Now that it has been shown that although many firefighters talked of explosions, and they can be observed in video and in seismographic evidence from LDEO, there was never any real investigations for explosive use conducted, and all those saying there were none can point to is their own personal search through Internet photo sets of unknown completeness for demolition devices, it is time to move to things with some level of official involvement with reports that can actually be critiqued. This obviously brings us to the NIST reports on the building collapses. The first one I would like to discuss is that for WTC 7.The NIST WTC 7 report claims that girder A2001, situated between exterior column 44 and corner core column 79 in the northeast corner of the building, had its web pushed beyond its 12” wide seat at column 79 under the 13th floor by five beams framing into the girder from the east. They say this applied the load to the girder’s flange, which could not take the load in flexure, causing the girder to fall with the northeast floor section it supported then falling onto the next floor down shearing its seat at column 79 and causing an eight floor cascade leaving column 79 laterally unsupported from the north for nine stories. Column 79 had girders on three sides and the report says the connections to it of those from the south and west had been broken due to thermal expansion on floors 7 through 13 leaving the column completely unsupported for a length of nine stories causing it to buckle. The report says this caused the entire east side interior to progressively collapse and the east penthouse to fall down into the building. The report then says the progressive collapse proceeded from east to west with the entire interior going down leaving the exterior as a hollow shell with all of its columns buckling over a 2 second period starting at the southwest corner and the entire exterior coming down.The problems with this story start with the amount of expansion required of the beams to push the girder web off its seat. The web is 0.580 inches thick and with the 12” wide seat the expansion would have to be 6.29 inches. At 600 °C the expansion of the longest beam at 53’ 8-11/16” would be about 5.5”, and actually around 5.4” when shortening due to sagging is considered. With shortening due to sagging overtaking expansion at 654 °C the expansion is limited to about 5.7”. It is interesting that the report said the seat was only 11” wide at first, which would work with the maximum expansion, until the drawings were released three years later and it was found that the seat was actually 12” wide. NIST was questioned on this and forced to admit the seat was actually 12” wide and wrote an erratum. However, the erratum simply said the lateral travel of the girder would have been 6.25” without explaining where they got the extra ¾” of expansion. See the Technical Discussion on pages 4 through 14 at the link below.In addition, all of the expansion is considered to go to the west and the ¾” gap between the beams and the east side exterior column web is ignored. Of course, there were four 7/8” diameter bolts at that end of the beam holding it to its seat and top clip, but it is not credible to expect the bolts not to shear at that end of the beams while the 28 shear studs on the beams and the 7/8” bolts on the girder were claimed to have broken due to thermal expansion. See figure 4 at the above link.An additional discrepancy found during review of the drawings was that the girder had partial height web stiffeners at its column 79 end which were not included in the NIST analysis. These stiffeners were ¾” thick and 18” high and went from the web to the edge of the flanges. See figure 5 in the link provided. These stiffeners would have provided support to the flange and significantly increased the section modulus preventing the flange failure even if the web could have been pushed beyond the edge of the seat. NIST did not admit to this omission of a pertinent structural feature at first, but finally did after 19 months of being questioned about it saying they were for web crippling and their analysis said there was no web crippling.The NIST report also ignores the side plates on column 79 interfering with the girder’s lateral travel. These plates protruded 1.8” from the flange of column 79 and would have been contacted by the expanded girder, which had broken its seat bolts, after just 3” of travel. The ARUP analysis shows the girder could not have been pushed past the column side plate. See figure A5.11 on pdf page 163 (JA-3237) at the below link to the ARUP analysis.The girder being trapped by the column side plate also makes a moot point out of any suggestion that column 79 could have been pushed to the east by the west side girder to generate additional lateral travel of the girder relative to the seat.The report says the east penthouse collapse was due to column 79 buckling starting from the 13th floor girder failure causing a full east side interior collapse. However, video evidence shows1. The shock wave from the penthouse collapse goes top to bottom.2. Daylight is only seen at the top story windows even though the building was 144 feetwide.3. Windows are only broken 15 stories down from the roof.4. There is no dust observed emanating from windows on the east side until the exteriorcomes down.5. There is no deformation of the east side exterior columns.These observations seem to show that the east penthouse collapse only involved failures at the top of the building.