Posted on 12/07/2001 9:16:27 AM PST by chkoreff
Sometimes, there are materials that are too dangerous and need to be banned. Not always,but indeed sometimes.
Goodness, what can I say? I am sorry to hear that your father died from asbestos exposure. And I'm sure there are many more stories like it out there.
Perhaps the answer isn't a total ban on the substance itself, but the adoption of more stringent safety standards for working with it. I wonder what the practices were in your father's day. Did they even wear respirators? I don't know, I'm just asking.
My father-in-law once worked in coal mines, and he knew many people with the black lung syndrome. But modern technology has transformed the coal-mining industry, and it is much safer to be a coal miner today than it used to be.
Perhaps the total ban on asbestos is an example of "throwing out the baby with the bathwater".
To the wacko's, pro-environment and anti-people are one-and-the-same.
Yes, when you put hot coffee in a thermos, it will eventually assume room temperature.
Perhaps the melting of the steel beams was inevitable. But if it had been delayed by even a couple of hours, thousands of lives might have been saved.
BTW My family did not take part in any of the class action lawsuits, though we were asked to many times over the years.
Distinguishing between types of asbestos:
There is not one but MANY different types of asbestos fibre, divided into two main categories: amphibole and serpentine asbestos.
The amphibole fibres used commercially (amosite, crocidolite) are extremely hazardous. Because of their chemical structure and straight, needlelike fibres, amphiboles are very dusty, as well as highly biopersistent. Once in the human body, they can remain indefinitely in the lung tissue, and may cause cancer and mesothelioma.
Chrysotile, the most common serpentine fibre, is considerably less hazardous than ampibole varieties. Silky in texture, with curly fibres, serpentine asbestos is unlikely to remain suspended in the air. Thus, less of it is inhaled, and it does not stay in the lungs very long. The human immune system can eliminate these fibres fairly quickly.
The Health & Safety Executive (HSE) of Great Britain recently concluded that, like asbestosis, the appearance of lung cancer linked to chrysotile is a threshold phenomenon, meaning that there is an exposure level below which the health risk, if any, is so low as to be undetectable. Moreover, the HSE confirms that very few cases of mesothelioma are attributable to chrysotile, despite extensive exposure of thousands of workers in the past.
Today, asbestos means chrysotile.
What you need to know is that 99% of the world's current asbestos production is chrysotile, a fibre which, when inhaled in small quantities, poses no health threat. Indeed, the controversy surrounding asbestos concerns fibres and products that were used in the past often improperly and which are prohibited today.
I agree with the other posters in that these madmen were actually lucky to hit the towers at all let alone at any specific floor. However, I do believe that there may have been the intention to “topple” the buildings over onto the streets. Toppling is big with these fundamentalist morons.
The beams didn't melt. The yield point of the steel goes way down as the temp. rises. At ~1000oF the steel is red and is very soft(sorry don't have any numbers at hand); way to soft to be used in building structure and support it's own weight w/o creeping. When the stuff got to ~800oF it certainly would give. In that diesel fire, very thick secitons of magnesium oxide brick would have been required to give you a couple of hours. Your talking a new kind of building altogether. The idea that the replacement of asbestos by whatever they used would have helped at all is bogus. Asbestos wouldn't work either. They built an office building, not a furnace.
However, I would add that if in fact the terrorists were looking for the failure mode they got--heat softening the columns, leading to movement of the upper structure, which then builds up speed and acts as a battering ram destroying everything below--you would have to consider the variation of the size of the columns with the elevation.
At ground level, those columns must bear the weight of the entire structure and accordingly must be very heavy. Near the top of the tower, the columns have relatively very little weight to support. If you made the columns the same size all the way to the top, those columns own weight would be probably four times the size they would otherwise need to be, on average. AND the weight of the larger column would be significant in the sizing of the bottom of the column, meaning that structural weight and cost penalty would be absurd. So inevitably the top of the building is built lighter than the base is.
Now if you have a certain amount of fuel you can plaster onto the building in an effort to soften the columns, you figure that that amount of fuel will affect a thinner column faster and more surely than it will a thicker one. And you figure that it's not gonna much matter how few stories are above the fire, once they start moving they ain't ever stopping. On that basis you might aim pretty near the top. And I think that the second tower hit was struck higher than the first tower hit--and the second tower hit came down first.
JMHO.
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