Thermite bombs !!! add water increases the heat!!!!!

Too many testified that bombs went off on basement lever 3 of the World Trade Centers 20 ,im before any airplane hit the building. Too much suspicious activity weeks before the 911 attack. New Owner increases the insurance policies. Maintance people working 12 hours shifts for 2 weeks before the attack and no one knows what they were working on.

That pool of white hot liqiud metal at the bottom of the pile of ruble could one be causes by one thing. Thermite.

Oh...I get it.

They blew up the buildings and just by chance some passing aeroplanes flew into a couple of the towers on the same day...

It all makes perfect sense now.

There was a parking garage in Bailey Crossroads, Virginia that pancaked straight down when the top floor support failed. I think the time was about '73. I believe there was also one in New Haven, CT with the same pattern but can't put a time on that. The trouble is that falling debris doesn't know about the nearby low resistance paths and doesn't know how to get there anyway. The collisions are fairly inelastic so debris stays together.

Well said, you nicely illustrate how the 'experts' and conspiracy theorists ignore or don't look for evidence which contradicts their assertions...

Del

_{(Unless of course it was a conspiracy between the motor manufaturers, aliens, AlQaeda and the CIA as part of an evil plan to extract higher parking fees from motorists...yeh that'll the explanation.)}

Wal-mart has a sale on aluminum foil, you need anothe layer.

I like your "its the only steel building to ever fall" What load of crap. When was the last building fire on a building over 20 stories?

I see you are not an engineer.

I don't normally like conspiracy theories, although there is that photo of Lady Bird sitting on the Grassy Knoll with an M40A1 that's hard to ignore.

But, there have been a number of fires in buildings higher than 20 stories. Shanghai, Caracas, Dubai, Madrid, Philadelphia, and Las Vegas (I think) have had fires, but I don't know which floor the fires were on.

The WTC was unusual in that there was almost a "perfect storm" of design flaws that led to the failures. Have you seen the structural engineer's analysis? Those odd beam hangers that had only to soften a bit were the proximate cause, I think. I believe most steel framed buildings would not fail in an ordinary fire.

My first job was in the demolition business, and whenever the local news would run footage of a building implosion, I was drawn to watch it. I noticed that a series of small explosions would occur down the center of the building, and then the sides would fall in towards the middle. You don't see that with the WTC collapses.

Now, about this crap that "jet fuel doesn't burn hot enough to melt steel" - IT DOESN'T HAVE TO! It only had to burn hot enough to weaken the steel so it couldn't support its load. And I have seen something that tells me it could burn that hot.

One night I went down an on-ramp to US75 on the west side of Tulsa, heading south. As soon as I turned onto the ramp, I saw a large red glow in the distance. A fuel storage tank north of Glenpool had caught fire. The tank held regular fuel such as gasoline or diesel, not jet fuel. I drove by the remains of the tank several days later because I heard on the news that the sides of the tank had buckled, and I wanted to see for myself. They had curled in, much the same way a piece of paper curls as it burns.

I'm sure that jet fuel burns hotter than regular fuel. When I sold auto parts, several of my co-workers were involved in the local racing scene. Some of them mentioned that some racers would buy avgas (aviation fuel) because of the higher octane (and thus higher oxygen content) than what they could get from regular fuel and not have to use octane booster.

Conspiracy theorists, you can rant and rave all you want. You will never convince me. You might be skeptical of the government, but I am skeptical of you because of what I have seen and heard.

If I remember correctly, AVGAS was a high octane petrol for aircraft with petrol engines. Jets use a fuel similar to parrafin or kerosene, not AVGAS!!!

I do believe that it (Jet fuel) can burn very hot though, a conventional jet engine burns this fuel at around 2000°C.....more than enough to soften iron/steel girders.....

Well, I didn't say that jets run on avgas, or that jet fuel and avgas are the same. I just wanted to point out that aviation fuels are more potent than fuels for surface vehicles. They have to be, because they have to burn in a thinner atmosphere. I knew someone would jump in and fill in with extra info. Thanks for responding, Andy.

Now ignite a large volume of aviation fuel at or near the surface of the Earth, where the atmosphere is richer in oxygen, and you have a very hot fire.

stop 3doug. You are over your head. Flame temperatures are a function og the number of H and C bonds. The fewer the bonds and more of H's versus C's makes for a hotter fire.

Octane has nothing to do with O in the fuel, by definition 100 octane is 100% iso octane, look ma, no O's.

So C2H2 acteylene burns hotter than C3H8, propane. see the trend.

Hang on a minute, this is all immaterial as pointed out in the original post, tower 7 was not hit by an aircraft so whether jet fuel avgas or ordinary petrol burns hotter than one another doesn't matter. The place wasn't an aviation filling station so there was no fuel there.

Al

Guys,

Sparky was the OP but he was quoting a BBC commentator. The original story mentioned diesel fuel stored in the building. I don't know about the quantity, but I worked in a large hospital where the diesel generators and fuel were kept on the top floor, so that seems pretty reasonable.

I think the only question is whether diesel without forced air burns hot enough to significantly weaken steel.

Anybody got a ready demo of that?

Well, last night i was burning a wood fire in my firepit and there is a welded steel grate. Apparently I had the wood burning hot enough to allow the grate to buckle. It sagged nicely...

I did have a bellows.

My guess is that there is a bit of a draft/ breeze on the upper floors of the building. not to mention convection drafts.

The low carbon structural steel will change microstructure to fully austenite at 1700 degrees F if low carbon; 1600 if higher Carbon. At this change, all prior mechanical properties from cold work, precipitaion, etc are erased.

Actually, at about 1350 F most mechanical properties are in flux.

http://www.ductile.org/didata/Section7/figures/fig7_2.GIF

milo "How clever that the DOD people could stage a flippin controlled demolition right in the middle of town, on virtually no notice,but couldn't get water and supplies to N'awlins with days of warning..."

steels first phase change is at around 1000 F. ASTM A53 steel goes from a yield strenght of 48ksi at 150 F to 7.5ksi at 1000 F at 1100F it 2.2ksi.

I don't think that that is a phase change, I think that is just a stress relief. I do not have elevated temperature data for pipe ; However a53 is 30 max Grade B, or .25 grade A.

I stand behind my phase change post, I accept that your data indicates a change of properties at the temperatures you describe. I do not see that as a phase change.

On heating, steel the following happens : 1) relaxation;2) grain growth, recrystalization. I do not see recrystalization at 1000F.

milo

i just remember from met 200 class I took as a free elective that mild steels go through their first phase change around 1000 F, additional "carbons" can move that point.

The temperatures I quoted and strenghts were to illistrait that you do not have to melt steel just heat it enough and its strenght drops nonlinearly.

Hey. Non-linearity of strength loss is right on.

Around 1000 is a bit low the link I posted above is the iron iron carbide equilibrium diagram and you'll see at that low a temp its ferrite and Iron carbide

___^

The steels we're discussing are to the far left of the diagram, left of the first vertical line ( which is .50 C wt %) about halfway.

Property change YES on heating, Phase change below 1000 degrees, i disagree.

(The eutectoid temperature is 723 C or 1333 F. WhHich i will agree, is "about" 1000F. In a very broad sense. The Eutectoid temperature line divides the ferrite and austenite phases)

My compliments on what you learned in your electives class. Most students study for the test and forget.

You clearly learned the material and more importantly the first principles- how stuff happens!

milo

thanks. I just use the charts now for piping design. I try to mentor the young engineers on the principles, my motto is "if you can't do it by hand (or as you said principles and how stuff happens), don't try to use a computer program to get your answers" So many times the new generation throws numbers into a program and they don't understand the results. When quizzed about the input, they don't understand the principles enough to know when the inputs are illogical.

I myself find it hard to believe that a building would/could collapse after a fire, but what do I know? I build them, not design them. I have problems with the whole 911 thing though. I think the gov't was looking for a modern Pearl Harbor, an excuse if you may, to go into the middle east (especially Iraq). I was watching something the other day on PBS about how the upper echelion reacted during and after the 911 attacks and almost immediately the powers that be were saying that Hussein was involved and that they were going to be going after him and after bin Laden as well. Call me a conspiracy theorist if you will, have fun even, I just do not think that our gov't would be above this type of act (sad to say, I know but...). I found something the other day while I was looking up flouride and how bad it is for us, as a people; especially, our children. (Hmmmmmmm, google flouride in toothpaste for more 411) I found a mention of something called directive 51, look it up it is kinda scary if it is used inadequately by the powers that be... huh, maybe I am just a CT (conspiracy theorist) at heart... No sweat off of my back, nor yours for that matter. Did you ever see the movie Men in Black? Where the guys used rags like the National Enquirer to get the real news because all of the other news outlets weren't reporting real info? (honestly; though, I do not read these rags. In fact if I am reading anything it is either a book, or I am here or googling something that I had heard about)

Cheers Ferris

I personally do not have the deep technical knowledge of steel, though I did learn how to bend and forge steel when serving in the RN, at high temperatures using a coke forge with blown air. You could get the steel to a very light yellow in color without any trouble at all, I have no idea what temperature that was exactly, but it had the consistency almost of butter (compared to its cold strength!) at that point and could be easily and quickly shaped with properly aimed hammer blows.

Even at cherry red it was possible to reform fairly easily.....

Which tells me that the strength of steel, is severely curtailed when hot and it would not surprise me to find out that steel had lost say 50% of its strength, even before getting to cherry red.....it would be nice to find out that for certain though.

Although all this talk about phase change and other properties of steel is quite interesting, it is not really going anywhere near to the original points of the Blog itself.

As to a Conspiracy with regards the US government blowing up these buildings and getting crazy Arabs to fly planes in at around the same time, its really difficult for me to believe....

I cannot and will not go for that far in trying to believe in a conspiracy and the massive and secret timing that would have needed to be made with the whole planning (it might make a good film or Tom Clancy book though!), too difficult to time, too easily could the timing have gone off, it would also serve no purpose for any logically minded person anywhere, and certainly not a US Presiden, no matter what the flavour!!.....

Was it not Clinton that sent missiles into Pakistan(?) or somehwere near to there, to try and kill Bin Laden, before Bush even took office? maybe thats what made BL sour over the USA in the first place?!!!

Even someone just thinking that ANY president of ANY western nation could try and plan and carry something like that shows that person to have severe personal/mental problems in the first place!

Sadaam Hussein is dead, but he is just about the only person that MIGHT have tried to do such a thing (but was not a president of a western country by the way!), which is why his name was bandied around at the time as was Bin Laden's name.....till of course the secret service found out more details!!

In fact, I would go as far as to say that those people who believe in such conspiracy theories are "totally off their rockers!" but if that is how they get their "Rocks off", then leave them to it I say, its better that than some of the other things a sick mind could get busy at!!!

These "conspiracy believers" could of course leave the country that bore them and where they have their jobs and family and go somewhere else where it is a lot "better".....only thing is they have a long search in front of them!!!! Which is why they stay at home and just complain and make up stupid fairy stories!!!

My Brother is one of these people who believe in such theories too and a least liked person/character, with such tendencies as he shows, demonstrates my thinking completely on them as a whole....and he is sadly not alone.

The Conspiracy believers are really people with massive personal problems, that are not quite enough to actually get them put away for good - sadly!

For anyone who really wants to know how the buildings went down and why should read the US Magazine PM's explanation, it fits all points, and also does not accuse the US Government of being involved, only in being slow to catch up if I remember correctly!!!

GA for you, I agree entirely.

The founder of the group, Richard Gage, says the collapse of the third tower is an obvious example of a controlled demolition using explosives.

"Building Seven is the smoking gun of 9/11… A sixth grader can look at this building falling at virtually freefall speed, symmetrically and smoothly, and see that it is not a natural process.

"Buildings that fall in natural processes fall to the path of least resistance", says Gage, "they don't go straight down through themselves."

All Towers of 9/11 and all air crashes pentagon/wherever were controlled demolition.

Watch the CD of GEO "Loose Change 2nd Edition" - A revealing documentary that delves beneath the official version of events to expose the truth of what really happened on 9/11.

It is not obvious from your post as to whether you are a supporter or not of the conspiracy theory.......which is it please?

whether you are a supporter or not of the conspiracy theory.......

It is not the question of being a supporter or not. I was actually near there when this happened and for days I watched smoke from my apartment window (the twin towers were no longer there). First I was angry at Osama Bin Laden & the talibans or the arabs for the loss of thousands of innocent human lives (still cannot shake off a pitcture that was in a leading newspaper with a man in a maroon shirt falling head down from one of the towers). As the smoke settled with time and you start reading that it was a planned thing it make me just MORE ANGRY for, you can expect anything from a terrorist attack but if it was planned then whose side would one take?

You are right on all counts, it was a planned terrorist attack, but not by anyone calling themselves an American, it was Bin Laden and his motley crew.....they caught the US Secret service sleeping......not the first time either......sadly.

The planning was badly made by the people concerned, which indicates to me a further reason to show that no government fingers were in the Pie, if they had sent the aircraft in an hour or more later, the loss of life would have been much much higher.........

I think it true to say all of us in the free western world were completely shocked for many days afterwards, my Wife was in a terrible state, I had to leave work early just to comfort here.

Yes I agree with you. However, if you can get hold of the Video of GEO I mentioned (try asking any Pakistani if you come across). If they cannot understand the english version name, ask them the urdu version name"khota sikka" (bad coin).