It looks like you're using an Ad Blocker.

Please white-list or disable AboveTopSecret.com in your ad-blocking tool.

Thank you.

 

Some features of ATS will be disabled while you continue to use an ad-blocker.

 

How Does Aluminum Cut Steel?

page: 57
13
<< 54  55  56    58  59  60 >>

log in

join
share:

posted on Dec, 27 2007 @ 02:03 PM
link   

Originally posted by OrionStars

Originally posted by jfj123
reply to post by OrionStars
 


I may be "black and white" for you. But it is hardly "black and white" for any scientiest, particularly a forensic scientist.

[edit on 27-12-2007 by OrionStars]


Should read It not I at the beginning of the sentence. The editor seems to be inconsistent with what can and cannot be edited in each post. How does one make corrections or add text when editing? All I see is an edit post button rather than a post button after editing. Sometimes my edit takes on preview and re-post, and sometimes it simply takes on preview but not re-post, no matter how many times I correct and preview the edit. The preview states it is edited. But when re-posted, there is no edit.




posted on Dec, 27 2007 @ 02:23 PM
link   
When there is a building fire, glass normally breaks and explodes out because of the pressure of hot gases building up with no place to go, and not due directly to fire being applied to glass:

www.doctorfire.com...

Glass breakage in fires
...by Dr. Vytenis Babrauskas, Fire Science and Technology Inc.

"The size (more technically, the heat release rate) of fires is limited by the flow of oxygen available to it. In all except very rare circumstances, the flow of oxygen into a room comes largely from open doors and open windows, and to a slight extent from any mechanical ventilation systems and from building leakage. Once a fire gets going, however, windows previously closed may crack and break out. Or...they may not. The results will often be drastically different, depending on whether the windows break or not. Thus, it becomes of significant interest to be able to predict if, and when, glass may break out.

Here, an important distinction needs to be made. When a window pane of ordinary float glass is first heated, it tends to crack when the glass reaches a temperature of about 150 - 200ºC. The first crack initiates from one of the edges. At that point, there is a crack running through the pane of glass, but there is no effect on the ventilation available to the fire. For the air flows to be affected, the glass must not only crack, but a large piece or pieces must fall out.
____________

The National Research Council of Canada (NRCC) has had a program for developing sprinkler protection for glazing. As part of that work, a few non-sprinklered tests have been run where glass 6 mm thick tempered glass was exposed to simulated room fire conditions, but without a sprinkler [9]. While such glass type would only be common in commercial buildings, the results are nonetheless of interest. Tempered glass behaves differently, in that it shatters upon initial cracking, but the initial cracking does not occur until the glass reaches rather high temperatures. An exposed-surface temperature of 290-380ºC has been found to be needed, with the unexposed surface temperatures being about 100ºC lower. Such glass temperatures are normally not reached until after room flashover has occurred. In a later study [10], NRCC examined glazing using radiant heat exposure. Under such conditions, "plain" glass of unspecified thickness was found to "break" when the exposed side reached 150-175ºC, with the unexposed side being at 75-150ºC.

Shields [18] conducted a number of room fire tests using 6 mm thick float glass and showed that first cracking does not occur until the bulk glass temperature reaches around 110ºC. This corresponds to a heat flux of around 3 kW m-2.


150 - 200ºC is 302 - 392ºC.



posted on Dec, 27 2007 @ 02:37 PM
link   

Originally posted by OrionStars
When there is a building fire, glass normally breaks and explodes out because of the pressure of hot gases building up with no place to go, and not due directly to fire being applied to glass:


But the WTC builidng had holes in them from the planes so the pressure and gas had places to go, and we still did not have glass breaking from the fires.



posted on Dec, 27 2007 @ 02:52 PM
link   
So back on topic. How can aluminum (a softer substance) damage steel (a harder substance). Obviously there are many factors going into this.

Obviously momentum comes into play.
the mass of each item and how the mass of the item is arranged. For example an aluminum tipped arrow can easily penetrate a thin sheet of steel if fired from a bow.

So under certain circumstances aluminum can damage steel. Hopefully everyone is on board with this?



posted on Dec, 27 2007 @ 02:58 PM
link   
reply to post by ULTIMA1
 


I understand. However, when all that dense black carbon smoke lingers and blocks exits, while atmospheric oxygen supply has been greatly utilized by the fire, lighter gases build up behind that smoke wall, and need somewhere to rapidly go. Hence, exploding out the windows for more atmospheric oxygen intake to keep the fire going, and release of explosive gases and other carbon impurities smothering the fire, due to lack of oxygen already absorbed by the fire.

The article I referenced explains using flasshover explanation.

Oxygen is utilized by fire, which expends carbon, hydrogen, nitrogen and other gases inside an envelope of smoke.

Such gases as hydrogen and nitrogen can be highly volatile combined with heat and bonded with other gases, particularly when contained with nowhere to go.

en.wikipedia.org...



posted on Dec, 27 2007 @ 03:26 PM
link   

Originally posted by jfj123
So back on topic. How can aluminum (a softer substance) damage steel (a harder substance). Obviously there are many factors going into this.

Obviously momentum comes into play.
the mass of each item and how the mass of the item is arranged. For example an aluminum tipped arrow can easily penetrate a thin sheet of steel if fired from a bow.

So under certain circumstances aluminum can damage steel. Hopefully everyone is on board with this?


Certainly got me in agreement there. We have managed to land a 767 inside a steel walled building at over 400mph in tragic circumstances.

All the discussion of fire properties and behaviour seems to confirm that the fire was delivered through the walls just as we observed although there is evidence of a lack of understanding of the science of that.

Apart from the massive kinetic energy of the 100 000kg+ of plane smashing its way in, there is also the considerable potential energy in chemical form of the ~10 000 gallons of fuel to contend with. This is enough energy to raise 100 000kg mass to near 10 000m above the ground and move it across a continent at 500mph with capacity to spare. How much damage could that potential alone do if expended in less than an hour in a confined area? I suggest a huge amount (as witnessed).



posted on Dec, 27 2007 @ 06:06 PM
link   
reply to post by Pilgrum
 


Unless someone can prove any aluminum skinned plane actually penetrated two exterior steel walls of either twin tower, the question"How Does Aluminum Cut Steel?" is a moot point. It has not been proved any alumunim skin cut through two exterior steel walls of either twin tower.



posted on Dec, 27 2007 @ 07:28 PM
link   

Originally posted by OrionStars
reply to post by Pilgrum
 


Unless someone can prove any aluminum skinned plane actually penetrated two exterior steel walls of either twin tower, the question"How Does Aluminum Cut Steel?" is a moot point. It has not been proved any alumunim skin cut through two exterior steel walls of either twin tower.


I didn't realize the exterior wall were solid steel walls? Could you please post information to support this? Thanks.



posted on Dec, 27 2007 @ 07:36 PM
link   

Originally posted by ULTIMA1

Originally posted by jfj123
So now I'm asking you for the 5th time. Are you going to post the information you claim to have in your above statement? YES or NO?



www.tms.org...

The fire is the most misunderstood part of the WTC collapse. Even today, the media report (and many scientists believe) that the steel melted. It is argued that the jet fuel burns very hot, especially with so much fuel present. This is not true.

Part of the problem is that people (including engineers) often confuse temperature and heat. While they are related, they are not the same. Thermodynamically, the heat contained in a material is related to the temperature through the heat capacity and the density (or mass). Temperature is defined as an intensive property, meaning that it does not vary with the quantity of material, while the heat is an extensive property, which does vary with the amount of material. One way to distinguish the two is to note that if a second log is added to the fireplace, the temperature does not double; it stays roughly the same, but the size of the fire or the length of time the fire burns, or a combination of the two, doubles. Thus, the fact that there were 90,000 L of jet fuel on a few floors of the WTC does not mean that this was an unusually hot fire. The temperature of the fire at the WTC was not unusual, and it was most definitely not capable of melting steel.





[edit on 27-12-2007 by ULTIMA1]


You're using this as a reference?

90k liters is what, 21-22k gallons? The planes held 8-8.5 k gallons when they hit.

If they can't even get this simple fact straight, I think that their info should be looked at with a wary eye...



posted on Dec, 27 2007 @ 07:38 PM
link   
reply to post by jfj123
 


I already have, in detail, on more than a few occasions in different discussions on this forum, complete with links to photos of both steel frame exterior walls. If you are interested, the information is easy to access. Key words such as the following will bring up the information.

WTC steel facade
WTC steel exterior primary load bearing supports

Or NIST has provided pictures of both the steel facade and steel exterior primary load support frames.



posted on Dec, 27 2007 @ 07:50 PM
link   

Originally posted by ULTIMA1

Originally posted by jfj123
So now I'm asking you for the 5th time. Are you going to post the information you claim to have in your above statement? YES or NO?


I have posted it before but will keep posting it.

911research.wtc7.net...

Fires in the North Tower covered extensive regions, at least near the perimeter walls, of about three floors. Fires in the South Tower also extended over about three floors, but were more localized to one side of the building.

The fires were not hot enough to produce significant window breakage in either Tower. Window breakage is a common occurrence in large office fires, particularly when temperatures exceed 600° C.

The flames mostly remained within the buildings. Significant emergence of flames from the buildings, another common feature of large office fires, was only observed in a limited region of the North Tower.

The fires did not spread significantly beyond the impact region. With the exception of a region of fire about 10 floors above the crash zone in the North Tower, the fires remained around the impact zones.

The fires did not cause parts of the building to glow. At temperatures above 700° C, steel glows red hot, a feature that is visible in daylight.




[edit on 27-12-2007 by ULTIMA1]



And this, NIST counted 1300-odd heat broken windows in the North Tower by the time of its collapse. Perhaps you should do your own research and read the NIST report before you post garbage like this. It just makes you look sorely misinformed when you do.....

And what do they mean when it is stated that the fires didn't spread significantly beyond the impact region. It involved entire floors. I don't know how much farther a fire could spread than that. Video documentation is available to prove this. Try Youtube, I hear there's a lot to be learned there. Again, another area where a little research on your part would have prevented this >>>


I agree with 1 part of this link though. It states that steel heated to 700C will glow red and can be seen in daylight. Nice find with that one. Kinda like the photo of the steel beam being pulled out of the pile by an excavator. These are temps easily reached by the burning debris found in the collapse. You'd know this if you did a little research on the typical temps of slow fires in poorly ventilated compartments. Do you need a link so that you can learn some facts?



posted on Dec, 27 2007 @ 09:31 PM
link   
reply to post by MikeVet
 


I am curious to know from where you took your NIST information of counting 1300 broken windows before collapse. I found nothing to that effect when I searched what you presented.

Do you have any idea how many windows each twin tower had? Because if you did, 1300 would not really be a significant figure for broken windows during a fire in either twin tower.



posted on Dec, 27 2007 @ 10:08 PM
link   
What was the Titanic made of ? Iron

What sank it? Ice

Case Closed.



posted on Dec, 27 2007 @ 10:16 PM
link   
reply to post by CaptainObvious
 


I would bet the size of that ice would rip through a commercial airliner skin a whole lot faster and easier.

Your general irrelevant comparative comment to 9/11 proved exactly what?



posted on Dec, 27 2007 @ 10:46 PM
link   
reply to post by OrionStars
 


Well, they should have saved the 7.5 million they spent building that ship out of Iron and made it out of ice.



posted on Dec, 27 2007 @ 11:02 PM
link   

Originally posted by CaptainObvious
What was the Titanic made of ? Iron What sank it? Ice Case Closed.


LOL everything is so black and white isn't it? Another famous captain obvious irrelevant analogy...


The sinking of the Titanic had nothing to do with the steel the hull was made from. It was found that the rivets used were made from sub-standard iron, and when the ship hit the ice the force of the collision caused the rivets heads to break off. If high quality rivets had been used it would not have sunk.

And the whole 'Titanic is unsinkable' thing was not unique to that ship, it was a common statement about steel hulled ships at the time.

Titanic - FAQ

Too many assumptions and not enough research on ATS nowadays....



posted on Dec, 27 2007 @ 11:26 PM
link   
reply to post by ANOK
 


Anok... try having a sence of humor.


I know it was the rivots. As far as the substandard Iron... it was being widely used in the industry at that time.

Geeesh!



posted on Dec, 28 2007 @ 12:10 AM
link   
reply to post by ANOK
 


The WTC used bolts and no rivets. A number of them with 2" diameters.



posted on Dec, 28 2007 @ 01:41 AM
link   

Originally posted by MikeVet

And this, NIST counted 1300-odd heat broken windows in the North Tower by the time of its collapse.

It involved entire floors. I don't know how much farther a fire could spread than that. Video documentation is available to prove this. Try Youtube

like the photo of the steel beam being pulled out of the pile by an excavator. These are temps easily reached by the burning debris found in the collapse.


You mean the broken windows caused by the planes impacts.

Please show me the videos you have of the fires on the floors inside the buildings, becasue most videos and photos i have seen of the outside of the buildings show no large flames coming out of the floors.

We are not talking about the debris pile, we are talking about the fire in the buildings prior to collapse.



[edit on 28-12-2007 by ULTIMA1]



posted on Dec, 28 2007 @ 02:44 AM
link   

Originally posted by CaptainObvious
Anok... try having a sence of humor. I know it was the rivots. As far as the substandard Iron... it was being widely used in the industry at that time.


Yeah, nice way to back out when you've been owned...


So if you really knew, you must have been hoping other peoples ignorance would let you get away with a lame analogy? Or are you just desperate for an argument?

Sry but I have no sense of humour when it comes to 9-11. If you're here to just joke around I suggest you go visit BTS...


'It was the jet fuel!'

(see I do have a sense of humour)

[edit on 28/12/2007 by ANOK]



new topics

top topics



 
13
<< 54  55  56    58  59  60 >>

log in

join