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23rd November 2015, 06:57 AM | #41 |
Penultimate Amazing
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Yours is a much better way to say what I said.
As far as undeniable by truthers though, Tony Sz does in fact deny it. He puts forth the completely unsubstantiated fantasy of explosives taking out the columns just a few floors below the roof to make it look like the column failed lower down. |
23rd November 2015, 07:40 AM | #42 |
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There is a bit of irony when there is talk of "column 79" failing because structures above it collapsed down.
Column 79 was supported on caissons and had several major beams/girders framed into it all the way down to floor 1. NIST posited a floor 13 failure, but the failure producing the same visuals could have just as easily have occurred lower down. So one can't deny that there was a column 79 failure because of the visuals... but one can't determine from the visuals how low down that failure actually occurred. The multi story vertical kink in the north facade tells us that it was likely much lower that the very top floors as Tony would have us believe. I am unaware of photos which show how far down the kink extended. That might be a clue. |
23rd November 2015, 07:54 AM | #43 |
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Tony , and a lot of truthers, completely ignore the north face 'kink' since it illustrates a problem with their 'all columns destroyed at once", and "it all fell at once" fantasies.
NIST simply found one area that was most affected by the fires in the building which also was proximate to col 79 which in turn obviously failed and was the cause of the first outward manifestation of the structural failure of WTC 7, the collapse of the East Penthouse. So, yes, col 79 could have failed much lower down but the only known driver of such failure is the fire on 12. There might have been fire lower down, there might have been impact damage lower down (elevator car was ejected from shaft at fifth floor), but evidence for these is scant. NIST goes with "most probable". |
23rd November 2015, 08:08 AM | #44 |
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I am aware of the NIST arguments... AND I have read many times... where is the evidence that something lower down "failed"? Of course the survey information and data collection from lower that the cameras could see... is obviously not going to be there.
I do recall seeing some photos and vids of extensive fire on the NW corner around floor 8 or so... I don't recall the precise floor of the time of these fires. But they are some manner of evidence that extensive fires occurred on the NE corner below 12 at some point. The irony to me is that the NIST presentation and the crowd here likes to imagine a pristine structure below col 79 on floor 13 because that is where NIST chose to model a failure from I suppose heat images of the facade at that level. Really this seems a bit odd. Doesn't it? |
23rd November 2015, 08:33 AM | #45 |
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All correct - also what jdh said: We, or NIST, can't be certain that it was the situation at the floor-13-girder-to-44 that initiated the failure of 79. It is true that there were also significant fires on several floors below the 12th.
Was already mentioned: The EPH descent plus the kink indicate c79 failure "lower down", window breakages near col 44 much of the way down corroborate. We just can't be sure how far "down" c79 failed. I don't sense that anyone here pretends thusly. Most are aware that there were large fires on floors 7, 8, 9, 10, 12, 13. NIST claims that various connections had already failed on several floors in that general area in the east. The f13-c79-c44 girder was merely the straw in NIST's model that broke the camel's back. When f13 fell, it failed f12, f11, f10 etc in dynamic overloading. Not sure if NIST comments if the already accumulated damage to those floors was significant for the cascading floor failure. Even an explosive charge place on c79 anywhere between ground floor and 15th floor (or whatever) could have done the trick, and that's why NIST considered that possibility - and rejected it on account of the missing blast sound. I wonder if perhaps even a failure of c80, ahead of c79, could have started such a cascade. But what's the point? The NIST scenario seems plausible, and if it can be shown wrong, then other plausible non-CD scenarios would be in the queue. There were horrendous fires - that's a fact Steel is vulnerable to fires - that's a fact The steel structure collapsed - that's a fact. Were there CD charges? No evidence exists - they are NOT fact. |
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23rd November 2015, 09:21 AM | #46 |
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The only "point" is to not leave the impression that the NIST explanation is THE correct and only possible one. Sadly I think this is precisely what is happening or has happened. The truthers, such as Tony and others have focused on disproving NIST. This forum refuses to even look at anything else and defends NIST's theory almost as FACT despite the fact that their own GIF widely diverges from what we all saw.
I've read many times that col 79 buckled from the floor 13 failure. I am not an engineer and I understand the purpose of lateral bracing but a single girder walk off leading to a 1000#/ft buckling is counter intuitive and actually not even explain as far as I know. And why would the GIF not look anything like what happened? So sure... column 79 had to collapse... but so far the NIST stuff is non convincing to me. And I think... they need to convince dumb people how this happened... even dumber than me. |
23rd November 2015, 10:04 AM | #47 |
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Sander, I am quite surprised you misrepresent the NIST scenario like this!
Are you not conveniently forgetting that, before c79 buckled in that scenario, not only had the girder on f13 walked of, but its counterparts on floors 12, 11, 10, 9, 8, 7 and 6 also had failed - as a result of f13 crashing down? That left c79 unbraced to one side over not 2 but 8 floors. Makes a vast difference, doesn't it? Do you mean the appearance of the perimter collapse ten seconds later? Easily explained: NIST, as you remember, did two simulations: One without, and one with south perimeter structural damage from the WTC1 debris impacts. This had a large effect on the appearance of the collapse late into the sequence (after the north wall started to descend). Now the damage estimate for the south face without a doubt was not accurate, did not match the true damage extent. Isn't easy to see that further corrections of the model, towards the (unknown) true damage pattern, might very well have further modified the appearance of the last collapse phase - possibly towards matching the true collapse? |
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23rd November 2015, 10:11 AM | #48 |
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I am unaware of all the details of this NIST scenario of the floor sections all being destroyed on one side of col 79 down to floor 6. What was the evidence presented for these floors collapsing? I am not asserting it is not possible. I am simply asking for the support for this. Why would it stop at floor 6?
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23rd November 2015, 10:30 AM | #49 |
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23rd November 2015, 11:12 AM | #50 |
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It is possible that the lower fire at the NE corner had an effect. Even if that effect was some local deformation. Such deformation could also contribute to forces on girder 44/col79.
I don't see that there is evidence that the lower fire could have affected col79 directly. Yes it might have if it burned further west. Problem is that there is no evidence it did and NIST operates on what there is good evidence for such as fire on 12 proximate to col79. Truthers ignore working with direct and good evidence in favour of speculations and fantasy. |
23rd November 2015, 04:01 PM | #51 |
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23rd November 2015, 04:09 PM | #52 |
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23rd November 2015, 04:17 PM | #53 |
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I have been saddened to see the issues Sander has been pushing for the last couple of years on WTC7 collapse initiation. Specifically these three - not in order:
A) He misrepresents the NIST explanation of C79 failure as it being caused SOLELY by girder walk off. (The point you identified in your second paragraph quoted above Oystein.) B) He has proposed an alternate hypothesis - transfer truss failure - which is a plausible alternate. Nothing more than plausible until it is supported by valid reasoning. C) Sander represents his own mechanism as superior to NIST's - whilst relying on his "straw man" misrepresentation of NIST as support and giving no persuasive argument to support his own claim in preference to that from NIST. His alternate may be better in his own judgement and he may be right that NIST is in error BUT there is no argument to support either of those two conclusion which Sander has been pressing forcefully for many months. The rest of us do not have to accept "reversed burden of disproof" to show whether you are right or wrong Sander. It is your claim. |
23rd November 2015, 05:03 PM | #54 |
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Apparently Nordenson along with some other engineers cited up thread...did a forensic engineering analysis and came to a different conclusion than NIST.
I am not here to prove anything. I haven't a clue as to how to prove it. I've given my reasons (dumb as they may be) why I was not sold on what I understood to be the NIST initiation location etc for the collapse. I think their GIF seems to undercut their theory because it doesn't resemble the real world visuals at ALL. Do others think it does? As the entire inside DID collapse because the screen wall area and the WPH did come down BEFORE the moment frame AND the entire moment frame rotated counter clockwise and kinked... the interior destruction had to have propagated east to west... and probably at the lowest levels of the structure where the transfers were across the north side of the core. The NIST theory as I understand the sequence was... Col 79 has a girder walk off a floor section collapses and that destroys the corresponding floor slabs below. this leaves 79 unbraced and it buckles this then collapses on TT1 and TT2 which then cause the transfers over the north end of the core to fail which then causes TT3 to collapse and the WPH then falls this leaves the insides gutted and the perimeter moment frame with no support below 8 collapses down Yes or no? Ozzie... remember.. I am not here to prove a theory but to understand the collapse in a manner that makes sense and is consistent with how the towers were built and the "forces" present which undid them. I like or prefer to visualize the sequence even if it's not the precise one... how the buildings un did themselves. I don't know what this can't be done... not a proof... |
23rd November 2015, 06:29 PM | #55 |
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A column only needs support in two orthogonal directions. Although the walk-off issue is impossible with stiffeners on girder A2001, I'll give it to you here for the sake of argument. What you apparently don't realize is that even if column 79 had been left laterally unsupported from the north over 8 stories it was still supported from the south and west. An everyday testament to this is exterior corner columns.
You may not be aware but NIST had to do some additional juggling to get the west side girders to fail. They say the west side girders failed due to thermal expansion breaking their bolts to their knife connections on the column. However, they have a problem on the girder under the 11th floor as there was no fire on the 10th floor. Column 79 could go at least 5 stories without lateral support. The fires were on the 7, 8, 9, 11, 12, and 13. That means that even if the girder connections had failed the way the NIST report says they did, column 79 was never unsupported laterally by less than two orthogonal directions for more than three stories. |
23rd November 2015, 10:12 PM | #56 |
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23rd November 2015, 10:20 PM | #57 |
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23rd November 2015, 11:01 PM | #58 |
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I see you guys on here are loving the fact that someone is producing an analysis of WTC7 for you....I mean....it's just what you always wanted isn't it. And you even get the chance to give your input to the project.
I have some suggestions. Perhaps it would be best to take the dimensions from column 80 or 81 or any other column when modelling the connection type and dimensions at column 79. I would particularly suggest that the seat plate length should be reduced by an inch or so to 11" rather than 12". This will actually make the model more predictable. Also, remember that in the real world steel beams only expand to the West, so don't worry about modelling column 38 - there's really no need for it. Also, let's not bother about steel sagging (unless we need it to) as this will just make the math complicated. Also, it's a mistake to release the input data. This will allow people to check the model and can only lead to trouble. Much better to stick with the NIST convention and keep the inputs to yourself. Also, I asked a highly qualified friend (she has a bsc in crochet) about the beam stubs shown in the drawings, to the NE of the C79 connection. According to her the beam stubs aren't really there. Sure they're there on the drawings and all specified in the BOM, but they had no purpose whatsoever, and were in fact spare off cuts from the floor beams, so they just connected them in to save the bother of carrying them back down to ground level. I would therefore suggest that these beam stubs are banned from the model. I am sure that if the above suggestions are taken on board, then the good skeptical souls on this site will have their minds put at rest as to the veracity of the results. |
24th November 2015, 12:16 AM | #59 |
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Sander I am well aware of your purpose - which is that YOU understand what happened. I have already explained what I think is possible and what is not.
I don't believe you will ever get certainty at the detail level you are looking for as to what initiated WTC7 collapse. What you can be certain of is: 1) NIST has published an hypothesis which is plausible. Sure you have doubts about it but you will never IMO get a valid "disproof" - falsifying of the NIST hypothesis; 2) You have proposed an alternative hypothesis - which as I have said consistently from the time you proposed it - is "plausible". It is no more than "plausible" until some process supports it. I do not see that ever happening; 3) The truth movement claims are dominated by the T Szamboti assertions about "girder walk off" and a suite of debating trickery that T Sz and the "truth" movement engage in. The T Szamboti claims have not been shown to be valid in rebuttal of the NIST hypothesis. If he cannot prove his own claim when I and others have shown where it is wrong - his problem, So we have the NIST explantion, yours and nothing worthy of consideration from T Sz et al (Pepper, AE911 - whoever makes the same nonsense claims) Your own choices include: A) Keep looking for definitive arguments which will prove what actually happened TO YOUR SATISFACTION and at the detail level. Sorry Sander but that will never happen. B) You back of from requiring detail proof and accept the proof that satisfies me and some others -- viz: There are plausible explanations; T Szamboti et al's claims are not proven; they are clearly unable to present proof and engage in trolling trickery to avoid the burden of proof; AND it is unlikely that you will ever get a proof at detail level - whether from honest rational persons OR dishonest "truthers". C) There are others but.... The challenge to you is to face up to the reality that: i) you will never get any argument at detail level which satisfies you; ii) The advice that I, Oystein, Dave Rogers and a couple of others have given is as good as you will get; iii) As I am sure you recognise the goal of a lot of debunkers is NOT explaining. It is ridicule of those they disagree with. They will not help your understanding; AND iv) I don't need to comment on the"truther side" posters - their objective is to mislead you or at least keep you confused. So - if you accept that as the real scenario for these discussions - I am prepared to summarise the status of debate and attempt to once again respond to your call for help. |
24th November 2015, 12:46 AM | #60 |
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Quote:
It's all sounding like the Mark Basile "independent study" which hasn't taken place and isn't independent. |
24th November 2015, 12:56 AM | #61 |
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Sounds to me very much as if you read my post, and just didn't get it. Understandable I guess.
Do you seriously think that I am suggesting that such a study should be secretive with inputs, and inaccurate with element dimensions whilst not accounting for elements that are present on the drawings? Why would anybody want to release a study like that? It would be pointless. |
24th November 2015, 01:06 AM | #62 |
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24th November 2015, 01:30 AM | #63 |
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24th November 2015, 02:46 AM | #64 |
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Good and valid points.
Now c79 was not a corner column, and thus the framing from west and south was not necessarily dimensioned to be sufficient in the anbsence of the northern girder and the eastern beams - it was, or perhaps wasn't, I can't tell. I am indeed not aware that "NIST had to do some additional juggling to get the west side girders to fail". Can you direct me to the sub-section that explains this juggling? So the 11th floor girder to the west did not fail in their model? But all of the north girders from f13 down to f6 did, right? There is another effect that I think played a role: The collapse of 8 floors adjacent to c79 wasn't clean and trouble free - no doubt some of their mass kicked laterally into c79 with large force. May all these factors be as they are - in the end, the NIST-model ran, and it resulted in the buckling of c79. And perhaps it is unfortunate that we don't have the details of the model input to scrutinze (frankly, I would very much lack the ability and capacity to do scrutinizing on that level anyway). Now as for the UAF study - what would we expect them to model to resolve these questions? |
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24th November 2015, 04:20 AM | #65 |
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The westward lateral propagation of failure i n7wtc was caused by the failure of the transfers from east to west...rather than buckling of the row of columns of the north side of the core.... Or so it would seem.
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24th November 2015, 06:49 AM | #66 |
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Ok so AE911T will show its work. Its work though is limited to girder walk off. The least certain of all NIST's hypotheses. What happened to AE911T's contention that a single column failure cannot lead to global collapse or that the collapse seen cannot occur without explosives? NIST's analysis showed that a col 79 failure, with or without south side impact damage, would progress to global collapse. Seems to me that an FEA along that line would be more to the point than supposedly proving NIST's 'most probable' initiating failure hypothesis. |
24th November 2015, 06:51 AM | #67 |
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24th November 2015, 06:59 AM | #68 |
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other lesser contributing factors,
-heating of adjacent flooring and structural members - spalling of concrete in adjacent areas South side impact damage stressing the structure - NE corner low (~6th floor) fires deforming floor beams and stressing the building etc. All of these minor factors may have contributed either to girder walk off or to instability once the girder was no longer in play. Therefore in an approximation such as the FEA of either girder walk off or of progression of collapse, if the FEA run comes close to demonstrating it, then the description of "most probable" applies well. |
24th November 2015, 07:00 AM | #69 |
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It's readily apparent that an earlier attempt to demo wtc7 failed, and in industry parlance, resulted in a hung structure. It's unimaginable that a rigged demo would intentionally be orchestrated so late in the day, with all eyes watching so to speak. Clearly the additional charges were added to "get it done", with little concern for the unavoidable free fall that will now prove CD. Sent from our shared looking glass platform |
24th November 2015, 07:03 AM | #70 |
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24th November 2015, 07:14 AM | #71 |
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24th November 2015, 07:23 AM | #72 |
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24th November 2015, 07:33 AM | #73 |
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I can't believe he's serious with any of his stuff, but some Truthers came round to the idea that WTC7 was "supposed" to have been cd'd much earlier and there was a major delay when that failed. Of course, those fixing the problem would have been working in an already damaged and burning building
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24th November 2015, 07:46 AM | #74 |
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Respectively: (a)He's obviously not if you follow his game playing. (b) Some of the time. (c) Of course.
- he's getting responses. ...and more of them since he dropped the conceptual level of comments a couple of grades further into nonsense. ...it takes a lot less effort than is being expended by our two currently more active trolls. ...one of whose style brings back memories. |
24th November 2015, 07:54 AM | #75 |
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Thermodynamics hates conspiracy theorists. (Foster Zygote) The business of Progressives is to go on making mistakes. The business of the Conservatives is to prevent the mistakes from being corrected. (Gilbert Keith Chesterton) Last edited by Oystein; 24th November 2015 at 08:20 AM. Reason: corrected spelling of Tony's last name |
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24th November 2015, 08:11 AM | #76 |
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24th November 2015, 08:13 AM | #77 |
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Oh yes, the pre-weakening referred to recently in another thread. The thermite burn that either occurred at the time of WTC 1 collapse, when there were still people in WTC 7, including, supposedly, Jennings and Hess on the 8th floor already(with the myriad of problems with Jennings' timeline), or later when firefighters were walking through WTC 7, or later still when the building's fires were raging and the structure was full of smoke and hundreds of rescue workers and reporters were in the vicinity, and no one noticed!
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24th November 2015, 08:17 AM | #78 |
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Ok, your chance to be clearer. Were you describing the 'kink' I refer to as being evidence of a hung structure? If not then why quote that part of my post? Why not address the issue of the kink instead.
If you are saying its evidence of hung structure then I suggest you view the collapse videos again(or for the first time, whichever suits best). |
24th November 2015, 11:49 AM | #79 |
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24th November 2015, 01:59 PM | #80 |
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