Though I suspect we'll never know the full details, I'd like to know exactly what it was that the alleged terrorists arrested were planning to do to JFK Airport in New York:

Federal authorities say they foiled an alleged plot by a retired airport worker, a former Guyanese Parliament member and other Muslim extremists to plant explosives on jet fuel arteries at John F. Kennedy International Airport, triggering massive casualties and economic havoc.

Three men were arrested and a fourth sought in Trinidad for reportedly hatching the brazen scheme that they boasted would be worse than 9/11 and put "the whole country in mourning," authorities said.

The idea was that fuel lines that bring fuel to the airport, and that run under some residential neighbourhoods, would have somehow have been ignited.

What I don't understand is just how the fuel was expected to burn. To burn fuel, it needs to be exposed to oxygen. If I plant a charge on a pipeline, the explosion would of course result in a fire. The fuel incoming to the point of the explosion would continue to fuel the fire at the point of the explosion (where the ruptured pipe exposes the fuel to oxygen). The flame would not run up the fuel line, though, as long as there was fuel blocking it. The burning would happen at the exposed face of the fuel supply where oxygen is available, but that's all. Likewise, downstream, with the fuel supply gone, the pipe would empty out. Flames could run into the fuel line but there would be no fresh fuel supply. Once the dwindling fuel was consumed, the flames would die fairly quickly. Perhaps even earlier than that, since it is likely that farther along the downstream portion of the surviving pipeline, the oxygen supply would be much more limited.

Major pipeline explosions like those that have happened in Nigeria occur when a damage pipe was allowed to pour fuel into an open surface area for a signficant amount of time. The explosion is fueled by those spilled pools of fuel which are exposed to oxygen over a large area, more than by the pipeline itself. The pipelines fueling JFK run underground, which further limits the oxygen supply, as well as the surface area required for fuel and oxygen to come into contact. That is not to say massive underground explosions have not occurred. In 1992, a series of underground explosions destroyed 20 blocks of downtown Guadalajara, Mexico. In that case and others, however, gasoline leaked over a long period of time into a sewer line. In the sewer, the gasoline evapourated into fumes, creating a huge bubble of gasoline and oxygen mixed in vapour form. Flaws in the design of the sewers meant that this mixture was never flushed out, and could build up over time. A gaseous mixture is as large a surface area as you can have for mixing gasoline and oxygen prior to ignition, and when a spark ignited the mix, the result was massive explosions. But the explosion did not occur in the gasoline line, nor did the gasoline line play a signficant part in the explosion.

Indeed, the pipeline experts are saying the same thing with regards to this terror plot:

Richard Kuprewicz, a pipeline expert and president of Accufacts Inc., an energy consulting firm that focuses on pipelines and tank farms, said the force of explosion would depend on the amount of fuel under pressure, but it would not travel up and down the line.

"That doesn't mean wackos out there can't do damage and cause a fire, but those explosions and fires are going to be fairly restricted," he said.

John W. Magaw, a former head of the Transportation Security Administration, told The Washington Post that such an attack "may not cause a lot of deaths, but it would be spectacular and seen around world."

Maybe the plotters thought that lighting a fire a few miles upstream would cause the fire to run through the fuel pipe like a fuse to the fuel tank farm at the airport, thus avoiding the trouble of laying charges at the tank farm itself, with all that security getting in the way. I just don't think that's possible.

I get the feeling that the alleged terrorists, Russell Defreitas, Abdul Kadir, Kareem Ibrahim, and Abdel Nur, watched too much American television, in which every struture and vehicle seems to be filled with a gasoline-air aerosal. When the inevitable explosion happens, great balls of fire fill the screen. And the fireballs linger too, as the filmed special effect pyrotechnics are inevitably shown in slow motion. From what I've seen, real explosions are more smoke and dust than flame, they happen in the blink of an eye, and they don't usually spread (having violently consumed most of the fuel and oxygen, and thrown the remaining fuel out of the fire zone by means of the explosion itself).

Though this was a serious plot, and the law enforcement agencies involved deserve the congratulations and the gratitude expressed for their hard work, I just don't think the results would have worse than 9/11:

Three of the men were arrested and one was being sought in Trinidad on Saturday. In an indictment charging the four men, one of them is quoted as saying the plot would “cause greater destruction than in the Sept. 11 attacks.”

“The devastation that would be caused had this plot succeeded is just unthinkable,” U.S. Attorney Roslynn R. Mauskopf said at a news conference, calling it “one of the most chilling plots imaginable.”

In the 9/11 attacks, fully fueled jets were shredded by the buildings they struck, the fuel was quickly vapourized and ignited. But even then the initial explosions did not result in the devastation that followed at the World Trade Center. Rather it was the consequence of long-running fire in a high-rise in which the anti-fire measures, sprinkler systems and flame-retardent covering of structural members, were themselves destroyed by the initial collision of the aircraft, combined with the severing of major load-bearing members. Indeed, even in the 9/11 attacks, the jet fuel (essentially fast-burning kerosene) was consumed within the first 10 minutes. The fires that ultimately caused the structural collapse of the Twin Towers over an hour after the impacts were fueled by paper and furniture.

The alleged terrorists thought it would have been worse than 9/11. Some law enforcement authorities think it would have been worse than 9/11. It looks like it's just us engineers who think it would have been a lot of smoke but not a lot of fire. Osama bin Laden is said to have an engineering degree. I wonder what he would have thought about this plot. Maybe he can pop his head out of whatever cave he's hiding in and call in an opinion by cell phone. A quick ten-minute conversation, just long enough for that Reaper to get a lock on him...