What really happened ....11 september

[dpt]

Quote from Bitstream:

first report [p28/78]

"aside from isolated areas, perhaps protected by surviving gypsum walls, the
cooler parts of the upper layer were at about 500-C and in the vicinity of the
active fires, the upper layer air temperatures reached 1000-C. the aircraft
fragments had broken trough the core walls on the 94th trough the 97th floors
and temperatures in the upper layers were similar to those in the tenant
spaces".

OK, thanks. I'm going to assume that this discussion doesn't change much in
the final report, for now. I have them both, but comparing takes time.

So it seems that what we have here is a statement that air temperatures in the
upper layers of the tenant spaces above regions of active fire reached 1000 C
at least for some period of time.

It's clear from statements made in the paragraphs right above the one you
quoted that the regions of active fire were continuously moving through the
tenant spaces. It seems from the description and the figure right above this
paragraph that the events described were supposedly happening roughly between
9:38 a.m. and 9:58 a.m.

In addition, we have the statement that hot gases from the fire floors were
able to move into the core from the tenant spaces on floors 94-97, where
gypsum walls had been broken by the impacts, so that similar
temperatures to those in the tenant spaces could have been reached in the
upper levels of the core air.

It's certainly not clear that this means 1000 C gases entered the upper air
levels of the core or whether it is mostly gases at the more generally
prevailing 500 C temperatures of the upper level air in the tenant spaces. It
isn't actually explicitly stated in the lines you've quoted exactly what air
temperature was reached in the upper levels of the core, or for how long, at
least not here.

It doesn't follow that the steel of the core columns would have reached
equally high temperatures throughout the whole of the columns, even if the
thermal cladding were completely stripped and the steel were fully exposed. It
would take some time before that could occur, and indeed, the next paragraph
of the description makes this clear enough:

`The perimeter columns, floors, and core columns were immersed in
these hot gases and began to weaken. Where the insulation was dislodged, the
temperature of the steel rose rapidly, in contrast to steel members where
insulation was intact. The heaviest core columns with damaged insulation
heated slowly, as the absorbed heat was dissipated throught their massive
cross sections. The temperatures of the lighter columns and the floor slabs
rose more quickly, and those of the stripped trusses even more
so.

in the upper layers of the core,


this contradicts its own study as u can see below the core temperatures never
got past 300-C:

http://911research.wtc7.net/essays/nist/docs/floortemps_f6_36.jpg

The image didn't come through in the forum, apparently, but it did come
through when I quoted your post to reply, so luckily I was able to see it, and
figure out what it actually is supposed to represent.

It's a 2-d graphic depicting the results of one of the fire simulations that I
was referring to before.

This particular graphic is found on page 127 of the final report, where it is
figure 6-36. It is also in the draft report, although there it is printed at
an angle, and is part of figure 6-37 which appears on page 126.

The caption of figure 6-36 in the final report reads:

Upper layer temperatures on the 94th floor of WTC 1, 15 min after
impact.

So this is a graphic of upper level air temperature on the 94th floor, as
opposed to upper level air temperature in the upper levels of the core near
the 97th floor.

Also, impact was at 8:46:30 a.m. So fifteen minutes after impact would have
been 9:01:30.

Therefore this graphic depicts a very different thing, than the temperature
in the upper air of the core near level 97, some 40 minutes to 1
hour later on, at 9:38-9:58 am.

So there's no contradiction, as far as I can see.

and of course also the analysis of the floor section :

"a floor section was modeled to investigate failures under combined gravity
and thermal loads. the floor section was heated to 700-C [with a linear
thermal gradient trough the slab thickness from 700-C to 300-C at the top of
the surface of the slab] over a period of 30min".[...][p98/148]

I can't find this quote either on p98 or on p148. Are you sure you
have the right page number?

why conduct an experiment to prove failure and consequent collapse using
temperatures that where not found to be reached.

As I said, I can't seem to find that quote right now. But I certainly believe
that the quote is there somewhere.

I think that, likely, the experiment was done because the simulations clearly
did suggest that such temperatures were actually reached in the floor
slabs as opposed to the core. See, for example Figure 2-11 on page 31 of the
final report, which represents the temperatures on the top and bottom surfaces
of the 96th floor slab at a time of 100 minutes after impact, and consider
also the quite high temperatures reported above active fires in the upper
level air of the tenant spaces.

"nits determined that there was no evidence that any of the sample had reached
temperatures above 600-C". [p90/140]

This refers to samples of structural steel that were analysed, and to me it
suggests also that some samples were found that reached temperatures as high
as 600 C. Of course, it was made clear in the report that the temperature that
various pieces of steel reached depended on what type of member was being
considered, how much insulation it had, and for what duration it was exposed
to high temperature.

So this certainly doesn't prove that the temperatures in the simulations
couldn't have been reached.

it sure gives the impression temperature were at a constant 1000-C on the
upper layers, distinguishing from lower temps in the other upper layers near
the fire...that's why i said deceptively implied.

No, I don't agree that it gives that impression. I don't think that the
section you quoted clearly says how high the temperature was or for how long
it was that high.

I agree that the language of the quote could be more explicit about the
temperatures. But it would only be deceptive to say what is said there if
the simulations never did reach high temperatures in upper level air of
the core near floor 97.

If you look at figure 6-37 on page 128 of the final report, you can see that
it appears that there were, at some times in the simulations, temperatures
near 1000 C in the upper level air of the core, on the 97th floor.










Cheers!

 

[dpt]

Quote from Bitstream:

"the jet fuel greatly accelerated the fire growrth. only 60% of the
combustible mass of the rubblized workstation was consumed. the near ceiling
temperatures varied between 800-C and 1100-C".[p125-6/175-6]

This quote describes the results of an actual experiment using materials and
geometry similar to what was burning in the floor spaces of the WTC, which was
done in order to test how well the fire simulation code (FDS) was able to
simulate. Here, I'll add back in some of the important context for the quote,
that you've omitted, so that it will be clearer what it is about:

The differences in the fire behaviour under the different
experimental conditions were profound in these roughly hour long
tests. The jet fuel greatly accelerated the fire growth. Only about 60% of
the combustible mass of the rubblized workstations was consumed. The
near-ceiling temperatures varied between 800 C and 1000 C. Nonetheless FDS
successfully replicated:

The general shape and magnitude of the time-dependent heat release
rate.

The time at which one half of the combustion energy was released
to within 3 min.

The value of the heat release rate at this time to within 9 percent.

The duration of the fires to within 6 min.

The peak near ceiling temperature to within 10 percent.

Much clearer, no?

 

[Cariocas]

Quote from ratboy88:

i just posted that video.. its on the previous two pages.

Apologies rb88, didn't check previous pages on forum before posting. Nonetheless, the video raises some interesting questions. Of all the 4 flights, this 1 is the most puzzling.

 

[Bitstream]

Quote from dpt:

OK, thanks. I'm going to assume that this discussion doesn't change much in
the final report, for now. I have them both, but comparing takes time.

So it seems that what we have here is a statement that air temperatures in the
upper layers of the tenant spaces above regions of active fire reached 1000 C
at least for some period of time.

It's clear from statements made in the paragraphs right above the one you
quoted that the regions of active fire were continuously moving through the
tenant spaces. It seems from the description and the figure right above this
paragraph that the events described were supposedly happening roughly between
9:38 a.m. and 9:58 a.m.

In addition, we have the statement that hot gases from the fire floors were
able to move into the core from the tenant spaces on floors 94-97, where
gypsum walls had been broken by the impacts, so that similar
temperatures to those in the tenant spaces could have been reached in the
upper levels of the core air.

It's certainly not clear that this means 1000 C gases entered the upper air
levels of the core or whether it is mostly gases at the more generally
prevailing 500 C temperatures of the upper level air in the tenant spaces. It
isn't actually explicitly stated in the lines you've quoted exactly what air
temperature was reached in the upper levels of the core, or for how long, at
least not here.

i am sorry but what they say is pretty clear and if is not to u, it is one more reason to assert it is deceptive. they compare upper layers and upper layers near the fire in the tenants areas to the cores area and they state that temperatures were similar: by saying 'similar temps' u can conclude that they didnt differ enough to grant a specification.

It doesn't follow that the steel of the core columns would have reached
equally high temperatures throughout the whole of the columns, even if the
thermal cladding were completely stripped and the steel were fully exposed. It
would take some time before that could occur, and indeed, the next paragraph
of the description makes this clear enough:








The image didn't come through in the forum, apparently, but it did come
through when I quoted your post to reply, so luckily I was able to see it, and
figure out what it actually is supposed to represent.

It's a 2-d graphic depicting the results of one of the fire simulations that I
was referring to before.

This particular graphic is found on page 127 of the final report, where it is
figure 6-36. It is also in the draft report, although there it is printed at
an angle, and is part of figure 6-37 which appears on page 126.

The caption of figure 6-36 in the final report reads:



So this is a graphic of upper level air temperature on the 94th floor, as
opposed to upper level air temperature in the upper levels of the core near
the 97th floor.

i think u either forgot or missed that they mention that temps ranging from 500-C to 1000-C were thought to be on the97th and in the 94th floor upper layers, it's even in your quote.

Also, impact was at 8:46:30 a.m. So fifteen minutes after impact would have
been 9:01:30.

Therefore this graphic depicts a very different thing, than the temperature
in the upper air of the core near level 97, some 40 minutes to 1
hour later on, at 9:38-9:58 am.

not sure i completely follow here but it doesnt make any difference since they same temps apply to both 94th and 97th floor as they write and as u quoted above, and the graphic is clearly of the 94th floor.
also it is pretty clear temps were never above 300-C, yet they state it is at least a persistent 500-C. well, that's not the case in the sim.

So there's no contradiction, as far as I can see.

well, it is obviously there. from whatever angle u wanna look at it.

I can't find this quote either on p98 or on p148. Are you sure you
have the right page number?

have to go trough the report once again, i have no time now.

As I said, I can't seem to find that quote right now. But I certainly believe
that the quote is there somewhere.

I think that, likely, the experiment was done because the simulations clearly
did suggest that such temperatures were actually reached in the floor
slabs as opposed to the core. See, for example Figure 2-11 on page 31 of the
final report, which represents the temperatures on the top and bottom surfaces
of the 96th floor slab at a time of 100 minutes after impact, and consider
also the quite high temperatures reported above active fires in the upper
level air of the tenant spaces.



This refers to samples of structural steel that were analysed, and to me it
suggests also that some samples were found that reached temperatures as high
as 600 C. Of course, it was made clear in the report that the temperature that
various pieces of steel reached depended on what type of member was being
considered, how much insulation it had, and for what duration it was exposed
to high temperature.

So this certainly doesn't prove that the temperatures in the simulations
couldn't have been reached.



No, I don't agree that it gives that impression. I don't think that the
section you quoted clearly says how high the temperature was or for how long
it was that high.

u see that's where i think both u and the nist are wrong here; first, no sample whatsoever ever reached temps above 600-C, that was made sufficiently clear. not only that but most of the steel analyzed cleary suffered temps of around 300-C. and u just cant explain what happened with the results of a simulation if the same results contradict the evidence. remember that the sim data was used to explain failure and consequent collapse. this is clearly unscientific.

I agree that the language of the quote could be more explicit about the
temperatures. But it would only be deceptive to say what is said there if
the simulations never did reach high temperatures in upper level air of
the core near floor 97.

If you look at figure 6-37 on page 128 of the final report, you can see that
it appears that there were, at some times in the simulations, temperatures
near 1000 C in the upper level air of the core, on the 97th floor.














Cheers!

i am talking about the 94th floor and those temps there sure weren't in the core, but in the borders of the core.

it is obvious to me that the whole temps analysis is not clear at best and borderline deceptive at worse.





thx for your reply.

 

[dpt]

Quote from Bitstream:


i am sorry but what they say is pretty clear and if is not to u, it is one
more reason to assert it is deceptive.

If something is unclear to me, it certainly
doesn't mean that it's necessarily deceptive.

they compare upper layers and upper
layers near the fire in the tenants areas to the cores area and they state
that temperatures were similar: by saying 'similar temps' u can conclude that
they didnt differ enough to grant a specification.

There's another possibility than that it is deceptive, there are actually at
least three: you misunderstand what is written, I misunderstand what is
written, or both of us do.

There's more than one temperature attributed to the upper air layer in the
tenant spaces. 1000 C above active fires, 500 C more generally. Active fires
are moving all around and hotspots of 1000 C move above them. 500 C
temperatures are much more widespread on the graphics of fire temperatures on fire floors.

i think u either forgot on missed that they mention that temps
ranging from 500-C to 1000-C were thought to be on the97th and in the
94th floor upper layers, it's even in your quote.

No I didn't forget that. It's in the quote with regard to the temperatures in
the tenant spaces. The upper layer air in the core is a different matter, I
think.

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.

not sure i completely follow here but it doesnt make any difference
since they same temps apply to both 94th and 97th floor as they write and as u
quoted above, and the graphic is clearly of the 94th floor. also it is pretty
clear temps were never above 300-C, yet they state it is at least a persistent
500-C. well, that's not the case in the sim.

You posted a graphic of the temperatures on the 94th floor 15 minutes after
impact and concluded from that, that temperatures in the core never
reached above 300 C. That's a mistake.

It's very easy to see: look at the graphic for the 97th floor, as opposed to
the graphic for the 94th. You will see that at impact + 15 minutes,
temperatures in the core region of the 97th floor were at 1000C in some spots,
as opposed to the 94th, where they were far lower in the core region.

u see that's where i think both u and the nist are wrong here; first, no
sample whatsoever ever reached temps above 600-C, that was made sufficiently
clear. not only that but most of the steel analyzed cleary suffered temps of
around 300-C. and u just cant explain what happened with the results of a
simulation if the same results contradict the evidence. remember that the sim
data was used to explain failure and consequent collapse. this is clearly
unscientific.

I simply don't understand your reasoning as to how this evidence contradicts
the results of the simulation of the air temperatures.

What is it that you think should have been found in the temperature
history analysis of the steel samples in order for thermal failure to have
been a possibility?

i am talking about the 94th floor and those temps there sure weren't in the
core, but in the borders of the core.

But on the 97th, those temperatures were there in the core, at least for some
time in the simulation. And obviously, we only have a few frames to look at,
not the full time history of the temperature profile.

You drew an extremely strong conclusion. You said that temperatures never
reached above 300 C in the core, in the simulations, based on a picture of the
94th floor at one instant: 15 minutes after impact.

it is obvious to me that the whole temps analysis is not clear at best and
borderline deceptive at worse.

I think one should be very reluctant to say that something is deceptive given
that one thinks it is unclear.

In my opinion, it would be a good thing for NIST to make the full time
histories of the simulations available. That would allow them to be analysed.

thx for your reply.

Cheers!

 

[Bitstream]

Quote from dpt:

If something is unclear to me, it certainly
doesn't mean that it's necessarily deceptive.



There's another possibility than that it is deceptive, there are actually at
least three: you misunderstand what is written, I misunderstand what is
written, or both of us do.

yeah agreed with that. but i find it odd that they would not make clear a passage of such relevance.

There's more than one temperature attributed to the upper air layer in the
tenant spaces. 1000 C above active fires, 500 C more generally. Active fires
are moving all around and hotspots of 1000 C move above them. 500 C
temperatures are much more widespread on the graphics of fire temperatures on fire floors.

yes, that's correct.

No I didn't forget that. It's in the quote with regard to the temperatures in
the tenant spaces. The upper layer air in the core is a different matter, I
think.

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.

anyways, let me clarify what i meant in my previous posts and let's go trough the nist first report once again:


"aside from isolated areas, perhaps protected by surviving gypsum walls, the cooler parts of this upper layers were at about 500-C, and in the vicinity of the active fires, the upper layer air temperatures reached 1000-C. the aircraft fragments had broken trough the core walls on the 94th trough the 97th floors, and temperatures in the upper layers there were similar to those in the tenant spaces".

as u can see in the bold lines nist doesn't distinguish which floors did sustain those temperatures and refers to both when comparing the temps in the core to those of the tenant spaces. and nist is obviously indicating here both tenants and core areas share the same temperaures, because, and u seem to disagree, the nist makes no clear distinction between the temps in the tenants areas upper layers and the core upper layers.

You posted a graphic of the temperatures on the 94th floor 15 minutes after
impact and concluded from that, that temperatures in the core never
reached above 300 C. That's a mistake.

It's very easy to see: look at the graphic for the 97th floor, as opposed to
the graphic for the 94th. You will see that at impact + 15 minutes,
temperatures in the core region of the 97th floor were at 1000C in some spots,
as opposed to the 94th, where they were far lower in the core region.

yeah but as i stated in the quote above there ain't no distinction between 94th and 97th, infact it seems obvious to me they are referring to the 94th floor and the 97th. and attributing higher temps to another entire floor makes a huge difference.

I simply don't understand your reasoning as to how this evidence contradicts
the results of the simulation of the air temperatures.

of course it contradicts the results: the map i posted shows the areas of the cores of the 94th floor in blue indicating that temps there were below 300-C. i can't see any reason to state that temps reached at some point 500-1000-C on both floors, there's just no graph of the 94th floor indicating that ...only the 97th, u say shows that. if nist didnt mention the 94th floor in the p28/78 quote it would be a totally different matter but the 94th is there and the temps were attributed to it as well. that seems inescapable to me.

What is it that you think should have been found in the temperature
history analysis of the steel samples in order for thermal failure to have
been a possibility?

much higher and persistent temperatures.

But on the 97th, those temperatures were there in the core, at least for some
time in the simulation. And obviously, we only have a few frames to look at,
not the full time history of the temperature profile.

You drew an extremely strong conclusion. You said that temperatures never
reached above 300 C in the core, in the simulations, based on a picture of the
94th floor at one instant: 15 minutes after impact.

well, first, it is pure speculation that other diagrams of the temps were made and i cant see any good reason why they weren't included in the report since they would be extremely relevant. also, i didn't see and have yet to see the 97th floor diagram so i might have been wrong saying core temps were definitely below 300-C, but the diagram of the 94th floor indicates temps were not as high as stated. i cant see any logical reason to believe based on the evidence that 500-1000-C were reached also in the 94th and i think i made that clear already and was infact correct to say that. so, it appears to me like an effort to make it look as if high temps were infact more widespread then they truly were: implying that another floor was also subject to high temps makes an enormous difference since it should be just 1 floor alone; it is like pumping the evidence by a full +100%. that aside, i think nist itself drew strong conclusions since it was only a simulation and there's no photographic evidence to back it. infact, temps of and above 1000-C are usually observed for a short period of time in building fires and the phenomenon is known as 'flashover' and typically last for seconds not minutes. and we have to remember how wrong nist sims were, after they backed the pancake theory with a simulation as well and then were forced to drop it.

I think one should be very reluctant to say that something is deceptive given
that one thinks it is unclear.

In my opinion, it would be a good thing for NIST to make the full time
histories of the simulations available. That would allow them to be analysed.



Cheers!

yes and we can keep arguing forever here without going anyhere. what's evident is that we need a new investigation, there's not a shred of doubt about that.

thx and have a good 1.

 

[Bitstream]

dpt, i'd like to discuss wtc7 and eventually wtc5-6 with u going forward. i think the colllapse of wtc7 is very telling and the least analyzed.

cheers

 

[Maverick1]

Is there an 'official' reason as to why building 7 collapsed?

I read somewhere that the official investigation into the collapse of the building has not been released yet and is due for early 2007, but cannot say if the source is reliable or not.

 

[Bitstream]

Quote from Maverick1:

Is there an 'official' reason as to why building 7 collapsed?

I read somewhere that the official investigation into the collapse of the building has not been released yet and is due for early 2007, but cannot say if the source is reliable or not.

official version: "probably due to fire but in reality it is extremely unlikely so we don't have a clue".

 

[ratboy88]

Quote from Maverick1:

Is there an 'official' reason as to why building 7 collapsed?

I read somewhere that the official investigation into the collapse of the building has not been released yet and is due for early 2007, but cannot say if the source is reliable or not.

all explanations for anything they put out so far come with the disclaimer 'has a low probability".... yet these fools just eat it up.