[Closed] 9/11 documentary

Did we figure out how many conspirators there were? Did jivehoneyjive give us his opinion on the roundness of the earth?

The real winners here are those of us who will enjoy lampooning future use of “the Lower Manhattan Defence”

impossible to take anything he says seriously

nobody here takes anything I say seriously anyway !

nobody here takes anything I say seriously anyway !

You made the fatal mistake of taking what I said seriously!

You made the fatal mistake of taking what I said seriously!

you serious ?

you serious ?

I am, but like you, nobody takes me seriously either..

TurnerGuy - Member
You made the fatal mistake of taking what I said seriously!
you serious

Ahh, the troll is trolled 😉

I like this guy's attitude. I assume that it makes a big difference that the towers floors are more connected than in his experiments. Edit experiments start at approx 5 mins if you find his droning on a bit boring 😉

Whilst what he has done is fun, it is incorrect.

Yep, none of those models appear to match the actual structure.

So I'm compelled to say I remain unconvinced.

I'm going to dive back in again, why not! 😀

I wouldn't want anyone to think I ran away, especially with 5plusn8 keen to talk at the time. I had some long meetings yesterday and things had moved on when I came back.

All I wanted to do in the first place was to have a poke. I find the whole set of circumstances baffling, and I find some people's 100% certainty in one explanation of what happened baffling. It annoys me that people accuse others of logical leaps, reliance on assumptions and rigid beliefs while not realising they're guilty of much the same.

The whole set of events is implausible, discounting objections because an alternative might also be implausible seems a bit... rigid.

"Give me Evidence!" TJ screams. NIST used no physical evidence in analsing WCT7 whatsoever, and say so on their website.

"Give me one piece that you think is credible and I will demolish it citing real scientists" then takes something off Wikipedia citing Jesse Ventura (on youtube, btw).

"There is no scientific doubt whatsoever!" NIST's report is ENTITLED "[u]Probable[/u] causes..."

So I'm awarding TJ the rabid intractability award.

amedias, you've been very reasonable and patient throughout. 10/10. :-), I'm happy to admit that my main issue is, as you say "it looks a bit funny" especially building 7. NIST say planes weren't a factor, collapses of 1 and 2 weren't a factor, debris from those collapses wasn't a factor, fuel oil not a factor. Scattered office fires (no photos I've seen show them to be especially raging), leading to thermal expansion of steel supports around the building, one girder becomes detached from one main column, which buckles, leading extremely quickly to the whole thing dropping out of the sky like a house of cards. Looks a bit funny - quite happy to say it again. 46 storey building, 20 years old.

They've produced a computer model to provide an animation of the progressive collapse, but what are people (outside of this discussion) quite happy to say about models? Sometimes useful, and... something else...?

amedias, you know more than me about physics, but essentially (as you've admitted you can't fully explain it) you've got a model in your head of weakened supports in 1&2, load sharing, collapsing, pancaking that you play over you don't have a problem with it. I can play that one as well, seems fair. I can also imagine asymmetric damage, leaning, (you've said it's impossible, but I think there's a picture of the top bit of one of the towers leaning?) one side being under more pressure than the other due to the movement, and steel being much stronger in tension than compression the leaning being exaggerated, rather than corrected.

I can't say that one or the other is impossible, but you can. Despite you having more physics knowledge than me, I'm still not convinced 100%.

So that's me, nedrapier, remaining compelled but unconvinced. Doesn't mean I know what happened, or even that I have a position on what I think happened, or even that I'm unaware that alternatives also have difficulties, but a lot of difficulties were overcome that day. and a lot weren't, and aren't.

What a lovely tone you've struck there ned. Thumbs up. 😉

nedrapier. MY point was no one has been able to come up with a single credible shred of evidence that the conspiracy theories are true or that the official line is not true

No one on this thread has posted one piece of "evidence" that stands up to the slightest scrutiny. NO one world wide has come up with the slightest bit of credible evidence that the official line is not true

But why should we take the official line as gospel?

What if the official line was controlled demo? Could you prove otherwise?

Has anyone disproved the official line?

Give me one piece that you think is credible and I will demolish it citing real scientists" then takes something off Wikipedia citing Jesse Ventura

The wiki piece has 3 reference to proper peer reviewed papers that completely debunked the nonsense about thermite. which was the only bit I was looking at.

But why should we take the official line as gospel

You shouldn’t. Use your own critical thinking. Watch and read the news from different sources, look into the reports that have been published. Consider expert testimony.

RE: The video up there^^^

Someone who isn't a physicist once again gets the wrong answer!

You cannot directly "scale" experiments because not all physical properties scale linearly with absolute size. For example Froude number (the ratio between inertia and gravity) Reynolds number (the ratio between inertia and viscousity) and many more critical parameters (Weber, Mach, etc etc) must be carefully scaled in order to produce a valid comparison with the full sized event.

Funnily enough, this science has it's own name, and history (Dimensional Analysis) and is generally not something a layperson understands implicitly.

The reason a 6foot model made of paper doesn't collapse like a 1200 foot building made of 1000's of tonnes of steel and concrete is precisely because of these non linear scaling issues (and also incidentally why a bumble bee can fly, despite basic physics suggesting it can't! (At the BB's scale, the air appears significantly more viscous, making flight possible)

Let me give you a simple example. He uses thin paper walls as supports. But paper has a very low density, so the viscosity of the surrounding air actually supports and damps a paper wall by a significant factor. meaning a small model with paper walls is massively more resistant to buckling that if that scale model was actually life sized, where the viscosity of the air is much less significant.

or another example, surface tension. if you are a small insect, you can walk on water due to the surface tension. try that as a human and you're going to get wet!

All these factors and many more invalidate basic scale modelling unless it is done extremely carefully indeed!

NIST's report is ENTITLED "Probable causes..

so, all this demonstrates is you don't understand the scientific model

I'm oot, pigeons, chess, arguing, idiots...rearrange to form a well known phrase or saying

For me, the collapse of the main towers looks absolutely to follow basic, expected patterns. Even if you hadn't seen the aircraft hit, the fact the towers buckled at the fire zone, and that the tower with more mass above that point fell first, all makes scientific sense. Add in the poor lateral connection between floors and the exoskeleton design of the main towers and a pancake style collapse from the point of impact isn't unexpected.

WTC7 is indeed different. It does look to collapse from low level first, btu that to me doesn't scream conspiracy, it screams that the collapse was due to a different mechanism.

Immediately the presence of a large underground void under the complex springs to mind. That void held up both main towers and WTC7 in some way (i'm sure the load sharing is extremely complex!). Considering that half a million tonnes of building had just fallen down, i'd suggest that a lower level structural failure, resulting in WTC7 being undermined is a likely possibility.
Undermining can bring down a structurally sound building, let aloe one already compromised by fire and impact.

So, here's the question:

Which is more probable:

1) WTC7 collapse through complex, not that understood and difficult to prove factors, but those factors do carry a weight of sensible and understood science behind them

2) WTC7 was for some (unexplained reason) deliberately blown down after the Towers Fell.

Given that 2) requires an enormous number of people, huge pre-planning, massive costs, has no proven benefit, and the fact that the same result could be achieved without the planes and tower bit (a lorry bomb, or simple fire could have been used to destroy what ever "evidence" was to be destroyed with a lot less hassle and chance of discovery) even without any evidence i'd suggest sane and logical people (in fact the majority) think the Conspiracy theorists are idiots.....

Scattered office fires (no photos I've seen show them to be especially raging)

You’ve not seen this one then ?

[img] [/img]

max, you're making stuff up. NIST ahve done a model that completely discounts what you say.

And you bring me back to my original point back on page humtytum: either neat collapses of buildings are extremely hard to achieve and demand huge time, planning, resources, skill and disruption, or they are (WCT1&2) the [b]inevitable [/b]result of asymmetric damage and heat in a localised area or 7) can happen as the result of random buckling on one vertical tower and some other damage by thermal expansion at hundreds of degrees below design parameters following some scattered office fires.

The two positions are hard to reconcile, even more so when you're being told that one follows from the other: that a neat collapse is so hard to co-ordinate that it must have been completely unco-ordinated.

The fact that the report was entitled Probable and they started clearing the site so early smacks of something strange - you would think they would want to conduct some more forensic examinations to move towards a better snd less questionable understanding of what happened.

You don't get a chance to examine such an unexpected failure mode often.

They are still examining the Grenfell tower site for example.

They might have been told that things have to turn around quickly on the site for some other reason, not necessarily a suspect one though.

"Probable" is there because they're scientists and they recognise there's always scientific doubt.

neal, I can't see any fire in that shot. fair bit of smoke (or dust?), bit of soot round a few of the windows.

neal, I can't see any fire in that shot. fair bit of smoke (or dust?), bit of soot round a few of the windows.

Yeah, that’ll be it. Probably dust pouring out of virtually every window.

The cleaners emptying hoover bags or something. That can be really dusty.

Certainly wouldn’t be the fires that were known to be burning unchecked for hours.

I said I've not seen pictures of raging fires. you show me a picture with no fire in it. The only evidence that fire has come out of any windows is a bit of soot round 8 of them windows. It's a small photo, so it's difficult to say for certain, but some of the windows are broken, all the ones with soot round them obviously, and you can see some of the interior frame, same with a few below and a few at the top. The rest are flat black. Does that mean a lot aren't broken?

I mentioned dust because it reminded me of this. Buildings near the water weren't on fire, and have dust (or smoke?) pouring off the leeward side.

[img] [/img]

I said I've not seen pictures of raging fires. you show me a picture with no fire in it. the only evidence that fire has come of of any widows is a bit of soot round 8 of the windows.

Damnit, I’m gonna have to finally share a you tube video

TurnerGuy
you would think they would want to conduct some more forensic examinations

why? Some jets hit the towers, they fell down. You'd have to be a complete idiot to conduct a forensic examination of a scene where the cause was plane (sic) to see by anyone with eyes and an iq of more than 7......

So not only did they not conduct a forensic exam, it probably didn't even cross their mind they might need to do so, so that in 15 years time they could provide "proof" as to why the building fell down (when they'd just watched it fall down with their own eyes after being hit by jet aircraft)

Funny enough, all these conspiracy theories have taken years to come out the wood work. You know why? It's because if the day after the event, when lets not forget, over 3000 people died, you said "ooh it was all a government plot" or whatever idiotic rubbish you freely spout today, you'd have been linch'd!

Please stop disrespecting and tarnishing those 3000 ordinary people who died that day, in an effort to get attention for yourself!

.

I said I've not seen pictures of raging fires. you show me a picture with no fire in it.

You can’t see the fire because of the massive amounts of smoke it’s giving off.
Covering the whole side of a massive building.

What would that suggest to you ?

A : Tiny fire.
B : Massive fire.

It's also easy to miss the scale of WTC7. It was 47 floors tall. For reference, the Grenfell tower is/was just 24 floors tall, pretty much half the height!

The whole set of events is implausible

Perhaps it seems unlikely that a load of criminals would get hold of 4 planes and be competent enough that 3 of the four would get to their targets and hit them. However, implausable or not the evidence that that happened is overwhelming.

discounting objections because an alternative might also be implausible seems a bit... rigid.

No, the alternatives aren't implausible. They are utterly impossible. There's no hint of any other credible way these events could have happened. This is why quibbling about the 'official' version is a waste of brain energy. Even if the official version was fundamentally flawed (it isn't) the alternatives are so insane and logically impossible that you'd discount them as well and have to admit you couldn't explain it at all.

The whole set of events is implausible

Well, you need to differentiate a bit here.

It was highly unlikely that a bunch of hijackers would get hold of some planes and successfully fly them into two of the tallest towers in the word. That's fairly improbable, I'll grant you that, but not in and of itself implausible...

But from that point on what happened is rather plausible indeed. Massive damage the building, jet fuel explosion, raging fire... it's not at all implausible that this would cause the buildings to collapse, I'd even go so far as to say probable.

amedias, you know more than me about physics, but essentially (as you've admitted you can't fully explain it) you've got a model in your head of weakened supports in 1&2, load sharing, collapsing, pancaking that you play over you don't have a problem with it. I can play that one as well, seems fair. I can also imagine asymmetric damage, leaning, (you've said it's impossible, but I think there's a picture of the top bit of one of the towers leaning?) one side being under more pressure than the other due to the movement, and steel being much stronger in tension than compression the leaning being exaggerated, rather than corrected.

just want to say a few words about this bit in case some clarity around my comments is required...

I've not said, and will not say, that differential weakening, or localised sagging/tipping/leaning is not possible, as not only is it clearly visible in pictures and video, it's to be expected. But [i]as a whole[/i] (and thats the important bit) the twin towers couldn't collapse in any other way than 'down into a localised area/their footprint. There may be minor deviations at a local level, but not on the overall scale.

The slight tipping of the top section thats visible is the start of initiated collapse due to the structure failing, it's not so much tipping (implying a coherent top structure pivoting) as it is sagging/deformation of the structure below. IT's a result of damage, and once the structure is comprised enough, it starts to give way. As soon as it starts 'to go' so to speak, there is nothing present that could divert it from pretty much straight down. The top section lacks integrity and they're simply too tall, too massive, and have insufficient integrity once compromised to topple or split or anything like that.

I hope I'm making myself clear?

I guess what I'm trying to say is that the observed collapse, to me, doesn't look unusual in any way. You cna argue the toss about the specifics of where the structure first started to fail and why, but the collapse looks totally explicable for a structure of that type and size.

And here's the kicker, controlled/initiated demolition or structural failure would BOTH result in an essentially similar looking collapse. The initiation events may be different, but as a whole it's gonna go down in the same way overall. Which is another reason that neat collapse doesn't imply demolition*.

I don;t know as much about 7, chiefly because I've not read that much about it. And while I keep an open mind about it I've really not seen compelling (that word again) evidence of anything fishy. I've see a few doubts cast on the official explanation, but most of those centre around scale of impact, eg: fires weren't big enough, it wasn't damaged enough. That's fine, but pointing at a few less than complete aspects of an explanation is very different from providing actual evidence of an alternative.

It somebody says the explanation has errors or holes in it fair enough, lets investigate further and see if we can plug those knowledge gaps, or if some calculations were wrong, or maybe there are simply some bits we will never have enough info on to know for sure, but again, that is VERY different from having any actual evidence of an alternative. And I'll hold my hands up to the fact I'm an evidence based kinda guy. Right now I've got a lot of evidence of a mostly explicable, and at least plausible collapse due to damage. I have no evidence of an alternative, the only thing close to evidence is doubt of the evidence we do have. Lets also be clear, doubt can be investigated and either resolved, or not, but it is not [i]actually[/i] supporting evidence of another theory.

*Also, the entire point of controlled demolition is not 'to blow it up' but to 'initiate collapse'. You'd essentially be trying to cause a structural failure, but in a controlled manner, the explosive bit is only used to compromise integrity and start the collapse, hence why collapse is in the same manner.

the Grenfell tower is/was just 24 floors tall, pretty much half the height!

Almost a third 610 feet vs 220 feet.

cheers jonnyboi. (Youtube?!?!?!?!? WTAF?)

Same 8 windows, I think, with fire coming out of them, some more round the corner of the same 8, and another fire in 6 windows, which spreads to the next floor. some of the flames are quite big I guess. Raging? guess so. wouldn't want to be stood near them.

Still, that's 3 or four sections of 3 or four floors shown in the video. And an awful lot of windows not even broken.

Those 10 words in brackets don't add much or take much away from the rest of my post, so if that's all you've got to object to...?

Also worth noting that it's extremely rare to do an explosive demolition of any building without first also weakening the primary (frame) and secondary (walls and floors) structural components first. To take down an un-weakened building with just explosives would require a massive amount of them, and to ensure a clean take down, pretty much every structural component would have to be individually rigged and sequenced.

Added to which, commercial explosive demolition with high speed explosives requires the explosives to be covered, generally with layers of wire mesh and nylon sacking, with the aim of trying to minimise high velocity debris, that can travel 100's of meters.

In all cases, the insides of the building are gutted first to allow access to the structure and to allow weakening of load bearing components. To do that to a steel framed building that is intrinsically strong and flexible would be hard enough, to do to a building that was still occupied without it being obvious would be beyond difficult.

And no, you can't build in charges when the building was built (explosives are "Lifed" they degrade and become unstable over time, even modern safety explosives). To rig a building at build would be extremely risky, not to mention i think the builders might notice

Or you can set a few floors on fire and you'll get the same result.

cheers jonnyboi. (Youtube?!?!?!?!? WTAF?)

I know, I hate myself a little bit

Same 8 windows, I think, with fire coming out of them, some more round the corner of the same 8, and another fire in 6 windows, which spreads to the next floor. some of the flames are quite big I guess. Raging? guess so. wouldn't want to be stood near them.

Still, that's 3 or four sections of 3 or four floors shown in the video. And an awful lot of windows not even broken.

Those 10 words in brackets don't add much or take much away from the rest of my post, so if that's all you've got to object to...?

Some evidence of a raging fire, no more no less. I’m not expecting you to extrapolate it into anything (which let’s be honest a lot of truthers do with tiny bits of information)

Just add it to the body of evidence to enable a value based judgement

cheers for the long post amedias. You've made yourself clear.

You're not 100%, but you've happy enough and you've seen no reason to think otherwise.

Not much to argue with there, I agree with a lot of it, and haven't said any more than you regarding alternatives.

Got your point about the demolition too. You just need to initiate it. one of two floors might be all you need?

But why should we take the official line as gospel?

What if the official line was controlled demo? Could you prove otherwise?

I like this....

Look how it came down just like a demolition, case closed.

jonnyboi, 🙂

jonnyboi, 🙂

Or you can set a few floors on fire and you'll get the same result.

Add impact damage from an enormous collapsing building, failure of sprinkler systems, withdrawal of the fire department and let the fire burn unchecked for seven hours and yes, that’s what happens in the case of WTC7.

Thermal expansion is a bitch eh?

apparently so. enormous collapsing building did not have a significant effect though. so office furniture equipment, fixtures and fittings burning for as long as they take to burn. Do you know how long the individual fires burned for?

Thing is though, surely if fire does cause damage to the steel, at best it will only cause localised buckling of the steelwork, which would mean only a small portion of the structure would be likely to collapse...

Even with the additional damage sustained from debris and seismic shock, such complete collapse is surprising, if nothing else.

However, let's not forget:

The thing is it really doesnt matter if it was a controlled explosion or if it was just the planes.

The only question is: Was anybody in on it?

no jhj. "global collapse ensues".

For some reason, that reminds me of AIG (American International Group)'s role in the 2008 global financial collapse, but that's not likely to be relevant here, is it...

What if the official line was controlled demo? Could you prove otherwise?

Look how it came down just like a demolition, case closed.

If demolition was the official line I think people *might* be asking difficult questions about the 4 missing planes with passengers on board, 2 of which crashed into the towers and started massive fires before they collapsed... Don't you?

Please stop disrespecting and tarnishing those 3000 ordinary people who died that day, in an effort to get attention for yourself!

go f*** yourself.

As I said, two weeks to collect and examine the site does not seem like it will lend itself to a very thorough examination and reconstruction.

Steel framed buildings like that are not suppossed to collapse as a result of office fires - a lot of qualified people were surprised by it - I would have thought that it would warrant more examinsation in that case to fully understand exactly what happened.

Do you know how long the individual fires burned for?

Nope, but from the available evidence it seems like they were burning when the building was evacuated and continued to do so until the building collapsed.

If there’s a sensible alternative hypothesis that explains the collapse of WTC7, I’m genuinely interested.

As I said, two weeks to collect and examine the site does not seem like it will lend itself to a very thorough examination and reconstruction.

I genuinely think that at the time they didn’t consider that it had been necessary. The world had witnessed what happened. It’s easy for us to judge in hindsight

@Amedias, @Maxtorque, assuming you have looked into the construction of WTC 1&2 are you happy that both airplanes(aluminium framed and skinned) hit both towers with sufficient force to not only penetrate the steel outer skin of the building but to also penetrate through the building to sufficiently damage the inner core of the building to such an extent that it would cause a complete collapse, a collapse so similar between both building that its hard to differentiate between each collapse, bearing in mind 1 and 2 were actually struck in different positions.
Regarding the core of these buildings there is plenty of info out there referencing the core construction, are you confident that the aircraft that hit the towers could damage the cores enough to ensure the collapse ?

Heres a nice vid from the 70`s showing construction.

Fuel fire ! the south tower which was probably the most spectacular of the hits and shows a massive fireball, what proportion of the fuel onboard would have not have ignited at that point and was therefore left to fuel the raging inferno that wrecked the structural integrity of that building?

Thing is though, surely if fire does cause damage to the steel, at best it will only cause localised buckling of the steelwork, which would mean only a small portion of the structure would be likely to collapse...

assuming you have looked into the construction of WTC 1&2 are you happy that both airplanes(aluminium framed and skinned) hit both towers with sufficient force to not only penetrate the steel outer skin of the building but to also penetrate through the building to sufficiently damage the inner core of the building to such an extent that it would cause a complete collapse

The fire caused the collapse, not the plane impact. That’s been well established.

We’re just going back over old ground again and again now. If your going to jump in, at least read up in the debate so far

Just the heat and the smoke from all the other

? buildings on fire, you couldnít see anything.

So it took us a while (i.5 hrs) and we ended up backing
p
p everybody out, and thatís when 7 collapsed.

Lieutenant William Ryan, Ladder 85

Yet they could see well enough to carry out a structural inspection to determine when it was going to collapse?

3 massive skyscrapers completely disappear due to fire..., on the same day...

gotta be...

[img] [/img]

Do i think a 100 tonne aircraft doing 500mph could damage the towers?

Seriously? No, i'd expect it to just bounce off without even scratching the paint......

(back of an envelope calc suggest around 4GJ of energy stored in the planes mass at that speed, or about the same as an entire tonne of TNT going off. so yes, plenty enough to damage a building! In fact, it's more amazing that the Towers even survived the initial impact at all!)

Whathaveisaidnow - Member
Just the heat and the smoke from all the other
? buildings on fire, you couldnít see anything.

So it took us a while (i.5 hrs) and we ended up backing
p
p everybody out, and thatís when 7 collapsed.

Lieutenant William Ryan, Ladder 85

Yet they could see well enough to carry out a structural inspection to determine when it was going to collapse

I’m really sorry, but you appear to be struggling to make any kind of coherent point in your posts.

The fire caused the collapse, not the plane impact. That’s been well established

We’re just going back over old ground again and again now.

Ive been here since page one Johnny boy

Whathaveisaidnow - Member

3 massive skyscrapers completely disappear due to [s]fire[/s]...

...terrorist attack you mentalist.
Care to comment on the fireproof explosives used?

No, because in the words of Mhairi Black, you're chattin' shite hen.

Completely disappear?
Didn't happen ya shitehawk.

You're not suitably equipped for this discussion pet.

TurnerGuy
go f*** yourself.

Hit a nerve did i? Imagine how angry you'd be if someone you loved had been killed and some other idiot was talking total rubbish about the way they were killed.......

Have some respect.

Ive been here since page one Johnny boy

Well do me a favour and pay attention, or at least read up on the previous answers.

(back of an envelope calc suggest around 4GJ of energy stored in the planes mass at that speed, or about the same as an entire tonne of TNT going off. so yes, plenty enough to damage a building!

So a thin skinned aluminium airplane can penetrate to the core and cause sufficient damage, could you scan in and post your back of an envelope calc, keep it simple eh 😉

In fact, it's more amazing that the Towers even survived the initial impact at all!)

So was it the fire or the impact that caused collapse ?

Johnny Boy has established it was fire !

 

Imagine how angry you'd be if someone you loved had been killed and some other idiot was talking total rubbish about the way they were killed.......

If you read about what the relatives of those who died are still dealing with, and not being able to deal with, you'll realise that people discussing their feelings about explanations of the day on a UK mountain bike forum are the least of their worries. Could even be that they're not worried at all.

And some of them are truthers anyway. So I refer you to TGs response, you've been quite happy to get stuck into the discussion too.

Johnny Boy has established it was fire !

I can’t take the credit, but you’d know that if you were paying attention rather than trolling

Nearly every large building has a redundant design that allows for loss of one primary structural member, such as a column. However, when multiple members fail, the shifting loads eventually overstress the adjacent members and the collapse occurs like a row of dominoes falling down.

The perimeter tube design of the WTC was highly redundant. It survived the loss of several exterior columns due to aircraft impact, but the ensuing fire led to other steel failures. Many structural engineers believe that the weak points—the limiting factors on design allowables—were the angle clips that held the floor joists between the columns on the perimeter wall and the core structure (see Figure 5). With a 700 Pa floor design allowable, each floor should have been able to support approximately 1,300 t beyond its own weight. The total weight of each tower was about 500,000 t.

As the joists on one or two of the most heavily burned floors gave way and the outer box columns began to bow outward, the floors above them also fell. The floor below (with its 1,300 t design capacity) could not support the roughly 45,000 t of ten floors (or more) above crashing down on these angle clips. This started the domino effect that caused the buildings to collapse within ten seconds,

...terrorist attack you mentalist.
Care to comment on the fireproof explosives used?

No, because in the words of Mhairi Black, you're chattin' shite hen.

Completely disappear?
Didn't happen ya shitehawk.

You're not suitably equipped for this discussion pet.

the explosives could have been strategically placed below the impact zone, the drone planes hitting exact spots. Entirely plausible.

the rest of your post leaves a bit to be desired.

ook how it came down just like a demolition, case closed.

No it didn't. Nothing like a controlled demolition. Nothing like it at all. In a controlled demolition the entire building falls at the same rate. The WTC didn't. There was a failure over a couple of floors, the top part of the building clearly fell before the bottom part of the building did. Not sure how heavy the top part of the building was - maybe around 10,000 tons? traveling at 20mph, it is going to be pretty hard to stop and can easily over stress steel and reinforced concrete.

assuming you have looked into the construction of WTC 1&2 are you happy that both airplanes(aluminium framed and skinned) hit both towers with sufficient force to not only penetrate the steel outer skin of the building but to also penetrate through the building to sufficiently damage the inner core of the building to such an extent that it would cause a complete collapse

The fact aircraft are made of aluminium is utterly irrelevant. A ton of aluminium weighs the same as a ton of steel and has the same energy at the same speed. The fact is 100,000kg of material slamming into the side of the building is going to do some damage no matter what material it is. But what about engines? 10 tons each of pretty much solid titanium, what about undercarriage, again pretty substantially solid projectile, all the motors, systems, boxes of equipment, avionics etc, seats, luggage, they're all pretty solid structures which became projectiles. The towers were designed to withstand the impact of aircraft anyway. Maybe not a fully laden 747, but upto 727/737 size at least.

The building didn't have a steel outer skin. It was not armoured in any way. It was a steel girder skeleton so perfectly feasible for the aircraft to penetrate the building - girders are designed to withstand forces in compression and tension - not in bending from a side impact. Have you not seen the footage? aircraft clearly penetrating the side of the buildings. You've seen it with your own eyes and yet you doubt it.

Anyway the towers are mostly fresh air with a very skeletal structure. So not that solid or sturdy in relation to impacts from the side:-

[img] [/img]

Thing is though, surely if fire does cause damage to the steel, at best it will only cause localised buckling of the steelwork, which would mean only a small portion of the structure would be likely to collapse...

Erm, yes....localised 'buckling' will do it. A buckled girder no longer has strength in compression. The failure mode of the collapse was an initial collapse localised to one or two floors. The sheer weight of the top part of the building did the rest. Perfectly understandable and explainable with simple engineering principles. The north tower was hit first, but at a higher level, so about 14 floors above the crash level. The south tower was then hit lower down with about 30 floors above the crash level. The South tower collapsed first because of the higher weight of the upper part of the building. Again, perfectly explainable by engineering.

Even with the additional damage sustained from debris and seismic shock, such complete collapse is surprising, if nothing else.

Only to those ignorant of basic structural engineering principles. Steel is not a very good material at elevated temperatures. It looses a significant amount of its strength at a relatively low temperature of 500 ish degs C. Why is it so difficult to grasp the concept that if you significantly weaken the structure of a building it will collapse??? Really, what is so difficult to grasp with that concept?

As the joists on one or two of the most heavily burned floors gave way and the outer box columns began to bow outward, the floors above them also fell. The floor below (with its 1,300 t design capacity) could not support the roughly 45,000 t of ten floors (or more) above crashing down on these angle clips.

wow was this guy in there? How did he survive?

wow was this guy in there? How did he survive?

You really don’t have a coherent argument to make. That is clear

I’m really sorry, but you appear to be struggling to make any kind of coherent point in your posts.

I just want someone to explain to me how they new WT7 was definitely going to collapse, seemingly to the minute.

They didn’t. Do some reading

the explosives could have been strategically placed below the impact zone, the drone planes hitting exact spots. Entirely plausible.

Neither drones nor planted explosives are remotely plausible. [1]

[1] If drones you have to explain how the aircraft went missing without anyone finding out (or any whistle blower coming forward), if explosives you have to explain how nobody noticed them being installed (and why no whistle blower came forward).

are you happy that both airplanes(aluminium framed and skinned) hit both towers with sufficient force

back of an envelope calc suggest around 4GJ of energy stored in the planes mass at that speed, or about the same as an entire tonne of TNT going off

plenty of info out there referencing the core construction, are you confident that the aircraft that hit the towers could damage the cores enough to ensure the collapse

surely if fire does cause damage to the steel, at best it will only cause localised buckling of the steelwork, which would mean only a small portion of the structure would be likely to collapse...

Whathaveisaidnow - Member

the explosives could have been strategically placed below the impact zone, the drone planes hitting exact spots. Entirely plausible.

Below the impact zone?
Of 7 WTC?
You're losing the suspension of your disbelief.

the rest of your post [s]leaves a bit to be desired[/s]...

...is plausible. 💡

the explosives could have been strategically placed below the impact zone, the drone planes hitting exact spots. Entirely plausible.

You seem like a gullible chap, care to help out a Nigerian prince looking to hide his money?

Nearly every large building has a redundant design that allows for loss of one primary structural member, such as a column. However, when multiple members fail,

Ok

The perimeter tube design of the WTC was highly redundant. It survived the loss of several exterior columns due to aircraft impact, but the ensuing fire led to other steel failures.

What other steel failures ? columns ? trusses ? which ones ?

So if the angle brackets failed all around the outer of the core and the inner of the perimeter tube, they must have failed simultaneously or the remaining angle brackets would have slowed the falling of the floors ! it still doesnt explain the total collapse of the core of the building, may I suggest you have a look into that before accusing folk of trolling.

Unless of course it was the impact of the planes which you vehemently refute.

Could people stop asking for "things to be explained" and then not listen to that very explanation!

I have explained in multiple posts how, using science, engineering and physics, the events of that terrible day most probably occurred. If you are so blinkered as to choose to ignore those explanations that is fine, that is your decision, but if so, you can't then ask for it to be re-explained to you.

Until the Ronan Point partial collapse in 1968, nobody really considered progressive collapse, but after that the UK building codes required larger buildings to remain stable if one column was removed. The US codes didn't make this change until after 2001.

greybeard, are those changes covered in these recommendations below, or were they made by someone else? Or were they made to the codes without recommendation? Given NISTs conclusions of single column failure being the cause, I would have thought that would be definitely be in here, but I can only see recommendations to fire protection of steel and items for life safety and evacuation.

[b]What specific code changes based on recommendations from NIST's investigation of the WTC towers have been approved for inclusion in the International Building Code?[/b]
The eight specific code changes adopted in the International Building Code based on recommendations from NIST's investigation of the WTC towers include:
1. An additional exit stairway for buildings more than 420 feet in height.
2. A minimum of one fire service access elevator for buildings more than 120 feet in height.
3. Increased bond strength for fireproofing (nearly three times greater than currently required for buildings 75-420 feet in height and seven times greater for buildings more than 420 feet in height).
4. Field installation requirements for fireproofing to ensure that:
installation complies with the manufacturer's instructions;
the substrates (surfaces being fireproofed) are clean and free of any condition that prevents adhesion;
testing is conducted to demonstrate that required adhesion is maintained for primed, painted or encapsulated steel surfaces; and
the finished condition of the installed fireproofing, upon complete drying or curing, does not exhibit cracks, voids, spalls, delamination or any exposure of the substrate.

5. Special field inspections of fireproofing to ensure that its as-installed thickness, density and bond strength meet specified requirements, and that a bonding agent is applied when the bond strength is less than required due to the effect of a primed, painted or encapsulated steel surface. The inspections are to be performed after the rough installation of mechanical, electrical, plumbing, sprinkler and ceiling systems.
6. Increasing by one hour the fire-resistance rating of structural components and assemblies in buildings 420 feet and higher. (This change was approved in a prior edition of the code.)
7. Explicit adoption of the "structural frame" approach to fire resistance ratings that requires all members of the primary structural frame to have the higher fire resistance rating commonly required for columns. The primary structural frame includes the columns, other structural members including the girders, beams, trusses, and spandrels having direct connections to the columns, and bracing members designed to carry gravity loads.
8. Luminous markings delineating the exit path (including vertical exit enclosures and passageways) in buildings more than 75 feet in height to facilitate rapid egress and full building evacuation.

the explosives could have been strategically placed below the impact zone, the drone planes hitting exact spots. Entirely plausible.

No it's not plausible at all. Drone planes???? The location of every 757 and 767 ever made is known. It is tracked. So where would you source a 757 or 767, make it 'disappear' only to re-appear as a drone? Also aircraft parts are serialised so the manufacturers have confirmed the serial number of every component retrieved from the site. It's impossible.

Even if they were drone aircraft you couldn't fly them accurately to a specific floor. I can't believe you really think this is more plausible than terrorists hijacking aircraft and flying them into the buildings.