2009-06-05, 19:55
Rassa
Ursprungligen postat av Azzabrazza
Det är ju mycket märkligt hur de som säger att de läst NIST-rapporten fortsätter att hävda att Wtc 7 strukturella skador skulle spelat roll för kollapsen. Antingen försöker de bluffa med oss och hoppas att vi som inte läst rapporten inte ska uppfatta det eller så ljuger man rakt av om att ha läst den och helt enkelt inte vet bättre. Jag tror väl på det första alternativet, då jag mycket väl kan tänka mig att man enfaldigt nog kan ha suttit och plöjt igenom 10 000 och inte fattat något, bara för att få känna sig lite viktig. Du har säkert precis som jag märkt hur Pad tycker om att dra till med överdrifter för att låta mer övertygande. Exempelvis i denna tråd har han dragit till saker som att " hörnet blivit helt upprivet från raset" och att han står på "rätt sida av bevisberget". Frågan är då, varför ska vi behöva acceptera att ett upprivna hörnet på wtc 7 ska spelat in i kollapsen om inte ens NIST gör det och vad är det för bevisberg han snackar om egentligen? Att något sådant, som stöder OT, inte existerar är jag ganska säker på. Om vi nu inte lever i parallella universum dvs.
Jag har inte läst hela NIST-rapporten, men det finns sammanfattningar: http://www.nist.gov/public_affairs/factsheet/wtc_qa_082108.html
How did the fires cause WTC 7 to collapse?
The heat from the uncontrolled fires caused steel floor beams and girders to thermally expand, leading to a chain of events that caused a key structural column to fail. The failure of this structural column then initiated a fire-induced progressive collapse of the entire building.
According to the reportÂ’s probable collapse sequence, heat from the uncontrolled fires caused thermal expansion of the steel beams on the lower floors of the east side of WTC 7, damaging the floor framing on multiple floors.
Eventually, a girder on Floor 13 lost its connection to a critical column, Column 79, that provided support for the long floor spans on the east side of the building (see Diagram 1). The displaced girder and other local fire-induced damage caused Floor 13 to collapse, beginning a cascade of floor failures down to the 5th floor. Many of these floors had already been at least partially weakened by the fires in the vicinity of Column 79. This collapse of floors left Column 79 insufficiently supported in the east-west direction over nine stories.
The unsupported Column 79 then buckled and triggered an upward progression of floor system failures that reached the buildingÂ’s east penthouse. What followed in rapid succession was a series of structural failures. Failure first occurred all the way to the roof line—involving all three interior columns on the easternmost side of the building (79, 80, 81). Then, progressing from east to west across WTC 7, all of the columns failed in the core of the building (58 through 78). Finally, the entire façade collapsed.
The heat from the uncontrolled fires caused steel floor beams and girders to thermally expand, leading to a chain of events that caused a key structural column to fail. The failure of this structural column then initiated a fire-induced progressive collapse of the entire building.
According to the reportÂ’s probable collapse sequence, heat from the uncontrolled fires caused thermal expansion of the steel beams on the lower floors of the east side of WTC 7, damaging the floor framing on multiple floors.
Eventually, a girder on Floor 13 lost its connection to a critical column, Column 79, that provided support for the long floor spans on the east side of the building (see Diagram 1). The displaced girder and other local fire-induced damage caused Floor 13 to collapse, beginning a cascade of floor failures down to the 5th floor. Many of these floors had already been at least partially weakened by the fires in the vicinity of Column 79. This collapse of floors left Column 79 insufficiently supported in the east-west direction over nine stories.
The unsupported Column 79 then buckled and triggered an upward progression of floor system failures that reached the buildingÂ’s east penthouse. What followed in rapid succession was a series of structural failures. Failure first occurred all the way to the roof line—involving all three interior columns on the easternmost side of the building (79, 80, 81). Then, progressing from east to west across WTC 7, all of the columns failed in the core of the building (58 through 78). Finally, the entire façade collapsed.
I huvudsak var det alltså de okontrollerade bränderna som var orsaken till kollapsen. De strukturella skadorna spelade mindre roll.