New York City activist

December 4, 2007

Fire temperatures and steel temperatures

In a comment on my post Twin Towers demolition hypothesis: Discussion with Pat Curley, anonanonanon posted a link to Cardington Fire Test: The Behaviour of a Multi-storey Steel Framed Building Subjected to Fire Attack on a website called Structural Fire Engineering: One Stop Shop by Professor Colin Bailey, University of Manchester.

When I said I’d respond later today, anonanonanon replied, “Please wait until I’ve got my discussion of the fire protection up, because it may answer some of your questions.”

anonanonanon, please post said discussion (or a link to it, if it’s on another website) here, below this post.

Also I would be interested in your specific comments on the following pages on Jim Hoffman’s 9-11 Research site dealing with the question of the likely fire temperatures in the WTC buildings and their likely effects on the steel:

See also various critiques of the NIST report, in the section The NIST report in my post Demolition of WTC: Let’s not overstate the case, please.

P.S., 12/7/2007: Jim Hoffman has made various changes to his website, in response to some of the comments below.

32 Comments »

  1. In, “What is 9/11 Truth? – The First Steps” Kevin Ryan writes, “Their test for fireproofing loss, never inserted in the draft reports, involved
    shooting a total of fifteen rounds from a shotgun at non-representative samples in a plywood box. Flat steel plates were used instead of column samples, and no floor deck samples were tested at all. In the end, they slid the results into a 12 page appendix to the final report. The so-called “12-page appendix” is right here, http://wtc.nist.gov/NISTNCSTAR1-6A.pdf. The careful reader will note that this is in fact a 275-page discussion of extensive testing and background research on the fireproofing in the WTC. They performed a large variety of standard and nonstandard tests, involving desnity, thickness, conformance to manufacture recommendations and adhesive and cohesive strength, to measure the strength of the fireproofing, allowing them to calculate how much force would be required to knock off the fireproofing. The shotgun tests were an additional test that used special shotgun shells designed to simulate the speed and and components (i.e aircraft nuts and bolts) of the airplanes that hit the building. In accordance with the rules of this site, I will leave open the possibility, however remote, that Ryan is ignorant of numbers over 12, hence could not count up to page 275, and also is unaware that one should begin reading at page 1 rather page 263.

    This information was clearly referenced used in chapter 1-6 of the main report to help establish that most of the fireproofing must have been been knocked off the fire floors. They determined that the force of impact on the towers was enough to knock off the fireproofing on floors other than the impact floor (they made their case based on the calculated force of impact, eyewitness reports of fireproofing being knocked off and photographs). The direct impact floors had debris that strich off the fireproofing as well. They then made some conservative assumptions (i.e. resulting in a lower estimate than is liely to have actually happened) of how much fireproofing was knocked off and used this as an imput in their modeling. Next they modelled the effect of the fire on the bare steel, and found that the floors would quickly sag under fire conditions that matched observations of the WTC fires. Sagging floors can be seen in this photo http://www.debunking911.com/sag.ht1.jpg.

    NIST hired UL labs to test a floor assembly with fireproofing on it, and the test found that the office fires could not have caused such sagging if the fireproofing was intact.

    Although NIST doesn’t say so explicitly, fire is the only thing that could cause the observed floor sagging. Explosives could not possibly have cause such sagging, since it requires high heat spread over a wide area. The sagging floors pulled in the outer columns (inward pulled columns can be seen in photos), and caused the collapse.

    So let me sum this whole argument.

    I contend that Kevin Ryan’s key point is that the steel wasn’t heated enough to damage the steel, based mainly on the fact that NIST didn’t test the floor trusses for heat exposure and found that outer columns had only been raised to 250 C at most. This is spurious because NIST didn’t test the heated floor assemblies, was apparently unable to perform such tests becasue there was no way to identify the floor assembly steel (unlike the columns, which were not individually marked during construction) and they did not need to perform such testing.

    NIST however produced clear evidence through testing, modelling, and calculation and principles of fire protection engineering that the floor assemblies almost certainly were heated enough to cause failure.

    If there is a disconnect here with the scientific method, it is because they used engineering methods rather than strictly scientific method. ALthogh engineering is based in science, engineers rarely have the luxury of infinite time and data to study their problem, so have many methods of solving real world problems with limited data. This is how NIST resolved the questions posed without building an exact replica of the WTC and flying a plane into it.

    Comment by anonanonanon — December 4, 2007 @ 6:24 am | Reply

  2. I’ll comment some of the key points.

    “800º C is near the maximum flame temperature of hydrocarbons burning in air without pre-heating or pressurization of the air. Even those temperatures are usually reached only with premixed (blue) flames, such as in gas stoves and blowtorches. Diffuse flames, of the type in the WTC, tend to be far cooler.”

    Experiments that can be found on the web show that office fires can easily reach 800 C. I already pointed you to some of them, but there are more.

    “Widespread fires reaching 700º C would have caused extensive window breakage and would have made the steel glow red-hot. No such events were observed. 1”

    Lots of windows were already broken, and unless you have xray or infrared eyes, how can you tell what the temperature of the fire inside the building is (some say by the smoke, but a natural fire will usually have a mix of areas, some burning much hotter than others.

    “Fires would have to be very extensive to raise the temperatures of columns to near the fire temperatures, given the thermal sinks of the steel structures. Columns of the perimeter walls and of the core structures were well coupled thermally. In order to soften columns, fires would have to exceed the capacity of the 100,000 tons of steel in each building to draw away the heat.”

    This is simply false. Steel is not THAT thermally conductive. If it were, welding would be a physically impossibility.

    ” In fact the fires did not even consume entire floors of either Tower.”

    He must have been watching a different fire, because it looks pretty extensive to me, and seems to have consumed a good portion of the floor, if not all of it.

    “Heating the external columns would be especially difficult because the columns were situated outside the interior volume, with only one of the four sides adjacent to the building’s interior. Heating of core columns would be especially difficult given the apparently poor ventilation of the core regions, being further from any air supply.”

    Which is exactly why the small pieces of steel on the underside of the sagging floors and where sitting directly in the over the burning office material below were the ones that were heated to failure.

    “As the jet fuel burned off and the fires became less severe, the columns would have cooled and regained most strength lost to elevated temperatures.”

    First true thing he said here, but it ignores that if any steel sagged or bend before cooling, it will not return to original shape after cooling, and the resulting misalignment can cause additional structural damage.

    “Even if such hot and widespread fires existed, they would still be unlikely to cause failures of the columns in either of the Towers.”

    “Even if such hot and widespread fires existed, they would still be unlikely to cause failures of the columns in either of the Towers.”

    Still, it has been known to happen, which is why firecodes insist on fireproofing columns.

    “The incompatibility of any fire-triggered column-failure scenario with the observed characteristics of the fires created the need for the truss theory.”

    Hey, he agrees with NIST!

    “Fire Severity: How Serious Were the Twin Towers’ Fires?”

    comment on entire. Fires not severe? He must have been watching a different fire than I was. I think you can find plenty of clear evidence that the fire was quite severe

    “The Fires’ Impact: How the Towers’ Fires Affected the Structural Steel”

    The section literally flies in the face of 200 years of engineering theory and practice, and I invite you to sit down in an engineering library and study the literature rather than listen to Mr. Hoffman. I don’t have anything on the web to show you on this. Try Columbia University.

    “Why Did the World Trade Center Collapse? Science, Engineering, and Speculation by Thomas W. Eagar and Christopher Musso ”

    “However, the building was not able to withstand the intense heat of the jet fuel fire. While it was impossible for the fuel-rich, diffuse-flame fire to burn at a temperature high enough to melt the steel, its quick ignition and intense heat caused the steel to lose at least half its strength and to deform, causing buckling or crippling. This weakening and deformation caused a few floors to fall, while the weight of the stories above them crushed the floors below, initiating a domino collapse.”

    If you understand this you understand everything. This is simple common sense and you don’t need a NIST model or an engineering degree to see that this is both entirely possible and exactly what happened.

    “http://911research.wtc7.net/mirrors/guardian2/wtc/how-hot.htm”

    He doesn’t consider the energy release by all the burning office furniture and fixtures. Also he assume uniform heating in a fire, which is very rare.

    “The Cardington and Broadgate Fires (mirror of Nerdcities/Guardian site)”

    Test data supports the idea that fire can cause severe enough structural damage to cause collapse, as evidenced by sagging floors and bend columns. The fact that the building did not actually collapse was either because the test was designed to ensure that no collapse occurred (which would prevent further study) or because conditions were not sever enough to cause collapse in THAT BUILDING under THOSE CONDITIONS. Arguing anything else would be like saying that if a auto crash dummy doesn’t get destroyed in a Cadillac at 30 MPH, it won’t be killed in a volkswagen at 60 MPH.

    “NIST Data Disproves Collapse Theories Based on Fire (PDF) by Frank Legge”

    “Sagging of the core was said to transfer load to the weakened
    wall which then failed. This is not reasonable however because there were three remaining walls, including four undamaged corners, which provided a rigid structure holding the core vertical by means of the hat truss. Collapse, if it were to occur, must therefore have been vertical, involving all core columns and the perimeter columns simultaneously.”

    Floors were required to hold core in place, hat truss was extra support, not primary. Without the floors, the whole thing goes. In either case you need to be a structural engineer to do the calculations, and Legge didn’t even bother to try, so his point is simply meaningless.

    Comment by anonanonanon — December 4, 2007 @ 7:42 am | Reply

  3. anonanonanon wrote:

    Experiments that can be found on the web show that office fires can easily reach 800 C. I already pointed you to some of them, but there are more.

    Some? I don’t recall you pointing me to any others besides the Cardington Fire Test mentioned above. If you did I would appreciate a reminder of which specific ones. Also I would appreciate links to a few more if you happen to have them handy.

    If/when you post about these, I would appreciate it very much if you could post both (1) a link to the report as a whole and (2) instructions on how to get to the specific info about the fire temperatures and steel temperatures – and the specific info about the fire itself, such as how the fire was started, what fuel was used, and how it was ventilated.

    The Cardigan Fire Test page contains links to various items including (1) 300+ page PDF document which consists mostly of photos of drawings, so I can’t convert it to text and search it; (2) two PowerPoint presentations which I won’t be able to look at until I have access to a machine with PowerPoint, hopefully tomorrow; and (3) some Excel spreadsheets, which I’ll also have to wait with looking at, for the same reason. And I’m not likely to have time to read all these documents in their entirety tomorrow, when I will have access to a computer with both Excel and PowerPoint. So it would be helpful if you could give me some hints as to where, in this collection of documents, I should look for the information about the fire temperatures and steel temperatures, if you’re familiar enough with these documents to be able to tell me.

    I would also like to learn more details about the fire itself, e.g. how it was set, what fuels there were, how long it lasted, etc.

    I hope to reply to the remainder of your comment later today.

    Comment by Diane — December 4, 2007 @ 5:05 pm | Reply

  4. Just FYI, There is a free powerpoint viewer to view (but not edit) pp presentations. It’s quite small ~2MB.

    http://www.microsoft.com/downloads/details.aspx?FamilyId=428D5727-43AB-4F24-90B7-A94784AF71A4&displaylang=en

    Also, openoffice (openoffice.org) will open excel & powerpoint files and is available for free, in case this helps.

    Comment by lozenge124 — December 4, 2007 @ 8:52 pm | Reply

  5. Quoting Frank Legge’s paper (PDF):

    “Sagging of the core was said to transfer load to the weakened
    wall which then failed. This is not reasonable however because there were three remaining walls, including four undamaged corners, which provided a rigid structure holding the core vertical by means of the hat truss. Collapse, if it were to occur, must therefore have been vertical, involving all core columns and the perimeter columns simultaneously.”

    anonanonanon replied:

    Floors were required to hold core in place, hat truss was extra support, not primary. Without the floors, the whole thing goes. In either case you need to be a structural engineer to do the calculations, and Legge didn’t even bother to try, so his point is simply meaningless.

    No immediate comment, but at some point I should probably contact Frank Legge about this, and at some point I should also see if I can get any of the structural engineers in Richard Gage’s group to comment. I’ve quoted this in a separate comment from everything else, for ease in so doing. I’ll reply to the rest of anonanonanon’s comment soon, probably later today.

    Comment by Diane — December 4, 2007 @ 9:10 pm | Reply

  6. In reply to this page on Jim Hoffman’s site, anonanonanon wrote:

    … Unless you have xray or infrared eyes, how can you tell what the temperature of the fire inside the building is (some say by the smoke, but a natural fire will usually have a mix of areas, some burning much hotter than others.

    Exposed steel was visible in the impact holes, and at least that steel, apparently, did not glow red-hot. Of course this, in and of itself, does not rule out the possibility that some other, more hidden steel might have glowed red-hot, at least briefly.

    Quoting Jim Hoffman:

    “Fires would have to be very extensive to raise the temperatures of columns to near the fire temperatures, given the thermal sinks of the steel structures. Columns of the perimeter walls and of the core structures were well coupled thermally. In order to soften columns, fires would have to exceed the capacity of the 100,000 tons of steel in each building to draw away the heat.”

    anonanonanon replied:

    This is simply false. Steel is not THAT thermally conductive. If it were, welding would be a physically impossibility.

    Welding torch flames typically reach approximately 3000 degrees C, or even hotter, much hotter than the melting point of steel, which is approximately 1500 degree C. (See Temperature of an Oxyacetylene Torch on the Physics Factbook site.) Thus a welding torch’s ability to heat steel up to its melting point, in a very short amount of time, does not, in itself, imply that an 800-degree-C flame should be able to heat any part of a large steel structure all the way up to 800 degrees C in any reasonably short amount of time.

    So it doesn’t seem to me that welding really contradicts Jim Hoffman’s point. Perhaps he exaggerates the extent to which his point is true, but it does seem to me that steel temperatures would be considerably cooler than fire temperatures, for exactly the reason he mentioned, except in those (probably not very many) places where the steel is in prolonged direct contact with a flame.

    Of course, the whole question of heat transfer analysis is something I should look at a textbook on at some point. Have you studied this topic in detail yourself?

    Quoting Jim Hoffman:

    “Heating the external columns would be especially difficult because the columns were situated outside the interior volume, with only one of the four sides adjacent to the building’s interior. Heating of core columns would be especially difficult given the apparently poor ventilation of the core regions, being further from any air supply.”

    anonanonanon replied:

    Which is exactly why the small pieces of steel on the underside of the sagging floors and where sitting directly in the over the burning office material below were the ones that were heated to failure.

    You left out at least one word in the above sentence, but I think I can figure out what you are saying. Anyhow, do you agree that heat-induced column failure is unlikely as the primary failure mechanism, given the observed characteristics of the fires?

    Quoting Jim Hoffman:

    “The incompatibility of any fire-triggered column-failure scenario with the observed characteristics of the fires created the need for the truss theory.”

    anonanonanon replied:

    Hey, he agrees with NIST!

    Actually, the “truss theory” refered to here is not NIST’s theory of truss sagging, but rather Thomas Eagar’s earlier theory (which NIST subsequently rejected) about the trusses snapping loose due to failing “angle clips.” Jim Hoffman discusses Eagar’s theory here.

    In response to this page on Jim Hoffman’s site, anonanonanon wrote:

    comment on entire. Fires not severe? He must have been watching a different fire than I was. I think you can find plenty of clear evidence that the fire was quite severe

    He didn’t say it was not severe at all. The first sentence does say there were “significant fires in both towers,” and the page also mentions some specific ways in which the fires were indeed severe, such as people jumping out of windows. But the question is how severe, and for how long. These are important quantitative questions, on which the credibility of any natural-collapse hypothesis depends.

    Perhaps this point would be clearer if the subtitle of the page were changed from “How serious…” to “How extreme…,” or something like that.

    In response to this page on Jim Hoffman’s site, anonanonanon wrote:

    The section literally flies in the face of 200 years of engineering theory and practice, and I invite you to sit down in an engineering library and study the literature rather than listen to Mr. Hoffman. I don’t have anything on the web to show you on this. Try Columbia University.

    If you have time, it would be nice if you could point to some specific errors, even if you can’t provide references.

    Anyhow, this page mentions the Cardington experiments and even mentions (quoting Appendix A of the FEMA report on the WTC) that the steel was heated to over 800 degrees, so it would appear that there is no dispute over that particular point regarding those experiments.

    Of course, the Cardington test building was only eight storeys tall. This means far less weight pressing down on the heated steel than in the case of the WTC buildings although this fact seems to be of only secondary importance to NIST’s hypothesis for the initiation of collapse in the WTC buildings, which begins with sagging floors rather than with failing columns. On the other hand, it also means that the Cardington test buildings had far less steel for the heat to dissipate into.

    In any case, judging by Susan Lamont’s Ph.D. thesis (a copy of which appeared on the Nerdcities/Guardian site, mirrored on Jim Hoffman’s site) both the Cardington experiments and the earlier Broadgate fire cast at least a modicum of doubt on at least a few aspects of the previous “200 years of engineering theory and practice,” at least to some limited extent.

    Hoffman’s page does contain the overstatement that “steel structures … never disintegrate into piles of rubble.” Apparently, at least one of the Kader toy factory buildings did collapse into a pile of rubble. But the Kader toy factory was rather shoddily constructed, according to every page I’ve seen on it so far. (I should, as you suggested earlier, go to the library and take out a book on the Kader toy factory, to get some more details on its construction.)

    Anyhow, don’t expect me to heed your advice that I not “listen to Mr. Hoffman.” For the past several months, he has always appreciated my efforts to help him correct errors on his website (mostly minor errors like typos, but also some factual errors).

    Quoting Thomas Eagar:

    “However, the building was not able to withstand the intense heat of the jet fuel fire. While it was impossible for the fuel-rich, diffuse-flame fire to burn at a temperature high enough to melt the steel, its quick ignition and intense heat caused the steel to lose at least half its strength and to deform, causing buckling or crippling. This weakening and deformation caused a few floors to fall, while the weight of the stories above them crushed the floors below, initiating a domino collapse.”

    anonanonanon wrote:

    If you understand this you understand everything. This is simple common sense and you don’t need a NIST model or an engineering degree to see that this is both entirely possible and exactly what happened.

    I understand the concept. The question is whether the “fuel-rich, diffuse-flame fire” was hot enough to weaken the steel enough to cause enough deformation to collapse the building and moreover enough to collapse the building so rapidly and completely as to pulverize, not just break up, nearly everything except the steel. These are quantitative questions, to which the answer might not be obvious. Personally I’m taking a wait-and-see attitude on these questions. There are intuitive arguments both for and against the claims in Eagar’s statement quoted above.

    Anyhow, Eagar’s theory is not “exactly what happened” according to NIST. Eagar’s theory had floors falling because they broke loose from columns, whereas NIST’s theory has columns breaking because they were being pulled on by sagging floors.

    In reply to this page of Jim Hoffman’s mirror of Nerdcities/Guardian, anonanonanon wrote:

    He doesn’t consider the energy release by all the burning office furniture and fixtures. Also he assume uniform heating in a fire, which is very rare.

    The Nerdcities/Guardian page does not claim that jet fuel was the only thing that burned. In fact, it does refer to “the typical office fire that developed” afterward. The author’s point is merely that the burning of the jet fuel did not, in and of itself, make a significant direct contribution to the total heat of the fire, as many people assume it did.

    What the jet fuel did, of course, was to spread the fire a lot further than it could otherwise have spread in such a short time.

    In reply to this page about the Cardington and Broadgate fires (actually a copy of parts of Susan Lamont’s Ph.D. thesis) on Jim Hoffman’s mirror of Nerdcities/Guardian, anonanonanon wrote:

    Test data supports the idea that fire can cause severe enough structural damage to cause collapse, as evidenced by sagging floors and bend columns. The fact that the building did not actually collapse was either because the test was designed to ensure that no collapse occurred (which would prevent further study) or because conditions were not sever enough to cause collapse in THAT BUILDING under THOSE CONDITIONS. Arguing anything else would be like saying that if a auto crash dummy doesn’t get destroyed in a Cadillac at 30 MPH, it won’t be killed in a volkswagen at 60 MPH.

    According to Susan Lamont’s Ph.D. thesis, one of the reasons why the the Cardington tests, and other similar tests, were carried out in the first place, was because of engineers’ surprise that certain buildings which might have been expected to collapse did not collapse, e.g. in the Broadgate fire. So it doesn’t seem likely that “the test was designed to ensure that no collapse occurred.” On the contrary, judging by the description in both Susan Lamont’s paper and the FEMA report on the WTC, it seems that one of the purposes of the Cardington tests was to determine whether a collapse would occur.

    This, of course, does not prove that no building could ever be capable of collapsing due to a fire. Nor does it prove that the WTC buildings, in particular, could not possibly have collapsed due to a fire. But it does show that collapses due to fire, at least under some circumstances, may be less likely than engineers have traditionally assumed, and it does seem to indicate that at least some buildings have perhaps been “over-engineered,” as Jim Hoffman put it.

    It also seems to me that the Cardington test results (if Susan Lamont is describing them correctly) may cast some doubt on NIST’s theory about the initiation of collapse for the Twin Towers, although I’ll need to study this issue quite a bit more to determine to what extent this is the case.

    Anyhow, I suspect that the Cardington experiments were not intended to model a typical office fire, but rather an extreme case. Of course, at some point I’ll need to study the Cardington experiments myself to determine whether this is indeed the case.

    On other subjects: There’s a bunch of stuff of yours that I have yet to reply to in the thread WTC 7: Reply to Pat at Screw Loose Change (November 21, 2007), having been distracted by subsequent comments on other issues. I haven’t forgotten about these comments of yours, and I still intend to respond to them, and the pages linked therein, in one or more future posts, though perhaps not in my very next posts.

    Comment by Diane — December 4, 2007 @ 10:59 pm | Reply

  7. After this page comes to a conclusion, even if total and immediate collapse by fire of the upper section did occur, we still have the rest of the undamaged building to account for, whose many many floors experienced no fire and showed no prior signs of stuctural deficits, and so will need a completely different explanation for their failure to have ensued.

    Comment by reader21 — December 5, 2007 @ 12:00 am | Reply

  8. reader21 wrote:

    … we still have the rest of the undamaged building to account for, whose many many floors experienced no fire and showed no prior signs of stuctural deficits

    This, allegedly, is accounted for by Bazant’s hypothesis, which is the other big thing we need to examine besides NIST’s hypothesis about the initiation of collapse.

    More about that later, in a separate post. I prefer to keep this thread focussed on the issues of fire temperatures and steel temperatures.

    Comment by Diane — December 5, 2007 @ 12:48 am | Reply

  9. More information on building fires:

    There was more than report on the link I provided for the cardington test, and the rest of the website has a lot more information on other tests, and also some interesting discussions on real building fire. There is a lot there, I suggest you take your time with it and feel no obligation to answer quickly. The only other source I am aware of is http://fire.nist.gov/ which has a wealth of fire testing information. I didn’t link to it because I thought you might not trust it – it is NIST own website.

    Table 4 of the cardington test report shows that temperatures over 800 C can be reached in as little as 15 minutes.

    I have studied heat transfer, but not in detail. Heat conduction in a steel beam can be solved using the heat equation, and there are a great many introductory texts that cover the principles quite well. “Transport Phenomena” by Bird et al is a well respected intro text. “Fire safety Engineering” by Purkiss is an advanced textbook that provides specific information on the fire properties of steel. You could also check the Handbook of Structural Engineering b Chen and Liu which has a chapter on Fire Design.

    As for the rest of your comments, I think that if you study this issue in depth, with an eye to understand the general principles first, and the WTC details second, you will see that everything that the official theory says happened is in fact highly likely and that the only dispute is about certain technical details that in no way or form lead to even a suspicion of controlled demolition. But don’t take my word for it all. Study it for yourself. I know that you said you did a lot of study during last summer, but I am surprised that I and other commenters here appear to have introduced you to a lot of material you haven’t seen before, despite its relevance to this topic. Most of this material goes beyond what you may have seen at basic debunker sites (though you can usually find it if you keep looking), so I wonder if you may not know the debunker case as well as you think. Only you can decide that question for yourself. Now go and and study 😉

    Comment by anonanonanon — December 5, 2007 @ 5:17 am | Reply

  10. Yep, I do have quite a bit of studying to do on the issue of fire temperatures and steel temperatures. In the meantime, I’ll refrain from making arguments based on that particular issue.

    My preliminary research this past summer seemed to confirm what Jim Hoffman was saying on these matters. But my examination of this particular topic was, I will admit, superficial.

    On another subject, I wrote earlier:

    This, allegedly, is accounted for by Bazant’s hypothesis, which is the other big thing we need to examine besides NIST’s hypothesis about the initiation of collapse.

    More about that later, in a separate post. I prefer to keep this thread focussed on the issues of fire temperatures and steel temperatures.

    Actually, I’m probably not going to be writing a post about Bazant’s hypothesis soon. So, in the meantime, if anyone here wants to discuss it, a good place would be comment thread following my post Demolition of WTC: Let’s not overstate the case, please, where there has already been lots of dicussion about Bazant’s hypothesis.

    Comment by Diane — December 5, 2007 @ 2:15 pm | Reply

  11. (This comment is an edited pingback.)

    I’ve added a parenthesized P.S. to the post linked below.

    -Diane

    Pingback by The 9/11 Truth movement and me: Further reply to Pat Curley « New York City activist — December 5, 2007 @ 3:46 pm | Reply

  12. For whatever strange and annoying reason, two comments that were posted yesterday, and which went into the moderation queue (one because it contained multiple links, and the other because it was from a first-time poster), were not visible to me until just now. These comments are:

    a comment by anonanonanon about Kevin Ryan’s critiques of the NIST report
    a comment by lozenge124 containing advice on how to view PowerPoint and Excel files

    Both of these comments now appear further up on this page.

    I’ll reply later to the first of these two comments.

    Comment by Diane — December 5, 2007 @ 9:33 pm | Reply

  13. >>Also, openoffice (openoffice.org) will open excel & powerpoint files and is available for free, in case this helps.

    Openoffice is a mess — I recommend against it. It slowed my computer down immensely and caused sorts of minor problems to the point where I finally removed it.

    Comment by reader21 — December 6, 2007 @ 2:14 am | Reply

  14. anonanonanon wrote:

    The so-called “12-page appendix” is right here, http://wtc.nist.gov/NISTNCSTAR1-6A.pdf.

    Separating the period from the URL, so that people can actually download it, that’s:

    Click to access NISTNCSTAR1-6A.pdf

    The careful reader will note that this is in fact a 275-page discussion of extensive testing and background research on the fireproofing in the WTC.

    The “appendix” that Kevin Ryan is referring to is evidently Appendix C of this subreport. Appendix C is indeed 12 pages long. It begins on page 263 and ends on page 274.

    They performed a large variety of standard and nonstandard tests, involving desnity, thickness, conformance to manufacture recommendations and adhesive and cohesive strength, to measure the strength of the fireproofing, allowing them to calculate how much force would be required to knock off the fireproofing. The shotgun tests were an additional test that used special shotgun shells designed to simulate the speed and and components (i.e aircraft nuts and bolts) of the airplanes that hit the building.

    The shotgun tests, apparently, were the tests intended to confirm the calculations that were made based on the other measurements. So it would seem to me that they weren’t merely “additional” tests, but rather the culmination of this whole sequence of tests. In science, you don’t just make preliminary measurements and then make calculations based on your measurements; you test the results of your calculations too. The preliminary measurements plus calculations are not enough.

    In accordance with the rules of this site, I will leave open the possibility, however remote, that Ryan is ignorant of numbers over 12, hence could not count up to page 275, and also is unaware that one should begin reading at page 1 rather page 263.

    No, he was talking literally about a 12-page appendix, not the entire sub-report NISTNCSTAR1-6A. He was neither lying nor ignorant about the length of the appendix, and I see no reason to suggest that he might be. You might feel that he should consider the rest of the sub-report to be adequate, rather than concerning himself with the methodology of the test detailed in Appendix C, but that’s another matter. The rest of the sub-report is not a substitute for an actual test of its calculated results.

    Sagging floors can be seen in this photo http://www.debunking911.com/sag.ht1.jpg.

    To make that clickable:

    Fascinating photo. Assuming that those red numbers are floor numbers, this must be the South Tower, correct? I wonder which side of the South Tower. Would you happen to know offhand? Better yet, would you happen to know of a good source containing this info?

    I’ll have more to say about it tomorrow.

    Comment by Diane — December 6, 2007 @ 2:46 am | Reply

  15. anonanonanon wrote:

    The so-called “12-page appendix” is right here, http://wtc.nist.gov/NISTNCSTAR1-6A.pdf.

    Separating the period from the URL, so that people can actually download it, that’s:

    Click to access NISTNCSTAR1-6A.pdf

    The careful reader will note that this is in fact a 275-page discussion of extensive testing and background research on the fireproofing in the WTC.

    The “appendix” that Kevin Ryan is referring to is evidently Appendix C of this subreport. Appendix C is indeed 12 pages long. It begins on page 263 and ends on page 274.

    They performed a large variety of standard and nonstandard tests, involving desnity, thickness, conformance to manufacture recommendations and adhesive and cohesive strength, to measure the strength of the fireproofing, allowing them to calculate how much force would be required to knock off the fireproofing. The shotgun tests were an additional test that used special shotgun shells designed to simulate the speed and and components (i.e aircraft nuts and bolts) of the airplanes that hit the building.

    The shotgun tests, apparently, were the tests intended to confirm the calculations that were made based on the other measurements. So it would seem to me that they weren’t merely “additional” tests, but rather the culmination of this whole sequence of tests. In science, you don’t just make preliminary measurements and then make calculations based on your measurements; you test the results of your calculations too. The preliminary measurements plus calculations are not enough.

    In accordance with the rules of this site, I will leave open the possibility, however remote, that Ryan is ignorant of numbers over 12, hence could not count up to page 275, and also is unaware that one should begin reading at page 1 rather page 263.

    No, he was talking literally about a 12-page appendix, not the entire sub-report NISTNCSTAR1-6A. He was neither lying nor ignorant about the length of the appendix, and I see no reason to suggest that he might be. You might feel that he should consider the rest of the sub-report to be adequate, rather than concerning himself with the methodology of the test detailed in Appendix C, but that’s another matter. The rest of the sub-report is not a substitute for an actual test of its calculated results.

    Sagging floors can be seen in this photo http://www.debunking911.com/sag.ht1.jpg.

    To make that clickable:

    Fascinating photo. Assuming that those red numbers are floor numbers, this must be the South Tower, correct? I wonder which side of the South Tower. Would you happen to know offhand? Better yet, would you happen to know of a good source containing this info?

    I’ll have more to say about it tomorrow.

    Comment by Diane — December 6, 2007 @ 2:48 am | Reply

  16. Diane wrote:

    Fascinating photo. Assuming that those red numbers are floor numbers, this must be the South Tower, correct? I wonder which side of the South Tower. Would you happen to know offhand? Better yet, would you happen to know of a good source containing this info?

    Comment by Diane — December 6, 2007 @ 2:48 am

    I don’t know what side it is. I found the photo in this discussion.
    http://www.debunking911.com/sag.htm

    Which is sourced it back to here

    Click to access Media_Public_Briefing_040505_final.pdf

    Comment by anonanonanon — December 6, 2007 @ 5:07 am | Reply

  17. Dinae Wrote:
    “The shotgun tests, apparently, were the tests intended to confirm the calculations that were made based on the other measurements. So it would seem to me that they weren’t merely “additional” tests, but rather the culmination of this whole sequence of tests. In science, you don’t just make preliminary measurements and then make calculations based on your measurements; you test the results of your calculations too. The preliminary measurements plus calculations are not enough.”

    Point 1. This is engineering not science. 99% of the time, all you ever have is preliminary measurements plus calculations. Half the buildings you’ve ever been in were never tested at all, they were simply designed to a code or spec and put together. The other half may have had some testing of assemblies. In either case nobody ever tested the final building to see if it performed exactly as designed. The sort of effort NIST put together for this report is far beyond anything that has every been done for any other building. Not that it is inappropriate. The magnitude and unusual nature of the collapse justified the effort. But if engineering were held to standards required for science, we’d spend so much time gathering data that nothing would ever be built. It is an extremely important distinction and it definitely applies here.

    Point 2. NIST performed multiple independent tests to establish that the fireproofing had been stripped off by more than one means. The shotgun blasts were only to demonstrate that some of the fireproofing could have been stripped off by the nuts and bolts in the plane travelling at high speed. The other 263 pages of Chapter 1-6A, plus related discussion in chapter 1-6 itself demonstrate that at least 2 other mechanisms were involved – direct impact of the plane itself (which was enough to break the steel outer columns on both the impact and exit sides, so its not unreasonable to assume it could have knocked off some firestripping too) and g force generated by the plane’s impact which according to eyewitnesses was enough to knock off fireproofing on floors other than impact floors. Ryan doesn’t even mention any of this, and makes it sound like all NIST did was shoot ordinary shotgun shells into a wooden box.

    Point 3. Ryan’s seems to miss the point of the shotgun test. It was solely to establish that metal parts moving at high speed could in fact strip off some of the fireproofing, not to establish that all of the fireproofing was in fact stripped off this way.

    Point 4. All of the test in Chapter 1-6A were used to help NIST make reasonable conservative assumptions for inputing damage to their model, which was then validated by comparing the model outputs with what was observed in the buildings. The actual model input parameters are on page 129 of Chapter 1-6.

    Comment by anonanonanon — December 6, 2007 @ 6:48 am | Reply

  18. anonanonanon wrote:
    “The section literally flies in the face of 200 years of engineering theory and practice, and I invite you to sit down in an engineering library and study the literature rather than listen to Mr. Hoffman. I don’t have anything on the web to show you on this. Try Columbia University.”

    Diane requested:
    “If you have time, it would be nice if you could point to some specific errors, even if you can’t provide references.”

    anonanonanon:
    The error is one of interpretation. It is known that fire can cause ANY building to collapse. This is based on both theory and experience with fire in 19th-century buildings made of structural iron (precursor to structural steel). By the time structural steel was invented, engineers developed ways to minimize the effects of fire, but never lost site of the fact that the effects of fire could be total and devestating. If Cardington proves that some buildings may perform much better than expected, WTC 7 proves that some buildings may perform much worse.

    It should also be noted that the group that worked

    Comment by anonanonanon — December 6, 2007 @ 7:05 am | Reply

  19. I’ve replied to your statement about WTC 7 on a separate page, in a comment after my post WTC 7: Reply to Pat at Screw Loose Change.

    The rest of your comment above seems to have gotten cut off. It ends with:

    It should also be noted that the group that worked

    I’ll reply to your other comment later.

    Comment by Diane — December 6, 2007 @ 11:21 am | Reply

  20. anonanonanon wrote:

    In accordance with the rules of this site, I will leave open the possibility, however remote, that Ryan is ignorant of numbers over 12, hence could not count up to page 275, and also is unaware that one should begin reading at page 1 rather page 263.

    No need for this kind of sarcasm. You may well have some justified complaints, e.g. that Kevin Ryan did not mention that the shotgun was no ordinary shotgun, and that he did not put the shotgun tests in the context of the other tests described elsewhere in NIST NCSTAR 1-6A. However, you too have misrepresented stuff you’ve read, and I didn’t respond with similar sarcasm. (For example, as I pointed out in this comment, you seem to have totally missed the point of this Nerdcities/Guardian page. In my response, I simply explained what I understood to be the point of the article.) So, please just focus on pointing out errors and mis-statements.

    Lest you accuse me of a “double standard,” I should perhaps also mention that, in my opinion, people who are getting paid money to do an investigation should be held to at least a somewhat higher standard (at least in terms of research methodology on the particular matters they’re being paid to investigate) than the rest of us. That’s why I feel free to voice at least mild suspicion when such people leave out of their reports what would seem to me to be glaringly obvious clues – as discussed in, for example, my post WTC 7: FEMA report and NIST prelim report: What about pre-collapse leaning and the transit???. You’re welcome to try to counter my suspicions, but please don’t try to do so by arguing that high-paid government employees should be treated exactly the same as everyone else.

    On another matter, thanks for the info about the photo. I’ll comment later, perhaps tomorrow.

    I’ll also reply later on other points.

    Comment by Diane — December 6, 2007 @ 6:28 pm | Reply

  21. anonanonanon wrote in this comment:

    Point 1. This is engineering not science. 99% of the time, all you ever have is preliminary measurements plus calculations. Half the buildings you’ve ever been in were never tested at all, they were simply designed to a code or spec and put together. The other half may have had some testing of assemblies. In either case nobody ever tested the final building to see if it performed exactly as designed.

    What you’re describing here is not a difference between “engineering” and science, but rather a difference between structural engineering and not just science, but also most other kinds of engineering. If structural engineering had the same methodology as most other kinds of engineering (e.g. electronic engineering), then complete prototypes would be built and thoroughly tested, not for every single building, but at least for every type of building, and for every building of a new and unusual design. Obviously this would be quite expensive.

    Anyhow, to me this implies that the whole field of structural engineering should be thought of as being pervaded by a huge degree of uncertainty. Thus, to the extent that buildings are “over-engineered,” the point would be an attempt to compensate for that uncertainty. Do you agree?

    anonanonanon also wrote in this other comment, about this page on Jim Hoffman’s site:

    The error is one of interpretation. It is known that fire can cause ANY building to collapse. This is based on both theory and experience with fire in 19th-century buildings made of structural iron (precursor to structural steel). By the time structural steel was invented, engineers developed ways to minimize the effects of fire, but never lost site of the fact that the effects of fire could be total and devestating.

    Would it be better if Jim Hoffman’s pages on this topic were to say that modern structural engineering practices have made the collapse of a steel-frame building due to fire very unlikely though not impossible?

    Anyhow, back to this comment by anonanonanon:

    The sort of effort NIST put together for this report is far beyond anything that has every been done for any other building. Not that it is inappropriate. The magnitude and unusual nature of the collapse justified the effort. But if engineering were held to standards required for science, we’d spend so much time gathering data that nothing would ever be built. It is an extremely important distinction and it definitely applies here.

    As I understand it, though, NIST’s investigation was supposed to be a scientific investigation, to the extent possible. In that case it should not be evaluated by the typical admittedly low epistemological standards of structural engineering.

    Not yet having read all the way through NIST NCSTAR 1-6 or NIST NCSTAR 1-6A myself, I can’t yet comment on the validity of your other criticisms. But thanks for letting me know what some of the specific points of contention are.

    Comment by Diane — December 6, 2007 @ 7:53 pm | Reply

  22. Diane wrote:
    “No need for this kind of sarcasm. You may well have some justified complaints, e.g. that Kevin Ryan did not mention that the shotgun was no ordinary shotgun, and that he did not put the shotgun tests in the context of the other tests described elsewhere in NIST NCSTAR 1-6A. However, you too have misrepresented stuff you’ve read, and I didn’t respond with similar sarcasm.”

    anonanonanon:
    You have right to make any rules you want on your own blog. I understand you don’t approve of my sarcasm. That makes it inappropriate for to participate further, because I often use sarcasm to make my points. No hard feelings. It’s been an interesting conversation. I wish you luck in your search.

    Comment by anonanonanon — December 7, 2007 @ 6:02 am | Reply

  23. anonanonanon wrote:

    You have right to make any rules you want on your own blog. I understand you don’t approve of my sarcasm. That makes it inappropriate for to participate further, because I often use sarcasm to make my points.

    Actually I haven’t seen you use sarcasm very often. And I don’t mind a little sarcasm now and then, as long as it’s directed at an issue rather than a person. The point is to keep discussion here civil.

    Anyhow, I realize that my comment policy needs to be clarified. So I just now modified the “no personal insults” rule, which now reads as follows:

    No personal insults against other commenters, or against other people likely to be reading this blog. (See note at the bottom of this page.) All comments should be civil and rational.

    and the note at the bottom says:

    In the “no personal insults against other commenters” rule, note that the “other commenters” are all people posting comments here, including those I disagree with, e.g. commenters defending the official story of 9/11.

    “Other people likely to be reading this blog” include members of New York 9/11 Truth, Scholars for 9/11 Truth and Justice, and Architects and Engineers for 9/11 Truth. I’m a member of the first group and in frequent email contact with some members of the other two groups. Thus, any comments about members of any of these groups are likely to get forwarded to the people in question. That being the case, please keep criticisms of these people civil. Substantive criticisms are certainly welcome, though.

    “Other people likely to be reading this blog” also include posters in the Truth Action forum and, on the other side of the fence, the JREF forum.

    Comment by Diane — December 7, 2007 @ 12:54 pm | Reply

  24. On 9/11 Blogger, Steven Jones has announced the publication of a letter by Kevin Ryan (PDF) in response to On Debunking 9/11 Debunking by Ryan Mackey.

    There’s now a thread about it in the JREF forum, which is mostly full of personal accusations, personal insults including some rather childish namecalling (such as calling Kevin Ryan “Waterboy,” apparently because he had been the manager of a water-testing plant at Underwriters’ Laboratories, which is somehow alleged to mean that he had not been a manager at UL and had been “lying” about the latter?) and other ad hominems. The only substantive criticisms I’ve found in the thread, so far, are these:

    – the second and third paragraph of this post by Ryan Mackey
    – the last paragraph of this post by cmcaulif, to which Ryan Mackey replied here
    another post by cmcaulif, to which see this reply by Apollo20 and a further comment by cmcaulif here
    this claim by Mark Roberts a.k.a. Gravy (JPG), to which see this reply by Swing Dangler and subsequent discussion on this page

    Not having yet read Mackey’s paper beyond skimming it and studying a few especially interesting-looking pages, I can’t really comment on the above-listed posts except to note one very interesting thing. In the discussion so far, no one has contested the following statement by cmcaulif (who also accuses Kevin Ryan of exaggerating):

    I think the removal of fireproofing is the weakest part of the NIST theory because of the uncertainty associated with assessing the condition of fireproofing in the tower ….

    I might be wrong, but it’s my impression, so far, that the removal of fireproofing is pretty much the crux of NIST’s theory about the initiation of collapse. So, if indeed it’s also the “weakest part” of the NIST theory, then it would seem to me that the main point of Kevin Ryan’s critique is correct, even if he has perhaps overstated it or gotten some of the details wrong.

    Comment by Diane — December 7, 2007 @ 5:13 pm | Reply

  25. I recommend you read Mackey’s paper — it’s very enlightening.

    >>I might be wrong, but it’s my impression, so far, that the removal of fireproofing is pretty much the crux of NIST’s theory about the initiation of collapse. So, if indeed it’s also the “weakest part” of the NIST theory, then it would seem to me that the main point of Kevin Ryan’s critique is correct, even if he has perhaps overstated it or gotten some of the details wrong.

    Good point.

    Comment by reader21 — December 7, 2007 @ 6:08 pm | Reply

  26. (This comment is an edited pingback.)

    The post linked below continues some of my discussion here with anonanonanon.

    -Diane

    Pingback by Engineers were surprised by the WTC collapses « New York City activist — December 7, 2007 @ 10:53 pm | Reply

  27. Diane,

    Some background on the Kevin Ryan topic. Kevin Ryan was fired because he misrepresented his credentials (the division of UL he worked at has nothing to do with steel or other building materials, but instead tests drinking water) and because he falsely implied that his personal beliefs were company opinions, when in fact he wrote the letter to Frank Gayle of NIST without his superiors’ knowledge or authorization.

    He has also challenged Mark Roberts on a couple of occations, Mark has responded, Ryan has made excuses and backed off.

    All these things have a long history. That’s why, when Kevin Ryan is brought up a zillionth time, most just don’t take him seriously anymore. Btw, that Apollo20 poster is Dr. Frank Greening.

    Comment by ref1 — December 7, 2007 @ 11:45 pm | Reply

  28. ref1 wrote:

    Kevin Ryan was fired because he misrepresented his credentials (the division of UL he worked at has nothing to do with steel or other building materials, but instead tests drinking water)

    What, specifically, did he say which constituted “misrepresenting his credentials”? When and where did he claim any personal involvement with UL’s testing of steel or other building materials? In everything of his that I’ve read about it, he spoke of such tests as things he had heard about from other UL executives, not as anything he personally was in charge of.

    and because he falsely implied that his personal beliefs were company opinions, when in fact he wrote the letter to Frank Gayle of NIST without his superiors’ knowledge or authorization.

    What did he say which specifically implied such a thing? Perhaps he didn’t adequately disclaim that his views did not represent company opinions. Offhand, I don’t recall anything in his letter which specifically implied that there was anything official about it, though perhaps it might have been taken that way without a sufficiently explicit disclaimer.

    Btw, that Apollo20 poster is Dr. Frank Greening.

    Thanks for the info.

    P.S.: I’ve sent you two email messages at the email address you used to register for WordPress.com.

    Comment by Diane — December 8, 2007 @ 12:01 am | Reply

  29. Well, in the UL grounds for his firing UL, for example, specifies that “he (Ryan)
    had commented inappropriately on UL tests conducted for NIST and misrepresented his
    opinions as UL’s”.

    Of course, you can argue these points.

    I’ll check the mail.

    Comment by ref1 — December 8, 2007 @ 8:51 am | Reply

  30. Unless you can support this assertion from something Kevin Ryan himself actually wrote, it would be more accurate to say, for example, that UL alleged that Ryan “misrepresented his opinions as UL’s” rather than to state as a fact that he actually did so.

    Comment by Diane — December 9, 2007 @ 1:14 am | Reply

  31. (This comment is an edited pingback.)

    The above post and subsequent comment thread are referenced in a P.S. to the section on WTC 1 and 2: The NIST report in the post linked below.

    -Diane

    Pingback by Demolition of WTC: Let’s not overstate the case, please « New York City activist — December 12, 2007 @ 3:09 pm | Reply

  32. In a comment in the thread following my post Twin Towers demolition hypothesis: Discussion with Pat Curley, I’ve posted a preliminary response regarding the sagging floor photo that “anonanonanon” called my attention to here earlier, above.

    Comment by Diane — December 23, 2007 @ 7:29 pm | Reply


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