WTC during construction

[DoYouEverWonder]

This is a rare view of the WTC during construction below street level. Keep in mind, that what you are seeing eventually became the top of the building because they would build a section and then jack it up. I would guess that the structure to the left of the building eventually became the ground level for the plaza?

Also note, that the entire visible structure is steel. A lot of steel. No masonry was used in the WTC. The floors were made of steel pans and poured concrete.

No conclusions or anything, just wanted to share what I think is an interesting picture.

[Sinti]

1. Top view during destruction

Those same pieces of steel falling like tin soldiers in a cloud of smoke :(

[Carefulplease]

2. Just one correction...

Only the construction cranes (that have diagonal bracing) would jack themselves up, not the tower structure itself. The new columns segments were spliced/bolted/soldered to the segments below. The prefabricated box columns of the core have progressively diminishing gauge and eventually transition to lighter wide flange I-beams.

There is a nice 30 min. video produced by the Port Authority that documents the construction. Maybe somebody can post a link.

[DoYouEverWonder]

7. My mistake - It was the cranes not the building itself

You are correct. It was the cranes that rose with the build, not the building itself.

Australia exported eight cranes designed specifically for the construction of the World Trade Center. Dubbed 'Kangaroo' cranes, they sat atop the building and rose with the height of the building.

http://www.constructmyfuture.com/hall-wtc.html

[dailykoff]

3. And yet

people still cling to the delusion that a fire on the 90th floor destroyed this building.

Pretty sad.

[hack89]

4. No ... we hold firm to the idea

that if those columns were severely damaged by a fully loaded 767 traveling at 500 mph then fires could destroy the building.

[dailykoff]

9. It would have taken 18+ well-aimed planes

just to overcome the column safety factor, assuming an SF of 5, which is probably low, and the column damage reported by FEMA, which is probably high.

Which would most likely have caussd the top section to settle, possibly to topple, period.

[AZCat]

10. Why do you continue to misrepresent safety factors?

Please - if you need help understanding this concept just ask.

[dailykoff]

11. Stick to your plumbing

and let the big boys handle the structure.

[AZCat]

12. Luckily...

plumbing isn't the only thing I do.

And what, exactly, does your response mean? Who here are the "big boys" relative to me? Are you suggesting that one anonymous poster has an advantage over another, or are you just looking to poke sharp sticks in the eyes of others?

[DoYouEverWonder]

13. Which colums?

The exterior columns on the outside curtain or the columns in the core?

[dailykoff]

14. Both.

Whether you calculate for core columns, perimeter columns, or all columns, the answer is between 18 and 20 planes.

[Carefulplease]

15. What calculation do you use? n/t

[dailykoff]

16. 2 core and 10 perimeter columns per plane. (n/t)

[AZCat]

17. Your model is lacking.

Perhaps you could use a little help with a better formulation? There are plenty of professionals who would be glad to offer their assistance.

[DoYouEverWonder]

18. Please feel free to present

some else's data?

Where are all of these core columns that were damaged by a passenger jet?

I would imagine that a column that was ripped apart from direct contact with the content of one of the planes would look different then other columns that were not hit. Beside all of the columns were marked with individual ID #'s. They know what floors the planes went in on. It shouldn't have been hard to find what was left of the steel columns from the impact zone.

[AZCat]

19. Someone else's data?

I don't understand what you're asking for. What data?

[DoYouEverWonder]

20. What do your experts say

How many columns do they estimate was damaged in the core?

If your are the going to claim the OP is wrong then it is on you to prove otherwise.

[AZCat]

21. I think we have a confusing provenance here.

As I understand it, the OP is the Opening Post of the thread. You don't make any claims here, so I'm not arguing about anything in that post.

What I am questioning is the methodology used by dailykoff for calculating how many aircraft impacts it would take to cause a collapse.

[DoYouEverWonder]

22. I was referring to dailykoff

has the OP of this particular set of responses.

[AZCat]

24. Ah - clarity ensues.

It appears that dailykoff's model relies on two assumptions:
1. The damage done by aircraft impacts is consistent and predictable
2. The building would not collapse until all the columns had been damaged by aircraft impact

I believe that both these assumptions are not reliable and a model based on these will produce inaccurate results. Do you need me to provide an analysis of why these are unreliable or is it self-evident?

[dailykoff]

26. No.

I said to overcome the SF, not to damage all columns.

[AZCat]

27. Whoops - you're right.

For some reason I am difficulty following the flow in this thread.

My argument still stands - your model is grossly oversimplified and inaccurate. You don't seem to understand what a safety factor is and how a structural system responds to removal of elements.

[dailykoff]

29. Thanks.

And when you come up with something specific let me know. :hi:

[AZCat]

31. You mean other than your fallacious assumption of linearity?

Let's start with that. Care to explain yourself, or will this subthread wither (like so many others)?

[dailykoff]

32. I mean something specific. (n/t)

[AZCat]

33. That IS something specific. n/t

[Carefulplease]

35. Well, your objection is quite specific and to the point...

But his confusion is broad and wide ranging ;-)

[AZCat]

59. I thought it was...

but I seem to have difficulty understanding dailykoff, although it has been pointed out before that this is not limited to me. Perhaps dailykoff would be considerate enough in the future to more carefully phrase his/her posts?

[DoYouEverWonder]

48. I don't care what you assume

someone else is assuming. I asked you the question. Some me the data on the damage to the columns in the core. How many columns were damaged? Which ones? What did the look like? All the columns in the WTC had unique ID #'s. I'm sure your experts were able to zone in on which columns they needed to look for.

Here's a pic if you need some visuals, so that we're clear about what the columns looked like:

[Carefulplease]

51. The trouble is unstated assumptions...

This picture is misleading. It displays some massive core box columns all right. There are two caveats however. First, the cross-braced structure next to the corner core columns isn't a WTC column. It is part of the construction crane. Second, the 3 massive box columns that can be seen aren't representative of the 47 core columns. That is because the corner columns are much more massive than the other core columns. And also, this picture displays the structure being constructed many floors below the aircraft impact zones. Further up, the core columns transition progressively to smaller cross section elements. Most box columns also transition to wide flange I-beams. The figures referenced below provides a better idea of the cross sections involved:

http://wtc.nist.gov/NISTNCSTAR1-1.pdf
pp.26-27

Another issue is: the core columns aren't so much more massive than the perimeter columns are. That is because, although the core bears about 60% of the static loads, the perimeter columns must be able to resist the worst possible wind loads in addition -- and these are even larger than the dead loads. The perimeter columns thus have much larger cross section that their share of the static loads alone would warrant.

[DoYouEverWonder]

65. I was just using the picture for a reference point

You still didn't answer my questions though?

Some me the data on the damage to the columns in the core from NIST or anywhere you please.

How many columns were damaged? Which ones? What did the look like? All the columns in the WTC had unique ID #'s. I'm sure your experts were able to zone in on which columns they needed to look for.

[dailykoff]

25. Lacking what?

:shrug:

[Make7]

42. For a start, it's lacking any basis for the numbers you are using.

You claimed "2 core and 10 perimeter columns per plane." This figure was assuming "the column damage reported by FEMA, which is probably high."

Chapter 2 of the FEMA WTC Building Performance Study states the following for impact damage to the perimeter columns:

WTC1 - "Interpretation of photographic evidence suggests that from 31 to 36 columns on the north building face were destroyed over portions of a four-story range."

WTC2 - "Photographic evidence suggests that from 27 to 32 columns along the south building face were destroyed over a five-story range."

Could you provide a quote and link to the FEMA damage estimate that you derived your figure of 10 perimeter columns from? Thanks.

- Make7

[dailykoff]

43. The relevant figures are columns per floor

not total columns.

[Make7]

44. Why don't you just provide your source and method for your numbers?

Or are only others supposed to supply the basis for their numbers?

"where is he getting his figures" - dailykoff, Post #34

"who knows where the hell he's getting his figures." - dailykoff, Post #39

Or is it your intention to simply post a conclusion without demonstrating that it has any validity?

- Make7

[dailykoff]

45. So where's your link?

Or his?

:shrug:

[Make7]

47. You haven't downloaded the FEMA WTC Building Performance Study?

Don't you even have it bookmarked? I thought you were basing your numbers on "the column damage reported by FEMA". If you aren't using their World Trade Center Building Performance Study, what report(s) are you basing your assumption of damage on?

Since you seem to be having difficulty finding the study, here are links that should open the file to the page where each of my previous quotations are found:

  First quote:    http://www.fema.gov/pdf/library/fema403_ch2.pdf#page=15
  Second quote: http://www.fema.gov/pdf/library/fema403_ch2.pdf#page=31

I am quite certain that I can expect you to return the favor by providing links and quotations to the FEMA information that you have used in order to establish some basis for the numbers that you have assumed to reach your conclusion.

- Make7

[dailykoff]

52. I can always count on you

to find it in your autographed desk copy. :)

[Make7]

60. That does not explain how you arrived at your numbers.

In my last post I requested that you provide your source. When you asked me for my source before, I posted the links to the document that I quoted from. Are you for some reason unwilling to do the same?

Could you please just provide the source for your assumptions concerning the FEMA impact damage estimates?

And could you also please somehow demonstrate that you are actually doing some research and calculations before posting a conclusion?

Thank you in advance.

- Make7

[dailykoff]

78. Use the highest FEMA figures and you get 5-6 planes.

Per tower.

[Make7]

79. That doesn't explain how you arrived at 18 to 20 planes before.

What source did you use for your previous damage estimates? What calculations did you use to arrive at your "between 18 and 20 planes" figure?

You originally said "It would have taken 18+ well-aimed planes" in post #9. and you basically confirmed that result in post #14 by saying, "the answer is between 18 and 20 planes."

You still haven't shown your reason for assuming a safety factor of 5 yet either. Actually, you haven't shown a reason for any of the numbers you have used or arrived at. Perhaps you could provide an explanation for your conclusion(s).

- Make7

[dailykoff]

80. I gave you the figures. If you can't do the calculation

you have no business criticizing anyone else's, but there's nothing new there.

Some of us prefer not to rely on wall-to-wall WH spin. :hi:

[Make7]

81. It is a simple request. Please show the reasoning behind your calculations

Why are you so reluctant to show how you have arrived at your results?

- Make7

[dailykoff]

82. It's a simple calculation

and you have all the variables. If you can't figure it out, ask one of your pals to recommend an online community college class in basic CE.

edit to add, I'd also recommend a private tutor. :hi:

[Make7]

83. And I'm asking you to show you how you did that simple calculation.

How difficult can it be for you to show such a simple calculation?

You have posted conclusions and you haven't shown how you arrived at them. I don't think it is unreasonable for someone to be requesting an explanation for how you reached your result. You said it was a simple calculation - why can't you just show how you did it?

- Make7

[dailykoff]

84. With a calculator.

Check in your computer under "accessories."

And here is where I bid this thread adieu. :hi:

[Make7]

86. Hey! I've got one of those too!

Mine doesn't tell me how you determined the relative gravity loads on the various columns. It also doesn't tell me if you assumed the "safety factor" of the perimeter columns would be any different than those of the core given that the perimeter columns were also designed to handle the majority of the wind loading. It doesn't tell me what you meant by "the highest FEMA figures". Hell, it doesn't even tell me if you used the right number of perimeter columns. However, it is possible that my calculator is broken.

You said that this was a simple calculation - so then it shouldn't be very difficult to show how you did it. I would think you would welcome the opportunity to show that:

1. you know what you are doing
   
2. your results are actually based on something
   
3. you are not just making stuff up

I am only asking you to verify how you arrived at your own results. But if it's too much trouble for you to actually show such a simple calculation, I guess everyone can just come to their own conclusions.

- Make7

P.S. I think you forgot to do something yesterday.

[Grateful for Hope]

85. I am so grateful for the cooperative, non-confrontational posts

that inundate this forum. Thank you very much for adding to them.

It is edifying to see real team work in action.

[Make7]

87. .

[Grateful for Hope]

88. ROFLOL!

Thank you for making me laugh - I needed it today. I am sure that "dot" was made in the spirit of cooperation. Thank you!

[Make7]

89. ..

[Grateful for Hope]

90. Two dots

How cooperative of you!

[Make7]

91. ...

[greyl]

96. Your post is ridiculous writ large.

It only served to interrupt a sincere(one sided) effort to reach understanding.

[Grateful for Hope]

97. I appreciate you pointing this out to me

Thank you, greyl!

[greyl]

98. I doubt that.

If you truly appreciated me pointing out that you interrupted a conversation, you probably would have helped dk with his calculations, or you would have refrained from another insincere and irrelevant reply.

I think insincerity sucks. Doesn't everyone? :D

:grouphug:

[Grateful for Hope]

99. I know you wouldn't be calling me a liar

So, I am assuming that you just think I need some advice. Thank you for giving it, greyl

[greyl]

100. Have you heard of Descartes' Radical Doubt ? nt

[sgsmith]

46. I don't think it's columns per floor

Columns can be broken on multple floors. No matter where the break occurs, that column is no longer carrying a load. So, if you've got 3 columns on floor 10, 3 columns on floor 11 and 2 columns on floor 12 broken, and they're not the same columns, you've got 8 failed columns.

[dailykoff]

53. Sure but the breaks weren't discontinuous. (n/t)

[Carefulplease]

55. They were indeed continuous. What is your point?

Pictures of the impacted towers show:

WTC1: One big continuous hole spanning 30 columns plus some more ruptured and damaged columns on both sides of the hole.

WTC2: One big continuous hole spanning 26 columns plus some more ruptured and damaged columns of both sides of the hole.

How can you assume anyone of these case to be the equivalent to just 10 ruptured columns?

[AZCat]

56. dailykoff seems to have trouble...

reining in his/her assumptions.

It would help us understand better if dailykoff would present more than one-liners in defense of his/her points, but apparently brevity trumps clarity in dailykoff's opinion. It's too bad, because the discussion seems stilted with those sort of posts.

[RedSock]

5. they built the top of the building first????

Keep in mind, that what you are seeing eventually became the top of the building because they would build a section and then jack it up.

They built the very top of the tower and kept jacking it up one floor at a time all the way up until it was a quarter mile in the sky?

I have a very hard time believing that.

[hack89]

6. The cranes were jacked up

not the floors.

[DoYouEverWonder]

8. Yes, my mistake

See above.

I definitely deserve one of these -

[John Q. Citizen]

23. Yes, but so does

Carefulplease:

"spliced/bolted/soldered" from his correction of your error.

I think he meant welded.

[Carefulplease]

28. Sorry, English is my second language...

My English is often lacking. The Frech verb for both "welding" and "soldering" is: "souder".

[greyl]

30. WTC during plane impact:

The potential force of the impact from each plane can be approximately calculated and the figures are very large. The weight of each plane would
have been approximately 150 tons, according to the media reports and Boeing data on this type of plane. The plane would have been traveling at around 800 kms/hour at impact. This gives a momentum of 150x800/3.6=33,333 tons.m/sec. If the plane was arrested by the building in effectively 0.6 seconds, which is a reasonable estimate based on a linear deceleration over the 63.5 m width of the building, then the force exerted on the building is the momentum/effective time to arrest, i.e. Force=33,333/0.6=55,555kN. To put that in perspective, the ultimate limit state design wind pressure over the entire height of the building is 220 kg/m 2 . This gives a ULS wind force on one face of the building of 58, 400 kN. Thus the potential force of impact from the plane is 95% of the design ultimate limit state wind load on the building! Especially in the case of the North Tower, not much of the plane was ejected from the building, so it is reasonable to assume the most of that potential force was absorbed by the building. Also the above calculation also does not take into account any additional force generated inside the building from blast loading due to, for example, exploding jet fuel.

Having done this calculation it is more easy to understand what our eyes showed us – namely the planes slicing through the perimeter frames “like a knife through butter” as one reporter has stated. I contend that, having penetrated the perimeter frames the planes would have done much more that just stripping the fire protection off the columns as has been surmised by some commentators. The effect would have been to completely shatter and eliminate large areas of floor slab and many of the internal supporting columns, thereby immediately destroying much of the vertical load carrying system and leaving the rest vulnerable to any subsequent fire attack. This impact damage - not the severity of the fire – I contend is the principal cause of the ultimate collapse. However the nature and position of impact was different in each case and this led to different effects on each tower, with different collapse mechanisms. These effects are now discussed in as much detail as is possible based on the known information.
_________________________________________

Fig 9 shows the view looking into the impact hole. Given that the floor slabs are at 3.66 m centers and the façade column centers are at 1.03 meter centers with façade window widths of only 0.48 m, the number of façade columns and perimeter beams severed by the airplane in its passage though the perimeter frame is considerable. From the major damage to the side opposite the impact it is also apparent that much of the airplane would have passed through the core.

It is likely that the impact destroyed most of the floors, at least on the impact side, and the core on at least three levels, removing many of the core supporting columns, at least on the North side of the core, and leaving the remainder buckled and stripped of their passive fire protection.
http://www.caddigest.com/subjects/wtc/select/clifton/p5.htm

This article is just one person's set of calculations. Anybody see a problem with them?

[dailykoff]

34. More crap science to wow the sheeple.

a) where is he getting his figures and b) so what? The impact was momentary and he admits that it was within the design limit. Steel moment frames are elastic so it wouldn't have any effect.

Next?

[AZCat]

36. Hysteresis can still occur.

The steel can be strained beyond elastic into plastic deformation. It doesn't take much (but then you knew that).

Momentary (or impulse) loading can be much more tricky than most people think. There are some interesting articles out there on impulse loading of containment vessels for partial detonation of nuclear devices, if you're up for some light reading.




Edit: f**king grammar.

[dailykoff]

37. As I was saying. . . .

Aren't you the guy who thinks a safety factor of 5 is supposed to compensate for manufacturing imperfections?

[AZCat]

38. You must have me confused with the guy over there...

I think manufacturing imperfections are part of why safety factors are used - any idiot could recognize that - but I realize that they compensate for more than that.

[greyl]

39. Do you see any errors? I can only presume you don't.

[dailykoff]

40. His conclusions do not follow from his premises,

and who knows where the hell he's getting his figures. So it's just another typical 9/11 crap sandwich.

mmmmmmmmmmmmm crap! :9

[greyl]

41. Your reply is divorced from reality.

You may convince me it isn't by giving some hint that you even read one sentence of it.

Name one conclusion that doesn't follow from the premise in the article, and quote the article directly.

edit: when you're finished, try backing up your statement from post 9:

dailykoff - It would have taken 18+ well-aimed planes
just to overcome the column safety factor, assuming an SF of 5, which is probably low, and the column damage reported by FEMA, which is probably high.

Which would most likely have caussd the top section to settle, possibly to topple, period.

[BootinUp]

49. 18 planes is one hell of an image though

Shields up!


Ack! Captain she can't take much more.

[hack89]

50. But of course you know what the correct figures are ..

but if not, then someone else in the 9/11 "truth" community. Don't you find it interesting that Dr Jones and his merry band have never done such basic calculations? Or perhaps they did and didn't like the answer?

[dailykoff]

54. Does anyone?

:shrug:

[hack89]

64. But you must know!

Why else would you sound so definite? How can you dismiss those calculations if you have no idea what they should be?

[DoYouEverWonder]

57. Do any of these calculations take into account

office contents? It seems desks, cubicles, rows of file cabinets, office equipment, conference rooms, stuff like that would have some effect on slowing down and destroying the plane before it reached the core of the building. In all the video simulations I've seen are as if the building were empty and that there was nothing in between the curtain wall and the core.

[AZCat]

58. Interesting thought.

I don't think such stuff would probably matter. The momentum of the aircraft was pretty large and the mass of office furnishings would IMO not be a significant impediment to the motion of the aircraft.

But I could be wrong. :)

[DoYouEverWonder]

61. We're not talking just furniture

Most of the floors would have been divided into smaller spaces with walls, doors, and other built-ins. There would have been computer rooms, lunch rooms, conference rooms, storage rooms....


Here's some pics from one company that was in the WTC. This is just an example of what you would expect the interiors of an office building to look like. Lot's of stuff to get in the way of a plane breaking up.

[AZCat]

62. I don't know.

I don't have the resources to figure out whether this would be an impediment or not. My previous post was just my opinion, not a calculated estimate. It would be difficult to get any sort of a reliable answer because if, as you suggest, the elements normally found in an office building would might significantly affect the motion of the aircraft the actual effect would be dependent on configuration of the office. This, IMO, is highly nonlinear and unless someone was willing to do a series of simulations (a la Monte Carlo method) you wouldn't get a very reliable answer because it would depend strongly on the particular layout of the simulated office. Simulations are best when used with linear (or quasi-linear) systems and don't do well with situations such as this.

[Carefulplease]

63. NIST took the office contents into account

This is detailed in this document:

http://wtc.nist.gov/NISTNCSTAR1-2.pdf
pp. 105 and following.

5.2.4 Interior Content Model Development

The interior nonstructural contents of the towers were modeled explicitly in the tower used for the global impact analyses (...) The distribution of the gypsum walls was obtained from architectural drawings and other information gathered as part of Project 5 of the NIST investigation (NIST NCSTAR 1-5) (...) data gathered by NIST for the floor layout plans in the impact zone were used to develop the approximate placement of workstations (...) There additional loads were important for obtaining an accurate mass distribution in the towers and inertial effects in the impact response. (...) The uncertainty in the amount of in-service live load was accounted for in the sensitivity analyses (Chapter 8 of NCSTAR 1-2B) and in the global impact simulations. The model of the building contents (partitions and workstations) over a single floor, as shown in figure 5-17, had 101,733 nodes and 97,284 shell elements. (...) As a result, the global models included the partitions and workstations only in the region of each floor directly in the path of the aircraft impact and debris. (...)

[DoYouEverWonder]

66. NIST did all of the modeling

based on spaces that looked like this:




They did not take into account spaces that look like this:




One other flaw. They didn't take into account the floors and areas in the impact zone that were empty.

[Carefulplease]

67. No they didn't assume that all the floors were alike.

NCSTAR1-5 was already referenced in the quote I provided above.

http://wtc.nist.gov/oct05NCSTAR1-5.pdf
pp.41-42

3.1.2 Floor Plans

The Port Authority reported that their copies of architectural drawings for the tenant spaces were destroyed when the buildings collapsed. The National Institute of Standards of Technology (NIST) staff then requested that the tenant companies provide architectural drawings of their space at the time of the most recent renovation. The requests were also for information regarding furnishings. As shown in Table 3-1, NIST obtained floor plans for a large fraction of the floors of interest in the two buildings. Discussions with Port Authority property managers, tower occupants, architects, and product manufacturers provided additional information, including estimates of the similarity of layouts of floors, for which no information was available, to others in the towers.

So, they made no more assumptions than were necessary, it seems.

[DoYouEverWonder]

68. "They did estimates for the layouts of floors

for which no information was available, to others in the towers."

Did they ever consider the idea that maybe there was no layout available because the floor had never been occupied? That happens a lot in big buildings. Even the Empire State Building still has unfinished floors that are just empty shells.

[Carefulplease]

69. No, I don't think they considered that possibility...

In view of the fact that their extensive consultations with the Landlord (the Port Authority,) with the tenants, and with dozens of WTC maintenance personnel, and since they conducted 1,200 first person interviews with building occupants and emergency responders, I don't think it is likely that they mistakenly assumed that some unoccupied floors were occupied.

However, it they did, then they would have underestimated the extent of the damage incurred by the core as a result from the aircraft debris impacts on those unoccupied levels. Do you think they should have given more thought to the possibility that the aircrafts were really impacting empty shells?

[DoYouEverWonder]

70. Of course

if there was nothing in the way of the curtain walls and the core that would have a much different effect on how the plane broke up, has opposed to floors that are partitioned and full of stuff.

However, of even greater importance is the difference it would make on calculating the fire damage. If the floor was empty there wouldn't be any contents to burn, you would expect to see less fire on those floors I would think?

[Carefulplease]

71. You are right...

And so, the fact the NIST's fire model results matched quite well the progression of the fires, the breakage of windows and the emission of smoke, as these were seen on some 3,000 timestamped photographs and videoframes, suggests that there were no such phantom empty floors that the Port Authority should have known about.

[DoYouEverWonder]

72. Are you suggesting

that all of the floors were occupied or had contents?

[Carefulplease]

73. No. I am not "suggesting" that all the floors were occupied.

I am suggesting that if some floors were not rented or were unoccupied, this would probably not have been a secret to the Port Authority and to the maintenance crew of the WTC.

[DoYouEverWonder]

77. Where did I say that they didn't ?

What does that have to do with the modeling used for the NIST report?

I want to know did the NIST REPORT take into account the empty floors in the impact zone or the empty floors that were on fire?

[Carefulplease]

92. NIST does not mention any vacant floor in the impact zones.

They modeled the combustible loads based on informations provided by the Port Authority and the tenants of the relevant floors. Floors 92 through 100 in WTC1 were occupied by Marsh & McLennan who provided NIST with all their floor plans. Representatives of the Port Authority and the occupants of floors 79 through 82 in WTC2 provided verbal descriptions of those floors. Chuo Mitsui Trust and Banking were occupants of Floor 83. NIST might have had limited information about the layout of that floor. This was the topmost floor modelled by NIST in WTC2. The drawings were available for floor 78. This floor was hit by the tip of a wing and there were no significant fires on it. There does not seen to have been any empty floors.

http://wtc.nist.gov/NISTNCSTAR1-5F.pdf
pp. 49-52

http://en.wikipedia.org/wiki/One_World_Trade_Center_tenants
http://en.wikipedia.org/wiki/Two_World_Trade_Center_tenants
http://worldtradeaftermath.com/wta/wtc_info/tenants.asp

[DoYouEverWonder]

93. Well according to your Wikipedia link

there are no tenents listed for the 83rd Floor of WTC2 which was right in the middle of the impact zone?

[Carefulplease]

94. The 83th floors was not right in the middle of the impact zone.

Chuo Mitsui Trust Tokyo was a tenant of the 83th floor. Check the other link I provided. They're also mentioned in the NIST report. Two employees from that company died in the attack.

The 83th wasn't "right in the middle" of the impact zone. It is the topmost of the 6 floors for which NIST modeled the fires (78th-83th). It was hit by the right wing of the aircraft and received just 2% of the debris. The damage to the fire insulation of the columns and trusses was limited. This is seen in the figures of the NIST global impact analysis. So the fires on that floor, though severe (as pictures and videos show), would have had less of an incidence on the behavior of the structure, I would presume.

[DoYouEverWonder]

95. According to the chart you posted

The impact zone for WTC 2 was between the 78th - 85th floor. Those are the floors marked in red, so I guess the 82nd Floor would be exactly the middle according to the chart? That does not mean that the chart in Wikipedia is correct, but you posted the link, not me.

Either way, according to the Wikipedia chart you posted there is no tenant listed for the 83rd Floor. The first link does shows Chuo Mitsui Trust Tokyo with zero sf? Their name does not appear on other lists of tenants that I've seen, so I would assume that even if they did have space on that floor it was probably a very small area and not significant. A lot of companies will rent small spaces in NYC just to have a prestigious address to get their mail.

According to another site, Chuo Mitsui Trust had 5 employees that worked at the 83rd floor office. So the entire 83rd floor had one company with 5 employees. I would assume most of the remaining space on that floor would still be empty.


Also in WTC 2, from what I can find, the 75th - 77th floors right below the impact zone were empty, the 78th floor had one tenant using 4500 sf. so it was another floor that was mostly empty.

BTW: Your last link which lists the tenants is not a complete list. There seems to be whole floors where the info is missing, that does come up on other lists.

[Carefulplease]

101. There were no significant fires on floor 78 of WTC2.

Regarding the 78th floor, I already indicated: "The drawings were available for floor 78. This floor was hit by the tip of a wing and there were no significant fires on it."

Floors 84 and 85 were also hit by the tip of a wing almost empty of fuel and NIST did not model the small fires on them.

Floor 83 is still located above the fuselage and engines impacts, it is not unoccupied and NIST got some data on the layout from a tenant from a floor below. It suffered little damage from the impact. It might be mostly empty, for all I know.

All this information is easily found in the NIST reports you've already looked at and quoted.

[Carefulplease]

102. Another issue...

If there were little combustible material on floor #83 of WTC2, then how would you account for the big fires that were *observed* on photographs and videos and that NIST compared its fire simulation results with?

[DoYouEverWonder]

103. That is the question

You're finally catching on.

I'm a little confused though. You say the 83rd floor suffered little damage, then you say in the next post that big fires were observed on that floor?

Either way, let's not worry about the amount of damage from the plane and for arguments sake, just consider the big fires that you say were observed on that floor. If the floor was empty and there was little combustible material, what did cause the big fires that were observed?

BTW: Do you have a list of the floors that were on fire. Like the list of tenants and impact zones, what I've seen seems incomplete?

[Carefulplease]

110. Yes, I might eventually catch on.

I'm really trying to catch on, but you take such long strides.

Message #57: "Do any of these calculations take into account office contents?

They do, in a quite detailed manner on most floors.

Message #61: "This is just an example of what you would expect the interiors of an office building to look like. Lot's of stuff to get in the way of a plane breaking up."

This was accounted for.

Message #66: "NIST did all of the modeling based on spaces that looked like this"

They did not. They considered the actual floor plans and/or got information on the furnishing from the tenants and representatives of the Port Authority.

Message #77: "I want to know did the NIST REPORT take into account the empty floors in the impact zone or the empty floors that were on fire?"

There weren't any. But wasn't your original concern the exact opposite? That they assumed furniture filled floors to be empty?

Message #77: You're finally catching on.

I'm a little confused though. You say the 83rd floor suffered little damage, then you say in the next post that big fires were observed on that floor?

They were big but not as big as the fires on most of the floors below.

Either way, let's not worry about the amount of damage from the plane and for arguments sake, just consider the big fires that you say were observed on that floor. If the floor was empty and there was little combustible material, what did cause the big fires that were observed?"

If the floor was empty? Then there might have been suicidal CIA agents posted on that floor that were aiming flamethrowers at some windows to simulate an office fire.

What if it wasn't empty? Could it be that the Port Authority did not lie to NIST; that the recollections of the guy who told NIST about the partition on the east side of that floor were correct; that NIST's estimate of the combustible load wasn't completely off; that two unfortunate office workers from that floor really died; and that the fires, smoke and broken windows that were seen on photographs were just the result of plain office fires just like they must have been on several other floors of WTC2 and WTC1?

[DoYouEverWonder]

111. Well according to the NIST report

only the 78th floor plan was available for WTC 2. The basic layout from the 78th floor was used for the higher floors with adjustments made to the elevators, vents and partitions based on the recollections of former floor occupants. Appendix A, Floor plans.

So they did not consider the actual floor plans, they had one floor plan for the 78th floor and used it for all the other floors that they modeled. Therefore they did not take into account that some floors were actually empty or mostly empty or that some floors were fully rented. They even admit that they had no floor plan for the 83rd floor, so they just went ahead and used the same plan from the 82nd floor, and then buried in an appendix they admit they use basically the same plan for all the floors in WTC 2. Wow, I guess they couldn't afford to spend the money to get the real plans for all the floors. Why wasn't this information available to them? You would think the Port Authority would have had detailed plans for every floor for fire safety, insurance and security reasons?

BTW: You still haven't responded to my request for info on the fires? Since you are so much more familiar with the contents of these reports then I am, I was hoping you could point me in the right direction for this info. I'm especially interested in floors that were on fire inside and outside the impact zone and which of those floors were empty. Thanks.

[Carefulplease]

112. Now it is your turn to do some catching up. (Edited)

Edited to add emphasis to "or a floor of similar use" (e.g. storage, conference room, or maybe, unoccupied!)

You might want to read again my message #92 and follow the first link and the page numbers I provided. You are just throwing back to me an selective version of the informations I already summarised and made available to you.

Information about the layout of the relevant floors was obtained
from architectural drawings provided by the occupants. For floors where information was not available, the geometry of a nearby floor or a floor of similar use was substituted, supplemented by information provided by Port Authority of New York and New Jersey (PANYNJ or Port Authority) engineers or occupants.

(...)

The layouts of the modeled floors in WTC 2 (except floor 78) were not available to the Investigation. However, representatives of the Port Authority and several occupants of the relevant floors provided verbal descriptions of floors 79 through 82. The layout of these floors was similar to those of WTC 1, with the exception of more elevator shafts and more compartmentalization outside of the core area. The layouts of floors 78 through 83 that were assumed for the purpose of the fire modeling are included in the Appendix.

[DoYouEverWonder]

115. You might want to read again my message #92?

You mean this one?

NIST does not mention any vacant floor in the impact zones.


Yes, NIST DOES NOT MENTION any vacant floors in the impact zones. That is the problem. Their modeling for WTC 2 is deeply flawed.

Not only do they NOT MENTION the empty or mostly empty floors, they didn't mention all lot of other important details. Like the detour the stairwells take to go around the enormous elevator machine room that happened to be located on the 81st floor. Since they only had the floor plan for the 78th Floor and based all the other floors on that, they missed the fact that the stairwells were not in the same place on all the floors in the impact zone. It also appears that they do not account for the elevator room either, which took up 1/2 of the floor space on 81 and contained a dozen 24-ton elevator hoists that were some of the largest in the world. Oops.

[DoYouEverWonder]

117. Gee, what are those birds I hear chirping?

What's the matter, does your precious NIST report have some fatal flaws?

[Carefulplease]

114. NIST could not afford to buy the plans.

Port Authority would have had detailed plans for every floor for fire safety, insurance and security reasons?

Those plans were destroyed when the towers fell. Blame the Port Authority.

[seatnineb]

104. Is the NIST your bible?

You wanna be more careful when you say stuff like this:

In the words of Carefulplease:

Sun Aug-27-06 05:49 AM
If there were little combustible material on floor #83 of WTC2, then how would you account for the big fires that were *observed* on photographs and videos and that NIST compared its fire simulation results with?

Brian Clark..............


....was on the 84th floor and was making his way down when he encountered those big fires.........oh yeah...I meant those quiet flames that were just licking up

BRIAN CLARK:
" Drywall had been blown off the wall and was lying propped up against the railings here, and we had to move it, shovel it aside. You could see through the wall and the cracks and see flames just licking up, NOT A ROARING INFERNO, just quiet flames licking up and smoke sort of eking through the wall.2
http://www.pbs.org/wgbh/nova/transcripts/2907_wtc.html

Next.

[DoYouEverWonder]

105. It doesn't take long

for a small fire to become an 'inferno' depending on where the fire is and what's around it. It also depends where Brian Clark was and what time it was when he observed the fire.

[seatnineb]

106. Yes that is true.............

But did that fire that was alledged to have become a big fire..........stay a big fire?

Below is the kind of foto of a hot fire that NIST apologists like carefulplease....would dream that they could find for the South Tower........

But alas...this one belongs to the Windsor Tower in Madrid.

[DoYouEverWonder]

107. Ah, that is the other side of the coin

Again, without knowing the exact time and place we have no way to know.

Add one more factor, some of the floors on fire were unfinished floors that never had occupants. If a floor had no contents, then what was burning?

[AZCat]

108. I think that is a dangerous assumption.

It is possible that unoccupied floors had contents. Perhaps the facilities people were using them as storage? If so, determining the actual makeup of the contents of the floor would be quite difficult IMO.

[DoYouEverWonder]

109. What is so dangerous about finding out whether or not

any of the floors in the impact zone or the fire zone were unfinished, empty floors, ie. floors and space that have never had occupants?


I've been on one of the 'empty' floors. In the 70's a former SO had a delivery route in downtown Manhattan. He had one client that was on the 90 something floor in the towers. Even then you had to have security clearance to go above the 90th Floor, especially if you were going up in a vehicle in the freight elevator. It was a fun delivery because you didn't have to park, you could just drive the van onto the elevator and go all the way up. When we got to the floor, the customer was always waiting at the door and would never let us off the elevator. However, you could easily see most of the floor on that side of the building. The floor was empty. All there was, was unfinished open space. He was probably the only guy that worked on that floor. Some small Japanese Company that wanted a fancy address I suppose. BTW: A lot of big office buildings have empty, unfinished floors and spaces. Even the Empire State Building. Most buildings never come near 100% occupancy.

Second, do you know how much rent costs in NYC? I don't think people would be renting space in the WTC just for storage and if they did City Codes would require some level of finishing in.

Third, yes - determining the actual makeup of the contents of the floor would be quite difficult. That is one of the big problems with the NIST report. If they didn't not take into account the empty floors in the impact and/or fire zones, their modeling is inadequate.

[AZCat]

113. "dangerous" might not have been the right adjective

I meant that it was not necessarily a good assumption.

I also didn't mean the space was rented for storage (you're right about rates) but rather that the facilities people might have put things there, but as you state you have seen empty floors without anything in them.

The NIST may have been able to get plans for the original tenant renovation of the space, but offices change over time and the floor plan on September 11th may not have matched what the NIST was given, but there may not be an accurate record of what the actual floor plan was.

[DoYouEverWonder]

116. For WTC2, NIST claims they could not get the plans from the PA

for any of the floors in the impact zone except for the 78th floor. They based all of their modeling on that one floor. Supposedly they used anecdotal evidence to adjust for some of the differences between floors, but it appears they missed some major differences.

Surprisingly, the man who was one of the lead investigators complained that he could not get access to a lot of the documents, building plans, pictures and videos that he would have liked to have seen. Makes it difficult to do much of an investigation when you've got one arm tied behind your back.

Testimony of Dr. Abolhassan Astaneh-Asl

Professor - Department of Civil and Environmental Engineering
University of California, Berkeley

March 6, 2002 Hearing on “Learning from 9/11: Understanding the Collapse of the World Trade Center”


The main impediments to my work were and still are:

1. Not having a copy of the engineering drawings and design and construction documents.

2. Not having copies of the photographs and videotapes that various agencies might have taken during and immediately after the collapse.

http://www.house.gov/science/full02/mar06/astaneh.htm

[mirandapriestly]

74. How can anyone believe that not one , but two towers

came down symetrically and entirely like a house of matchsticks from an office fire? The damage done after the impacts was to several floors and left the building appearing intact and stable. The explosions on the other hand....

[greyl]

75. I doubt that anyone does. I can't believe you've heard

anyone saying that, or read those words.

[Carefulplease]

76. Welcome to DU Mirandapriestly...

I see that you are new here. You will find some those issues discussed in the archive ;-)

[mirandapriestly]

118. No, it took me years to reach

1000 posts, which is the way it is for most DUers. And, to date, I have not seen a good explanation for what I described, that is one that is free from "Bush science". Google "Bush science" and see how highly it is regarded.

[greyl]

119. Way to miss the point. Btw

you haven't been a DUer for years. How can your claim that it took you years to reach 1000 posts, when you have 3800 today, be true?