Engineer finds clues in WTC wreckage

CNN ^ | Saturday, October 6, 2001

[JohnHuang2]

JERSEY CITY, New Jersey (CNN) --The jets that sliced through the twin towers of the World Trade Center were like bullets shot into people, a structural engineer said Friday.

Funded by a grant from the National Science Foundation, Abolhassan Astaneh-Asl has spent the past two weeks collecting "perishable data."

[Interesting Times]

The professor at the University of California at Berkeley said preliminary evidence indicates the structures withstood the impacts of the planes.

Ah. That would explain why they didn't fall down right away.

Whatever they pay this guy, it just isn't enough...

[HiTech RedNeck]

Astaneh-Asl said he hopes his work might one day be used to help design a different structure perhaps using different materials that would keep a plane from piercing the core of a building and spilling its explosive cargo of jet fuel, he said.

It's unlikely that we will be plagued with more incidents of this kind, now that we have a radically different attitude -- keep the cockpit at all costs -- towards attempted jet hijackings. It wouldn't be cost effective to armor-shield all tall buildings this way.

Something which might make marginal sense would be a means of quickly delivering Halon to several floors of a building. Halon is used in fire extinguishing systems in computer rooms; it is expensive but it is not harmful to equipment or to people. A sufficient quantity of Halon would have put out the jet fuel fires from the 9/11 attacks.

[Rokke]

ROFLMAO

[SunnyUsa]

"Whatever they pay this guy, it just isn't enough... "

ROFL!!!....And I thought I was being mean thinking I really couldn't handle *his name*
...and then I read your post! :)

[tbeatty]

Astaneh-Asl said he hopes his work might one day be used to help design a different structure perhaps using different materials that would keep a plane from piercing the core of a building and spilling its explosive cargo of jet fuel, he said.

Sort of like a Building Prohylactic. I'm sure PLanned Parenthood would be willing to donate all their Red, White and Blue condoms for this project.

[Interesting Times]

Halon is used in fire extinguishing systems in computer rooms; it is expensive but it is not harmful to equipment or to people.

Equipment no; people, yes.

Halon makes a relatively poor substitute for oxygen...

[RnMomof7]

Ah. That would explain why they didn't fall down right away. Whatever they pay this guy, it just isn't enough...

LOL

[John Jamieson]

We put an middle easterner in charge of this? I hope this guy is being checkout. I didn't notice one sentient remark.

[medved]

In an age of carbonfibre tennis racquets and ceramic tank armor, it's not at all obvious to me we ought to be building skyscrapers out of concrete and steel anymore. You might could figure a way to prefab individual levels out of very light and strong stuff and simply stack them on top of eachother and have the whole thing back up in six months.

[Koblenz]

Damn, I must be a pretty good structural engineer. Although I've never studied structural engineering or architecture, I knew everything that this professor did. And I didn't spend two weeks looking at scrap metal.

[Interesting Times]

They were exceedingly well built. They held up long enough for thousands to escape.

True. From the casualty numbers and reports, it appears that most people killed were at or above the impact points, especially on the first strike. Add to that people who stayed put instead of getting out, those killed by falling debris, and of course, the heroes who were headed up instead of down...

[nightdriver]

"Halon makes a relatively poor substitute for oxygen..."

Yes, that's how halon puts out fires (quite effecitvely, too). Maybe a foam system (the foam is, ironically, made from pig's blood!) or a dry soda-type system would be effective while not suffocating the poor people trapped in the building.

[drlevy88]

You don't have to smother the fire with Halon. A still-breathable Halon mix would work just fine; it chemically stops the combustion reaction, rather than physically blocking the oxygen.

[drlevy88]

dry soda-type system

Releases CO2... to smother the fire

[supercat]

Halon makes a relatively poor substitute for oxygen...

Unlike CO2, halon does not extinguish fires by displacing oxygen. Halon can be present in sufficient concentration to extinguish most fires without displacing so much oxygen as to prevent breathing.

I don't know the exact details, but halon takes advantage of the fact that most materials don't burn by oxidizing directly; instead, they go through several reactions in sequence. Halon blocks this process by combining with intermediate combustion products. According to the warnings I've seen on halon fire equipment, halon gas itself is non-toxic, but the gasses produced when halon combines with intermediate combustion products can be downright nasty.

All that being said, I don't think that a halon fire suppression system would have been much help on 9-11. A foam-based fire suppression system might have helped since--once sprayed--it would remain on top of the fuel and prevent re-ignition until the fuel was cleaned up. Halon, however, would most likely disperse before all possible re-ignition sources could be dealt with (given how hot the jet fuel burned, it would have quickly heated parts of the building well above the ignition point of jet fuel; unless those parts of the building cooled below the ignition point of jet fuel they would probably cause a re-ignition even if there weren't any other sparks or ignition sources still present).

[nm_james]

It's difficult to smother a fire with CO2 - particularly in an open building, unless somebody is directing it.

Foam is by far your best bet for a jet fuel fire. You need something that sits on top of the fuel and smothers it.

You could have lots of small foam packs throughout the building that expand when exposed to fire.

Another approach would be to try to provide a means to drain away the jet fuel. But it would be difficult to keep everything in place after a hit by a plane like that.

[Interesting Times]

Interesting. I wasn't aware that you could put out fires with breathable levels of Halon...

[Will]

SMASH THESE MURDERERS AND ALL OF THEIR PERSUASION AS HARD AS POSSIBLE IN THE MOST CONVENIENT FINAL WAY!!!!

They don't deserve another breath of the air on this planet...