Demolition 3

Squibs

GIF of squibs detonating

squibs_and_streamers.gif

Squibs and streamers from WTC

http://www.liveleak.com/view?i=4d5_1191120893

Images of squibs

http://www.debunking911.com/overp.htm

Terminology

Squibs are “blasting caps (initiators) used in the explosive industry to set off high explosives.” In discussions of the collapses of the WTC skyscrapers, the term has been appropriated to describe the physical appearance of puffs or jets of dust emerging from buildings during a demolition, caused by the detonation of explosive charges. Several such “squibs” can be seen in videos and photographs capturing the collapses of the North and South Towers.

It has been suggested that the evident squibs could have been added to the photographs and videos after the fact, given that much of this evidence has found its way onto the web via undocumented routes. However, the squibs show up in many diverse videos and photographs, and we have not been able to find any showing the squibs to be absent. A conspiracy of incredible proportions would be required to forge such convincing evidence of squibs in such diverse sources.

http://911research.wtc7.net/wtc/analysis/collapses/squibs.html

More image of squibs

Some of the ‘puffs of smoke’ observed during the Twin Towers collapses. [Source: Richard Lethin]

http://www.cooperativeresearch.org/entity.jsp?entity=kevin_ryan

The still video frame above shows several explosive ejections of material from the sides of the North Tower well below the zone of collapse. There are at least three such “squibs” of debris shown here. In particular, the one on the right has been measured in the video to have an average velocity over 200MPH

http://9eleven.info/SmokingGuns.html

Squibs along the southwest corner of WTC 7

http://st12.startlogic.com/~xenonpup/Flashes/squibs_along_southwest_corner.htm

Squibs from WTC 7

Dailymotion

More pictures of squibs

Img: http://www.mediumrecords.com/wtc/jets1b.jpg URL: http://www.abovetopsecret.com/forum/thread214138/pg1 Caption: Demolition charges

http://forum.physorg.com/index.php?act=Print&client=printer&f=10&t=3108

Img: http://web.archive.org/web/20020802022752/http://www.controlled-demolition.com/images/mendes.jpg URL: http://www.the7thfire.com/Politics%20and%20History/DemolitionWTC.htm Caption: A photo of a 1975 controlled demolition of 361 foot Mendes Caldeira Building in São Paulo, Brazil. Note the demolition squibs at intervals along the face of the building. These were simultaneous explosions.

http://www.the7thfire.com/Politics%20and%20History/DemolitionWTC.htm

Img: http://www.the7thfire.com/images/911-4_small.jpg URL: http://www.the7thfire.com/Politics%20and%20History/DemolitionWTC.htm Caption:

Frame shows a row of explosives detonating right across the east face at the [79th] floor.

It has been claimed that the explosions of dust that span the east face of the tower, were caused by air being forced from the windows as each of the floors above collapsed. This explanation is obviously incorrect. If it was correct, such lines of dust would have been expelled from the windows of each floor in succession. That is, we would have seen such lines of dust expelled from floors 79, 78, 77, 76 and 75 in succession, but what we observe is an explosion of dust at floor 79, no new clouds of dust for a few floors, then another explosion of dust at floor 75.

http://www.the7thfire.com/Politics%20and%20History/DemolitionWTC.htm

Img: http://www.debunking911.com/wtc-southtower.jpg   URL: http://www.debunking911.com/   Caption:
World Trade Center, South Tower (photo by Gulnara Samoilova / AP)

Flashes and fireballs before Sth Tower collapses

FROM: http://www.dailymotion.com/skyblue09/video/5199594

Shaking before the tower collapses

Click on image to view video

FROM: Dailymotion

Fireballs before WTC 1 collapses

Dailymotion

Squibs and cascade of explosions

Dailymotion

More pictures of squibs

http://www.luogocomune.net/site/modules/911/index.php?filename=911/7-Misc/stampa/focus/focus.html

http://www.luogocomune.net/site/modules/911/index.php?filename=911/7-Misc/stampa/focus/focus.html

wtcsquibscollapse.gif

http://www.luogocomune.net/site/modules/911/index.php?filename=911/7-Misc/stampa/focus/focus.html

http://911research.wtc7.net/wtc/evidence/photos/wtc1exp1.htm

http://www.luogocomune.net/site/modules/911/index.php?filename=911/7-Misc/stampa/focus/focus.html

Videos of controlled demolitions of towers

Pirelli Tower falling

Dailymotion

This is like the collapse of WTC Building 7.

Footage of a building blowing up in China

Dailymotion

This is like the collapse of the Twin Towers. The disintegration of the Chinese building show the head mushrooming off in an explosion the same as the Twin Towers.

Simultaneous demolitions of the Pirelli Tower and WTC Building 7

VIDEO: WTC 7 and Pirelli Tower demolitions by bombs   Dailymotion

Pirelli and WTC7 side by side

VIDEO: Pirelli and WTC 7 side by side   Dailymotion

Caption: Chernobyl, dirty atomic reactor gone critical. Img: http://chernobyl.co/files/2010/12/Copy-of-Chernobyl_Disaster1.jpg URL: http://chernobyl.co/

Caption: WTC Building 6 JPG: http://911research.wtc7.net/wtc/evidence/photos/docs/gzd_059.jpg URL: http://911research.wtc7.net/wtc/evidence/photos/gzsurround.html

http://www.armageddononline.org/forums/printthread.php?t=7901

The other towers in the WTC complex

Caption: The thermal survey of the WTC 9/16/2001 (NASA /US Geological Survey). Despite of fire department having cooled the rubble, aluminium would still be melting in some sites 5 days after the incident. Img: https://apunked.files.wordpress.com/2017/02/wtc_temps.jpg URL: http://www.saunalahti.fi/wtc2001/soldier4.htm

http://www.saunalahti.fi/wtc2001/soldier4.htm

http://wtc-the-truth.i8.com/catalog.html (dead link)

Chopped off columns

Caption: Chopped columns Img: http://www.nycpba.org/wtc/images/ph-legislation.jpg   URL: http://www.nycpba.org/wtc/legislation.html

Bomb heard in this video

VIDEO: Firemen hear bombing

Dailymotion

FBI thought that a truck bomb was involved

Dailymotion

Beams pre-cut by demolition squibs (charges)

http://www.911research.com/wtc/evidence/photos/groundzero.html

30-ton tridents twisted and snapped like matchsticks

http://www.amny.com/entertainment/news/am-wtcrelics-pg2006,0,6613706.photogallery?index=15 (dead link)

http://www.amny.com/entertainment/news/am-wtcrelics-pg2006,0,6613706.photogallery?index=3 (dead link)

http://www.amny.com/entertainment/news/am-wtcrelics-pg2006,0,6613706.photogallery?index=15 (dead link)

http://drjudywood.com/articles/dirt/dirt4.html

http://drjudywood.com/articles/dirt/dirt2.html

http://www.amny.com/entertainment/news/am-wtcrelics-pg2006,0,6613706.photogallery?index=15 (dead link)

http://www.amny.com/entertainment/news/am-wtcrelics-pg2006,0,6613706.photogallery?index=15 (dead link)

http://drjudywood.com/articles/why/why_indeed.html

Where are the tridents? Cut up in this picture of GZ.

http://www.911research.com/wtc/evidence/photos/groundzero.html

Tridents are twisted, shred and snapped in this pre-cleanup photo.

http://www.911research.com/wtc/evidence/photos/groundzero.html

Tridents bent, cut and shredded.

http://www.911research.com/wtc/evidence/photos/groundzero.htm

Caption: These photographs were apparently taken shortly after the attack. The first three photographs were taken from Church Street, immediately east of the World Trade Center block. They show the remains of Building 4, and a large section of the perimeter wall of a tower leaning against it.

http://www.911research.com/wtc/evidence/photos/docs/wtc_shattered2.jpg   URL: http://www.911research.com/wtc/evidence/photos/gzlocal.html

Snapped trident in the foreground on the left. (Pre-cleanup photo)

http://www.911research.com/wtc/evidence/photos/groundzero.html

Caption: Figure 2-4 Base of exterior wall frame. Img: http://911research.wtc7.net/mirrors/guardian/WTC/fig-2-4.jpg URL: http://911research.wtc7.net/mirrors/guardian/WTC/WTC_ch2.htm

Caption: Lobby of WTC 1  Img: http://photos1.blogger.com/blogger/5459/522/400/wtcinlobby1.jpg    URL: http://covertoperations.blogspot.com/2006/11/wtc1-debris.html

Hypothetical schema of the bombs in the WTC – Finnish military expert

Caption: Note: This drawing is schematic only. The actual towers were much taller and the observed arch of destruction of the energy-directed thermonuclear device was correspondingly more narrow. Img: http://www.saunalahti.fi/wtc2001/nuke.gif   URL: http://www.saunalahti.fi/wtc2001/soldier2.htm

Schema of bombs in the World Trade Center Twin Towers

Bombing_schema2_mod (2)

Caption: Diagram of bomb placement

Gelatin Art Students

VIDEO: “The Mysterious Gelatin Art Group Living in WTC prior to 9/11″[Dailymotion|Youtube]

Other buildings and simultaneous explosions

WTC Building 3

Caption: Img: http://911research.wtc7.net/mirrors/guardian/WTC/fig-3-8.jpg URL: http://911research.wtc7.net/mirrors/guardian/WTC/WTC_ch3.htm
Figure 3-8 Remains of WTC 3.

Caption: Partial collapse of WTC 3 after collapse of WTC 2. Img: http://911research.wtc7.net/mirrors/guardian/WTC/fig-3-7A.jpg  URL: http://911research.wtc7.net/mirrors/guardian/WTC/WTC_ch3.htm

Peripheral damage

A building at 90 West St.—located across the street and just south of WTC-2—was undergoing extensive exterior surface renovation. Before the attack, scaffolding had been erected on the east, west and south sides of the 12-story turn-of-the century art deco building. When Tower 2 collapsed, the building was pelted with steel, glass and concrete debris. Its first six floors were burned-out and the remaining six floors suffered heavy structural damage.

http://911research.wtc7.net/cache/wtc/analysis/asse_groundzero1.htm

Map of peripheral damage

Img: http://911research.wtc7.net/cache/wtc/analysis/asse_groundzero1_files/groundzero_wtcmap.jpg   URL: http://911research.wtc7.net/cache/wtc/analysis/asse_groundzero1.htm

World Trade Center1. Tower 1 (WTC-1)

(collapsed)

2. Tower 2 (WTC-2)

(collapsed)

3. Marriott Hotel (WTC-3)

(destroyed/collapsed)

4. Office Building (WTC-4)

(destroyed)

5. Office Building (WTC-5)

(destroyed)

6. Office Building (WTC-6)

(destroyed)

7. Office Building (WTC-7)

(collapsed)

World Financial Center8. American Express (WFC-3)

(major structural damage)

9. Office Building (WFC-2)

(minor structural damage)10. Dow Jones (WFC-1)

(minor structural damage)

Other Affected Buildings11. Federal Building

(minor superficial damage)

12. 140 West Street (NY Telephone)(structural damage)

13. 1 Liberty (Brooks Brothers)

(structural damage)

14. Century 21 Building

(structural damage)

15. Millennium Hilton

(serious structural damage)

16. 90 West Street

(serious structural damage)

17. Greek Orthodox Church

(destroyed)

18. 130 Liberty (Bander’s Trust)

(serious structural damage)

http://911research.wtc7.net/cache/wtc/analysis/asse_groundzero1.htm

http://911research.wtc7.net/wtc/analysis/collapses/explosions.html

Ring of squibs in South Tower

Video

VIDEO: South Tower collapses. Ring of squibs at the fracture line.

Dailymotion

Explosive ejection of dust early in the collapse of the South Tower is clearly visible in the NBC video taken from far to the east, and in still frames from that video, portions of five of which are shown on the right. In addition to the large ejections of white dust from the left wall, the video shows a small high-speed ejection toward the back of the right wall, visible as a small white fleck in the first frame to the right.

Many of the photographs of the tower collapses show solid objects, such as sections of steel columns and aluminum cladding of the outer walls, being thrown ahead of the expanding dust cloud. This pattern is characteristic of explosive demolitions. According to Chapter 1 of FEMA’s own report pieces of the steel columns and plates of the perimeter walls were thrown over 500 feet from the towers. The distribution pattern they diagram suggests that, with both towers, perimeter wall pieces were thrown an average of about 150 to 200 feet outward.

http://911research.wtc7.net/wtc/analysis/collapses/explosions.html

Sphere of peripheral damage

Banker’s Trust building

Caption: North face of Bankers Trust building with impact damage between floors 8 and 23. Img: http://911research.wtc7.net/mirrors/guardian2/wtc/fig-6-1.jpg    URL: http://911research.wtc7.net/mirrors/guardian2/wtc/WTC_ch6.htm

Caption: Closeup of area of partial collapse. Note debris accumulated at the bottom of the damage area, resting on the 8th floor. Area of initial impact is not shown in this photo.   (North face of Banker’s Trust building) Img: http://911research.wtc7.net/mirrors/guardian2/wtc/fig-6-2.jpg  URL: http://911research.wtc7.net/mirrors/guardian2/wtc/WTC_ch6.htm

American Express, WFC 3

Caption: Southeast corner of WFC 3. Img: http://911research.wtc7.net/mirrors/guardian2/wtc/fig-7-2.jpg   URL: http://911research.wtc7.net/mirrors/guardian2/wtc/WTC_ch7.htm

The 50-story WFC 3 building has a plan area of approximately 200 feet by 250 feet. Exterior column trees from WTC 1 were found hanging from the southeast corner of WFC 3 (Figure 7-2) and on the setback roof and against the east face of the Winter Garden (Figures 7-3 and 7-4). The impact of exterior column trees caused structural damage in both structures. Building faces not directly oriented toward the WTC site suffered minimal damage, even at the close proximity of several hundred yards.

http://911research.wtc7.net/mirrors/guardian2/wtc/WTC_ch7.htm

The Winter Garden

The Winter Garden lies between WFC 2 and WFC 3. It is a large greenhouse structure with a glass and steel telescopic barrel vault roof and is one of the largest public spaces in New York. The structure covers an area of approximately 200 feet by 270 feet and includes a public space of 120 feet by 270 feet. The largest vault has a clear height of about 130 feet and a span of 110 feet. The west elevation is made entirely of glass panels. The east end of the building has five composite steel floors that support a glass dome that covers a ceremonial stair. The structure has expansion joints where it meets WFC 2 and WFC 3. The spatial stability of the frame is insured by trussed arch framing. The east end was linked to the WTC complex by the North Bridge, which had a 200-foot clear span and was 40 feet wide. The west end has an entrance door.

Columns from WTC 1 hit the east end of the structure, particularly the area directly adjacent to the North Bridge. The Winter Garden experienced severe collapse of the eastern end framing. Several other semicircular trusses and parts of the dome were also badly damaged. The western two bays of the roof structure remained intact, but were covered with debris. Inspectors estimated that 60 percent of the roofing glass panels of the structure had collapsed.

Additional structural collapse occurred on parts of the 2nd and 3rd floor framing adjacent to WFC 2 and WFC 3, the North Bridge connection extension, the ceremonial stair above the circular landing, and the 4th and 5th floors at the eastern end. Localized structural collapse occurred in various other areas of the barrel roof.

As the eastern roof trusses were sheared in several places, support was provided only by the transverse plate girders that remained in place. These conditions, coupled with the shearing of trussed arch framing, led the first round of inspectors to conclude that the structure was potentially unstable, and a rating of Partial Collapse was assigned. After installation of shoring, a new evaluation of the building led engineers to determine that the building was repairable, and the rating was revised to Major Damage.

http://911research.wtc7.net/mirrors/guardian2/wtc/WTC_ch7.htm

Caption: View of Winter Garden damage from West Street, with WTC 1 debris in front of WFC 2. Img: http://911research.wtc7.net/mirrors/guardian2/wtc/fig-7-3.jpg   URL: http://911research.wtc7.net/mirrors/guardian2/wtc/WTC_ch7.htm

Caption: View of Winter Garden damage from West Street, with WTC 1 debris leaning against WFC 3. Img: http://911research.wtc7.net/mirrors/guardian2/wtc/fig-7-4.jpg URL: http://911research.wtc7.net/mirrors/guardian2/wtc/WTC_ch7.htm

Verizon Building

The Verizon building is located on the block bounded by Barclay Street on the north, Washington Street on the east, Vesey Street on the south, and West Street on the west. It is north of WTC 1 and WTC 2, and immediately west of WTC 7, which all collapsed.

The 30-story Verizon building was built in the 1930s and has a steel frame with infill exterior walls of unreinforced masonry, and five basement levels. The steel frame is encased in cinder-concrete and draped-wiremesh, with cinder-concrete slab floor construction. Beams are rolled sections (mostly 12 inches deep) with cover plates at floors with high live loads. Girders are either rolled sections or built up from plates and angles. Columns are also built-up sections. Partially restrained moment frames at the building perimeter provide lateral resistance. The masonry walls are about 12 inches thick (on average), and the columns are encased in brick. The facade and 1st floor lobby are registered as historic landmarks. At the time of the adjacent building collapses, the Verizon building was in the midst of an extensive facade restoration program.

The proximity of the building to WTC 2 resulted in considerable damage to the south and east faces of the building. Damage included collapsed floor slabs and deformed beams and columns, including some local buckling. Window damage was moderate, and it is notable that the windows contained wire mesh. The west (West Street) and north (Barclay Street) sides of the building were not damaged.

The east (Washington Street) side of the building was damaged from about the 9th floor down, primarily due to the impact of debris sliding out from the base of WTC 7 (Figures 7-6, 7-7, and 7-8). Some damage may have also been caused by WTC 1 debris. In addition to fairly extensive facade damage (bricks and windows), there was damage to two bays of slab and framing at the 1st, 4th, and 7th floors and to one bay of slab and framing (including spandrel beam) at the 1st floor mezzanine and at the 5th floor. Two exterior columns suffered major damage between the 1st and 2nd floors (Figure 7-9), one exterior column suffered minor damage between the 3rd and 5th floors, and two exterior columns suffered major damage between the 6th and 8th floors. In addition, one interior column suffered minor damage below the 7th floor.

The south (Vesey Street) side of the building was damaged from approximately the 13th floor down, primarily due to the impact of projectile debris from the collapse of WTC 1 (Figure 7-10). In addition to fairly extensive facade damage (bricks and windows), two bays of slab and framing were damaged at the sidewalk arcade at the 1st floor, and one bay of slab and framing (including spandrel beams) was damaged at the 6th, 7th, 9th, 11th, 12th, and 13th floors (Figures 7-11 and 7-12). In addition, one interior column suffered minor damage below the 1st floor.

None of the damage to the floor framing threatened the structural integrity of the building. Although the damaged columns were deflected out-of-plane, it was determined that the columns were stable and not in danger of imminent collapse.

In general, the Verizon building performed well, especially given its close proximity to WTC 7. On the south (Vesey Street) side of the building, damage was extremely localized near the point of impact of projectile debris. In some cases, only a short section of spandrel beam and small area of floor slab were damaged, leaving the remainder of the structural bay intact (Figure 7-12).

On the east (Washington Street) side of the building, most of the damage appeared to be due to the lateral pressure of the spreading debris at the base of WTC 7 (Figure 7-7). Two of the columns between the 1st and 2nd floors were deflected into the building by as much as 2 feet (with most of the rotation occurring at the column splice just above the 1st floor); at one of the columns, very little contact remained at the column splice (Figure 7-9). Even so, the columns did not buckle, and structural bays above did not collapse or deflect significantly. Similarly, the structural bays supported by the column between the 6th and 8th floors that was completely destroyed by the impact of projectile debris were essentially undamaged.

Several factors may have contributed to the performance of the Verizon building. The thick masonry walls, brick-encased columns, and cinder-concrete-encased beams and girders probably absorbed much of the energy of the impacts while also providing additional stiffness and strength to the building frame. The lower floors (up to the 10th floor) were designed for either 150 pounds per square foot (psf) or 275 psf, depending on the intended occupancy. Consequently, the member sizes and end connections are unusually stocky. Although designed for higher-than-normal live loads, at the time of the adjacent building collapses, actual live loads were relatively low.

Most floors are framed with 12-inch-deep beams with cover plates, presumably to maintain uniform floor clearances. These sections had full lateral bracing and were probably able to develop close to their full plastic capacities without buckling. Almost every beam-column connection was nominally moment-resistant, making the structural system highly redundant. All of these characteristics combined to both absorb the energy of the debris impacts and provide alternate load paths around the damaged areas.

The performance of this building led to several observations. The original design was for a substantially heavier live load and use as a telephone switching facility. Even so, the exterior columns on the east side were substantially damaged at the lower floors by the collapse of WTC 7. The nominally 12-inch thick brick masonry perimeter walls absorbed a significant portion of the impact energy, resulting in less damage to the structural steel framing. Impact damage was localized and did not propagate beyond immediate points of impact (sometimes not even full bays were damaged). It was noted that the windows performed better than those in other peripheral buildings, likely due to the wire mesh.

Caption: Interior damage at floor 20 of WFC 3. Img: http://911research.wtc7.net/mirrors/guardian2/wtc/fig-7-5.jpg URL: http://911research.wtc7.net/mirrors/guardian2/wtc/WTC_ch7.htm

Caption: Verizon building – damage to east elevation (Washington Street). Img: http://911research.wtc7.net/mirrors/guardian2/wtc/fig-7-6.jpg URL: http://911research.wtc7.net/mirrors/guardian2/wtc/WTC_ch7.htm

Caption: Verizon building – damage to east elevation (Washington Street) due to WTC 7 framing leaning against the building. Img: http://911research.wtc7.net/mirrors/guardian2/wtc/fig-7-7.jpg URL: http://911research.wtc7.net/mirrors/guardian2/wtc/WTC_ch7.htm

Caption: Verizon building – damage to south elevation (Vesey Street). Img: http://911research.wtc7.net/mirrors/guardian2/wtc/fig-7-10.jpg URL: http://911research.wtc7.net/mirrors/guardian2/wtc/WTC_ch7.htm

Caption: Verizon building – detail of damage to south elevation (Vesey Street). Img: http://911research.wtc7.net/mirrors/guardian2/wtc/fig-7-12.jpg URL: http://911research.wtc7.net/mirrors/guardian2/wtc/WTC_ch7.htm

West Broadway

The office structure at 30 West Broadway is most recently known as Fiterman Hall of the Borough of Manhattan Community College campus of the City University of New York. It is located just north of WTC 7. The 17-story building was constructed in the 1950s and has a concrete-encased structural steel frame with cinder-concrete floor slabs with draped steel mesh. The structure had riveted, bolted, and welded connections, and roof setbacks at the 6th and 15th floor levels. The curtain wall consists of horizontal bands of windows over glazed brick. There are continuous lintels at every floor. The building was in the final stages of rehabilitation work at the time of the terrorist attacks.

The southern half of the west facade and most of the south facade were severely damaged or destroyed. The south face of the building suffered structural damage in the exterior bay from impact by large debris from WTC 7 (Figure 7-13). There was no damage to the east and north faces of the building, and no fire in the building, even though there was a substantial fire in WTC 7.

Caption: West Broadway – south facade, 6th floor to roof, looking northeast. Img: http://911research.wtc7.net/mirrors/guardian2/wtc/fig-7-13.jpg URL: http://911research.wtc7.net/mirrors/guardian2/wtc/WTC_ch7.htm

130 Cedar Street

Constructed in the 1930s, the building at 130 Cedar Street is a 12-story reinforced concrete frame structure with setbacks at the 10th, 11th, and 12th floors (Figure 7-14). The building is directly east of 90 West Street and is bordered by Cedar Street to the north, Washington Street to the east, and Albany Street to the south.

The floor framing consists of reinforced concrete flat slabs supported on square columns with capitals and dropped slabs. Columns are spaced at approximately 16 feet on center in the east-west direction and approximately 21 feet on center in the north-south direction. Perimeter concrete spandrel beams beneath the windows and interior infill walls of brick, terra cotta, or concrete masonry provide additional lateral stiffness.

Some facade damage was noted (primarily to the parapets), but most of the damage occurred at the roof level where the slab of the northeast corner collapsed under debris with the column capitals punching through the slab. A column section from WTC 2 penetrated the 10th floor roof slab. The southern portion of the building was not damaged. Structural damage from projectile impact and fire occurred primarily above the 9th floor. Fire damage was evident on the 11th and 12th floors in the northwest corner. Several concrete columns were cracked, possibly from the impact. Several bays at the northeast corner were severely damaged from debris impact. Concrete samples from two fire locations indicated that the concrete structure may have experienced fire temperatures of between 315 degrees Centigrade (600 degrees Fahrenheit) and 590 degrees Centigrade (1,100 degrees Fahrenheit). Spalling of capitals was observed in the fire areas.

The masonry infill walls were cracked throughout the building. It is not clear whether the condition pre-existed, or if it was due to the fire, floor settlement, or frame movement.

Caption: 130 Cedar Street and 90 West Street. Img: http://911research.wtc7.net/mirrors/guardian2/wtc/fig-7-14.jpg URL: http://911research.wtc7.net/mirrors/guardian2/wtc/WTC_ch7.htm

West Street

This building is located south of the WTC site, and adjacent to the 130 Cedar Street building located on the west side, as shown in Figure 7-14. The 24-story building has a steel-frame structure with a terra cotta flat-arch floor system and infill walls of unreinforced masonry. It was designed by architect Cass Gilbert and structural engineer Gunvald Aus in 1907. The floor plan has a skewed “C” configuration, with overall dimensions of approximately 124 feet by 180 feet. At the higher floors, the typical exterior wall assembly is terra cotta tiles on a brick wall. This building is a designated New York City landmark. In 1907, the building towered over the waterfront and warehouses in the area. Its top floor had a restaurant that was billed as the “world’s highest.”

The riveted steel framing consists of rolled and built-up sections for the columns and beams. Columns are spaced approximately 18 feet apart. The primary framing runs north-south, with secondary members in the east-west direction. Lateral load resistance is provided primarily by partial-strength, partially restrained moment connections of frame members and the infill masonry walls. The floor slabs of terra cotta flat arches appeared to be topped with low-strength cinder-concrete. Terra cotta and masonry enclosures provided fireproofing for all original architectural areas and structural elements. The building construction is shown in Figure 7-15

The New York City Building Code required the floors to be tested for 4 hours while exposed to a fire maintained at 927 degrees Centigrade (1,700 degrees Fahrenheit) and a load of 150 psf. Following the fire test, the fire-exposed underside was exposed to a fire hose stream with a nozzle pressure of 60 pounds per square inch (psi) for 10 minutes. The floor was then loaded and unloaded with a uniform load of 600 psf in the middle bay. The test was considered successful if the deflection of the beams supporting the assembly was less than 2.5 inches over a 14-foot length, after cooling.

The building was undergoing facade rehabilitation and was fully covered with scaffolding. Many of the interior columns still had the original terra cotta covers, and some were covered with plaster, but others were covered with sheet rock and intumescent paint, and, at one location, there was a metal deck with spray-on fireproofing. In some locations, spray-on cementitious fireproofing was used for later tenant work. Some scaffolding planks caught fire and may have contributed to the spread of the fire between floors.

Terra cotta and hollow-clay tile arches were common in fireproof office construction. Most of them were patented systems with 6- to 15-inch depths and spans from 54 to 90 inches. The arches were supported on the bottom flanges of steel beams. The bottom flanges of the supporting steel beams were generally protected by clay tile or terra cotta fireproofing. To provide a smooth finish, the arches were usually topped with a cementitious material that also protected the haunches of the steel beams. The arches had tie rods to resist the thrust of the arch. An 8-inch flat arch with hollow tile and a span of 6 feet could carry a safe load of 170 psf (Kidder 1936). At 90 West Street, the tile floor arches usually span 6 feet. At lower floors, the tiles have a 12-inch thickness and cover the bottom flanges of the beams.

The roof was damaged by debris falling from WTC 2, and approximately half of the north face of the building experienced projectile impact and fire damage. WTC 2 projectiles severed spandrel beams at floors 8 to 11 in the 2nd bay from the west end, and in a middle bay at the 6th floor. Terra cotta slabs were damaged mostly in the exterior bay at these locations. In general, the projectiles damaged only the masonry and broke many terra cotta features. The damage to the interior structural terra cotta floor slabs was primarily due to the brittle fracture of the terra cotta slabs upon impact by large debris. Most of the damage was restricted to the two northernmost bays, with the exception of fire damage on the 1st through 5th, 7th through 10th, 14th, 21st, and 23rd floors. The fire did not spread to the south side of the building, except for the first 4 floors. Columns were buckled 1-2 inches on the 8th and 23rd floors, approximately a foot below the ceiling, as shown in Figures 7-16 and 7-17. A tube column supporting a north exit stair from the roof and a built-up column supporting the roof were the only other heat-induced buckling damage observed during initial inspections.

This type of construction, with terra cotta tiles providing fire protection, was common in early 20th century construction. The style of construction resulted in a highly compartmentalized building, which may have helped slow the spread of fire. The Fire Department of New York was able to control the fires in this building. The fire damage observed in the building, with minimal structural damage from a normal fire load, is considered typical for this type of construction and fire protection; however, it has been suggested that the scaffolding that was in place for renovations contributed to the spread of fire between floors that may not have occurred otherwise. However, the only structural damage observed was buckling damage near the tops of two columns.

Caption: Interior of 90 West Street showing typical construction features. Img: http://911research.wtc7.net/mirrors/guardian2/wtc/fig-7-15.jpg URL: http://911research.wtc7.net/mirrors/guardian2/wtc/WTC_ch7.htm

Caption: Buckling damage at top of column on floor 8 of 90 West Street. Note the loss of fire protection at the top of the column. Img: http://911research.wtc7.net/mirrors/guardian2/wtc/fig-7-16.jpg URL: http://911research.wtc7.net/mirrors/guardian2/wtc/WTC_ch7.htm

One Liberty Plaza

One Liberty Plaza (One Liberty) is a 54-story, 730-foot-high building, comprising a footprint of 238 feet in the north-south direction by 163 feet in the east-west direction. The building area is approximately 2,000,000 square feet (Figures 7-18 and 7-19). It was designed by Skidmore, Owings, and Merrill in 1970 and served as corporate headquarters for U. S. Steel Corporation.

During the afternoon of September 11, following collapse of WTC 1 and WTC 2, rumors were spread that One Liberty was in imminent danger of collapse. This was due to a report by an untrained observer that the building face appeared to be moving or leaning.

The majority of damage incurred at One Liberty consisted of broken window glass and frames. Most of that broken glass was in the lower six floors of the west-facing elevation, with less breakage on the floors above. There was, however, some broken glass on the north- and south-facing elevations as well. At those elevations, most of the broken glass was located at floors 1 through 6. There were approximately 550 broken lites of glass, and approximately 200 frames were damaged beyond repair.

On September 12, there was a persistent rumor that One Liberty was still in danger of collapse. The building was inspected by structural engineers conducting building surveys and safety evaluations of buildings around the WTC site. The building vertical alignment was measured with a transit to determine whether any lateral drift had occurred along the height of the building. Three locations on the west face were evaluated, and no apparent movement was observed in the building. The One Liberty Plaza building was determined to be safe, except for dangers related to broken glass.

Statements were released about the safety of the building, but the rumors persisted on September 13. To stop the rumors and convince the public of the building’s safety, DDC surveyors continuously monitored the building and engineers inspected each floor.

Caption: Buckling damage at top of column on floor 23 of 90 West Street. Img: http://911research.wtc7.net/mirrors/guardian2/wtc/fig-7-17.jpg URL: http://911research.wtc7.net/mirrors/guardian2/wtc/WTC_ch7.htm

Caption: One Liberty Plaza – south elevation, lower floors. afternoon, it was rumored to be a partial collapse. The findings of the engineers and surveyors concerning the structural safety of One Liberty were reported on the nightly news, and the rumors stopped. Img: http://911research.wtc7.net/mirrors/guardian2/wtc/fig-7-18.jpg URL: http://911research.wtc7.net/mirrors/guardian2/wtc/WTC_ch7.htm  (NIST Report: McAllister, Biggs, DePaola, Eschenasy, Gilsanz)

Problem with the fire down the elevator shaft theory

Img: http://upload.wikimedia.org/wikipedia/commons/2/2a/World_Trade_Center_Building_Design_with_Floor_and_Elevator_Arrangment.jpg    URL: http://www.911oz.com/links/dummies/2?PHPSESSID=810f18a46d4764ec02dd551123fc76ee

Caption: The twin 110-story New York World Trade Center (WTC) towers are a perfect example of stacked office building applications. Each 33-story portion is serviced by four zones ­ each with six single-deck local lifts, with the local lifts of zone II and III separated by two sky lobbies. Building tenants or visitors desiring elevator transport to the floors of zone II or III must first travel on a sky-lobby shuttle elevator to the upper sky-lobby and then transfer to the appropriate local lift for final transport to their destination. A passenger departing an upper-zone floor must first travel via a local lift to the sky-lobby and then transfer to a sky-lobby shuttle elevator for final travel to the ground floor (Elevator World)

In fact there was only one shaft which connected all floors (Click on the image for a more detailed view). It seems surprising that enough jet fuel could pour down this one shaft to cause such massive damage in the lobby and sub basements.

Plane trajectory

http://www.911oz.com/links/dummies/2?PHPSESSID=810f18a46d4764ec02dd551123fc76ee

World Trade Centers 3, 4, 5, 6

Comparison with Chernobyl

Caption: Chernobyl Img: http://1.bp.blogspot.com/_Wm0Sv8PLSc4/S9Ca0UBBw0I/AAAAAAAAAl4/lqJV5d55fU8/s320/chernobyl%2520after%2520accident.jpg URL: http://marahalme.blogspot.com/2010/04/atomivoimaako-ei-kiitos.html

Chernobyl

URL: http://www.childrenuk.co.uk/chjan2001/chjan2001/whbs.htm  (dead link)

Caption: Chernobyl, dirty atomic reactor gone critical. Img: http://chernobyl.co/files/2010/12/Copy-of-Chernobyl_Disaster1.jpg URL: http://chernobyl.co/

Caption: WTC Building 6. http://911research.wtc7.net/wtc/evidence/photos/docs/gzd_059.jpg URL: http://911research.wtc7.net/wtc/evidence/photos/gzsurround.html

http://www.armageddononline.org/forums/printthread.php?t=7901

Ring of explosions

Caption: Destruction of the towers by explosions is clear according to the photographs and reports of the eye witnesses. In the picture below, a range of cutting charges have just exploded in the down left sector and a typical white cloud is formed outwards from the wall. Down right, explosions are seen as well. Even a flame is seen. Img: http://www.saunalahti.fi/wtc2001/sor8.jpg URL: http://johnmccarthy90066.tripod.com/id472.html

“Secondary devices”

Video of report of secondary devices

VIDEO: NBC’s Pat Dawson on secondary devices

Dailymotion

Video of South Tower falling – closeup

VIDEO: The antenna topples as WTC1 falls

Note the glow, the explosion squibs and the streamers.

Dailymotion

Trinity Church – completely collapsed on 9/11

Trinity Church completely collapsed on 9/11

URL: http://www.boston.com/news/packages/underattack/attack.htm

http://www.boston.com/news/packages/underattack/attack.htm

Collapses of peripheral buildings

URL: http://www.boston.com/news/packages/underattack/attack.htm

Seismic record of WTC South Tower collapse

URL: http://www.mgs.md.gov/esic/publications/download/911pentagon.pdf

Evidence of foreknowledge

VIDEO: Rudy Giuliani expose – forewarnings to firefighters missed

Dailymotion

“In this expose of Rudy Giuliani’s actions pertaining to the 2001 attacks, an interesting fact emerges that because of faulty radios, the firefighters did not receive word to evacuate WTC1 and more than a hundred perished from the collapse. The police officers did receive their warnings to evacuate and there was not a single police officer death from the North Tower’s collapse.”

Damage assessment map of November 7, 2001

Caption: New York City DDC/DoB Cooperative Building Damage Assessment Map of November 7, 2001 (based on SEAoNY inspections) Img: http://911research.wtc7.net/mirrors/guardian2/wtc/fig-7-1.gif URL: http://911research.wtc7.net/mirrors/guardian2/wtc/WTC_ch7.htm

IMG: http://home.debitel.net/user/andreas.bunkahle/jpg/Plate4.JPG   URL: German engineer site

IMG: http://home.debitel.net/user/andreas.bunkahle/jpg/Plate10.JPG

IMG: http://home.debitel.net/user/andreas.bunkahle/jpg/Plate12.JPG

IMG: http://home.debitel.net/user/andreas.bunkahle/jpg/Plate13.JPG

IMG: http://home.debitel.net/user/andreas.bunkahle/jpg/Plate14.JPG

Core of WTC

Caption: What actually stood was a steel reinforced cast concrete rectangular tube. Here is the WTC 2 core standing at around 400 foot tall. Img: http://breakfornews.com/3i/algoxy_files/southcorestands.gif URL: http://www.breakfornews.com/forum/viewtopic.php?t=2854

Caption: The interior box columns were cut every third floor by custom, optimized cutting charges built into the floors and were detonated approximately every 300 milliseconds. Here is the smooth, square end of the tempered steel columns found at ground zero. Img: http://breakfornews.com/3i/algoxy_files/wtc066-crop.jpg  URL: http://www.breakfornews.com/forum/viewtopic.php?t=2854

Caption: Close up with brightness and contrast enhanced. Img: http://breakfornews.com/3i/algoxy_files/wtc066-close.jpg  URL: http://www.breakfornews.com/forum/viewtopic.php?t=2854

Caption: The first is the classsic helicopter photo of the top floor of a tower under construction. Img: http://breakfornews.com/3i/algoxy_files/interiorboxcolumnsarrow.jpg URL: http://www.breakfornews.com/forum/viewtopic.php?t=2854

Caption: Here is another image taken from the street level when the tower was but 5 or 6 floors tall. Img: http://breakfornews.com/3i/algoxy_files/elev_guide.jpg URL: http://www.breakfornews.com/forum/viewtopic.php?t=2854

Caption: The WTC towers, also known as WTC 1 and WTC 2, were the primary components of the seven building World Trade Center complex. Each of the towers encompassed 110 stories above the Plaza level and seven levels below. WTC 1 (the north tower) had a roof height of 1,368 feet, briefly earning it the title of the world’s tallest building. WTC 2 (the south tower) was nearly as tall, with a roof height of 1,362 feet. WTC 1 also supported a 360-foot-tall television and radio transmission tower. Each building had a square floor plate, 207 feet 2 inches long on each side. Corners were chamfered 6 feet 11 inches. Nearly an acre of floor space was provided at each level. A rectangular service core with overall dimensions of approximately 87 feet by 137 feet, was present at the center of each building, housing 3 exit stairways, 99 elevators, and 16 escalators. (FEMA)

Both the central core and the outer wall supported the gravity load (were load bearing). The core provided the strength needed to support the bulk of the weight, while the outer wall provided the necessary rigidity to resist lateral loading due to the wind. The requirement to resist lateral loading, is the dominant feature determining the design of tall buildings. (Guardian)

URL: http://911research.wtc7.net/mirrors/guardian2/wtc/WTC_ch2.htm

Kerosene stove made of metal – videos

MSR Dragonfly

VIDEO: MSR DRAGONFLY  Dailymotion | Youtube

MSR Whisper Lite International

VIDEO: MSR Whisper Lite International  Dailymotion | Youtube

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Case against thermite

Summary

  • Thermite is incendiary – there was very little flame in the WTC explosions; prior to the WTC explosions, fire was only present on several floors, not throughout the whole building
  • Thermite destroys by causing fire because of high temperatures. However, there were people still alive on the floors close to the plane crash site right up until buildings suddenly exploded.
  • The quantity of thermite needed to destroy the whole building is too great. Requires hundreds of thousands of tons of thermite to be brought in – see the car bonnet experiment below. Size of the hole is the same size as the flowerpot base.
  • Thermite needs to be applied next to the metal surface for it to be effective. Steel girders throughout the two Twin Towers would have to be stripped down to their bare metal surfaces and the thermite placed in close proximity. This would have been impractical and was not done.
  • Thermite is not strong enough to produce dissolution of heavy iron beams that weighed 30 tons.
  • Thermite explosions do not have sufficient energy to produce concrete particles of 10 micrometer in size; only nuclear explosions have this energy – See “A Physician Explains”chapter.
  • Thermite explosions cause a vast quantity of flame and black smoke; very little flame and black smoke was seen prior to and after the explosions of the WTC. White smoke plumes dominated.
  • Gelignite/TNT is more effective than thermite in building demolition
  • Thermite is used mainly in welding, not in building demolitions
  • Ignition requires a sparkler or magnesium ribbon – ignition of all the thermite in the WTC, if used, would have been impractical. Furthermore, ignition would have to be coordinated to occur at the same time to produce almost simultaneous and sudden instantaneous collapse of the building.

Conclusion

Thermite was not used in the WTC demolitions. Nuclear weapons were used to destroy the main scaffolding and the steel core. Additional explosives (TNT/gelignite) were used to produce sequential “top-down” collapse of the floors.

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From: Thermite – Wikipedia

  • Thermite is a composite of metal powder, fuel and metal oxide
  • When ignited by heat produces an exothermic redox reaction
  • Most varieties are not explosive
  • Can produce brief bursts of high temperature in a small area
  • Diverse composition: aluminium, magnesium, titanium, zinc. Aluminium is common
  • Thermite is used in welding, often for joining rail tracks. Other uses: metal refining, demolition of munitions, incendiary weapons, fireworks
  • Thermites with nanosized particles are called super-thermite, nano-thermite, etc
  • Thermite is generally not explosive: it produces high temperatures in a very small area; heat focused on a small area can cut metal or weld metal components together by melting metal
  • Thermites used for repair of thick steel sections such as locomotor axles
  • Military uses: hand grenades, destruction of small-sized equipment such as cryptographic equipment. Incendiary anti-material weapon
  • Standard iron-thermite is difficult to ignite, standard thermite is rarely used on its own. Pyrotechnic additives often added.
  • Used as incendiary bombs in WWII

Wikipedia

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Quote from Instructables:

Thermite

A mixture of iron oxide Fe2O3 (rust) and aluminum powder. When it is ignited the aluminum powder reacts with the O3 part of the rust in a highly exothermic reaction, the resulting product is molten iron. Thermite is commonly used in welding, because the molten iron has the ability to seep into cracks in metal.

Instructables

Note thermite is generally not used in building demolitions

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Quoted from: Nano-thermite – Wikipedia

“Nanothermites contain an oxidizer and a reducing agent, which are intimately mixed on the nanometer scale. MICs, including nano-thermitic materials, are a type of reactive materials investigated for military use, as well as for general applications involving propellants, explosives, and pyrotechnics.”

“Potential Uses

Historically, pyrotechnic or explosive applications for traditional thermites have been limited due to their relatively slow energy release rates. Because nanothermites are created from reactant particles with proximities approaching the atomic scale, energy release rates are far greater.[1]

MICs or Super-thermites are generally developed for military use, propellants, explosives, and pyrotechnics. Research into military applications of nano-sized materials began in the early 1990s.[2] Because of their highly increased reaction rate, nanosized thermitic materials are being studied by the U.S. military with the aim of developing new types of bombs several times more powerful than conventional explosives.[3] Nanoenergetic materials can store more energy than conventional energetic materials and can be used in innovative ways to tailor the release of this energy. Thermobaric weapons are one potential application of nanoenergetic materials.”

Wikipedia

Note that nano-thermite is not generally used for building demolitions.

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Thermite vs. Car

VIDEO: Thermite vs. Car – abridged

Dailymotion | Youtube

From video: A flowerpot of thermite produced this sized hole in the car bonnet. It would not have been cost-effective to use thermite. It would have required at least 100,000 tons of thermite per WTC tower.

setting-tank-thermite.jpg

fuel-tank-8-liters-thermite.jpg

explosion-car-tank.jpg

From the video: Even though 8 liters of petrol were added to the tank and a canister of thermite was placed on top of the car, the car is still intact, even though it is on fire. In contrast, the WTC towers disintegrated into concrete dust and bent and twisted steel girders after less than two hours from the time the planes hit.

wtc-wreckage-exterior_shell_of_south_tower.jpg

URL: https://en.wikipedia.org/wiki/September_11_attacks

c95_mod.jpg

Very little flame was seen on the floors that had been hit by the planes FROM: NIST

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Thermite Reactions – Compilation 

VIDEO: Thermite Reactions – Compilation  Dailymotion | Youtube

From this video, it’s clear how weak thermite is as a building demolition explosive. It does not completely destroy aluminium sheets. The bricks holding up the various objects remains intact throughout the experiments. Thermite doesn’t even fully melt the dry ice block.

“Christ School Honors Chemistry and General Chemistry classes ignite thermite over the following materials: Aluminum sheets, ice blocks, water, dry ice, kerosene, diesel fuel, silicon dioxide (silica), a monitor and a scanner. A thermite reaction was also mixed with iodine to produce violet smoke.”

6 pounds of thermite doesn’t destroy a single brick in this experiment

There were 500,000 cubic metric tons of concrete in a single tower. If 6 pounds of thermite can’t destroy a single brick in the video, it’s unlikely they would have used thermite as the main explosive for the destruction of the towers. The quantity would have to been too great as thermite is too weak.

6 pounds of thermite2-sml.jpg

Six pounds of thermite

thermite-bricks400.jpg

None of the bricks were destroyed by six pounds of thermite

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Conventional bombs were used too

Nowadays mixtures containing ammonium nitrate are the most commonly used explosives used industrially in America today.

750px-ammonium_nitrate-sml110h-e1503995184133Ammonium nitrate – It is a nitrate salt of ammonium. In its pure form, it is not explosive, but when combined with other substances, can produce explosive mixtures. These explosives are used in mining, quarrying and demolitions for civil construction. It is a major constituent of ANFO (ammonium nitrate/fuel oil), an industrial explosive that accounts for 80% of explosives used in North America.

trinitrotoluen-sml100hTNT – This stands for 2,4,6-trinitrotoluene, a compound produced by the nitration of toluene. It is the standard measure of explosive yield. The Germans adopted TNT as a filling for artillery shells in 1902. It can pierce the armor of ships and was used in armor piercing shells. It is used in naval mines, bombs, depth charges and torpedo warheads in the US military. TNT is also one of the most commonly used explosives in industrial and mining applications, including shale mining. It is much safer to handle than nitroglycerin-based explosives. For detonation, it must be triggered from a pressure wave from a starter explosive. Nowadays, it is commonly combined with other explosives in synergistic explosive blends.

Examples of explosive blends containing TNT include:
Amatex: (ammonium nitrate and RDX), Amatol: (ammonium nitrate), Ammonal: (ammonium nitrate and aluminium powder plus sometimes charcoal), Baratol: ( barium nitrate and wax), Composition B (RDX and paraffin wax), Composition H6, Cyclotol (RDX).

Gelingnite_general_view.pdf-crp-sml110hGelignite – It is known colloquially as blasting gelatin or blasting jelly. It is made from collodion-cotton (a type of nitrocellulose) which has been dissolved in nitroglycerin or blasting gelignite-sml75hnitroglycol, and mixed with  wood pulp and saltpetre (sodium nitrate or potassium nitrate). It was invented by Alfred Nobel, who also invented dynamite. It is safer to handle than dynamite as it is more stable. It is widely used in mining and quarries.

130918_0021-nobel-100hDynamite – This is an explosive made from nitroglycerin, sorbents (such as powdered shells or clay), and stabilizers (sawdust, wood pulp, flour, starch or calcium carbonate). It gained use rapidly as a safer alternative to gun powder and nitroglycerin. Today dynamite is used in the mining, quarrying, construction and demolition industries.

Plastic explosives – This group includes C-4, RDX, Semtex, and gelignite (the first discovered plastic explosive). Plastic explosives are favored by engineers for use in demolitions that involve destroying fortified structures. They can be easily molded into the best shapes for cutting structural members and have a high enough velocity of detonation and energy density (J/kg) to cut metal. They are used in civil engineering and in combat situations.

800px-eod2-sml110            usmc-100609-m-0761b-014-lgr-110h

LEFT: C4 plastic explosive (off-white rectangular blocks).  RIGHT: A marine shapes a charge of C4 to cut through steel at a demolitions range.

220px-semtex_h_1-sml110h            c-4-japanese-site-110h

LEFT:  Two blocks of Semtex (note the characteristic orange color) and a charge containing C4 (black).  RIGHT: C4 explosive is also known as M112 (link).

Semtex – a plastic explosive consisting of RDX and PETN (a major ingredient of Semtex). Widely used in military applications and by terrorists due to its high power, but too expensive to be used for routine construction and mining work. 

Cordite – It is a low explosive like gunpowder. It became a substitute for gunpowder in the military. It is used in many military applications: in tank guns, artillery and naval guns. It was also used in the detonation system of the Little Boy atomic bomb dropped on Hiroshima.  At one point, it was extruded in spaghetti-like rods, which was called “cord powder”. This was swiftly abbreviated to “Cordite”, the name by which it is known today. Its main use is to deflagrate, or burn, and to produce high pressure gases.

Detonating cord – This is strictly not a different type of explosive material but the name for a certain configuration of explosives. In this configuration, explosives (usually PETN) are stringed together. A common trademark is “Cordtex”. Another trademark is Primacord. In this type of explosion, the length of detonation cord appears to explode instantaneously due to the fact that PETN explodes at a rate of 6400 m/s.

Wikipedia: Dynamite
Wikipedia: Gelignite
Wikipedia: TNT
Wikipedia: Ammonium nitrate
Wikipedia: Plastic_explosive
Wikipedia: Cordite
Wikipedia: Detonating_cord
Wikipedia: Gunpowder

Building implosion

Numerous small explosives, strategically placed within the structure, are used to catalyze the collapse. Nitroglycerin, dynamite, or other explosives are used to shatter reinforced concrete supports. Linear shaped charges are used to sever steel supports. These explosives are progressively detonated on supports throughout the structure. Then, explosives on the lower floors initiate the controlled collapse … (cont.)

Read more:  Wikipedia

In building implosions during demolitions, little or no flame is observed in the event, unlike collapses and disintegrations due to fire.

220px-Athlone_cooling_towers_demolition_2010-08-22.gif

Implosion of the Athlone Power Station cooling towers on 22 August 2010. (Wikipedia)

xExplosives-sml200h.jpg

Types of explosive

The most commonly used types of explosive for construction demolition are:

Slurry explosives:

Ammonium nitrate and other nitrates in solution. Materials are sensitised by air during the manufacturing process and have good fume characteristics and are suitable for wet conditions … (cont.)

Read more: designingbuildings