Crawl Spaces Between Wtc Floors Options

[grizz]

Only a few of the actual pilots that belong to the core group post on this board. Most of us are not pilots. Some of us (like me) are just concerned citizens mixed in with people who have expertise in various fields.

Long story, but when this board was young it served as a place for refugees of another board that collapsed. Since then it has grown into the great place you see now.

Nice to have you here, Anduril.

[lunk]

P4T is the place to be.

This is the portal that
rises up and away,
from unreality.

welcome, lunk

[Roark]

Since it is unlikely that tenants would want bare asbestos-covered trusses running across their ceilings, and since light fittings, cable ducting, and other services needed to be provided across each floor, it must be the case that suspended ceilings were used, with a 33" minimum crawl space between the false ceilings and the underneath of the floor pans. These crawl spaces must have been accessible from the service areas of the central cores.

They would be ideal for accessing the internal surfaces of the exterior structure for placement of cutting charges; the trusses; the floor pans with their (later wholly pulverized) concrete, using multiple C-4 charges or similar; and the exterior of the steelwork of the central cores (for thermate or similar charges).

That is absurd. Do you have any idea of the mass of conduit and ducting in the plenum?

Do you really think suspended ceiling tiles will support the weight of a person?

LOL Thanks for the good laugh.

[grizz]

Could it be possible that 'pathways' among the conduits and ducts existed that had solid platforms so that workers could move around in the crawl spaces?

[Roark]

Could it be possible that 'pathways' among the conduits and ducts existed that had solid platforms so that workers could move around in the crawl spaces?

Why?

It's a hell of a lot easier to just stick the ladder where you want to go and pop up the ceiling tile.

[grizz]

Well, maybe so. But could it be possible?

[beatles64]

With all of the steel beams criss crossing each other inside of those towers, all of the cables for utilities being run through the floors, and all of the interior designs (panels, walls, etc...) I would guess that it is possible to have a platform of some sort to work in between those spaces...

I don't know if that would be the most practical when compared to the ladder....I guess it depends on the space, and how high the ceilings are...but, why would you do this addition on every floor, and if not every floor, why the floors that you do include 'platforms' on..seems like a bit of a waste of resources but I am not experienced in this field

The more I think about this the more it SEEMS unlikely, but it is certainly possible

This post has been edited by beatles64: Jun 3 2008, 10:21 PM

[dMz]

That is absurd. Do you have any idea of the mass of conduit and ducting in the plenum?

Do you really think suspended ceiling tiles will support the weight of a person?

1. Have you looked at the infamous "floor truss" diagrams in the NIST report at all? I'm pretty certain that those were at least strong enough to hold the LD concrete "floor pans" of 109 stories for ~30 years.
1A. Is a person very heavy as a percentage of the floor-truss supported "floor pan" load?

2. Have you ever seen scaffolding or worked in the building construction industry?

3. How many vacant floors and offices were in the WTC towers again?

4. Are you at all familiar with the construction of the "mechanical floors" of WTC towers?

5. Do you ask questions rhetorically and merely to type LOL?

NOT-lol...

[Anduril]

That is absurd. Do you have any idea of the mass of conduit and ducting in the plenum?

Do you really think suspended ceiling tiles will support the weight of a person?

LOL Thanks for the good laugh.

I know you...

You talk to us about "the mass of conduit and ducting", which is not supported by a suspended ceiling, of course, then you quibble about "the weight of a person" as if movable aluminium supports cannot be placed between the bottom rails of the trusses. Are you aware of the spacing of the trusses? How do you think all that stuff got there? Maintenance? Alteration?

There are several illustrations around of the trusses, their construction and spacing.

I strongly commend these to your attention, before you make a fool of yourself again.


Some commentary from a maintenance engineer or two would be a good idea, too.


While I welcome criticism, I prefer it to be thoughtful, and if possible, intelligent.

Regards,

Tony Hollick

[Roark]

You talk to us about "the mass of conduit and ducting", which is not supported by a suspended ceiling, of course, then you quibble about "the weight of a person" as if movable aluminium supports cannot be placed between the bottom rails of the trusses. Are you aware of the spacing of the trusses? How do you think all that stuff got there? Maintenance? Alteration?

1. Have you looked at the infamous "floor truss" diagrams in the NIST report at all? . . . snip . . .
5. Do you ask questions rhetorically and merely to type LOL?

I'm not going to play a bunch of silly games here. The idea is just stupid. Here are some pictures of the space you are talking about.

(IMG:http://www.debunking911.com/sn1.jpg)

(IMG:http://www.debunking911.com/sn2.jpg)

(IMG:http://www.debunking911.com/sn3.jpg)

(IMG:http://www.debunking911.com/wtc1sfrm.jpg)

This suspended ceiling consists of a grid made of thin aluminum strips that is only designed to support the weight of the ceiling tiles and the light fixtures.

Note the extent of the damage to the fireproofing in the above photos. This is after 30 years use.

If that fireproofing is indeed asbestos containing material, then any access or disturbance of it is tightly controlled to avoid contaminating occupied spaces.

This eliminates the use of "movable aluminum supports."

Be practical here.

[Anduril]

Roark:

What you don't seem to understand is that the trusses run in parallel from the central core to the outer structure. People move _between_ the trusses, not _through_ them. A light alloy "bridge" will rests on the lower runs of a pair of trusses. You can kneel on it. This is what I meant by movable aluminium supports.

Someone who is about to blow up a skyscraper is not going to be overly worried about dislodging the odd bit of asbestos (as someone evidently _did_ going by your photographs -- which are welcome, BTW). Anyone could move around a great deal in the spaces shown in your photographs, equipped only with a lightweight platform. Do you know the spacing of the trusses?

Regards,

Tony

[grizz]

Let's look at that last photo presented by Roark, which is dated 1993 btw. It shows dislodged fireproofing. How did that little scrape get there? Also, what is that little pile of wood pieces? Who took the picture and why? Why were they in between floors in the first place? Was somebody working there?

[Roark]

Anduril, you seem to be moving from the idea that there were permanent "Crawl Spaces" that were established and in use by maintenance to the concept of a movable platform that was just specifically used for the purpose of setting explosives. Is that an accurate assessment?

[Roark]

Let's look at that last photo presented by Roark, which is dated 1993 btw. It shows dislodged fireproofing. How did that little scrape get there? Also, what is that little pile of wood pieces? Who took the picture and why? Why were they in between floors in the first place? Was somebody working there?

Fireproffing gets damaged in a number of ways. Over the course of 30 years of use, remodeling, addition of data lines, etc, the fireproofing will be dislodeged.

Furthermore, there is evidence that there was a surface layer of oxidation / scale on many of the strucutral components prior to the application of the fireproofing. This affected the adhesion of the material to the substrate.

Finally, look at the diameter of the truss diagonal. It was only about an inch in diameter. Add another 1.5 inches of fireproofing (what it was supposed to be) and it becomes 4 inches in diameter. Obviously it is not that thick. Even if it was, that would make 75% of the fireproofing not backed by substrate from a lateral blow. (I digress a bit here).

The pictures were taken by Roger Morse, a consultant hired to inspect the quality of the fireproofing in the building in the mid 1990s.

and those are not wood pieces, those are pieces of the ceiling tile that were cut out for speakers, sprinklers, duct registers, etc. Ceiling tile installers are lazy and will leave it up there rather than carrying it down to the garbage.

This post has been edited by Roark: Jun 4 2008, 01:55 PM

[Anduril]

Anduril, you seem to be moving from the idea that there were permanent "Crawl Spaces" that were established and in use by maintenance to the concept of a movable platform that was just specifically used for the purpose of setting explosives. Is that an accurate assessment?

No, I'm not moving anything anywhere. I used the term "crawl spaces" because they were used for moving about in. "Plenum" does not convey this as graphically. I'm not implying that people walked all over a light suspended ceiling (although I do wonder if it might be possible for a small person wearing something like snow-shoes to spread the load). A 3 ft. diameter duct running parallel to the truss would not present an obstacle. It may have been something of an obstacle course up there, but there are plenty of people trained to run obstacle courses. Competent burglars frquently ransack a house with the occupants indoors.

Whatever design of lightweight moveable platform was used might have been designed for earlier use. I just don't know -- I'm not an expert on skyscraper maintenance. As it happens, it should be a fairly easy theory to test -- there's a Tower in Seattle (the IBM Tower) which is built to the same structural plan. I had a most interesting discussion a few years back with the V-P of the company that owns it, to alert him. We certainly wouldn't want to lose it.

In your example, people working _above_ the ceiling left odd pieces behind them?

Regards,

Tony

[Anduril]

Also, I would like to look more closely at the design, materials and construction of those suspended ceilings. An acre of them constitutes a considerable distributed mass. In the photos, we see what resembles a shallow box structure. What were their design parameters for load-bearing? Was it _in fact_ possible to walk on them?

Regards,

Tony

[Roark]

Was it _in fact_ possible to walk on them?

No.

[dMz]

That is absurd. Do you have any idea of the mass of conduit and ducting in the plenum?

Do you really think suspended ceiling tiles will support the weight of a person?

LOL Thanks for the good laugh.

Post #30

I'm not going to play a bunch of silly games here. The idea is just stupid.

http://www.nizkor.org/features/fallacies/a...o-ridicule.html

Also Known as: Appeal to Mockery, The Horse Laugh.
Description of Appeal to Ridicule

The Appeal to Ridicule is a fallacy in which ridicule or mockery is substituted for evidence in an "argument." This line of "reasoning" has the following form:

1. X, which is some form of ridicule is presented (typically directed at the claim).
2. Therefore claim C is false.

This sort of "reasoning" is fallacious because mocking a claim does not show that it is false. This is especially clear in the following example: "1+1=2! That's the most ridiculous thing I have ever heard!"

It should be noted that showing that a claim is ridiculous through the use of legitimate methods (such as a non fallacious argument) can make it reasonable to reject the claim. One form of this line of reasoning is known as a "reductio ad absurdum" ("reducing to absurdity"). In this sort of argument, the idea is to show that a contradiction (a statement that must be false) or an absurd result follows from a claim

[dMz]

I'm not going to play a bunch of silly games here. The idea is just stupid. Here are some pictures of the space you are talking about.

[snip]

This suspended ceiling consists of a grid made of thin aluminum strips that is only designed to support the weight of the ceiling tiles and the light fixtures.

[snip]

Be practical here.

Aluminum strips eh? According to Hearst Publications' "debunking gurus" Popular Mechanics:

http://www.popularmechanics.com/home_journ...nt/1276121.html

"For the do-it-yourselfer, though, the real bonus is easy installation that requires only simple household tools. Comprised of a metal grid that supports lightweight panels, a suspended ceiling is well within the capabilities of most homeowners. If you're worried about the institutional look, drop-in ceiling panels have become more attractive in recent years, with a wide range of designs to choose from.
...
The installation steps vary from one manufacturer to the next, but not significantly. We chose an Armstrong Tegular Ceiling (Armstrong World Industries Inc., P.O. Box 173058, Denver, CO 90217). Tegular ceiling panels have a recessed flange that allows them to protrude below the grid roughly 1/4 in."

Hmm, well I thought aluminum would be cost-prohibitive, and the WTC was a commercial building, so a typical "commercial" dropped ceiling says:

http://www.armstrong.com/commceilingsna/su...tFamilyNameId=7

Whose MSDS sheet says:

http://www.armstrong.com/pdbupimages/2160657.pdf

"A. Product Name: Hot Dipped Galvanized Sheet Steel Suspension Systems (Ceiling Grid)- MIS #9"

Correct me if I'm wrong but aren't the "debunkers" and (ASCE/FEMA, NIST, Popular Mechanics, History Channel) the popularly-construed "experts" on metallurgy and on the usage and properties of steel and aluminum?

I hereby challenge you Roark to find me:
1. A source of aluminum suspended ceiling grid components.
2. Conclusive, verifiable, documented proof that such aluminum grid components were actually used in the WTC Twin Towers pre-collapse.

Good day and good luck.

P.S. The "spin cycle" is over- buzzer already went off some time ago. Ta.

[Roark]

That's the best you can do?

In any case, it is clear that the premise of a "Crawl Space" above the ceiling is a non-starter.