[Closed] 9/11 documentary

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

So answer my second question then !

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

I call that reviewing !

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

It's irrelevant that they were aluminium - that mass of water at that speed would have made the same size hole

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

My calc is near 6GJ - and I did also calculate once that the chemical energy in the fuel is about 3 orders of magnitude bigger.

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

Unlike most buildings, the cores in WTC 1 and 2 were not the primary structure, that was the perimeter columns.

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...

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.

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.

cheekyboy

So if the angle brackets failed all around the outer of the core and the inner of the perimeter tube, they [b]must[/b] have failed simultaneously or the remaining angle brackets [b]would[/b] have slowed the falling of the floors !

I've highlighted two of your words.

Please show the mathematics to support those assumptions. If you are unable to provide the mathematical proof(s) then you cannot use those two highlighted words.

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,

Based on your failure to understand the science or your disregard for the information provided,,I don’t think there’s a way to dumb this down to a level you’ll understand. Sorry

I have never been so enthralled by a thread, or more aware of complete refusals to acknowledge logically and accessibly presented science. Almost replied to a JHJ post too!

It’s actually quite depressing how people who claim to seek the truth are so eager to ignore it.

Please show the mathematics to support those assumptions. If you are unable to provide the mathematical proof(s) then you cannot use those two highlighted words.

I asked first !
(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!)

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

You are hiding behind academic drivel, try answering my questions re: the core, how did the core collapse, impact or fire

Keeping it simple for you,

Velocity x Mass = Force

Now your turn.

Velocity x Mass = Force

Maybe that's what 'they' want you to think?

academic drivel?

So now you are suggesting the very foundations of modern society are wrong?

For example, what are you sitting in front of right now, typing on? A computer, and that computer was developed by scientists and engineers using the laws of science that a vast number of people way cleverer than you have developed over thousands of years. Those laws enable us to do things like make computers etc.

It's your choice if you want to be an ignorant simpleton, But you can't have it both ways. You ask for things to be explained, but not using science. Well not using science means using beliefs and superstitions, which is precisely the reason that people without the necessary scientific aptitude believe fallacies such as the "fact" that an aluminium aeroplane couldn't damage a steel tower......

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

‘King hell, how many times do you have to be beaten over the head with the evidence before you start to pay attention and understand what you’re being told?
[b]What. Drone. Aircraft?[/b]
As has been pointed out repeatedly, remote-piloted aircraft are the least plausible answer, because, as was pointed out above, all aircraft are tracked, their whereabouts in flight known, serial numbers of all components on record, but even if someone had magically conjured up four ghost aircraft, flown by remote control, kindly explain where the other four aircraft that took off on scheduled flights went to, with all the several hundred passengers that were on board.
Or are you seriously suggesting that ‘they’ managed to lose four aircraft, while they were in flight, with all the passengers, and put the identical four ‘drone’ aircraft into the exact same airspace, [b]without a single person seeing it happen on radar?[/b]
And presumably murder all the missing passengers and destroy the inconvenient planes they were in.
Hey, maybe they did, by flying them into the Twin Towers and the Pentagon!
Oh, wait...
Christ, this just goes round and round, like a dog chasing its tail, with about as much intellectual coherence. 🙄

Actually it's

Acceleration x Mass = Force

F = MA

(Velocity x Mass is proportional to Energy)

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

What was the outer skin of the building made up of then ?
who stated it was armoured ?

impact or fire

does it have to be mutually exclusive?

how about, cumulative damage incurred through a combination of impact from a big object at high velocity, explosion (of jet fuel + massive energy release from impact), and resultant unchecked fire caused a number of structural overloads resulting in various load bearing elements no longer being able to withstand the forces involved, which in turn caused localised failures and thus initiated a cascade collapse, at which point gravity took over, and well, you know the rest...

What. Drone. Aircraft?

Come on, get real!

We're talking about a government that's demolished the World Trade Centre! You don't think they're capable of mustering a couple of drone planes from somewhere?!

Actually it's

Acceleration x Mass = Force

F = MA

(Velocity x Mass is proportional to Energy)

OK so where does the 4GJ come from and how was that force distributed acros the impacting surfaces of the aircraft to the building ? any theories as to the core yet ?

cheekyboy, what is the point you're trying to win here? Is it that crashed aircraft couldn't destroy the towers?

If so, for the sake of moving the debate on, maybe the non-Truthers and Truthers could all temporarily accept that hypothesis, and move on to the obvious next question:

If planes can't destroy the towers, why did the Lizard Overlords behind this choose to use planes as their cover story? They must have known planes can't destroy towers, because they had to hire a team to demolish the buildings with explosives.

and resultant unchecked fire caused a number of structural overloads resulting in various load bearing elements no longer being able to withstand the forces involved, which in turn caused localised failures and thus initiated a cascade collapse, at which point gravity took over, and well, you know the rest...

Unchecked fire causes structural overloading ? What do you think Max ?

nice selective quoting there, you even started it with the 'and' to show that you missed the rest of it, was that deliberate?

In answer to your question - It might, if there was also other damage, from a plane impact and an explosion...like the rest of the post said.

I could probably kick one leg out from a chair with you sitting on it and it'd not collapse, but it sure as heck would if I'd already kicked out one of the other legs.

any theories as to the core yet ?

What are you getting at here, suggesting that the core should have still been standing even if the rest collapsed? 'Cos it doesn't work like that...

Unchecked fire causes structural overloading ? What do you think Max ?

Prove it doesn’t

Those clips! That was the problem!

cheekyboy - Member
What was the outer skin of the building made up of then ?

Do you know know? If you don’t understand anything about the design and construction of the WTC how are you equipped to debate these issues?