Yes. As a floor expands from beneath, where the fire is, it is forced to bow. It first expands its length, and then as it bows, its effective length shortens and it forms a catenary (hanging chain) in elevation.
I lost them on a previous computer. I cannot find them in NIST's new format.
"7 collapsed internally over an extended period and only the facade/skin was left so that's why it fell so uniformly and quickly'... 'the back fell first whilst no one was looking and that's why the facade fell so quickly and straight'.
NIST didn't test for that, which is presumably why they didn't find any evidence. When are you planning on revealing this to NIST... they will be sooooo pleased... ROFLMFAO.
I spent five minutes finding that off the cuff. There's a huge body of evidence out there, lot's of it on truther sites, which confirms NIST's findings.
and an Walter Mitty type imagination? I mean... they could be anything... disturbed owls flying out...explosions... fire...reflections... dust the list goes on... But no I forgot... you will simply tell them who you are and what you say is always right... blah blah... zzzzzzzzzzzzzzzz
Says the guy who keeps posting totally unrelated videos of balls clacking together, choo choo trains and bits of wood on springs... keep it up... all to your usual standard.... pure garbage.
Don't blame me for talking down to you. You are the one that stepped into the hole you're in.
Yep that's excellent.... really pleased you finally managed to learn something.... pictures really are a good teaching aid... hope the big arrows and the 79 helped... carry on learning this fast and who knows where you may end up
I find it laughable that you can maintain this snide, insulting, patronizing attitude from post to post to post without so much as a wag of the finger in your direction. Gotta love that unbiased politeness policy.
It was an impact test. The aim was to produce a specific impact of the sort that might occur in a transport accident. The train would have had enough fuel to achieve impact speed, and no more. There wouldn't be any point.
The obvious point would be in producing conditions that could be comparative to an actual rail accident, in which the engine would of course not be running on empty. It's also entirely obvious the Engine has a a relatively full tank of fuel, given the considerable flaming explosion upon impact... unless that's just the result of 'friction welding'.
It wasn't "superheated". A railgun uses a magnetic linear motor to accelerate any conductor.
The flame was produced through the weapon's firing process, which, as I said, superheats the bolt. When the bolt, traveling at extreme speeds, collided with a concrete wall, there was no spark/flame. Metal impacting concrete/glass/office furniture isn't at all likely to spark/flame. If 'sparks' caused the WTC 7 collapse, it would have to have been from metal-on-metal impacts. Steel on steel impacts would mean a lot of pulverized glass, concrete, insulation, ect. in the air that had previously been between the falling beams from the towers and the standing beams in wtc 7.. not to mention all the massive amounts of dust from the towers the debris would have carried with it.
That comment was actually directed at SR for his insistence on accusing Oxy of rudeness while being very impolite toward him. Still, if you think the shoe fits, go ahead and put it on.
You take the time out to be critical of my post with the flimsiest of misdirection, and then the flimsiest of smears.
I pointed out how a little a train-crash has to do with the subject being discussed. As for 'smears', I don't recall ever leveling an insult against you. You've rather unabashedly tossed several my way.
The reason why you find yourself contradicted, and feel yourself insulted, is that you are [...]. If you find yourself disagreeably dissonant, you should try being correct. You might like it.
The reason I feel insulted now (I didn't prior, as I was hardly a participant in the thread... was simply pointing out behavior toward others) is that you've directly insulted me. You're a generally insulting fellow a fair portion of the time. It's a pity really, as otherwise I'd probably respect your opinion.
Again I would like all to cool down on the personal insults and sarcasm . . . I have begun to send personal messages to the people most involved with copy to MICK . . . please self police yourselves . . . Thanks!
"Friction-fire" is once more a misdirection, and unrelated.
Impact-fire is what I presented. It seems perfectly reasonable to me to show a train weighing about a hundred tons impacting a steel block at 100 mph to demonstrate what the impact of a similar amount of WTC steel traveling at a similar speed would create. The objections about the fuel might seem reasonable until you accept that office furnishings are also just so much fuel. Such an impact will always produce a fire if there is anything combustible present. Get over it.
I find it laughable that you can maintain this snide, insulting, patronizing attitude from post to post to post without so much as a wag of the finger in your direction. Gotta love that unbiased politeness policy.
The obvious point would be in producing conditions that could be comparative to an actual rail accident, in which the engine would of course not be running on empty. It's also entirely obvious the engine has a a relatively full tank of fuel, given the considerable flaming explosion upon impact
I think the engineers were concerned with impact. The "considerable flaming explosion" was probably burning paint. It went out immediately. The fuel in a full tank would have no effect at all on one of those flasks. To affect a flask by heat one would have installed it in a burning derailment of fuel gas trucks with a blevvey. They haven't tried that as far as I know.
unless that's just the result of 'friction welding'.
Obviously not. The bolt was light metal. Had it been superheated it would have glowed.
The flame was produced through the weapon's firing process, which, as I said, superheats the bolt. When the bolt, traveling at extreme speeds, collided with a concrete wall, there was no spark/flame.
Steel makes sparks which ignite things. Lighters spring to mind. But also the impacted areas of the steel can be turned red hot, which also ignites things on a more permanent basis.
I have agreed with you occasionally. It's when you assume an engineer's hat and utter bunk that you'll find me getting descriptive.
The reason I feel insulted now (I didn't prior, as I was hardly a participant in the thread... was simply pointing out behavior toward others) is that you've directly insulted me. You're a generally insulting fellow a fair portion of the time. It's a pity really, as otherwise I'd probably respect your opinion.
103 floors. 210 ft square. 4" thick. Lightweight concrete mix density (est.) 109 lb/cu.ft. gives 73,600 tons, disregarding stair and lift apertures. Show me where I said 40,000.
Estimates of the total weight of each of the working towers vary between 410,000 to 500,000 tons. Obviously the tops of WTC1 and WTC2 weighed less than that - 91,000 and 159,000 tons approx.
I apologise. My memory must be playing tricks. You never said the concrete in each tower amounted to just 40,000 tons; you said 34,000 tons, here: https://www.metabunk.org/threads/10...-there-any-Why-What-About-the-Hot-Spots/page4 in the thread which gave birth to your spectacular 'inevitable, friction welding hot spot core all slagged up theory'!
In replying to my back of an envelope calculation of how much concrete existed in each tower (90,000 tons) and how much energy was required to reduce it in extremis, you said, with typical certainty and the usual embellishments:
No there weren't. There was only the concrete in each floor slab. 34,000 tons per tower. The concrete used in the floors was a special lightweight concrete made by admixing pearlite [Haydite @3/4 inch, actually - and it's perlite]. It has the consistency of tough biscuit and a low density.
Tough biscuit, eh? In the same post you also deny there was any concrete in the core, when I said:
There was undoubtedly a lot of steel reinforced concrete in the core of each tower - but it's not easy to tell how much with the dimensions and system not clear.
Correct me if I'm wrong, but didn't those buildings have stairwells? What might they be made with? Tough biscuits? No, steel reinforced mass concrete. I think I'm happy with my estimate.
You say above:
Estimates of the total weight of each of the working towers vary between 410,000 to 500,000 tons. Obviously the tops of WTC1 and WTC2 weighed less than that - 91,000 and 159,000 tons approx.
I don't see how you can expect to be taken seriously when you haven't even got an idea of the actual weight of the structures. We've been over this before, maybe you forget. We know from the record that there was 80,000 tons of structural steel per tower; previously, on the back of my envelope, I've added 10,000 tons to that to account for plant and reinforcing steel. And then I made an estimate of 550 tons per floor over 110 floors to account for furniture, office equipt., carpet, curtains etc - in other words all the additional live load save for human activity. That makes a grand total of 90,000 (concrete) + 90,000 (steel) + 60,500 (furniture etc.) = 240,500 tons - if you want that in tonnes it's about 244,317. As a professional with nearly thirty years experience in engineering and construction and project/site management and Quantity Surveying, I'm quite confident my figures are right in the ball-park. And, just as a simple example: take that 91,000 tons you quote as the lower figure for the top of the tower - the actual figure would be about 36,500 tons - it makes a difference - a difference of 54,500 (tons).
This (and it is but one example of many many more) all just goes to show that it's pointless 'discussing' such matters with anyone who changes their 'facts' to suit the argument they favour. It's dishonest, that simple.
It seems perfectly reasonable to me to show a train weighing about a hundred tons impacting a steel block at 100 mph to demonstrate what the impact of a similar amount of WTC steel traveling at a similar speed would create.
but its a wholly inaccurate demonstration, given the train is a vehicle with a large fuel-tank, which isn't remotely comparative to a solid steel beam in any respect.
The objections about the fuel might seem reasonable until you accept that office furnishings are also just so much fuel.
No. Office furnishings are office furnishings, not a highly reactive liquid fuel condensed around the area of direct impact. Something being flammable doesn't make it a tank of diesel.
Such an impact will always produce a fire if there is anything combustible present. Get over it.
I try not to patronize or insult anyone on this forum. I'm only aware of having taken a patronizing tone with one other person on this forum, and only when I was being asked to produce verifying evidence for matters of common knowledge. Can you point out where I've ever directly insulted you or anyone else..?
And when you cease interpreting contradiction as insult I'll probably respect yours.
Polyurethane foam, once ignited, can burn rapidly, consuming
oxygen at a high rate and generating great heat. Like any other
organic material, when it ignites and burns, polyurethane foam
liberates smoke containing toxic gases, the primary one being carbon
monoxide. Hazardous gases released by burning foam can be
incapacitating or fatal to human beings if inhaled in sufficient
quantities. Oxygen depletion in an enclosed space can present a
danger of suffocation....
Flexible polyurethane fires generally tend to create very high
temperatures - high enough to damage steel framework of buildings
if enough of a fuel load is involved. Once ignited, foam fires can
spread rapidly, producing intense heat, dense smoke, flammable
liquids, and toxic gases.
For decades, polyurethane foam has been used as filler in upholstered furniture. It can be found in almost every home in America. It is used as padding in sofas, couches, chairs, loveseats, pillows, and mattresses, as well as for padding under carpets.
Polyurethane foam that has not been treated with flame retardant chemicals is referred to as "solid gasoline" by fire experts. Some experts compare sitting on an untreated foam cushion to sitting on a bag of gasoline. When untreated foam is ignited, it burns extremely fast. Ignited polyurethane foam sofas can reach temperatures over 1400 degrees Fahrenheit within minutes. Making it even more deadly is the toxic gas produced by burning polyurethane foam. When it burns, foam emits hydrogen cyanide gas. Hydrogen cyanide gas causes reduced oxygen, and when combined with carbon monoxide, the effects are particularly deadly. Just one breath of superheated toxic gas can incapacitate a person, preventing escape from a burning structure.
Soft in metal has a different meaning than it does in pillows.
If you wish to buy silver, copper or even brass wire for wire working you will need to specify, if you want hard, half-hard or dead soft wire. It refers to how 'workable' or deformable it is. Dead soft is the most flexible, hard will break with a lot of movement.
Steel has similar 'tempers'. The structure of the steel changes in response to heat. I am having problems understanding why you seem to have such a problem in understanding, what seems to me, to be a simple physical fact.
I must be failing to explain it properly.
I will attempt, tomorrow to find a simple explanation of this fact.
Ok. Third time lucky. This is not 'personal' (how could it be?)
Imagine a fifteen year old has some homework on what happens to structural steel after it's been heated and cooled. She Googles her question and up pops your one paragraph, unequivocal statement of fact:
If the steel got to the softening temperature, then it stayed soft and deformable.
The way steel in the manufacturing process is cooled has an effect on the type of steel produced - its flexibility, stiffness, hardness - ductility etc.; but you said:
If the steel got to the softening temperature, then it stayed soft and deformable
in the context of a building fire. Will you accept it is an incorrect statement in this context and in every other possible context?
As an aside, your 'tag line', I think that 'knowledge' is what makes many people fearful, if you think about it - the antidote to fear is not 'knowledge', quite the opposite (it's just a word/thought designed to give the illusion of knowing) - love is the antidote to fear, isn't it?
A Waziristan goat herd hears a buzzing in his ears and is afraid there is something wrong with him. He goes to his father and explains about the buzzing sound in his head. His father tells him it is the sound of US drones over the village. The boy accepts the explanation, the knowledge, now he understands - but is he less fearful?
What is your problem with me? You seem to DISLIKE my tag line.
I am tired of your insults. YOU choose to misunderstand and then attack me, for something that is common knowledge among folks that have EXPERIENCE working with metals.
I have no problem with you, as I said before, it's not personal. I'm worried about that 15 year old. I think it would be better if she came back to find out why she got an F, and now she might find out why. And you could help.
The 15 year old should be looking at a source like the one I posted instead of a discussion on 9/11. No teacher should accept a comment here as a fact.
That 15 yr old is your red herring for your refusal to understand what heating and cooling does to metals.
Pete, if got hot enough, it could retain it permanently. If it was cooled too quickly, it could instead become hard and brittle and even crack. The guys doing the NIST paper knew that.
It appears Jane Stansby's gaff about wtc 7 falling was outdone by CNN at 10 45 a.m... a good 6 hours earlier. Could be 7 was supposed to collapse at the same time as wtc 1, under cover of the collapse and dust.
The plot might well have been to bring down B7 at 10:45 AM in the wake of the destruction from the towers. The explosion reported at this time might have been the one experienced by Jennings/Hess. A botched attempt at demo?
"Aaron, just two or three minutes ago there was yet another collapse or explosion. (I am now out of sight. A good Samaritan has taken me in on Dwayne Street.) At a quarter to eleven there was another collapse or explosion following the 10:30 collapse of the second tower, and a firefighter rushed by us estimated that 50 stories went down."
This all fits with the instructions to evacuate the triage area between 12 noon and 1 p.m... before any fires were really seen.
It appears Jane Stansby's gaff about wtc 7 falling was outdone by CNN at 10 45 a.m... a good 6 hours earlier. Could be 7 was supposed to collapse at the same time as wtc 1, under cover of the collapse and dust.
The plot might well have been to bring down B7 at 10:45 AM in the wake of the destruction from the towers. The explosion reported at this time might have been the one experienced by Jennings/Hess. A botched attempt at demo?
"Aaron, just two or three minutes ago there was yet another collapse or explosion. (I am now out of sight. A good Samaritan has taken me in on Dwayne Street.) At a quarter to eleven there was another collapse or explosion following the 10:30 collapse of the second tower, and a firefighter rushed by us estimated that 50 stories went down."
This all fits with the instructions to evacuate the triage area between 12 noon and 1 p.m... before any fires were really seen.
The 15 year old should be looking at a source like the one I posted instead of a discussion on 9/11. No teacher should accept a comment here as a fact.
That 15 yr old is your red herring for your refusal to understand what heating and cooling does to metals.
Pete, if got hot enough, it could retain it permanently. If it was cooled too quickly, it could instead become hard and brittle and even crack. The guys doing the NIST paper knew that.
Is your statement correct? That once a steel becomes softened by heat it remains that way?
In fact, it's obvious you can't admit your error, so I'll say it again: the statement is wrong. Steel does not remain soft after being heated, it hardens upon cooling. This is very basic stuff.
Polyurethane foam, once ignited, can burn rapidly, consuming
oxygen at a high rate and generating great heat. Like any other
organic material, when it ignites and burns, polyurethane foam
liberates smoke containing toxic gases, the primary one being carbon
monoxide. Hazardous gases released by burning foam can be
incapacitating or fatal to human beings if inhaled in sufficient
quantities. Oxygen depletion in an enclosed space can present a
danger of suffocation....
Flexible polyurethane fires generally tend to create very high
temperatures - high enough to damage steel framework of buildings
if enough of a fuel load is involved. Once ignited, foam fires can
spread rapidly, producing intense heat, dense smoke, flammable
liquids, and toxic gases.
For decades, polyurethane foam has been used as filler in upholstered furniture. It can be found in almost every home in America. It is used as padding in sofas, couches, chairs, loveseats, pillows, and mattresses, as well as for padding under carpets.
Polyurethane foam that has not been treated with flame retardant chemicals is referred to as "solid gasoline" by fire experts. Some experts compare sitting on an untreated foam cushion to sitting on a bag of gasoline. When untreated foam is ignited, it burns extremely fast. Ignited polyurethane foam sofas can reach temperatures over 1400 degrees Fahrenheit within minutes. Making it even more deadly is the toxic gas produced by burning polyurethane foam. When it burns, foam emits hydrogen cyanide gas. Hydrogen cyanide gas causes reduced oxygen, and when combined with carbon monoxide, the effects are particularly deadly. Just one breath of superheated toxic gas can incapacitate a person, preventing escape from a burning structure.
Lee, I am correct and you are not. Yes is can stay deformable, ie 'soft'. The fact that you can READ an article on annealing and then claim "It's got nothing to do with annealing" or is your point that the fires couldn't have heated the steel enough to anneal it? Your post is not clear.
Annealing, in metallurgy and materials science, is a heat treatment that alters a material to increase its ductility and to make it more workable. It involves heating material to above its critical temperature, maintaining a suitable temperature, and then cooling. Annealing can induce ductility, soften material, relieve internal stresses, refine the structure by making it homogeneous, and improve cold working properties.
The crystal structure of the steel is changed. With heat it is changed to austenite, from ferrite. As it cool it can change into other mineral structures as well. Some of those can be very brittle as well.
One the steel was heated in the fire, I was ALTERED. That alteration STAYED. It did not become the same steel it was before being heated.
I am going to suggest a simple experiment for you. Go down to the dollar store and get some cheap screwdrivers. Then using a propane torch, heat 2 of them up to where they glow red in low light. Then quench one in some water and allow the other one to air cool. Then try to bend them. Keep one for a control. Hold them on metal at an angle and hit the blade are with a hammer.
austenitization means to heat the iron, iron-based metal, or steel to a temperature at which it changes crystal structure from ferrite to austenite.[3] An incomplete initial austenitization can leave undissolved carbides in the matrix.[4]
For some irons, iron-based metals, and steels, the presence of carbides may occur during the austenitization step. The term commonly used for this is two-phase austenitization.[5]...
As austenite cools, it often transforms into a mixture of ferrite and cementite as the carbon diffuses. Depending on alloy composition and rate of cooling, pearlite may form. If the rate of cooling is very swift, the alloy may experience a large lattice distortion known as martensitic transformation in which it transforms into a BCT-structure instead of into ferrite and cementite. In industry, this is a very important case, as the carbon is not allowed to diffuse due to the cooling speed, which results in the formation of hard martensite. The rate of cooling determines the relative proportions of martensite, ferrite, and cementite, and therefore determines the mechanical properties of the resulting steel, such as hardness and tensile strength. Quenching (to induce martensitic transformation), followed by tempering will transform some of the brittle martensite into tempered martensite. If a low-hardenability steel is quenched, a significant amount of austenite will be retained in the microstructure....
During heat treating, a blacksmith causes phase changes in the iron-carbon system in order to control the material's mechanical properties, often using the annealing, quenching, and tempering processes. In this context, the color of light, or "blackbody radiation," emitted by the workpiece is an approximate gauge of temperature. Temperature is often gauged by watching the color temperature of the work, with the transition from a deep cherry-red to orange-red (815 °C (1,499 °F) to 871 °C (1,600 °F)) corresponding to the formation of austenite in medium and high-carbon steel.
Maximum carbon solubility in austenite is 2.03% C at 1,420 K (1,150 °C).
Didn't one of y'all guys jump someone for describing the heated steel with a color?
"Temperature is often gauged by watching the color temperature of the work, with the transition from a deep cherry-red to orange-red (815 °C (1,499 °F) to 871 °C (1,600 °F)) corresponding to the formation of austenite in medium and high-carbon steel."
He was right, the person that attacked him was wrong.
Your knowledge of steel/metal seems to be limited.
I suggested elsewhere that the friction of the compacting floors passing the cores produced spherules of iron from the sparks that would have occurred.
Lee, I am correct and you are not. Yes is can stay deformable, ie 'soft'. The fact that you can READ an article on annealing and then claim "It's got nothing to do with annealing" or is your point that the fires couldn't have heated the steel enough to anneal it? Your post is not clear.
Annealing, in metallurgy and materials science, is a heat treatment that alters a material to increase its ductility and to make it more workable. It involves heating material to above its critical temperature, maintaining a suitable temperature, and then cooling. Annealing can induce ductility, soften material, relieve internal stresses, refine the structure by making it homogeneous, and improve cold working properties.
The crystal structure of the steel is changed. With heat it is changed to austenite, from ferrite. As it cool it can change into other mineral structures as well. Some of those can be very brittle as well.
One the steel was heated in the fire, I was ALTERED. That alteration STAYED. It did not become the same steel it was before being heated.
I am going to suggest a simple experiment for you. Go down to the dollar store and get some cheap screwdrivers. Then using a propane torch, heat 2 of them up to where they glow red in low light. Then quench one in some water and allow the other one to air cool. Then try to bend them. Keep one for a control. Hold them on metal at an angle and hit the blade are with a hammer.
austenitization means to heat the iron, iron-based metal, or steel to a temperature at which it changes crystal structure from ferrite to austenite.[3] An incomplete initial austenitization can leave undissolved carbides in the matrix.[4]
For some irons, iron-based metals, and steels, the presence of carbides may occur during the austenitization step. The term commonly used for this is two-phase austenitization.[5]...
As austenite cools, it often transforms into a mixture of ferrite and cementite as the carbon diffuses. Depending on alloy composition and rate of cooling, pearlite may form. If the rate of cooling is very swift, the alloy may experience a large lattice distortion known as martensitic transformation in which it transforms into a BCT-structure instead of into ferrite and cementite. In industry, this is a very important case, as the carbon is not allowed to diffuse due to the cooling speed, which results in the formation of hard martensite. The rate of cooling determines the relative proportions of martensite, ferrite, and cementite, and therefore determines the mechanical properties of the resulting steel, such as hardness and tensile strength. Quenching (to induce martensitic transformation), followed by tempering will transform some of the brittle martensite into tempered martensite. If a low-hardenability steel is quenched, a significant amount of austenite will be retained in the microstructure....
During heat treating, a blacksmith causes phase changes in the iron-carbon system in order to control the material's mechanical properties, often using the annealing, quenching, and tempering processes. In this context, the color of light, or "blackbody radiation," emitted by the workpiece is an approximate gauge of temperature. Temperature is often gauged by watching the color temperature of the work, with the transition from a deep cherry-red to orange-red (815 °C (1,499 °F) to 871 °C (1,600 °F)) corresponding to the formation of austenite in medium and high-carbon steel.
Maximum carbon solubility in austenite is 2.03% C at 1,420 K (1,150 °C).
Didn't one of y'all guys jump someone for describing the heated steel with a color?
"Temperature is often gauged by watching the color temperature of the work, with the transition from a deep cherry-red to orange-red (815 °C (1,499 °F) to 871 °C (1,600 °F)) corresponding to the formation of austenite in medium and high-carbon steel."
He was right, the person that attacked him was wrong.
Your knowledge of steel/metal seems to be limited.
No you seem to be in a novel of your own beliefs. One where you deny that steel changes when it is heated and that those changes can remain afterward.
You can cool it with the 'talking down' to me. I am tired of it. I have given you plenty of sources to understand my point and you seem to refuse to accept any of them. I wonder why? Could it be that they punch a hole in your conspiracy theory?
Cairenn, the issue here is that annealing is a timed process through which metal is heat-treated, so it becomes softer and more workable upon cooling. That's different from steel being brought to the softening temperature, at which it begins to deform or even sag/drip/flow. You made the statement:
If the steel got to the softening temperature, then it stayed soft and deformable.
But obviously when a steel beam gets to such a temperature that it starts to deform, it wont remain in a state as soft as that when it has cooled. Its composition would certainly have changed, and it may be more flexible/brittle, but it's not going to stay in the state it was in while hot. To use your own screwdriver example: if you held that blow-torch (maybe make it a welding torch) on the screwdriver long enough for it, being held outward, to droop toward the ground under its own weight like a 'smoking causes impotency' ad, could you wait for it to cool and then bend it back into shape with equal ease? Of course not.
No you seem to be in a novel of your own beliefs. One where you deny that steel changes when it is heated and that those changes can remain afterward.
You can cool it with the 'talking down' to me. I am tired of it. I have given you plenty of sources to understand my point and you seem to refuse to accept any of them. I wonder why? Could it be that they punch a hole in your conspiracy theory?
It can and I have answered you MULTIPLE times. Why do keep asking the same question? If you had read the links I posted you would know that it can and that how it is cooled that change it.
I feel that you are now badgering me since I have EXPLAINED it to you several times.
Right. So in wtc7 a beam has been badly fire damaged to the point that it sags (try and imagine the connections didn't fail, because that would be almost like reality). The fire has moved on to greener pastures having exhausted the fuel in the area of the damaged steel, so the steel cools to ambient temperature; is that steel, now it's cooled, 'soft and deformable' as a result of being over heated previously?
YES. I have answered you multiple times, why are you badgering me over it? When steel is heated to a certain temp, it changes into a softer and more malleable metal. It loses the crystlline stucture that gives it strength. It is SOFTER, not like semi molten steel, but much softer and more workable than it was before. It becomes weaker also. If it is quickly quenched, it can become hard and brittle and the rapid cooling can cause the metal to crack.
Sword makers have reported blades that broke in half without any impact from the cracks. There is a reason that in many cultures the blacksmith was considered to have special powers.
of how much concrete existed in each tower (90,000 tons) and how much energy was required to reduce it in extremis, you said, with typical certainty and the usual embellishments: Tough biscuit.
Yep. Fill concrete with air holes and that's what you get.
In the same post you also deny there was any concrete in the core, when I said "There was undoubtedly a lot of steel reinforced concrete in the core of each tower - but it's not easy to tell how much with the dimensions and system not clear", (and) you said "I don't think that there was any at all. The cores were steel alone. The dividers/partitions were wall boarding". Correct me if I'm wrong, but didn't those buildings have stairwells? What might they be made with? Tough biscuits? No, steel reinforced mass concrete. I think I'm happy with my estimate.
You may be correct, and the people that found a stairwell and escaped lied when they said they used a scraper to hack their way into a staircase and escape. Or they were extraordinarily strong...
I don't see how you can expect to be taken seriously when you haven't even got an idea of the actual weight of the structures. We've been over this before, maybe you forget. We know from the record that there was 80,000 tons of structural steel per tower; previously, on the back of my envelope, I've added 10,000 tons to that to account for plant and reinforcing steel. And then I made an estimate of 550 tons per floor over 110 floors to account for furniture, office equipt., carpet, curtains etc - in other words all the additional live load save for human activity. That makes a grand total of 90,000 (concrete) + 90,000 (steel) + 60,500 (furniture etc.) = 240,500 tons - if you want that in tonnes it's about 244,317. As a professional with nearly thirty years experience in engineering and construction and project/site management and Quantity Surveying, I'm quite confident my figures are right in the ball-park.
Still makes not the slightest difference to my argument that the hotspots were produced by the potential energy of the towers. It just makes a slightly smaller quantity of hotspot likely - if you were correct, which the above illustration debunks rather.
This (and it is but one example of many many more) all just goes to show that it's pointless 'discussing' such matters with anyone who changes their 'facts' to suit the argument they favour. It's dishonest, that simple.
Well, you would say that, wouldn't you? What else can you do? You don't want the real explanation for hotspots when you're trying trying to propagate some thermite inside-job myth.
The thing is that we real engineers get out our calculators and can figure out quite quickly what proportion of that 110,000 kW of potential energy found its way to the basement to manifest itself as hotspots, while people like you look for paint residues and grind your teeth.
Right. So in wtc7 a beam has been badly fire damaged to the point that it sags (try and imagine the connections didn't fail, because that would be almost like reality). The fire has moved on to greener pastures having exhausted the fuel in the area of the damaged steel, so the steel cools to ambient temperature; is that steel, now it's cooled, 'soft and deformable' as a result of being over heated previously?
Lee, your ignorance of metallurgy is astounding. Cairenn has provided you with a wealth of information, but you insist on being willfully ignorant.
A steel beam is hardened to a specific level to provide strength and flexibility depending on its intended use. If you heat steel to red hot and let it air cool it is annealed, the crystalline structure of the steel has cooled to a random mass. If you beat it with a hammer, you work-harden it. This is the same process as taking a soft steel hanger and bending it back and forth until it breaks. Each time you bend it, you align the crystalline structure a little more and harden it until it becomes brittle and breaks.
Structural steel is heat tempered to harden it. Steel is heated to a specific temperature to allow the crystalline structure to align in a certain way and the temperature is slowly reduced over hours, sometimes days, so the alignment remains unchanged during cooling.
but its a wholly inaccurate demonstration, given the train is a vehicle with a large fuel-tank, which isn't remotely comparative to a solid steel beam in any respect. No. Office furnishings are office furnishings, not a highly reactive liquid fuel condensed around the area of direct impact. Something being flammable doesn't make it a tank of diesel.
The train was a hundred tons of steel doing a hundred miles an hour. Its chassis comprised two very solid beams. An impacting WTC tower panel was also a hundred tons of steel doing a hundred miles an hour. The fire in the train test wasn't a fuel fire. It was more likely a paint and driver cabin furnishings fire.
Yes, remarkable that gasoline didn't catch fire. Perhaps it was a diesel car. It's amazing how crumpling absorbs energy, isn't it? Low mass. Right speed. Low impact energy. A hundred times too low.
So before I 'get over it', care to provide any proof whatsoever?
Proof of impact I have supplied you with already. You have not come back with a match. I have shown you a hundred tons of steel doing a hundred miles per hour. You haven't, which has apparently saved you from getting over anything.
I try not to patronize or insult anyone on this forum. I'm only aware of having taken a patronizing tone with one other person on this forum, and only when I was being asked to produce verifying evidence for matters of common knowledge.
Apart from the implied double insult to the NIST engineers and all the world's engineers who agree with the NIST Report, including myself, no. But those are constant insults with you.
This is a direct insult mocking my choice of words, not a 'contradiction'. Own up to it at least.
The train was a hundred tons of steel doing a hundred miles an hour. Its chassis comprised two very solid beams. An impacting WTC tower panel was also a hundred tons of steel doing a hundred miles an hour. The fire in the train test wasn't a fuel fire. It was more likely a paint and driver cabin furnishings fire.
Low mass. Low speed. Low impact.
Bags of mass. Low speed. Had it been really quick there would have been a large impact and something would have caught fire.
Low mass. Low speed. It probably ran out of gas. If it didn't, it stalled. Not much of an impact.
Yes, remarkable that gasoline didn't catch fire. Perhaps it was a diesel car. It's amazing how crumpling absorbs energy, isn't it? Low mass. Right speed. Low impact energy. A hundred times too low.
Proof of impact I have supplied you with already. You have not come back with a match. I have shown you a hundred tons of steel doing a hundred miles per hour. You haven't, which has apparently saved you from getting over anything.
Well we all fail sometimes.
Apart from the implied double insult to the NIST engineers and all the world's engineers who agree with the NIST Report, including myself, no. But those are constant insults with you.
Certainly not. I was being sympathetic. My sympathy might increase were you not to be so unwilling to understand anything.
All you do is bait and insult... back up what you say and stick to the question in hand. What you call 'insulting NIST and those who support them' is known as due process and peer review... get over it. So far, people still have the right to do that. The rules of the forum are that it should be done politely. I suggest you make a far better effort to do that in future.
