by elevators - there were 103 of them in each tower (97 passenger and 6 freight). Express elevators stopped only on the 44th, 78th and top floors (the so-called skylobbies- heavenly vestibules). For intermediate floors, it was necessary to transfer to local elevators.

In the center of the Plaza was a fountain with a rotating sphere

Under the plaza there was a mall, below the mall there was an underground garage for 2000 cars. At the level of the seventh floor there was a railway tunnel.

Endure - fall in love

The initial reaction of New Yorkers and guests of the capital of the world to Yamasaki's creation was very cool:

The twins are the boxes that the Chrysler Building and the Empire State Building were delivered in.
(New York folklore)

The most ruthless critics were professionals:

Ada Huxtable , architectural critic:
The towers are bare technology, the lobbies are tearful sentimentality, the New York influence is pure fantasy... Twenty-two inch (56 cm) windows are so narrow that one of the marvelous possibilities afforded by high-rise buildings, the breathtaking view from above, is completely absent. ... Towers are great buildings, but they are not great architecture.

Paul Goldberger , architectural critic:
It [Center] is big. It is larger than any building. He showed once again that a person can adapt to anything ... His influence on the city, whether it concerns the skyline, the downtown environment and real estate prices, cannot be overestimated. But the Center's buildings themselves are so boring and banal that they wouldn't even be worth building for a bank in Omaha.

In the end, the Twins repeated the fate of the Eiffel Tower - they got used to them, then they stopped noticing, then they began to be proud.
Filmed against the backdrop of the World Trade Center:

The Statue of Liberty

Church of St. Nicholas

If someone wanted to see Manhattan without the World Trade Center, he had to climb
to the upper floors of the Twins - the only place where they could not be seen.

It was possible to survey "the whole of New York"
- from the windows of the Windows on the World restaurant, located on the 106/107 floors of the North Tower

from the Observation Deck, located on the 107th floor of the South Tower

from the platform on the roof of the South Tower (110th floor)

The Gemini soon began to attract adventurers.
The "sky walk" of the French tightrope walker became a sensation.

Philippe Petit Big Show

When I see three oranges I have to juggle; when I see two towers I have to walk between them
(F. Petit)

At six o'clock on the evening of August 6, 1974, Philippe Petit, a self-taught tightrope walker, climbed onto the roof of the South Tower. He was not alone - several people participated in the "conspiracy". Pretending to be messengers, they carried the necessary equipment to the roofs of the towers - a steel rope, a collapsible pole, a bow and an arrow. It took all night to transfer and secure the rope.

At seven o'clock in the morning, Philippe Petit stepped onto a rickety "bridge" stretched at a height of 415 meters, one inch (2.5 cm) wide and 40 meters long.

Far below, people hurrying to work stopped and looked in disbelief at a small human figure strolling between giant towers at an unimaginable height.

The first ten viewers were soon joined by thousands. A few minutes after the "performance" began, the police arrived on the roof of the South Tower.

Sergeant Charles Daniels testifies:

When police officer Meyers and I went out on the roof, we found this "dancer" halfway up the tower - it would not be enough to call him just a tightrope walker. When he saw us, he smiled and started dancing. When he knelt down, we retreated, worried that our presence would affect his concentration. We called everyone to silence. The tightrope walker lay down on the rope, then sat down, dangling his legs - it was incredible ...

Standing up, he began to dance again, laughing and approaching us... When he approached the tower, we demanded that he get off the rope onto the roof, but he turned and walked back... He began to jump, completely tearing his legs off the rope We are all petrified...

Petit himself recalls:

In 45 minutes I made 8 transitions. During one of them, I lay down on a rope, looked into the sky and saw a seagull above me. I could see her - she had red eyes. I was reminded of the myth of Prometheus. The bird circled in the sky and looked at the alien intruding into its space - who I was here, at this height ...

When Petit returned to the roof, he was immediately arrested.

He was charged with a lot: penetration into private territory, disobedience to the police, dangerous behavior for others, and even public speaking without permission.

Of course, later all charges were dropped, Philippe Petit was only obliged to speak to a children's audience in Central Park.
Philippe Petit was followed by representatives of other genres.

Brave heroes of very small stature

They just don't notice us
Due to size difference
And so they forgive
Very small but brave...

If at Vladimir Mayakovsky the unemployed rushed off the Brooklyn Bridge, then one modern disadvantaged chose the World Trade Center. Not intending to take his own life, he wanted to draw attention to the plight of the unemployed.

He landed safely, becoming one of the forerunners BASE jumping (Building, Antenna, Span, Earth)- an extreme activity in which daredevils jump with a parachute from buildings, antennas, bridges and cliffs.
WTC won not only from above, but also from below.

George Willig, "man-fly", on May 26, 1977, climbed the South Tower, spending 3.5 hours on it. For disturbing the peace, he was fined $1.36 - a cent for every foot he crossed.

Various performances were staged on the stage called the World Trade Center.
In 1995, the match for the title of world chess champion (according to the PCA) between Garry Kasparov and Viswanathan Anand was held here.

Such a platform could not be neglected by Hollywood. In the 1976 remake of King Kong, the final scene takes place not on the Empire State Building, but on the roof of the World Trade Center.

The film, as you know, does not end with a happy ending for King Kong - mortally wounded, he falls from the roof of the South Tower into the plaza of the complex.

First blood

On that day, a truck bomb exploded on the second floor of the underground garage under the North Tower.

Wards of Omar Abdel-Rahman (the Blind Sheikh) hoped that the North Tower would collapse on the South, but the Twins resisted.

6 people were killed, about a thousand were wounded. As a result of the explosion, the skyscrapers were de-energized, the elevators stopped, the warning system stopped working. The firemen's portable radios did not function well, and the 911 system was overloaded.

The foot evacuation by stairs took more than 4 hours. A small group of people were taken by helicopters from the South Tower, and one person even from the hard-to-reach roof of the North Tower.

Helipad on the roof of the North Tower; police helicopter

These operations have given people the false belief that rooftop helicopter rescues are part of the rescue plans.

The attack demonstrated the poor readiness of the World Trade Center for such catastrophic events and forced them to take action.
Alas, as the events of 2001 showed, these measures turned out to be half-measures.

11 September

But the wind blew and you're gone
Who do you want to surprise...

The first ramming occurred at 8:46 am, the second tower collapsed at 10:28 am.
The World Trade Center, which took seven years to build and stood for thirty years, was destroyed in 102 minutes.

Completely destroyed
1 - 1 WTC
2 - 2 WTC
3 - 7 WTC
4 - North Bridge
5 - Church of St. Nicholas
Partially collapsed
6 - Marriot Hotel
7 - 4 WTC
8 - 5 WTC
9 - 6 WTC
Significantly damaged
10 - building at 30 West Broadway
11 - Verizon Telephone Company Building
12 - 3 World Financial Center
13 - Winter Garden
14 - building at 90 West Street
15 - Bankers Trust building
Facade damaged
16 - One Liberty Plaza
17 - building at 22 Cortlandt Street
18 - Millennium Hilton Hotel
19-Federal Office Building
20 - 2 World Financial Center
21 - 1 World Financial Center

The next day

When the ruins of the World Trade Center were removed, a practically intact wall emerged from the ground. bathtub

The place was named ground zero - this is how, since the time of Hiroshima and Nagasaki, they have called a point on the surface of the earth, located directly under the center of an air nuclear explosion ...

World Trade Center (1966-2001)