@berlinandi & co.
NIST:
Annealing studies on recovered steels established the set of time and temperature conditions necessary to alter the steel microstructure. Based on the pre-collapse photographic evidence, the microstructures of steels known to have been exposed to fire were characterized. These microstructures show
no evidence of exposure to temperatures above 600 °C for any significant time
NCSTAR1-3ExecutiveSummary E 3.6
---------------Wann verliert Stahl seine Festigkeit? -----------------------------------
"This is why the temperatures in a residential fire are usually in the 500 °C to
650 °C range [Cote, 1992]. It is known that the WTC fire was a fuel-rich, diffuse
flame as evidenced by the copious black smoke.... It is known that structural steel
begins to soften around 425 °C and loses about half of its strength at 650 °C [Cote,
1992]."
-----Auch wenn wir mal annehmen, dass die Feuer so heiß wurden (geschenkt) ----
"But even a 50% loss of strength is still insufficient, by itself, to explain the WTC collapse... The WTC, on this low-wind day, was likely not stressed more than a third of the design allowable... Even with its strength halved, the steel could still support two to three times the stresses imposed by a 650 °C fire."
http://www.journalof911studies.com/volume/200609/WhyIndeedDidtheWorldTradeCenterBuildingsCompletelyCollapse.pdf+Steven+Jones+fire+steel&hl=en&ct=clnk&cd=4&gl=de&lr=lang_de|lang_en&client=firefox-a
---- hätten die geschwächten Stahlstrukturen das Gebäude weiter tragen MÜSSEN---
According to engineers in documents dated February 13, 1965 the towers were over designed by a factor of 16.. (...) The fact remains that the towers were designed to stay standing even after losing most of their columns "live loads on these columns can be increased more than 2,000% before failure occurs"( ENR, Feb 4, 1964).
http://911research.wtc7.net/wtc/analysis/design.html#engineers
---Ein weiteres Problem ist das geschmolzene Metall. Wie kann Metall schmelzen, wenn die Feuer nur (nach offizieller Darstellung) 400-600 Grad heiß waren? Eine Video von geschmolzenem Metalls:---
Molten Metall
The yellow color implies a molten-metal temperature of approximately 1000 Grad, evidently above that which the dark-smoke hydrocarbon fires in the Towers could produce. If aluminum (e.g., from the plane) had melted, it would melt and flow away from the heat source at its melting point of about 650 Grad and thus would not reach the yellow color observed for this molten metal.
------ Zu Robertson Aussagen gibt es starke Zweifel anhand der Aussagen seines verstorbenen Kollegens, Skilling, aber auch weil Robertson seine Behauptungen nicht mit Dokumenten belegen kann, im Gegenteil, Dokumente widersprechen ihn.----
NIST did find a three page White Paper, dated February 3, 1964, summarizing a 21,000-page study of the effects of a Boeing 707 carrying 23,000 US gallons (87 m³) of fuel hitting the buildings at 600 mph (1,000 km/h). The study found that the buildings would not collapse in the event of aircraft impact.
Wikipedia: Collapse of the World Trade Center