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4th April 2016, 02:28 PM | #241 |
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4th April 2016, 02:32 PM | #242 |
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4th April 2016, 02:37 PM | #243 |
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4th April 2016, 02:43 PM | #244 |
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4th April 2016, 02:46 PM | #245 |
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4th April 2016, 02:59 PM | #246 |
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FTFY to be more precise.
The floors came straight down while they pancaked. That's what I call the collapse front. Approximately. It's the trail of dust of a free-falling cluster of panels. There were several like that. Nothing special about it, even if Chandler claims this is proof they had rockets or some nonsense like that. Those who have measured the speed of that collapse front say that it reached a constant speed (zero acceleration). I attribute that to air compression (air friction, cushioning) causing a terminal velocity. With constant velocity, the expected air pressure is the same. Robert McCoy, ex-AE911T panel member, said he expected to see exactly that kind of ejections in a pancake collapse. He didn't see them, but that speaks poorly of his capacity for watching the collapse, because obviously they were there: Now we have the mass of that building from up above coming down, in strong... you know, it's going to begin to impact the whole building as it comes, as everyone has described. But it's going to come down in a pancake fashion, in a staccato kind of a way, bang bang bang bang bang as it comes. It's not going to come as a smooth fall. You're going to see puffs of pulverizing concrete, each time a floor or a series of floors hits another floor. I didn't see that.https://www.youtube.com/watch?v=sfgXDnn8V_I It's also pretty obvious that the ejected dust is not the majority of the concrete in pulverized form. The volume hardly justifies that, and the density is clearly low (otherwise it would fall much faster, if not at free fall). Dust is produced when concrete is fractured, then said dust is ejected. You can see it in this still from the moment of the collapse (due to fire) of the TU Delft building: And in this demolition: https://www.youtube.com/watch?v=8qKIikDcDII (around second 17). You're not claiming that the majority of the concrete in these floors went out the windows, are you? Dust is also produced when gypsum board is crushed, and when fireproofing is dislodged. |
4th April 2016, 03:39 PM | #247 |
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The proof that no special consideration was given to a fire started by a fuel-loaded plane is that there was nothing special in the fire systems and fireproofing used: They were just "to code," which was based on a normal office fire.
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4th April 2016, 03:40 PM | #248 | |||
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Take a look at the street on the :30 mark in this video. This is after impact, before collapse. Most of the dust you see there would be fireproofing.
Fireproofing is by far the most fragile when compared to concrete or drywall you can crush it into dust with your bare hand. The concrete is also covered on one side by steel floor pans and carpet or vinyl on the other. The drywall is also covered both sides by paper and or vinyl. This would act to contain a portion of the dust. If you watch video of the impact you will see a column of what looks like smoke that falls to the ground and just lays there. My opinion is most of what you see below the red arrows is fire proofing. You also need to add fire proofing to this list. If you look at the photo below and imagine what happens when the mass above crashes on to this floor. Most of that fire proofing is going to come off, mix with the air, and be carried out the windows with it. Also remember that all those red grey chips that Jones found in all the samples, is in reality buried underneath the fire proofing on those trusses. If the chips were scattered all across the city, the fire proofing that covered them had to be too. |
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4th April 2016, 04:49 PM | #249 |
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4th April 2016, 05:37 PM | #250 |
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Steel is used because it is strong and, all things considered, cheap. In developed countries, reinforced concrete is more expensive because of labor costs. In 3rd world countries, lower labor costs make reinforced concrete cheaper than steel. So ironically, 3rd world countries have an edge in fire safety.
In developed countries, builders compensate for the relative vulnerability of steel by (1) passive means (applying insulation), (2) automatic means (sprinkler systems) and (3) active means (firefighting). 90 West St. burned for days, but survived. It had absolutely outstanding passive fire resistance, and the fire was fought. In the Twin Towers, (3) was not possible, and 1 and 2 were knocked out by the airliner impacts. But at least you got one of the three. You're making progress, of a sort. |
4th April 2016, 08:33 PM | #251 |
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4th April 2016, 08:54 PM | #252 |
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Still utilizing the LOGICAL FALLACY of shifting the burden of proof, I see.
DGM simply asked you for your source of your claim. Can you provide support for your claim? It appears not, as you're once again asking for others to disprove your assertions instead of you providing any proof of those assertions. Why should anyone take your assertions seriously, given that history?
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I have never ”refused” to provide evidence. I provide evidence if requested to do so in a specific and relevant manner. Hanks ”method” [of requesting evidence] is not going to [get me to] provide any evidence since it has a completely different purpose. To create the the illusion of me not providing evidence when requested to do so. - Manifesto |
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4th April 2016, 09:29 PM | #253 |
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5th April 2016, 03:58 AM | #254 |
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FF has got this wrong almost every time. His disbelief and lack / limit of understanding of physics and engineering drive his disbelief and so he demands others prove what is essentially settled science and engineering to him on his level. He and most truth guys refuse to learn or understand and rely on false notions of how these things work. So you get block mechanics as demonstrations of what they see as applying physics and engineering.
For example... truth guys cannot understand how collapses create dust from most building materials... dust which can be carried aloft and leaves no recognizable "thing" post collapse. Where are all the telephones and toilets and computers?... and so on. NB that the top down collapses of the twins produced the same sort of "dust" as the bottom up destruction of 7wtc. Take away is that hundreds of thousands of tons of collapsing building materials can be equally destructive... crushing up or crushing down. |
5th April 2016, 04:25 AM | #255 |
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5th April 2016, 04:30 AM | #256 |
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I do understand that collapses can create dust - lots of it. You can clearly see the massive amounts of dust in collapses of any type. Dust is not proof that anything is wrong with the official story.
The issue is not dust. The issue is massive amounts of pulverized building contents being ejected laterally at a near constant rate. What is causing this? You claim the upper mass is causing this. Newton disagrees. I disagree based on what Newton is telling me. I don't reject your argument because I want to. I reject it because it does not conform to basic physics. The laws of physics tell us what happened. Your explanation is based on failed support columns, fire, poor engineering, etc. I don't deny that those issues could cause a building to collapse. They can, without a doubt. The issue is how the building collapsed, not what caused the collapse. That is a huge fact that skeptics refuse to accept. Cause is not the issue. The actual collapse, and what is observed during the collapse, are the issues. |
5th April 2016, 04:50 AM | #257 |
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A building is only as strong as the connections, parts that hold it together, FF, take those away and the building becomes a set of disunited parts, connections can not be made perfect and welds and bolts are never as strong as the steel they join.
A pin from a Bell saw tree cutter. |
5th April 2016, 05:53 AM | #258 |
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Ummmmmm,.... no. Just no.
While this metaphor is not new, it bears repeating; A box of matches falls off a table, spreading its contents all over the floor. The investigator wants to know why the box fell off the table. The conspiracy theorist wants to know why each match ended up where it did. You FF, are firmly in that second camp. Once collapse initiation began, collapse progression was inevitable and there was nothing going to stop it. Everything that happened after collapse initiation is simply a product of the chaos of collapse. What maters then, really the only thing that matters is what initiated the collapse. And we certainly do not need to discuss things that did not happen in the collapse progression phase, like lateral ejection of building components. The situation gets confused enough without bringing in stuff that didn't happen. |
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5th April 2016, 05:56 AM | #259 |
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Since dust and pulverized building contents are precisely the same thing in this context, and you are clearly stating that "massive amounts" are expected to be created in any collapse, is it therefore your claim that the issue is that these fully expected massive amounts of dust are being ejected "laterally at a near constant rate," and that this disagrees with Newton's laws?
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5th April 2016, 05:58 AM | #260 |
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You have been informed that studies have been done that show the collapse front reached a constant velocity. Why then is ejections at a constant rate, remarkable.
wrt what is being ejected, how do you arrive at the conclusion that it is significant, and exactly what is significant about it? You say cause of collapse is not the issue. Good to know. You just want to know the mechanism by which it did so. One question though, what's the difference between the cause of collapse, and how it collapsed? That said, if you read the OP and the subsequent revisions, you will see how the majority of us understand the collapse. Odd, you haven't ever referenced the OP or the revisions. |
5th April 2016, 06:02 AM | #261 |
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5th April 2016, 11:12 AM | #262 |
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5th April 2016, 11:39 AM | #263 |
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As promised.
Revision 3: Generic Description of the Collapse Progression of the Two WTC Towers: Video evidence demonstrates aircraft impact destroyed or bent a number of perimeter columns. A lesser amount of core column severance or damage is expected. Some floor spans also directly damaged. Aircraft fuel spread through several vertically adjacent floors of the structure and ignited. This created a condition of very large area office contents fire on those floors with various levels of "rubblization" of the contents. This is a fire condition well beyond design expectations for fire spread. Office fires are expected to usually begin small, in a waste basket, or an electrical fault in a device or circuit, for instance. Aircraft impact debrided spray on fire insulation in varying degree, on a significant number of structural components on impact floors. This reduced fire resistance of those structural steel components. Structural response to impact was a redistribution of loads previously carried by missing or foreshortened ( due to being bent) columns. Load redistribution was not even across all remaining columns. Fire spread and movement was similar, but not identical, on each involved level and also spread to higher levels. Heat began affecting steel structural components, both vertical and horizontal, and the connecting components between them on all fire involved levels. Floor spans had long trusses with their lower chords exposed to the heat and the trusses in several areas began sagging. A few areas had already seen truss or truss to perimeter connection failure at impact. Perimeter columns and truss to perimeter connecting components heated less than the core columns and truss to core structure components. The interface between long span trusses and core was a belt truss rather than direct connection to core columns. Core columns are subject to heating basically from all sides, over the several floors fully involved in the fires, and over the course of fire spread around each level. ( that is to say a column at level x may heat more on one face than that same column at level x-1 or x+1 but that over the several levels involved some columns are heated on all sides and taking into account the changes through time) The capability of the structure to resist any collapse was being eroded. One very obvious indication of this is the inward bowing of part of the perimeter. Each tower also twisted and tilted noticeably up to collapse. These demonstrate that the structure was responding to further weakening due to the heat. Loads were continually changing and redistributing during this time. At some point a redistribution caused one or more columns to exceed its capacity. Column capacity in this case does not necessarily mean it original engineered load bearing ability. Loads were not necessarily on axis (due to impact or heat unduced creep, or expanding floor beams) and many columns were subjected to significant heating, both of which would tend to lower any individual column's strength. At one point a rapud progression of column failures occurs. A column or columns fail and in redistributing the load, cause other columns to exceed capacity, causing another rapid load shift. Column failures rapidly progressed to all columns over one or more levels With all columns now having failed over one or more adjacent levels, a large section of the upper building is now falling, accelerating through approximately the distqnce of one level, to next contact. A combination of factors result in few, if any, buckled columns impacting on lower parts of themselves. Upper falling section column ends are, in many locations, the first contacts with lower structure. That contact would be proximate to the lower section columns and thus the greatest impact occurs near or directly on lower floor truss to column connecting components immediately failing the lateral support provided by those trusses. This is occurring both to long span truss to column connecting components, at perimeter and belt truss, as well as with the core's beams running between core columns. As upper mass continues its lowest floor begins contacting floorspace below the initial failure level. This first contact is between floor systems that are already severely compromised. They are among those that have been affected by impact and heat and one has suffered loss of connections to columns as per last paragraph. With columns largely being bypassed by the vast majority of falling upper section, they contribue very little in opposing collapse. Concrete floor pans shatter. Both upper structure and lower structure now have major connection failures, both in the vertical/horizontal connections as well as connections between column sections. The later is due to both the destruction of lateral support and the buffeting collisions from the falling mass. Perimeter column "trees" peel away, the first to do so are on the order of 1000 feet above ground as they pivot away. Collapse continues with a relatively small amount of falling mass being ejected at the collision interface. Since initial contact was an order of magnitude greater than that which the long span open floors could absorb, little effect is seen on the falling mass. This means that the still intact portion of upper mass will continue to accelerate. Further contact of falling upper mass with lower structure will have mutual destruction of both. As collapse continues lower levels will be impacted by more mass , albeit more rubblized, that is necessarily moving faster than first contact. Those floor spans must also be hit by an order of magnitude greater load than they can withstand, and indeed greater than at that earlier, first contact impact. There existed no mechanism by which this floor pan, truss and perimeter peel, destruction could be arrested as this continues. The core area beam destruction may well have lagged that of the long span destruction since those beams are heavier and shorter. Evidence for this is the so called "spire" of core structure that existed momentarily after the rest of one tower had fully collapsed. Perimeter peel necessarily lags long span destruction as it is a direct result of that long span truss destruction. Core columns stripped of inter-core lateral support succumb to a combination of slender column buckling and heavy buffeting from falling debris. A relatively small, heavily damaged, portion of the core remains after long span floor and perimeter destruction (no longer being buffeted by debris impact) but cannot remain intact and it comes apart as well |
5th April 2016, 02:16 PM | #264 |
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Not entirely correct. Each collision lessens ke, but during the fall to the next floor, ke is increased again by 1- increased mass, 2- velocity being increased due to fall through empty space. Your physics understanding is only valid for horizontal collisions, where gravity isn't increasing velocity between collisions. Think of it this way - coast your car into a series of moderately weak barriers and soon, the ke is "consumed". What happens if instead of coasting into the barriers, you are accelerating into the barriers, and keep your foot on the gas. You keep going until you're through all the barriers, right? |
5th April 2016, 02:23 PM | #265 |
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5th April 2016, 02:28 PM | #266 |
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5th April 2016, 02:32 PM | #267 |
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5th April 2016, 02:36 PM | #268 |
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5th April 2016, 02:47 PM | #269 |
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5th April 2016, 03:08 PM | #270 |
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Nope.
Won't work. Let me cite some history from my area of expertise, the JFK assassination. The assassin of JFK, Lee Harvey was shot and killed by Jack Ruby two days after Oswald assassinated Kennedy. He was buried on 11/25/63 in Rosehill Cemetary. Oswald's body was then exhumed in the early 1980s to verify it was truly Oswald in that grave and not an Oswald double, as some critics, specifically one Michael Eddowes, charged. The determination by experts was that, yes, it was Oswald. http://www.hourofthetime.com/1-LF/No...vey_Oswald.pdf That did NOTHING to quell that line of argument. Conspiracy theorists simply utilized the exhumation report, and some new decade-after-the-fact recollections by Oswald's embalmer to come up with new, inventive reasons to argue the report was wrong, and it really wasn't Oswald's body, and the Norton report was a coverup. Some JFK conspiracy theorists are now calling for JFK's body to be exhumed so we can verify what wounds he suffered. Guess what will happen there? Based on history, conspiracy theorists will fail to accept any report that says there was only one shot to the head, from behind, and will instead quote-mine the new report to argue that the body examined isn't JFK's... it's somebody else's! And in fact, a conspiracy theorist named Robert Morningstar has already argued for something similar - that a Dallas policeman that Oswald shot and killed that day in Dallas - J.D.Tippit - was actually the subject of the JFK autopsy. That is, Tippit was purposely murdered by conspirators to give them a body that wasn't JFK's that wouldn't reveal to the autopsists that JFK was shot from multiple directions. http://www.redicecreations.com/article.php?id=17710 So why would we expect anything different from a new investigation into the WTC attack? History already tells us the likely result: critics won't accept anything they disagree it, "Rubberstamp" charges will be heard, and the new report will simply be used as fodder for new arguments. Hank |
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I have never ”refused” to provide evidence. I provide evidence if requested to do so in a specific and relevant manner. Hanks ”method” [of requesting evidence] is not going to [get me to] provide any evidence since it has a completely different purpose. To create the the illusion of me not providing evidence when requested to do so. - Manifesto |
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5th April 2016, 03:29 PM | #271 |
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I have never ”refused” to provide evidence. I provide evidence if requested to do so in a specific and relevant manner. Hanks ”method” [of requesting evidence] is not going to [get me to] provide any evidence since it has a completely different purpose. To create the the illusion of me not providing evidence when requested to do so. - Manifesto |
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5th April 2016, 04:14 PM | #272 |
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Anybody can start a new investigation tomorrow morning if they really wanted to do so.
Some of the WTC material is still around, the WTC complex is open for business, and the FDNY and NYPD unions can help set up interviews with the men and women who were there. There are hundreds (?) of engineering firms out there who can run computer simulations for you at a reasonable fee. With them you can run every scenario possible and impossible and check the results. Anybody can do this. The true conspiracy is to revealed when one asks this question: With all of the money A&ETruth has raised over the years, they could have run 5 or 6 quality investigations...so why haven't they done so? It's been 15 years, enough time to earn a couple of PhDs in physics, engineering, and other cool things. If Truthers were serious about answers they would go out and get them, and not hang out on the internet misrepresenting other people's hard work. Truthers are not serious. To me, evaluating the collapses of any of the 3 WTC buildings would make a worthwhile Masters thesis for a structural engineering student. Why not make your obsession with 9-11 pay off with a good paying (inside) job? I can think of three engineers who did their homework on the Twin Towers, Osama bin Laden, Khalid Sheikh Mohamed, and Mohamed Atta, and they got results which makes them more productive and honest than Truthers. |
5th April 2016, 04:38 PM | #273 |
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5th April 2016, 04:43 PM | #274 |
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Not to mention that all those parts come with their own flaws, over torquing, under torquing, variance from specifications, damage etc which changes ever so slightly their load carrying capacity (high and lower) which makes it impossible to model in a computer accurately.
It is easy to design in a computer model.....everything is per spec......in real life not so much, hence the "factor of safety built into structural design. |
5th April 2016, 04:44 PM | #275 |
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6th April 2016, 03:07 AM | #276 |
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6th April 2016, 05:01 AM | #277 |
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I like the graphic... and notable is the disintegration of the upper portion "innards" before it descends. #4 #5 are the "beginning" of ROOSD... the so called "initiation".
Note that many believe that the facade buckled from load redistribution from the core. Your #5 (which I think is correct) suggests that the facade was not carrying redistributed OOS floor loads at all locations. The IB of the SE is explained by loss of bracing perhaps or something related to a local collapse of the floor system. |
6th April 2016, 01:38 PM | #278 |
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ozeco, JSO, you two were among the most contributory to the task I had in mind for the thread. Would you mind critiquing the latest (and possibly last) revision above (post 263), please.
gumboot, I love the graphic though. Mind If I repost the last revision of my summary and include your graphic? The plan of mine is to simply link to it anytime a truther asks what we/I believe happened. |
6th April 2016, 02:48 PM | #279 |
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Will do - saw the post. Time constraints in RL.
Take care - it is a good overall summary BUT if anyone reads detail into it the way JSO did in a recent comment - the sequence is not quite right. (e.g. probably the main issue I would watch - tilt came before drop) |
6th April 2016, 03:38 PM | #280 |
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