The 9/11 Forum

Heiwa --- My understanding is that the perimeter sections were bolted only. The exception was at the mechanical floors, with construction bolts followed by through welding.

David B. Benson wrote:Heiwa --- My understanding is that the perimeter sections were bolted only. The exception was at the mechanical floors, with construction bolts followed by through welding.

Well, it seems the spandrels were bolted/rivetted together, which must have cost much more than welding them, but the strength is equivalent. But the box columns? You cannot bolt them together! Or, was the little square hole below the top end access for bolting???? How?
Anyway, you cannot analyse the strength and do damage analysis of a perimeter assembly without knowing how they were connected to one another.

Heiwa wrote:Or, was the little square hole below the top end access for bolting????

Yes. I suppose there was also such a hole at the bottom.

Heiwa and others, do you see the rectangular holes at the bottom and top ends of each perimeter section?




You can use the bottom hole to insert a socket wrench, the top hole is the perfect height to insert your forearm to hold the top of the bolt stationary while you turn the bottom nut.

Notice how they are placed near the mid level of the windows, the standing height of an average man.

Easy to install and quite easy to undo if you plaster over the access holes afterwords and use a blow-dryer to accelerate the drying time.

Just the other day I watched a painter patch a hole this way, dry and paint with very little delay using a heating gun.



Please notice the basic air pressure (pneumatic) driver the workers below are using and notice how many spandrel bolts are above floor level (at the base of the spandrel plate just to their left).




Screw the socket wrench in these cases, I'll take the air driver instead (found in any auto shop). He has a right-angle driver so he can handle the tool while applying decent torque.

These guys are probably working around the hat trusses. As you go high in each building, core box columns become H beams and bolted connections in the core are common. I'll show some examples in the next few posts.

I think it is useful to identify the "seams" along which the WTC1 and 2 perimeters were seen to split.


In answer to the question: How do you cut a cage?


WTC1, 2 perimeter failure can be understood as bolt or column failure along identifiable seams.


There are 3 types of seams along which the perimeters failed:

Horizontal seams, 2 types:

a) cut through columns along a straight horizontal line just under a spandrel plate.

b) zig-zag breaks along staggered bolt and spandrel connections working their way across the side of the building


Vertical seam, 1 type

c) a seam straight down the building using a vertical row of bolted spandrel connections




I've already given examples of each of these seams.

A horizontal cut seam is like the WTC1 W face failure line

A horizontal zig-zag bolt seam is seen on the top of the WTC2 E face peeling sheet

A vertical bolt seam is witnessed along the WTC2 NE corner among other places




2 of the 3 types of seams witnessed can be made intentionally with nothing more than a socket wrench.


Therefore the only type of seam that involves the softening or cutting of columns along their length is the horizontal seam just under a spandrel plate.


I'll follow with examples of each type of seam.

TARGETS OF A VERTICAL SEAM




Removed bolts or broken connection plates within the red rectangle split the spandrels allowing the two faces to peel separately.


Such a seam was already identified along the NE corner of WTC2. In order to identify a seam, it doesn't matter whether or not you suspect demolition.

Such a seam exists despite one's interpretation of it's cause.



The seam marked in blue may also be a good choice if you wish to pull the corner flooring leftwards during the resulting peel. Please notice that the seam in the sheet metal flooring lines up with the blue perimeter seam and not the red one.

So if the demo planners anticipate pulling flooring outwards behind the perimeter peel, they may choose a vertical seam a few bolt lines in from the corner.

Yes, it seems a 3 outer perimeter columns/3 spandrels assembly was joined to other similar assemblies with 4 bolts per column (accessible via the holes above/below) and 8 bolts per spandrel joint. All cold work. Quite smart design. All vertical, static gravity and horizontal, dynamic wind loads are transmitted without problem.

I assume the core used other methods; full pen welding and rivets - hot work.

It doesn't change my opinion about the structural destructions. CD was used and sheared off the perimeter column bolted joints - the squibs - followed by big sections of perimeter assemblies being blown out as seen on the videos.

I assume the outer core columns were cut by some energetic means - the proximate cause of destruction - before being dislocated by explosives - the squibs - that also sheared off the perimeter assemblies . The destruction of the core resulted in the mast dropping prior to the rest.

That heat/fire could weaken the perimeter and core steel columns resulting in local buckling, free fall (?) of upper part C and an impact C with lower part A becomes more and more unrealistic as cause of 'one-way crush down of A by C' - the latter an impossible event.

there were 208 ( - 4 center of corner beams?) X 4 (two bolts, two viscoelastic dampers with bolts) holding the floors up to break, too, eh?

notice at the top of the outer two columns on the spandrels, there are plates which must fit into slots on the columns placed on top of them. those plates don't look weak, and i would guess that they were there for strength as well as alignment. you can see that there is a bolt hole in the center of them (look at the closest one visible, lowermost spandrel on the left). i would guess two plates which were welded inside the bottom of the the columns would slide around these on the inside of the beam, and then a bolt passed through the three plates.

Here is an example of how to make a horizontal seam across a whole face using only bolt connections (red lines).



You can separate the side of the building into upper and lower perimeter sheets without cutting through a single column (and no buckling, a fact which you hide by using a lot of smoke).


There is evidence both in video of the fall and debris footage which shows that the WTC2 E perimeter fell (peeled) away from the building broken along the 3 seams shown in the photo above (two vertical seams and one horizontal).

My first impression of the above ejection was that this is what a spandrel bolt attack looks like which goes slightly wrong.

The horizontal lines in the aluminum cladding line up with the tops of the windows and the bottom of the spandrel plate on a typical floor.

A proper spandrel attack may channel the device upwards along the bolt line. It would be shielded from the outside world because the discharge would be contained by the spandrel plate itself and by the flooring just above so the discharge would ultimately be directed inwards towards the office space.

If the charge mistakenly penetrates the concrete floor slab, a portion of the ejection may shoot out the window on the next higher floor at floor level as seen above.

Notice how the ejection leaves the building at floor level just above the top of the spandrel plate.

Oops!


The image below may help the reader understand the location of the pieces of aluminum cladding relative to the tops of the windows.





Along the perimeter the spandrel bolts may be much easier to attack than column-to-column bolts.

The spandrel bolts plates are totally assessible above the dropped ceiling all along the outside perimeter of the building. Devices are naturally shielded from the view of those working in the office. The devices themselves can look like small cell phone repeater stations. The resulting discharge can be pointed inwards and outward ejections are naturally shielded by both the spandrel itself and the concrete slab above.


In contrast, column-to-column bolt connections are located about 4 feet off the floor, about half way up each window about "face high". The planting of each device must be followed by plaster work to conceal it within the bolt access hole.

Much more work, much more visible.

The close-up photo of the poor woman in the opening of initial damages show how limited the initial failures were (1 hr + before final collapse) and how light-weight the whole perimeter structure was. The wall and floors above the failures are not sagging at all, etc. The spandrels, except where completely cut, are still 'active' and transmit load right and left. The floors are still connected to the spandrels where they are still there. Removed claddings make impression that real damages are greater. Whatever caused these initial failures avoided the bolted connections. Purpose was to make impression that a plane had crashed through the wall. I have my doubts.

Heiwa wrote:The close-up photo of the poor woman in the opening of initial damages show how limited the initial failures were (1 hr + before final collapse) and how light-weight the whole perimeter structure was. The wall and floors above the failures are not sagging at all, etc. The spandrels, except where completely cut, are still 'active' and transmit load right and left. The floors are still connected to the spandrels where they are still there. Removed claddings make impression that real damages are greater. Whatever caused these initial failures avoided the bolted connections. Purpose was to make impression that a plane had crashed through the wall. I have my doubts.

Anders, there would have been very high bending moments and shear when the fuselage and wings impacted the building. The pressure impulse would have been quite high. The spandrels would also keep the moments from getting to the column bolt connections. You can see some of the columns were yielded and bent over. If you look at the whole thing, the moments affected the aircraft also, as the wings don't enter at their tips and neither does the top of the tail. There isn't much doubt that the planes could enter the buildings with the wall thickness of the approximately 14 inch square perimeter columns being about .250 to .300 inches at that level.

Additionally, even if one had any doubts, due to so many other things being wrong with the present official story, it isn't worth talking about whether the planes could enter the buildings and only has the effect of causing some to doubt one's credibility. You have done too much for the movement to have your credibility questioned over something that is really unimportant.

What MT is discussing, with data which seems to back up what he is pointing out, is how charges/incendiaries could have been cleverly positioned to demolish the building later, after the aircraft impacts. He isn't getting into anything about whether or not the planes caused the initial breach.

Tony, thanks for message. Another strange thing with the local structural failures in the WTC 1 hole in the wall is the absence of soot everywhere. If there had been a jet fuel fire, even short, e.g. this famous fireball on the Naudet video, I would expect everything to be covered by a layer of black powder/soot afterwards. Where is it? So I think the Naudet video is a Hollywood production. And why not also the local failures seen afterwards?
Re the later CD that MT is disussing the perps evidently went for the strongest structural elements inside, i.e. first the four outer corner core columns and second the other outer core columns using some special, energetic, quick, steel cutting devices. I wonder where they can have been manufactured.

OneWhiteEye wrote:How time passes. I saw this thread the day it was started, and intended to comment. And here it sits.

is that the bolt connection?

Guess so. My mind reels. WTF? Isn't a 5/8" bolt what you use to bolt the head onto a lawnmower engine?

Stunned. I still don't know what to say. Now wonder the building behaved like a fluid.

Pyro-bolts? Not very loud. Unzip a whole floor without sounding much different than it happening... through some other means. Do two half-perimeters on adjacent stories and it's history.

What would 30 years worth of wind and salt air do to these bolts? Especially in a building that was designed to sway? Wouldn't these bolts corrode and loosen up over time?