# Skyscrapers on fire, not collapsing **URL:** \ **Category:** Great Debates\ **Created:** [September 12, 2010, 10:53pm UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541 "2010-09-12T22:53:57Z")\ **Posts on this page:** 20\ **Page:** 19
**Author:** ![Skywatcher](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/skywatcher/32/254_2.png) [@Skywatcher](https://boards.straightdope.com/u/Skywatcher)\ **Post date:** [September 25, 2010, 3:22am UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/362 "2010-09-25T03:22:14Z")
> [@Mozart1220](#): > > > [@Fear\_Itself](#): > > > > Which is 100% of all steel frame skyscrapers that have ever collapsed. If you have exceptions, post 'em. > > THat’s kinda what I’m saying here. Steel buildings DO NOT collpase due to fire. Oh, really? Then what [happened](http://www.charlestoncitypaper.com/imager/first-take-city-fire-memorial-plans/b/big/1169364/2f12/unknown.jpg) [here](http://wusa9.com/news/columnist/blogs/uploaded_images/CharlestonVIEWimage001-795784.jpg)? Did some meteor slam into it while it was [on fire](http://lh4.ggpht.com/_wMqDrPF0c30/RysZK_W5kII/AAAAAAAAAPA/Kplp8FCXepk/STP61780.JPG)? ---
**Author:** ![psikeyhackr](https://avatars.discourse-cdn.com/v4/letter/p/97f17d/32.png) [@psikeyhackr](https://boards.straightdope.com/u/psikeyhackr)\ **Post date:** [September 25, 2010, 3:29am UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/363 "2010-09-25T03:29:26Z")
> [@xtisme](#): > > [QUOTE=psikeyhackr] > The problem is the collapse TIME. Serious question here…assuming you are 100% correct (you aren’t of course, but for shits and giggles assume you are), do you really think no one else can do math? [/QUOTE] Can you do the math. It is not my fault if you TRUST in people that you regard as smarter than yourself. How much TIME do you think it took for the north tower to collapse and how much time would it take for a bowling ball to drop from the top? Do the math. The formula is: D = a \* t^2 / 2 psik ---
**Author:** ![psikeyhackr](https://avatars.discourse-cdn.com/v4/letter/p/97f17d/32.png) [@psikeyhackr](https://boards.straightdope.com/u/psikeyhackr)\ **Post date:** [September 25, 2010, 3:35am UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/364 "2010-09-25T03:35:47Z")
> [@Czarcasm](#): > > I think a moratorium should be called on any more answers until you and your deliberately ignorant compatriots acknowledge the facts that have repeatedly been provided you. So let’s see you provide a link that supplies the weight of a floor assembly if you think all questions are answered. You know those 206 foot by 206 foot concrete slabs poured on corrugated steel pans supported by 35 and 60 foot trusses. It’s only been NINE YEARS and there were 84 of those floor assemblies in each tower. The other floors had different designs. So if the answer is out there show us a link to it. The weight of the concrete slab alone can be computed from dimensions and density though it isn’t seen much, 600 tons. So the weight of a complete assembly is? With a link of course. psik ---
**Author:** ![Skywatcher](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/skywatcher/32/254_2.png) [@Skywatcher](https://boards.straightdope.com/u/Skywatcher)\ **Post date:** [September 25, 2010, 3:40am UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/365 "2010-09-25T03:40:06Z")
> [@psikeyhackr](#): > > > [@xtisme](#): > > > > Serious question here…assuming you are 100% correct (you aren’t of course, but for shits and giggles assume you are), do you really think no one else can do math? > > Can you do the math. > > It is not my fault if you TRUST in people that you regard as smarter than yourself. > > How much TIME do you think it took for the north tower to collapse and how much time would it take for a bowling ball to drop from the top? > > Do the math. The formula is: > > D = a \* t^2 / 2 The NIST also says that nearly half of the Towers’ cores (60 floors of WTC 1 and 40 of WTC 2) remained standing for up to 25 seconds. How does that fit into your little equation? ---
**Author:** ![Cisco](https://avatars.discourse-cdn.com/v4/letter/c/ccd318/32.png) [@Cisco](https://boards.straightdope.com/u/Cisco)\ **Post date:** [September 25, 2010, 3:49am UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/366 "2010-09-25T03:49:31Z")
> [@Cisco](#): > > > [@Mozart1220](#): > > > > I think I mentioned the odds of even one skyscraper falling straight down into it’s own foorprint. We had THREE, and one wasn’t even hit by a plane. > > What are those odds, and how did you calculate them? > > > [@Mozart1220](#): > > > > I think the “official” explaination for building 7 was “overwheight air conditioning units on the roof” > > > > Please… > > Where did you see this explanation? Will you abandon this idea if we can show you that it is not, in fact, the “official” explanation? > > Also, now that post #153 has been clearly explained to you at least 6 or 8 times, including a link to a concise Wikipedia article, will you actually respond to it? > > And how 'bout post #302-- any interest at all in responding to that? Mozart1220, will you respond to this? And to everyone else: if you don’t take these guys to task for not answering valid points and questions, they will lead the discussion absolutely **indefinitely** , in no particular direction other than a blatantly non-productive one. It’s a wild goose chase. They’re just going to keep asking questions and ignoring answers until we stop and make them address the points already brought up before moving forward with them. Answer post #153, Mozart. Answer post #302. Answer this post. Start responding to people or get a blog. This is a dialogue board. ---
**Author:** ![Fear\_Itself](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fear_itself/32/19637_2.png) [@Fear\_Itself](https://boards.straightdope.com/u/Fear_Itself)\ **Post date:** [September 25, 2010, 4:08am UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/367 "2010-09-25T04:08:02Z")
> [@psikeyhackr](#): > > Do the math. The formula is: > > D = a \* t^2 / 2 Well, it’s _a_ formula. It’s not _the_ formula. ---
**Author:** ![Czarcasm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/czarcasm/32/4050_2.png) [@Czarcasm](https://boards.straightdope.com/u/Czarcasm)\ **Post date:** [September 25, 2010, 5:35am UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/368 "2010-09-25T05:35:53Z")
> [@psikeyhackr](#): > > > [@Czarcasm](#): > > > > I think a moratorium should be called on any more answers until you and your deliberately ignorant compatriots acknowledge the facts that have repeatedly been provided you. > > So let’s see you provide a link that supplies the weight of a floor assembly if you think all questions are answered. > > You know those 206 foot by 206 foot concrete slabs poured on corrugated steel pans supported by 35 and 60 foot trusses. It’s only been NINE YEARS and there were 84 of those floor assemblies in each tower. The other floors had different designs. > > So if the answer is out there show us a link to it. The weight of the concrete slab alone can be computed from dimensions and density though it isn’t seen much, 600 tons. So the weight of a complete assembly is? > > With a link of course. > > psik No more answers until you acknowledge the ones given you already. You forfeit your turn until you do this. ---
**Author:** ![Magiver](https://avatars.discourse-cdn.com/v4/letter/m/4491bb/32.png) [@Magiver](https://boards.straightdope.com/u/Magiver)\ **Post date:** [September 25, 2010, 5:38am UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/369 "2010-09-25T05:38:50Z")
> [@Mozart1220](#): > > _ **Not when the top is already sliding off to the side…** _ I asked for an explanation once before. How does a stick built structure slide? What parts are sliding against each other? You have yet to answer a single question anybody has put to you. ---
**Author:** ![Magiver](https://avatars.discourse-cdn.com/v4/letter/m/4491bb/32.png) [@Magiver](https://boards.straightdope.com/u/Magiver)\ **Post date:** [September 25, 2010, 5:42am UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/370 "2010-09-25T05:42:15Z")
> [@psikeyhackr](#): > > > [@xtisme](#): > > > > Serious question here…assuming you are 100% correct (you aren’t of course, but for shits and giggles assume you are), do you really think no one else can do math? > > Can you do the math. > > It is not my fault if you TRUST in people that you regard as smarter than yourself. > > How much TIME do you think it took for the north tower to collapse and how much time would it take for a bowling ball to drop from the top? > > Do the math. The formula is: > > D = a \* t^2 / 2 > > psik by all means, show us the math. While you’re at it, calculate the time between the collapse of each floor because the building is not in free fall. It’s snapping apart 1 floor at a time. ---
**Author:** ![Garfield226](https://avatars.discourse-cdn.com/v4/letter/g/9e8a1a/32.png) [@Garfield226](https://boards.straightdope.com/u/Garfield226)\ **Post date:** [September 25, 2010, 5:53am UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/371 "2010-09-25T05:53:55Z")
> [@psikeyhackr](#): > > How much TIME do you think it took for the north tower to collapse and how much time would it take for a bowling ball to drop from the top? Hmm…is it less than MORE THAN NINE YEARS? [sub]Later.[/sub] ---
**Author:** ![Magiver](https://avatars.discourse-cdn.com/v4/letter/m/4491bb/32.png) [@Magiver](https://boards.straightdope.com/u/Magiver)\ **Post date:** [September 25, 2010, 6:12am UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/372 "2010-09-25T06:12:33Z")
> [@psikeyhackr](#): > > > [@Czarcasm](#): > > > > I think a moratorium should be called on any more answers until you and your deliberately ignorant compatriots acknowledge the facts that have repeatedly been provided you. > > So let’s see you provide a link that supplies the weight of a floor assembly if you think all questions are answered. Lets see yo provide a reason to know the exact weight of the floors. Any rational person can understand that the structural weight above the impact zones represented a tremendous load and the combination of severed columns and weakened floor joists caused structural failure of the remaining columns. You can clearly see the failure of the buildings starting at the impact zones. Where is the controversy? If you can’t make a declarative statement of theory and support it with something then I call shenanigans on you. ---
**Author:** ![Ibanez](https://avatars.discourse-cdn.com/v4/letter/i/a4c791/32.png) [@Ibanez](https://boards.straightdope.com/u/Ibanez)\ **Post date:** [September 25, 2010, 9:34am UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/373 "2010-09-25T09:34:06Z")
I see Psi is back with his paper and steel washers vid where that was torn apart in another thread already, here to do it all over again. Ins’t that the definition of something ? These people aren’t interested in answering questions. They’re just interested in asking them, over and over again despite responses given. They come here under the impression of looking to be convienced but are actually here to convert. Their minds are made up and feel special to be part of that little club who feels important to think they know the truth to something so few others have knowledge of and want to share that joy no matter how insane. ---
**Author:** ![psikeyhackr](https://avatars.discourse-cdn.com/v4/letter/p/97f17d/32.png) [@psikeyhackr](https://boards.straightdope.com/u/psikeyhackr)\ **Post date:** [September 26, 2010, 1:23am UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/374 "2010-09-26T01:23:46Z")
> [@Magiver](#): > > Lets see yo provide a reason to know the exact weight of the floors. . Here is a quote from the NCSTAR1 report > [@](#): > > 2.4.3 Single Impulse Excitations > Accurate estimation of the tower’s motion during the airplane impact required detailed knowledge of the geometry, weight distribution, and impact velocity of the aircraft, as well as **detailed knowledge of the geometry, weight distribution, and structural strength of the tower**. At the time of this test series (fall 2003), much of this information was unknown, and the impact motion could only be roughly estimated. To allow this estimate to be made quickly, many simplifying assumptions were made regarding the nature of the impact. [World Trade Center Investigation | NIST](http://wtc.nist.gov/NISTNCSTAR1-5D.pdf) page 74 That link doesn’t work anymore though. It’s in here: [World Trade Center Investigation | NIST](http://wtc.nist.gov/NCSTAR1/NCSTAR1-5index.htm) I extrapolated that the south tower moved 15 inches at the level where the plane impacted. The NIST report says it deflected 12 inches at the 70th floor 130 feet below the impact point. So how much of the planes kinetic energy went into deflecting the building? Did that energy do structural damage or was it just absorbed like the wind would be. So how much of the plane’s total kinetic energy went into doing structural damage. How can that energy be computed without knowing distribution of mass data which had to include the floor assemblies. psik ---
**Author:** ![tomndebb](https://avatars.discourse-cdn.com/v4/letter/t/b9e5f3/32.png) [@tomndebb](https://boards.straightdope.com/u/tomndebb)\ **Post date:** [September 26, 2010, 1:44am UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/375 "2010-09-26T01:44:15Z")
**TWEEET!** There will be no more accusation or imputations of trolling. If anyone feels that it is necessary to make (or imply) such an accusation, be prepared to receive a Warning. Dealing with True Believers and CT proponents can be frustrating, but that frustration does not abrogate the rules of the forum. Given that none of the CT adherents appear to be persuading anyone to accept their weird claims, there is no major need to engage them to fight ignorance. (It can be fun, but it is not necessary.) If the frustration gets too much, simply walk away from the thread. **[/Moderating]** ---
**Author:** ![Mozart1220](https://avatars.discourse-cdn.com/v4/letter/m/f1d935/32.png) [@Mozart1220](https://boards.straightdope.com/u/Mozart1220)\ **Post date:** [September 26, 2010, 4:52am UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/376 "2010-09-26T04:52:43Z")
> [@Fear\_Itself](#): > > > [@Mozart1220](#): > > > > THat’s kinda what I’m saying here. Steel buildings DO NOT collpase due to fire. > > That is significant only if you can show comparable skyscraper fires that did not collapse. Otherwise, meh. > > \*\*\*Define “comparable”. \*\*\* > > Irrelevant. They don’t need to melt, just get hot enough to weaken the steel. Gravity does the rest. > > \*\*\*What about the 100 floors that were not “weakened”? \*\*\* > > > [@](#): > > > > And the straight down thing was pretty strange. > > No, falling like a tree would be strange. Straight down is fully consistent with gravity. \*\*\*Not when the area above the damage tilted sideways and then straightened it’s self out. Gravity wouldn’t do that. \*\*\* ---
**Author:** ![Magiver](https://avatars.discourse-cdn.com/v4/letter/m/4491bb/32.png) [@Magiver](https://boards.straightdope.com/u/Magiver)\ **Post date:** [September 26, 2010, 6:02am UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/377 "2010-09-26T06:02:51Z")
> [@psikeyhackr](#): > > > [@Magiver](#): > > > > Lets see yo provide a reason to know the exact weight of the floors. . > > Here is a quote from the NCSTAR1 report > > > [@](#): > > > > 2.4.3 Single Impulse Excitations > > Accurate estimation of the tower’s motion during the airplane impact required detailed knowledge of the geometry, weight distribution, and impact velocity of the aircraft, as well as **detailed knowledge of the geometry, weight distribution, and structural strength of the tower**. At the time of this test series (fall 2003), much of this information was unknown, and the impact motion could only be roughly estimated. To allow this estimate to be made quickly, many simplifying assumptions were made regarding the nature of the impact. > > [World Trade Center Investigation | NIST](http://wtc.nist.gov/NISTNCSTAR1-5D.pdf) page 74 > > That link doesn’t work anymore though. > > It’s in here: [World Trade Center Investigation | NIST](http://wtc.nist.gov/NCSTAR1/NCSTAR1-5index.htm) > > I extrapolated that the south tower moved 15 inches at the level where the plane impacted. The NIST report says it deflected 12 inches at the 70th floor 130 feet below the impact point. So how much of the planes kinetic energy went into deflecting the building? Did that energy do structural damage or was it just absorbed like the wind would be. So how much of the plane’s total kinetic energy went into doing structural damage. > > How can that energy be computed without knowing distribution of mass data which had to include the floor assemblies. > > psik The energy is calculated based on the best information that was available at the time. Whether the building moved 12 inches or 15 inches as you suggest has no bearing on the subject. Clearly the planes damaged the buildings setting them on fire. The floor joists sagged pulling the support columns inward where they failed under load. What are you contesting? ---
**Author:** ![tomndebb](https://avatars.discourse-cdn.com/v4/letter/t/b9e5f3/32.png) [@tomndebb](https://boards.straightdope.com/u/tomndebb)\ **Post date:** [September 26, 2010, 6:12am UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/378 "2010-09-26T06:12:11Z")
> [@Mozart1220](#): > > \*\*\*Not when the area above the damage tilted sideways and then straightened it’s self out. Gravity wouldn’t do that. \*\*\* Sorry. Posting that opinion in bold does not make it more true. First, it might not have been “gravity” that caused the descending upper floors to wobble–because that is all that we’re decribing, a wobble. The top did not lean over 45°, then right itself. It simply leaned a bit one way, then began to lean another during the collapse. Any number of factors might have caused that, such as the shift putting more burden on vertical members on the “stretched” side, causing them to collapse faster and pull the falling structure back to a more vertical stance. Gravity would be one aspect of the action, but other events would also play a part. And, in any event, a wobbling top is not “explained” by any odd claims of “demolition” or “thermite” or any other spurious claims, either. As to your other points: A “comparable” skyscraper would be one that used the same design features of a central core of support and a separate “tube” structure of the perimeter. That was a radical design in the late 1960s that has not been included in any other skyscraper that has burned. The other skyscrapers that have burned have used a more traditional framework of a series of interconnected cages. And several of them have been built of steel-reinforced concrete rather than simply steel, so that the steel was protected from the heat by the concrete. That is why “comparable” is relevant. The “100 floors” that were not weakened by fire were subjected to the impact of having the massive weight of the floors above them striking them. Just as one can carefully stand on a beer can or cardboard box and have it support one, but if one jumps on that same beer can or box, it will collapse. ---
**Author:** ![Ale](https://avatars.discourse-cdn.com/v4/letter/a/f19dbf/32.png) [@Ale](https://boards.straightdope.com/u/Ale)\ **Post date:** [September 26, 2010, 6:53am UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/379 "2010-09-26T06:53:42Z")
> [@Mozart1220](#): > > \*\*\*Not when the area above the damage tilted sideways and then straightened it’s self out. Gravity wouldn’t do that. \*\*\* Oh, I’ll bite, what other “force” “straightened out” the top floors then? Extra points if you can link it to Silverstein operating a tractor beam from his secret Moon base. ---
**Author:** ![psikeyhackr](https://avatars.discourse-cdn.com/v4/letter/p/97f17d/32.png) [@psikeyhackr](https://boards.straightdope.com/u/psikeyhackr)\ **Post date:** [September 26, 2010, 7:19pm UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/380 "2010-09-26T19:19:16Z")
> [@Magiver](#): > > The energy is calculated based on the best information that was available at the time. Whether the building moved 12 inches or 15 inches as you suggest has no bearing on the subject. > > Clearly the planes damaged the buildings setting them on fire. The floor joists sagged pulling the support columns inward where they failed under load. > > What are you contesting? One floor slab weighed 600 tons and the NIST admits the building move 12 inches 130 feet below the impact so it had to move more at the impact. So there were 10 floor slabs in that distance It takes energy to move 6000 tons in less than 2 seconds but you dismiss and ask what am I contesting. LOL :smack: psik ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [September 26, 2010, 7:41pm UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/381 "2010-09-26T19:41:39Z")
> [@psikeyhackr](#): > > One floor slab weighed 600 tons and the NIST admits the building move 12 inches 130 feet below the impact so it had to move more at the impact. So there were 10 floor slabs in that distance > > It takes energy to move 6000 tons in less than 2 seconds but you dismiss and ask what am I contesting. Yes, it is hard to explain that movement in the absence of a large plane traveling at 600MPH and exploding on impact. Good thing there was one, or the engineers would really be puzzled. [Previous page](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541.md?page=18) [Next page](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541.md?page=20)