Can a fuel fire (like 9/11) melt steel (like 9/11) and cause structural collapse?

Question

http://img.breitbart.com/images/2007/4/29/D8OQLKSG1/D8OQLKSG1.jpg

Fiery Crash Collapses Bay Area Freeway

OAKLAND, Calif. (AP) - A gasoline tanker crashed and burst into flames near the San Francisco-Oakland Bay Bridge on Sunday, creating such intense heat that a stretch of highway melted and collapsed. Officials predicted a traffic nightmare for Bay Area commuters for weeks or months to come.
Flames shot 200 feet in the air, but the truck's driver walked away from the scene with second-degree burns. No other injuries were reported in the 3:45 a.m. crash, which officials said could have been deadly had it occurred at a busier time.

"I've never seen anything like it," Officer Trent Cross of the California Highway Patrol said of the crumpled interchange. "I'm looking at this thinking, 'Wow, no one died'—that's amazing. It's just very fortunate."

Answer 1

The 9-11 conspiracy theory is garbage.

Everyone knows that steel has no strength once heated by a simple fire, especially a jet fuel fire. Every building in the world with a steel frame has plaster put around the steel to prevent it from softening in a fire.

Once you heat steel in a simple fire, it doesn't melt, but it becomes soft like taffy. You can't hold up 100,000 tons of weight on soft taffy. Now, in a fire, the protective plaster will only last a limited time, and on 9-11, the jets smashed off much of the plaster anyway (it's in the reports). The steel softened from the fierce fire. Some of the supports were already knocked out by the jets. Then it bent as 100,000 tons pressed down on it. When this happens, concrete & other things snap. Then catastrophic failure ensues. Plain & simple.

IF THIS COULD NOT HAPPEN, THEN THE ENTIRE WORLD WOULDN'T BE PROTECTING STEEL FRAMES.

Yes, this is EXTREMELY similar to the bridge failure, except that the Bridge didn't have 100,000 tons pushing down on it and it STILL collapsed.

Answer 2

The official 9/11 Commission report does not claim that the steel melted. Above about 400 degrees the strength of steel starts to be reduced; above 1,000 degrees it is softened and weakened drastically. Why do you think blacksmiths heat steel in a fire before they hammer it into shape? When taken separately, neither the fire, nor the destruction of 60% of the building's internal structure in the impact sites, would have been enough to bring down the buildings by themselves. If the buildings had been entirely intact even a catastrophic fire would probably not have weakened them to an extent that they would have collapsed. Your idea about a "huge spike in pressure" doesn't make any sense to me. Any increases in temperature would immediately return to normal the instant the pressure dissipated. Also let me point out the the plane and any flying debris were not traveling at supersonic speeds, so they could not cause much appreciable "shock compression" of air. In any case if your theory was correct the buildings would have collapsed right away, not after 56 minutes and 102 minutes later, respectively. The factor that affects MAX flame temperature is oxygen concentration. The only way to produce a flame hot enough to melt steel is to use pure oxygen. Atmospheric air is only 21% oxygen. There is no fuel which produces a flame hot enough to melt steel when it is burned in open air. Furthermore the fire in the WTC was largely a "diffusion" type flame where there is poor mixing of fuel and air, meaning that the normal flame temperatures would be significantly lower than the theoretical maximum if the fuel/air were perfectly mixed. None the less, temperatures of 1,000, or even 1,200 degrees could have been reached. this is well below the melting point of steel but as I said it more than enough to make ordinary structural steels extremely soft and weak.

Answer 3

Way to go Yak. I figured someone would post the Bay Bridge collapse. Also--I was pretty sure what some of the answers would be like. Maybe some of the move on.org. bloggers will dummy up some pictures of it and say Bush had it blown up too.

Answer 4

I could accept that the towers could have collapsed not by melting but by weakening of the metal. However, how can that explain the molten pools of steel found all over the debris field?

Answer 5

Steel loses 50-90% of its strength at the temperature jet fuel burns (800 to 1500 F).

Answer 6

its possible. 6 years ago a truck blew and burned under a bypass on the highway in Birmingham. that section had to be closed down. to much damage done to the bridge, they had to rebuild it. unfortunately the driver of the truck got killed.

Answer 7

Rosie should send a fact finding mission to Oakland, Ca. Jet fuel burns much hotter.

Answer 8

Steel also does not need to fully melt to collapse a structure. It can simply bend and warp because of heat that is less than the melting point of steel.

Answer 9

I am obviously no expert. However, the steel doesn't need to be melted. It only needs to be structurally compromised.

If the steel becomes weak enough, the enormous pressures exerted upon them can crumble the structure.

Answer 10

Look, it happened. Ergo demonstratum or whateve the Latin logic for it is. 9/11 conspiracty theorists take note.