Why a controlled demolition?

reply to post by bsbray11


The only aluminum cladding was that on the steel facades for appearance sake.

For those who do not know, HVAC duct, in buildings such as the WTC complex, are fabricated on site not back at the shop or on assembly lines. Aluminum would only be used on short connecting pieces where heat is an issue. It bends and creases too easy, and leaves creases and bends in the aluminum.

They cannot get a square fit to connect, when creases and bends occur when forming/fabricating or installing. Galvanized steel bends easy, but not as easy as aluminum sheets and pipe - pre-formed or not. Then dust becomes a health issue, when creases and bends occur in ductwork for intake and outtake of heat and cold air.

Originally posted by OrionStars
The only aluminum cladding was that on the steel facades for appearance sake.

Is this supposed to be some kind of rebuttal to something I'm missing? What's wrong?

Galvanic corrosion could definitely have been occurring. Asbestos also had to be removed. I've also heard that the foundations were slowly sinking over the years and that it was understood that this would eventually cause major problems.

I'm not sure of your assessment of that piece of metal, either, because it looks an awful damn lot like all the other aluminum coverings thrown around GZ, and most everything from inside the floors seems to have been completely destroyed. See how many panelings you can spot in the images below:








And everywhere perimeter columns are piled, you'll also find these. All coincidentally looking to be about the same length as the column sections they were covering. But then again, I'm not out to argue with everybody like a rabbit is out to mate.

Edit: I can't find the high-resolution image where you can really see the aluminum panels flying outwards, so nevermind.

[edit on 13-1-2008 by bsbray11]

reply to post by bsbray11


We must be missing communication.

There was no aluminum cladding on any steel, but the steel of the facade. The facade was attached to the outside of both buildings.

Galvanized steel HVAC duct has been used for years in steel buildings, residential wood framed homes, and steel framed pre-fab homes, but has never corroded from other metal contact. The pieces you are showing were not wrapped around steel. Not in the WTC buildings they were not. They are the wrong shape and too small to be wrapped about the steel in the WTC buildings.

What aluminum, besides the facade, was that supposed to be wrapped around steel? The pieces in your photos are in pristine condition, after being pounded with hundreds of thousands of pounds of collapsed steel and reinforced concrete, with HVAC ductwork inside under all that pounding. How could something in pristine condition be corroding anything without melting or being corroded itself?

What are those pieces supposed to fit? Neither of your photos indicated what they are supposed to be wrapped around for steel.

They can be used for decorative facades outside shops in the WTC buildings.

What indicates that is aluminum? Is there written information to describe what is in the photos?

The twin towers were built on solid bedrock, and I have found nothing that says they were sinking at any point time. Do you have some information on that?

Asbestos does not corrode steel or anything else, or they would not have used it fire proofing in steel buildings. Absestos was banned for health reasons and no other reason.

Regardless of where it was stacked in such pristine condition, it is not incdicative it was wrapped around any steel.

The aluminum cladding on the facade was brown (dark coppertone).

reply to post by bsbray11


In your 4th photo down, that is a piece of formed ductwork but not primary ductwork. It is in the bottom right corner. It is hollow. No steel is seen and no corrosion.

Dude! After 6 years of research you are just now realizing the entire outter framework of the WTC towers was covered in aluminum?

Who cares about duct-work.

What Bsbray posted was the aluminum cladding..on the police car and in all those other pictures.. There were tons of it all attached to the outter support columns and framework.

[edit on 14-1-2008 by Taxi-Driver]

reply to post by Taxi-Driver


Excuse me. How did you translate out of what I stated I was just now realizing aluminum cladding was on steel frames of the facade? Could you please explain how you managed to do that?

What is being stated to be "aluminum cladding" on any other steel is not. What aluminum cladding corroded any police cars or any other vehicles? Where is the certified metallurgical report on that?

Ok you are going on ignore now... I think it is safe to say you are a "Combative Troll"

I have seen many in my 15 years of newsgroup experience.

How can the aluminium cladding be a point of argument when it's established fact that every column was fully clad inside and out with aluminium. It provided the mounting point for the windows and was even fitted with window washer tracks which is the visible groove seen on that piece resting on the police car.

The cladding in the foreground of this pic shows the washer track clearly


Dissimilar metals together with moisture forms a galvanic cell normally resulting in the more electro-positive metal corroding faster as a sacrificial anode. Ask any builder of steel ships what those big blocks of zinc mounted on the hull below the waterline are all about.

Originally posted by OrionStars
The pieces you are showing were not wrapped around steel. Not in the WTC buildings they were not. They are the wrong shape and too small to be wrapped about the steel in the WTC buildings.

Ok, Mr. Detective, why am I seeing 10 million pieces of HVAC laying all over Ground Zero, and where DID all the aluminum panels go? I suppose this is just some bizarre coincidence.

What aluminum, besides the facade, was that supposed to be wrapped around steel?

This question doesn't even deserve to be answered. The aluminum on the outside alone exposed probably half of the steel of the entire building to corrosion (even if only at the connections, that's a TON of connections), when any significant corrosion anywhere at all would potentially violate code and require replacement.

The pieces in your photos are in pristine condition

Only one of the metals corrode in galvanic corrosion. The other metal actually corrodes more slowly than it otherwise would.

When two or more different sorts of metal come into contact in the presence of an electrolyte a galvanic couple is set up as different metals have different electrode potentials. The electrolyte provides a means for ion migration whereby metallic ions can move from the anode to the cathode. This leads to the anodic metal corroding more quickly than it otherwise would; the corrosion of the cathodic metal is retarded even to the point of stopping.

en.wikipedia.org...

Asbestos does not corrode steel or anything else, or they would not have used it fire proofing in steel buildings. Absestos was banned for health reasons and no other reason.

I'm not sure what you think I'm trying to say but you really need to cool it. I don't get my rocks off arguing with people about stupid things on internet forums and I take offense when someone else who does comes onto me as if I have something they want to win from me. I don't have anything for you. If you want to argue for the sake of arguing then I'm not going to subject myself to the stupidity.

If you want an intelligent exchange, then all of the things I've been talking about in the last posts have had to do with why the towers were losing money and/or in need of deconstruction or serious renovation. The costs to remove the asbestos alone were more than the towers were worth, and NY kept extending the Port Authority's time on clearing it out even though it was already banned. They could have only lost money. I'm still not exactly sure what you feel you need to defend yourself from, when I post these things. Do these ideas bother you? Or do you just need to play role games on here or what?

The aluminum cladding on the facade was brown (dark coppertone).

Why would aluminum be brown? What towers are you looking at?

Originally posted by OrionStars
In your 4th photo down, that is a piece of formed ductwork but not primary ductwork. It is in the bottom right corner.

That you have to tell me where to look is the clue. There is also a collapsed bridge in that photo, several steel columns, etc.

The lack of corrosion on the aluminum is irrelevant, because like I sourced on the last post, only one of the metals corrodes during galvanic corrosion. Electrons flow from one metal, into the other, causing damage over time. One metal is corroded while the other is pristine (actually corrodes less than it would).

reply to post by bsbray11


It is the hollow tube in the 4th photo in the bottom left. One part is bent away from the forming at the upper corner, on the left end of the long what looks to be square piece lying on its side. I did not look again to see if it was square or rectangular. I know it was not round. That looks like either ventilation or exhaust duct.

In those days, particularly in hermetically sealed high rises, they were prone to putting in smoke exhausts for all the heavy smoking allowed in buildings, when the WTC complex first opened. They also needed ventilation blowers - fresh air in, and stale air out - circulation throughout the entire buildings. Then there was the restaurant on the 107th floor, that also needed exhaust and ventilation, plus, smoke exhaust from all those smokers using the restaurant.

As pristine condition as that was, I would ventrue to say that came from the very top of the building not below. Because it would be centered in the core units (central heating, ventilation, air conditioning aka HVAC). The heating and air is not the same duct as ventilation, including exhausting smoke. They are separate units. One is hermetically sealed back to the heating unit. And the other is vented to the roof.

reply to post by bsbray11


If some metal is alleged to corrode/erode/melt another metal, it has to be important as a factor. Both pieces of metal are definitely going to be affected, and it will be highly visible on both. Chemical reaction happens on both pieces not just one. I do not see any damage on the pieces of what you are referring to as aluminum in any of your photos. If aluminum gets near molten steel, it will melt. I see nothing resembling melted or molten aluminum in any of your photos.

Originally posted by OrionStars
If some metal is alleged to corrode/erode/melt another metal, it has to be important as a factor. Both pieces of metal are definitely going to be affected, and it will be highly visible on both.

Check this out:

Galvanic corrosion, often misnamed "electrolysis," is one common form of corrosion in marine environments. It occurs when two (or more) dissimilar metals are brought into electrical contact under water. When a galvanic couple forms, one of the metals in the couple becomes the anode and corrodes faster than it would all by itself, while the other becomes the cathode and corrodes slower than it would alone. Either (or both) metal in the couple may or may not corrode by itself (themselves) in seawater. When contact with a dissimilar metal is made, however, the self-corrosion rates will change: corrosion of the anode will accelerate; corrosion of the cathode will decelerate or even stop. We can use the seawater Galvanic Series, shown in Table 1, to predict which metal will become the anode and how rapidly it will corrode.

www.ocean.udel.edu...

The Twin Towers were right next to a large body of sea water, and were exposed to their share of rain, across extended surface areas, over about 30 years, but that's beside the point. Galvanic corrosion occurs anyway, in that it just accelerates the corrosion of one of the metals.

Chemical reaction happens on both pieces not just one.

The increase in chemical reactions (corrosion) on the anode metal is because of the electrical current being generated into it for being placed against the cathode metal. A reaction occurs with both pieces, but it doesn't mean an increase in corrosion for both pieces.

[edit on 14-1-2008 by bsbray11]

reply to post by bsbray11


The twin towers were standing not far from freshwater Hudson River not marine Atlantic Ocean. If they were, exactly how would any marine water end up in the twin towers to cause any catalytic reaction between any aluminum and any steel? Or even galvanize steel on structural steel?

Seawater does not provide humidity. Freshwater does.

Originally posted by OrionStars
The twin towers were standing not far from freshwater Hudson River not marine Atlantic Ocean.

My mistake.

If they were, exactly how would any marine water end up in the twin towers to cause any catalytic reaction between any aluminum and any steel? Or even galvanize steel on structural steel?

Seawater does not provide humidity. Freshwater does.

It looks like you answer your own question there, but all I was really looking at was that corrosion is accelerated for one metal and lessened for the other. Apparently the environmental conditions around the metals have an effect but basically one still corrodes faster while the other doesn't.

Originally posted by OrionStars

The twin towers were standing not far from freshwater Hudson River not marine Atlantic Ocean.

The lower Hudson River is a tidal estuary and indeed does have a higher salt content than freshwater. Mesurable amounts of salt can be detected at high tide up to 30 miles upriver from Lower Manhattan in the wet season. It can travel much further, in some instances 90 miles, during the dry summer months or during droughts.

[edit on 15-1-2008 by AugustusMasonicus]