IDIOTS! We are surrounded by idiots!

[Hawkmoon]

Highway bridge in Missouri collapses after being hit by TWO trains. No surprise there, IMHO.

http://apnews.myway.com/article/20130526/DA6GU3T00.html

Then we get this gem from the NTSB spokescritter:

NTSB board member Robert Sumwalt said while the investigations into both collapses are in the early stages "there is no similarity" between the Missouri accident and the bridge collapse in Washington, which sent two vehicles and three people falling into the chilly water.

He noted that the Missouri bridge was rated "good" after its last inspection in February.

"This was not because of any lack of integrity of the bridge in southeast Missouri, but because of a train that derailed and had a bunch of rail cars slamming around," he said.

...

Investigators also are expected to scrutinize the bridge's design, Sumwalt said.

And why would they waste time and energy "scrutinizing" the design of the bridge? Just as we don't design high-rise buildings to withstand having 747s flown into them, we don't design highway bridges to withstand having a derailed freight train slam into the supports. And why should we?

A bit of advice, Mr. Sumwalt: Be sure brain is engaged before putting mouth in gear.

[lee n. field]

[Ben]

[Lee]

Well... To be fair, just remember that they are dealing with a media that MIGHT mention the fact that a train hit it, after issuing a screaming headline that another bridge has collapsed.

[Lee]

And BTW- a great deal of study went in to figuring out why the twin towers pancaked after being hit by jets...with valuable lessons learned.

[Hawkmoon]

And BTW- a great deal of study went in to figuring out why the twin towers pancaked after being hit by jets...with valuable lessons learned.

I am very well aware of the studies. That's my line of work. And the fact is the twin towers were actually designed to sustain the impact of a Boeing 707 hitting one. That was the largest airliner flying at the time, and designing for that was NOT required by any building code. However, the engineer was aware that aircraft had hit the Empire State Building, so he thought it would be a good idea. Kudos to him.

But the twin towers handled the impact of the much larger planes, too. What they couldn't handle was the heat generated by the jet fuel-fed fires. The impact knocked a lot of the fireproofing loose, and the steel lost sufficient temper due to the heat that it collapsed. This can all be figured out, as it was. But I don't see any movement to require that all high rise buildings henceforth must be designed to withstand the heat of thousands of gallons of jet fuel being touched off two-thirds of the way up the building.

[Tallpine]

I am very well aware of the studies. That's my line of work. And the fact is the twin towers were actually designed to sustain the impact of a Boeing 707 hitting one. That was the largest airliner flying at the time, and designing for that was NOT required by any building code. However, the engineer was aware that aircraft had hit the Empire State Building, so he thought it would be a good idea. Kudos to him.

But the twin towers handled the impact of the much larger planes, too. What they couldn't handle was the heat generated by the jet fuel-fed fires. The impact knocked a lot of the fireproofing loose, and the steel lost sufficient temper due to the heat that it collapsed. This can all be figured out, as it was. But I don't see any movement to require that all high rise buildings henceforth must be designed to withstand the heat of thousands of gallons of jet fuel being touched off two-thirds of the way up the building.

Didn't they stop using asbestos insulation on the steel about halfway up 

[birdman]

Didn't they stop using asbestos insulation on the steel about halfway up 

No asbestos, and no, the fireproofing material (an intumescent paint) was applied to the structural elements all the way up.  The paint protects by swelling into a foam on heat exposure, which then insulates, and through ablation, removes heat.  However, it does have both peak temperature limits (the material breaks down) and total energy limits (the heat penetrates and/or the material is removed eventually)