# 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:** 7
**Author:** ![JohnT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnt/32/15048_2.png) [@JohnT](https://boards.straightdope.com/u/JohnT)\ **Post date:** [September 19, 2010, 2:37pm UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/121 "2010-09-19T14:37:32Z")
The flames in the photo linked by **Mr. Miskatonic** can hardly be described as “dying”, Mozart. ---
**Author:** ![x-ray\_vision](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/x-ray_vision/32/351_2.png) [@x-ray\_vision](https://boards.straightdope.com/u/x-ray_vision)\ **Post date:** [September 19, 2010, 2:38pm UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/122 "2010-09-19T14:38:30Z")
> [@Contrapuntal](#): > > > [@Stranger\_On\_A\_Train](#): > > > > In fact, the reason airline passengers are instructed to turn off phones isn’t that they’ll interfere with aircraft communications (which are not only much higher signal power but also on a completely different frequency band) but because rapid switching between cells tasks cellular networks. > > > [@xtisme](#): > > > > The FAA doesn’t want you to use your phones on a plane, not because they won’t work but because there is a small chance it will interfere with the planes instrumentation. > > Does anyone have a cite for which of these is true? Or are they both true (communication vs. instrumentation)? The FCC banned having cell phones on in flight because of possible disruption to the cell systems’ towers because of channel reuse and the FAA has banned in flight use (but gives the airline the power to make an exception to this rule if the operator deems that device safe) because of possible issues with aircraft systems or computers that could cause aircraft failure and passenger deaths. > **[Mobile phones on aircraft](https://en.wikipedia.org/wiki/Mobile_phones_on_aircraft)** > > In the U.S., the Federal Communications Commission (FCC) regulations prohibit the use of mobile phones aboard aircraft in flight. Contrary to popular misconception, the Federal Aviation Administration (FAA) does not actually prohibit the use of personal electronic devices (including cell phones) on aircraft. Paragraph (b)(5) of 14 CFR 91.21 permits airlines to determine if devices can be used in flight, allowing use of "any other portable electronic device that the operator of the aircraft has In... ---
**Author:** ![Mr.Miskatonic](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mr.miskatonic/32/310_2.png) [@Mr.Miskatonic](https://boards.straightdope.com/u/Mr.Miskatonic)\ **Post date:** [September 19, 2010, 4:04pm UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/123 "2010-09-19T16:04:43Z")
> [@Mozart1220](#): > > Ever try breathing the smoke from a dying fire? I have when an apartment below me burned and I had to stand in lne to get to the window fire escape. It’s terrifying. We were on the 4th floor and I was actually thinking of taking my chances at the other window. But you didn’t did you? And you were probably considering that it was only 4 floors and not certain death. Most people pass out from smoke exposure before they get to a suicidal stage. Not so with fire - there is no passing out there. > [@](#): > > And “barely burning” is reletive. Did you look at the photo I posted?! > [@](#): > > What is a horrible thing to a human being is not much of a problem for steal and concrete. Steel is actually very bad in fires. That is why they fireproof it. If a human can’t get away from the fires and chooses to jump then there is going to be trouble with an unprotected steel structure. Concrete is much, much better in fires, but there was no structural concrete elements in any of the three tower. ---
**Author:** ![psikeyhackr](https://avatars.discourse-cdn.com/v4/letter/p/97f17d/32.png) [@psikeyhackr](https://boards.straightdope.com/u/psikeyhackr)\ **Post date:** [September 19, 2010, 6:16pm UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/124 "2010-09-19T18:16:13Z")
> [@Magiver](#): > > It doesn’t take a Harvard degree to understand what happened with the WTC buildings. The floor joists sagged because of the heat of the fire. [THIS](http://www.google.com/imgres?imgurl=http://www.tms.org/pubs/journals/JOM/0112/Eagar/fig5.gif&imgrefurl=http://www.tms.org/pubs/journals/jom/0112/eagar/eagar-0112.html&h=321&w=600&sz=12&tbnid=t6Md_MdD_rqSpM:&tbnh=72&tbnw=135&prev=/images%3Fq%3Dfloor%2Bjoist,world%2Btrade%2Bcenter,picture&zoom=1&q=floor+joist,world+trade+center,picture&usg=__Mah4RYtoysJejkMFlghoGDr1aXk=&sa=X&ei=jZOVTPaPBuSQnwfy0dHKBw&ved=0CB8Q9QEwAw) is what a floor joist looks like. It’s not a massive steel beam. It’s not designed to carry the weight of the building. The joists serve 2 functions, to carry the weight of the floor, and to connect the outer and inner columns together so they maintain a vertical stance. As you can see from the picture we aren’t talking about tons of steel being heated, we’re talking about pounds of steel. The floor joists sagged in the fire, they didn’t fail entirely, they sagged. The sagging floor pulled the outer walls inward and they snapped under the tremendous weight from above. That is one UNSUBSTANTIATED CLAIM but the NCSTAR1 report says that the core supported 53% of the weight and the perimeter 47%. How was the core destroyed? We are not told the amount of steel in the core and in the perimeter on every level. The core was held together by horizontal beams. We are not supplied with information about those beams either. So how could that much mass come down in less than 18 seconds? Regardless of what started the collapse how could the top falling portion force that much mass down that quickly? Oh yeah, we aren’t told the distribution of mass. [![](https://i.ytimg.com/vi/caATBZEKL4c/hqdefault.jpg?sqp=-oaymwEmCOADEOgC8quKqQMa8AEB-AHeAoAC8AGKAgwIABABGGUgVihLMA8=&rs=AOn4CLD2Q6U_x6g4lAMHx50P-v7cDaPRdg "Gravitational Collapse onto Cumulative Supports") ](https://www.youtube.com/watch?v=caATBZEKL4c) People that **BELIEVE** don’t need data. It’s the 9/11 Religion! psik ---
**Author:** ![psikeyhackr](https://avatars.discourse-cdn.com/v4/letter/p/97f17d/32.png) [@psikeyhackr](https://boards.straightdope.com/u/psikeyhackr)\ **Post date:** [September 19, 2010, 6:20pm UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/125 "2010-09-19T18:20:21Z")
> [@Bryan\_Ekers](#): > > > [@psikeyhackr](#): > > > > But then there was the FIRE. So there were 10,000 gallons of jet fuel sometimes known as kerosene. If you could burn that with 100% efficiency, which cannot happen in an open air fire, you will only get so much energy. If you could put all of that energy into 1 ton of steel at 75 deg F it will raise the temperature to some specific level. But if you put it into 10 tons it will raise it to a lower temperature and if 100 tons then much lower still. So talking about the fire weakening the steel without talking about the QUANTITY OF STEEL is nonsense. > > This is why nobody of any reasoning skills takes you guys seriously. It wasn’t the fuel alone that kept the fire burning, it was a significant amount of furniture and carpeting and whatnot that was set ablaze and accelerated by the fuel. > > But go ahead and ignore that if it’ll keep your little theory on life support. So you are saying what was burning eliminates the need to know the quantity of steel to get an idea if it could weaken enough to make the buildings completely collapse in less than TWO HOURS? psik ---
**Author:** ![Magiver](https://avatars.discourse-cdn.com/v4/letter/m/4491bb/32.png) [@Magiver](https://boards.straightdope.com/u/Magiver)\ **Post date:** [September 19, 2010, 7:04pm UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/126 "2010-09-19T19:04:42Z")
> [@psikeyhackr](#): > > That is one UNSUBSTANTIATED CLAIM but the NCSTAR1 report says that the core supported 53% of the weight and the perimeter 47%. It’s not an unsubstantiated claim, that is what engineers determined happened and not some moron with paper, washers and a camera. > [@psikeyhackr](#): > > How was the core destroyed? We are not told the amount of steel in the core and in the perimeter on every level. The core was held together by horizontal beams. We are not supplied with information about those beams either. So how could that much mass come down in less than 18 seconds? There is no WE in this, it’s you. The core is a series of vertical pillars just like the outer structure. The joists between them is what gives the building stability. It is a different engineering concept than the Empire State Building. We don’t need to know the amount of steel in the core to understand that the trusses are the weak point in a fire. We don’t need to know the amount of steel to know the upper floors represented a substantial amount of weight and when dropped 12 ft it is a tremendous amount of kinetic energy to impart on the next floor which is already structurally weakened. The videos clearly show this process. > [@psikeyhackr](#): > > Regardless of what started the collapse how could the top falling portion force that much mass down that quickly? Oh yeah, we aren’t told the distribution of mass. > > [http://www.youtube.com/watch?v=caATBZEKL4c](http://www.youtube.com/watch?v=caATBZEKL4c) > > People that **BELIEVE** don’t need data. > > It’s the 9/11 Religion! > > psik There’s a religion all right and it takes a tremendous amount of faith to believe that the buildings were sabotaged at the exact location of each airplane impact. ---
**Author:** ![tomndebb](https://avatars.discourse-cdn.com/v4/letter/t/b9e5f3/32.png) [@tomndebb](https://boards.straightdope.com/u/tomndebb)\ **Post date:** [September 19, 2010, 7:17pm UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/127 "2010-09-19T19:17:31Z")
> [@psikeyhackr](#): > > People that **BELIEVE** don’t need data. > > It’s the 9/11 Religion! This should be your sig–as long as it is self-referential. 😃 ---
**Author:** ![Cisco](https://avatars.discourse-cdn.com/v4/letter/c/ccd318/32.png) [@Cisco](https://boards.straightdope.com/u/Cisco)\ **Post date:** [September 19, 2010, 7:26pm UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/128 "2010-09-19T19:26:49Z")
> [@psikeyhackr](#): > > So how could that much mass come down in less than 18 seconds? > > Regardless of what started the collapse how could the top falling portion force that much mass down that quickly? Wait, you think more massive objects fall more slowly? We might have just diagnosed your problem. ---
**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 19, 2010, 8:08pm UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/129 "2010-09-19T20:08:36Z")
> [@psikeyhackr](#): > > > [@Bryan\_Ekers](#): > > > > This is why nobody of any reasoning skills takes you guys seriously. It wasn’t the fuel alone that kept the fire burning, it was a significant amount of furniture and carpeting and whatnot that was set ablaze and accelerated by the fuel. > > > > But go ahead and ignore that if it’ll keep your little theory on life support. > > So you are saying what was burning eliminates the need to know the quantity of steel to get an idea if it could weaken enough to make the buildings completely collapse in less than TWO HOURS? Here we go with the [“quantity of steel” shit](http://boards.straightdope.com/sdmb/showthread.php?p=11329071) again. ---
**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 19, 2010, 8:16pm UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/130 "2010-09-19T20:16:12Z")
> [@I\_Love\_Me\_Vol.I](#): > > > [@Mozart1220](#): > > > > The buildings were designed to withstand airpcraft impacts > > And yet, sadly, they did not. Technically, they did; it was the fires–which had not been taken into consideration–that brought them down. ---
**Author:** ![Magiver](https://avatars.discourse-cdn.com/v4/letter/m/4491bb/32.png) [@Magiver](https://boards.straightdope.com/u/Magiver)\ **Post date:** [September 19, 2010, 8:51pm UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/131 "2010-09-19T20:51:31Z")
> [@Lute Skywatcher](#): > > > [@I\_Love\_Me\_Vol.I](#): > > > > And yet, sadly, they did not. > > Technically, they did; it was the fires–which had not been taken into consideration–that brought them down. The impact was taken into consideration (at least for a DC8 sized plane) and the fire was taken into consideration (steel structure insulated) but the 2 weren’t connected. Loss of insulation was key to what happened. The Empire State building was hit by a WWII bomber filled with gasoline. It’s steel structure was covered in cement so no loss of insulation occurred. ---
**Author:** ![Cisco](https://avatars.discourse-cdn.com/v4/letter/c/ccd318/32.png) [@Cisco](https://boards.straightdope.com/u/Cisco)\ **Post date:** [September 19, 2010, 8:58pm UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/132 "2010-09-19T20:58:09Z")
> [@Magiver](#): > > Loss of insulation was key to what happened. Combined with the severing of the fire suppressant system. ---
**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 19, 2010, 9:19pm UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/133 "2010-09-19T21:19:30Z")
> [@Magiver](#): > > > [@Lute Skywatcher](#): > > > > Technically, they did; it was the fires–which had not been taken into consideration–that brought them down. > > The impact was taken into consideration (at least for a DC8 sized plane) and the fire was taken into consideration (steel structure insulated) but the 2 weren’t connected. I was referring to the designer’s statement that the fuel load after impact wasn’t taken into consideration. ---
**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 19, 2010, 9:26pm UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/134 "2010-09-19T21:26:47Z")
[Engineer](http://boards.straightdope.com/sdmb/showthread.php?p=12723565), sorry. ---
**Author:** ![Bryan\_Ekers](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bryan_ekers/32/183_2.png) [@Bryan\_Ekers](https://boards.straightdope.com/u/Bryan_Ekers)\ **Post date:** [September 19, 2010, 10:23pm UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/135 "2010-09-19T22:23:34Z")
> [@psikeyhackr](#): > > > [@Bryan\_Ekers](#): > > > > This is why nobody of any reasoning skills takes you guys seriously. It wasn’t the fuel alone that kept the fire burning, it was a significant amount of furniture and carpeting and whatnot that was set ablaze and accelerated by the fuel. > > > > But go ahead and ignore that if it’ll keep your little theory on life support. > > So you are saying what was burning eliminates the need to know the quantity of steel to get an idea if it could weaken enough to make the buildings completely collapse in less than TWO HOURS? > > psik I wasn’t saying anything about the quantity of steel, but if I _were_ going to say something along those lines, I’d express my doubts that even if a figure was presented to you, it would make the slightest difference. ---
**Author:** ![psikeyhackr](https://avatars.discourse-cdn.com/v4/letter/p/97f17d/32.png) [@psikeyhackr](https://boards.straightdope.com/u/psikeyhackr)\ **Post date:** [September 20, 2010, 12:02am UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/136 "2010-09-20T00:02:27Z")
> [@Bryan\_Ekers](#): > > I wasn’t saying anything about the quantity of steel, but if I _were_ going to say something along those lines, I’d express my doubts that even if a figure was presented to you, it would make the slightest difference. So you change the subject from physics to psychoanalysis to accomplish what? The nation that put men on the Moon can’t tell the entire world the tons of steel and tons of concrete that were on every level of the towers. But everyone is supposed to believe that airliners could TOTALLY destroy structures **TWO THOUSAND TIMES THEIR MASS** in less than TWO HOURS even though skyscrapers cannot stand and withstand the wind without getting those design characteristics correct. But Richard Gage and his buddies won’t bring up the subject either. How much computing power should they have compared to what was available in the early 60s when the WTC was designed? It didn’t take NINE YEARS to design or construct the towers. His dog and pony show is just silly propaganda instead of trying to get people to actually understand anything. psik ---
**Author:** ![psikeyhackr](https://avatars.discourse-cdn.com/v4/letter/p/97f17d/32.png) [@psikeyhackr](https://boards.straightdope.com/u/psikeyhackr)\ **Post date:** [September 20, 2010, 12:05am UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/137 "2010-09-20T00:05:40Z")
> [@Lute Skywatcher](#): > > Here we go with the [“quantity of steel” shit](http://boards.straightdope.com/sdmb/showthread.php?p=11329071) again. Oh sorry! I forgot that was irrelevant to getting skyscrapers to hold themselves up. 😃 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 20, 2010, 12:27am UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/138 "2010-09-20T00:27:40Z")
Trying to get warned for trolling again? ---
**Author:** ![Raygun99](https://avatars.discourse-cdn.com/v4/letter/r/6f9a4e/32.png) [@Raygun99](https://boards.straightdope.com/u/Raygun99)\ **Post date:** [September 20, 2010, 12:56am UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/139 "2010-09-20T00:56:57Z")
> [@psikeyhackr](#): > > The nation that put men on the Moon can’t tell the entire world the tons of steel and tons of concrete that were on every level of the towers. But everyone is supposed to believe that airliners could TOTALLY destroy structures **TWO THOUSAND TIMES THEIR MASS** in less than TWO HOURS even though skyscrapers cannot stand and withstand the wind without getting those design characteristics correct. No one says the impact was the reason the towers collapsed, because it wasn’t. The towers did withstand the impact of the airplanes. If there had not been subsequent fires, that would have been the extent of the damage. The “skyscrapers are not Jenga blocks” analogy comes into relevance again here. ---
**Author:** ![tomndebb](https://avatars.discourse-cdn.com/v4/letter/t/b9e5f3/32.png) [@tomndebb](https://boards.straightdope.com/u/tomndebb)\ **Post date:** [September 20, 2010, 12:57am UTC](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541/140 "2010-09-20T00:57:39Z")
> [@psikeyhackr](#): > > So you change the subject from physics to psychoanalysis to accomplish what? He did not mention psychoanalysis. Do you have some reason to believe that your psychological state was being questioned? His point was that you have had all this explained on numerous occasions and you always hand-wave away every bit of evidence that is presented. That is a legitimate observation. > [@psikeyhackr](#): > > The nation that put men on the Moon can’t tell the entire world the tons of steel and tons of concrete that were on every level of the towers. But everyone is supposed to believe that airliners could TOTALLY destroy structures **TWO THOUSAND TIMES THEIR MASS** in less than TWO HOURS even though skyscrapers cannot stand and withstand the wind without getting those design characteristics correct. Why do you keep repeating this nonsense? We know how much steel and concrete was used, even if you cannot be bothered to simply look it up. How can you make a claim that the buildings were two thousand times the mass of the airplanes if you really don’t know what went into the buildings? Either you know and you are pretending to not know or you are making up your claim regarding the masses involved. Your claim that the disparate masses between the planes and the buildings has anything to do with anything, given that you need to ignore the fire to make that claim, has all the signs of trolling. It is rather like claiming that a 1500 lb. torpedo is incapable of destroying a 30,000 ton ship. [Previous page](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541.md?page=6) [Next page](https://boards.straightdope.com/t/skyscrapers-on-fire-not-collapsing/553541.md?page=8)