Quote from dpt:
My understanding is: once hot gases move from the tenant spaces through gaps
in the gypsum walls surrounding the core column structures on any of levels
94-97, they are then free to begin moving upwards within the core. They don't
necessarily remain on the level at which they entered the core. They can move
upwards until they are blocked by some horizontal partition.
no i dont agree it is a different matter for what regards the
cores. and yours is just an interpretation of what is written. it is not clear
at all and open to debate if gases were free to move upward within the core,
nothing in the nist quote seems to suggest that.
But this is silly.
You can't consider this one quote in isolation from everything else in the
report. You're free to call what I say interpretation, but it is reasonable
interpretation, given a great deal of other information that is present.
Of course, you are also using `just an interpretation' of what is written in
this quotation to assert that the report is deceptive. This is a 292 page
long text that we're discussing. Looking at a single quote and reading it in
isolation from all of the other evidence is not very sensible, IMO.
There is in fact a great deal of evidence in the report to suggest that gases
were free to move vertically in the core spaces, especially on the
impact damaged floors.
For a start, even with the towers completely undamaged it is quite clear that
there are structures present within the cores which run vertically between
floors and which allow for gases to be transmitted both upwards and
downwards. These include, among others: elevator shafts and stairwells.
See for example, the plan of the 96th floor (Figure 1-5, page 9, final NIST
report).
I don't know whether you recall this or not, but I do: around the time of the
attacks it was widely reported on the news that people in the
lobby of
WTC 1, far below the impact zone, had suffered severe flash burns from the
initial fireball that was created on the impact of the airliner. Flames and
overpressures from these enormous fireballs were certainly transmitted
downwards across many floors, through the elevator shafts. From the NIST final
report we read:
`Some of the burning fuel shot up and down the elevator shafts,
blowing out doors and walls on floors all the way down to the
basement. Flash fires in the lobby blew out many of the plate glass
windows.
(page 24, final NIST report, emphasis added)
This alone is enough to show that gases could be transported vertically
between floors in the core of the building.
By way of contrast, such vertical gas transfer is, clearly far more difficult
within the tenant spaces, owing to the presence of the heavy concrete floor
slabs between each successive floor space. Due to their large mass, the floor
slabs were not, in general, completely destroyed by the impact of the
airliners. (See figure 6-20, page 112, final report)
To see some of the vertical paths that might have existed in the damaged core
on the impact levels, one can simply take a look at the elevation diagrams of
the towers (Figure 1-10, page 16), showing the three stairwells in WTC1 -- all
of which were
completely cut at the level of the impact floors.
We can certainly expect that some of the elevator shafts were cut too, since
these reside immediately behind the stairwells, and in the path of the
oncoming airliner, on floors near the impact level. The simulations of the
impact damage in the report strongly suggest that this was the case. (See
figures 6-18 (page 111) and 6-21 (page 113) and, of course, compare with the
plan of the 96th floor.)
So I believe that it is
not interpretation on my part that many open
vertical pathways existed between the floors, in the core of the building,
near the level of impact. And it is
not interpretation on my
part that hot gases rise, when a path is available for them to do so.
More to come ...
