'What if' question on the fate of the WTC buildings ... [NOT conspiracy theories!]

Factual Questions
1

I’ve been following the redevelopment process of the Ground Zero area in Manhattan for some time now, and sparing any real discussion about the plans that are being made to develop a new series of buildings (the whole process is a very emotional and time-consuming affair with many polarizing opinions of what should be built), my intention was to pose a question about the events that ‘could’ have taken place that fateful day.

Most of us are aware of the fact that the impact of those jetliners contributed little to their collapse. The immense heat of the continuing fire caused the trusses to lose structural integrity … but what if that had not been the case? The WTC was a very innovative design engineered to withstand the immense winds common to the area, and would have surived an impact like that if it weren’t for the fact that thousands of gallons of jet fuel burned it from the inside out. I don’t think anyone – in the mass chaos that ensued that day – had really been giving consideration to any plan of attack beyond evacuating the buildings and securing the area before dealing with the damage, and there was obviously never an opportunity to.

Now that new buildings are being planned to address and anticipate such horrific situations (I’ve read briefings about how there will be a much more modernized internal frame for structural redundancy, as well as redundant fire suppression systems), I actually found myself wondering what would have been done to salvage the buildings assuming they could have stood up to that kind of immense fire. How would the fire department and other authorities have dealt with extinguishing such a hellish blaze so high up in the air? Obviously there’s no way to get fire hoses to shoot that high, and the water supply in both of the buildings had been severed. I know it’s a horrible thing to proposition, but many building engineers have probably been asking themselves the same question over the last two years: if such a thing happened again, in New York or elsewhere, what would be the best way of dealing with such a massive, uncontrollable building-contained fire? I wanted to stir up some conversation about what might have been done if the buildings had actually survived.

2

I think if the WTC had survived their ordeal they would have been condemmed and dismantled. They simply hadd too much damage to probably be repairable. I am not an engineer however but at the least I suspect the building would have been dismantled down to several floors below the impact sites and then rebuilt up from there. I just can’t see that being economical and safe or worthwhile.

As to fighting a fire of the sort that happened at the WTC you really can’t. At least you can’t with water. Water would just spread the jet fuel around. Foam would be necessary if you hoped to seriously fight the fire.

Oddly enough while watching the Chicago Bears get spanked tonight by the 49ers I spoke with a structural engineer in the bar and we talked about this very thing. The WTC was unique in its construction and that uniqueness led to its collapse. To the buildings’ credit they survived the initial impact and stayed up for long enough to let most people escape (as bad as it was it could have been MUCH worse as far as death were concerned). In the end the way the floors hung on the ourside walls (unique to the WTC) was their downfall as jet fuel weakend the hangers thea held the floors up. Most buildings have internal supports and the outside wall is not what holds everything up. As such had a plane struck a building like the Sears Tower in Chicago it is highly unlikely the Sears Tower would have collapsed (also because the Sears Tower is more like a bundle of square tubes so even if one failed the rest would probably stay up).

Given what they learned I am sure they can build a building that can withstand a similar attack. Such an attack would still be horrendous and incredibly damaging but the building would probably stay standing.

3

Whack,

Nice to hear from another Chicagoan IT guy … I should have known when you made mention of the Windy City. I used to work in IT with another very intelligent IT guy, best coworker I ever had the opportunity to spend my days with. :slight_smile:

I do know about the structural failure of the building and how the floor trusses depended on support from the perimeter walls. This alone was the big reason for why the towers collapsed in one specific area without tilting or breaking in half, which would have caused even more horrible collateral damage. I often wondered how our Sears Tower would have fared under such damage. It is indeed an entirely different type of design.

I guess my biggest curiosity is how they would have put out that kind of fire. Regular fire suppression systems would have never worked, water would just push the flammable fuel around, and they’d need massive amounts of foam. I just got thinking about this and wondered if there are specialized techniques for dealing with high rise office fires.

FYI, I also read recently about how the commissioned engineers for the newly planned office buildings are also integrating massive emergency ventilation and exhaust systems which the original buildings never had. Ostensibly, they will be designed to control air climate very specifically, able to evacuate oxygen from select areas of the building, or to exhaust air to the top of the building in large quantites, such as in the case of a biological attack or other chemical agent set loose in the building. Very impressive stuff.

On another note, even today they’re still in negotiations over the final design of the buildings. I think I speak for most when I say that people would like to see some very classical, majestic designs put up – not unlike what stood before. People aren’t really embracing the radical, modern designs that have been proposed by Daniel Libeskind’s studio. I hope the architects involved come to a better middle ground with the property leaseholders, the development commissions, port authority and the New York citizenry over the design of the buildings. This is one situation where it’s going to be nigh impossible to make everyone happy and still be aesthetically progressive.

Okay, I guess it’s really obvious that I’m really into this subject, I’ll shut up now. :slight_smile:

4

But how would you dismantle something that big?

5

Controlled implosion. That’s basically what happened to them anyway. According to this PBS show (which is airing as I type this) the builders failed to take into account the effects that the burning fuel from a plane crash would have on the buildings.

6

Dropzone & Tuckerfan,

From the top down, with very big cranes. Whack-a-Mole didn’t say completley dismantling or demolishing the remaining structures. He said dismantling them down to the points of impact in order to build them back up. Yes, it would take a long time … probably twice as long as it takes to build a skyscraper (not counting the damage the buildings received, which would obviously slow the progress down even more).

If you have ever seen a modern skyscraper under construction, you usually see a central crane that hauls the materials up to the top floor that’s being built via the elevator shafts. With the stairways and elevators destroyed, they actually wouldn’t have to dismantle the elevator system as much for debris removal … the shafts would be mostly empty already. The buildings didn’t have express elevators straight to the top, though … they’d have taken up so much floor space that the layout of the floors would be impractical. The towers had three main express elevators that each went one-third of the length of the building. If you wanted to get to the top, you’d have to take at least three separate elevator rides. Either way, the shafts would still have needed repair to ensure integrity prior to a full repair effort. It wouldn’t be impossible, but it would take a very long time.

7

How would they put out a fire this big, this high up?

They’d probably just let it burn itself out, mostly. The jet fuel would burn up pretty fast, then the only stuff left to burn would be the papers & furnishings in the offices. After those are gone, there isn’t muh left to keep a fire going. (The building walls, floors, etc. are not very flamable.)

It would have been very hard to get water, foam, whatever up to a fire that high, and had the buildings not collapsed, the fire probably would have died out on it’s own before too long.

8

anamnesis, I doubt that they’d dismantle the building. The Loizeaux family could have brought the towers down using explosives, I’m sure. However, I have to think that the American folks would have insisted that the buildings be rebuilt and repaired.

9

And what exactly would be the point in demolishing two 110-story buildings if they were still salvagable or repairable? Controlled implosions are used for small buildings, not skyscrapers. Buildings of such size are not demolished with explosives, they are carefully deconstructed. Nobody blows up skyscrapers to bring them down … excepting terrorists, obviously. It is a very procedural and planned process, not a destructive one, Tuckerfan. And in the case of the trade centers, I don’t think they’d have needed to be completely disassembled. As Whack-a-Mole suggested (and which is commonly accepted as fact), we’re assuming the structures could have been repaired or rebuilt above the points of impact … and it’s my guess that such an approach would have been more cost effective than their complete removal, too.

I also think it’s rather tactless and unprofessional to suggest blowing up the hypothetical remains of those two massive buildings. I was hoping for some thoughtful – not destructive – theoretical discussion about what could have been done if they remained standing.

10

Well it wasn’t very controlled actually. I mean When WTC 1 and 2 went down they did so much damage that WTC 3-7 also went down eventually.(As well as a couple other buildings.)

11

Before the tragic demise of the towers, it seems few New Yorkers found these buildings either ‘classical’ or ‘majestic.’ Upon construction, my understanding (I wasn’t around) was that most people found them a giant, ugly eyesore that ruined a lot of views from the City. They became a super-recognizable featuer of the NYC skyline, but I’m not sure that your description would match a lot of people’s honest recollections.

12

IIRC, in the FEMA analysis, it was calculated that the jet fuel burned itself out within 20-30 minutes. After that, it was all the combustable material within the offices that continued burning and led to the failure of the structure.

With the magnitude of the fire, and the destruction of the water lines in the bulding, I don’t know that you could have fought the fire with any effectiveness. Letting it burn out would likely have been the best option.

–Patch

13

Marley,

Yeah, you are right about the public reaction 30 years ago. When the WTC originally went up, the majority of people thought they were a bland eyesore. Only over time did they become appreciated for their grandness, moreso now that they’re gone, of course. A true example of not missing something until it’s actually gone. Plain as they were, they stood there defiant and unashamed. I don’t think the public reaction lasted long back then, and even though I wasn’t around either, I think the negative publicity that surrounded the towers overshadowed their historical significance. Naysayers have a tendency to find mention in the history books first because they stir up so much trouble. :slight_smile:

Thirty years from now, who knows if whatever is standing there will be regarded the same way? I personally don’t like Daniel Libeskind’s current proposal of all those hideously angular, modern glass buildings and that knife-like “Freedom Tower”, but it seems that plan is getting the go-ahead. The public reaction toward the planned memorial is fairly strong, but the buildings new buildings … ? I think people are still hoping for something more significant which gives a strong, classical, distinctly American look to the New York skyline … and I don’t think those postmodern collections of jagged angles which resemble broken shards of glass send that message! But that’s my opinion and I guess it doesn’t belong in this thread. :slight_smile:

14

Well, the Murrow building in OKC was salvagable, but folks felt that what had happened there, it was better to destroy the building and put up a memorial than to repair it. **

Wrong. The Loizeaux family has dropped pretty much every kind of building, not to mention chimneys, radio towers, bridges, and the freakin’ Kingdome to name a few. **

Have you ever seen the Loizeaux family work? They are the experts in controlled demolition. They can calculate to the inch how far out debris is going to go. 99 times out of a 100 they can drop it all into the basement.**

I want a cite for your “commonly accepted as fact” statement. As for cost effectiveness of repairing the Towers, that’s a “maybe”, at best. Last I heard, was that even with the higher property costs it’s cheaper to build two 50 story buildings than one 100 story building. As for the disposal costs, anybody know what NYC spent on the clean up for the towers? We know that it cost roughly a billion in 1970s dollars to build the towers, with inflation, it’d probably be 1.1 billion or more to rebuild them from the ground up.

**

Tactless and unprofessional in what way? One of the engineers of the buildings stated that when he saw the footage of the planes hitting the buildings, he immediately began calculating how long it would be before they collapsed. **

In order to understand how it might have been possible to repair them, you have to understand why they collapsed, you also have to understand that if even if they had remained standing, folks might have wanted the buildings to come down because they sight of them had too many painful memories for the folks who live and work there.

Do not assume that I am happy that the buildings came down, or that I want whatever’s built in their place looks entirely different from what was there. I, personally, would love to see the rebuilt WTC look exactly like the towers which stood there until 9/11. If you doubt my word, then I suggest you do a search, you’ll find that I have posted numerous times that I wish NYC would rebuild the towers exactly the way they were.

15

Well, it would have been nice if he would have communicated his answer to the NYC Fire Dept, who had hundreds of fire fighters entering the building at that time! Or even just his basic conclusion that the buildings were going to collapse would have been useful info to them.

But this really sounds like an urban legend to me. Or at least someone’s after-the-fact claim. Can you give a cite for this? I can’t find any such statement attributed to Leslie Robertson, the actual engineer on these buildings.

16

It was shortly after the events of 9/11 that I saw/heard him make the claim. It may have very well been an NPR program about it, or a CNN interview, I don’t honestly remember, much of that time period has blurred into one long memory for me with news coverage from one network slurring into another.

And really, there’s not a hell of a lot good calling the NYC FD to tell them what’s going to happen. First of all, phone lines were jammed shortly after the plane crashed. Here in TN, it was impossible for us to get an out of state line to make a call until about 3 PM CDT. Land lines, and cell phone lines in NYC were overloaded. Since I was working at a satellite phone company at that time, I can tell you that even sat phones were useless because the sheer volume of calls being made.

Besides, I’m sure that the NYC FD expected the buildings to come down at some point. The buildings were not designed to withstand the impact of a 767 (it not being on the drawing board at the time the towers were being designed), and the fact that they didn’t immediately collapse is a testiment to the design.

17

And let me clarify “him” being the engineer in question. I’m not sure if it was Leslie Robertson or one of the engineers who worked with him on the project.

18

They were ugly, and hell yes I want those ugly towers back!

19

This may be a slightly garbled memory of a claim in one of the New Yorker’s articles from 2001 about the engineering of the collapses - quite possibly the one based around the interview with Robertson. As part of the research, the writer had talked to a dozen or two skyscraper engineers and had asked them whether they had expected the Towers to fall. None had, at least not catastrophically. However, one expert claimed that his immediate reaction to the news footage of the crashes was the realisation that both buildings would come down within an hour or two. The kicker: he doesn’t build anything, but was a specialist demolition expert with a knowledge of how to bring large structures down.
I can’t recall whether he attempted to contact any authorities. It may have been that he simply assumed that those in NYC would have experts on hand who had came to the same conclusion.

20

Further to the above, I’ve just dug out the John Seabrook article “The Tower Builder” about Robertson from the Nov. 19th 2001 edition of the New Yorker.

The article goes on to quote him on how he tried to contact the Fire Department in order to warn them. But all the lines were jammed.