Demtech issues warning ahead of today’s blast…

Blaster asks residents to stay away from Chain of Rocks bridge blast.

Already a shell of its former self, come 10 am (local time) the bridge that carried eastbound Interstate 270 travelers over the canal for 50 years will come down in giant pieces, if all goes as planned.

And, if everything works out, spectators can watch it from the West Chain of Rocks Bridge just to the south. But the demolition company would just as soon everybody stay away.

“Our lead blaster says, ‘I wish people would understand that this is not a spectator sport. I wish they would all stay home,’” said Albert Godfrey, general manager of Demtech, the company tasked with the actual explosion.

Godfrey said Demtech’s primary objective is safety. “I don’t care if it takes three weeks to get it done, because it’s just not worth it” to have someone hurt, he said.

Interstate 270 will be closed to all traffic for up to two hours on Tuesday morning to allow for the demolition. Westbound lanes will be closed at Illinois 3; eastbound at Riverview Drive in Missouri. Detours will not be marked, Illinois Department of Transportation officials have said.

This demolition is to remove the remaining steel structures over the Chain of Rocks canal. Taking down the span directly over the canal is Tuesday’s objective; later the westbound span over the canal and the portions of both east and westbound bridges that are above ground will be removed in a similar fashion.

The concrete and other materials in the deck have already been removed. Crews last week and over the weekend were cutting the steel to later allow for the explosives — which will be RDX wrapped in copper jackets — to separate the bridge at very specific points. The men worked from a basket hanging from a crane held by a barge; they were not connected to the bridge.

Those explosives shoot off at 28,000 feet per second, Godfrey says, and shoot with 6 million pounds of force per inch. The RDX preheats the steel and drives the copper jacket through the steel. It is the industry standard in steel bridge demolitions, he said.

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