Blast blows Amite bridge into river

• By BOB ANDERSON
• Advocate Florida parishes bureau
• Published: Oct 22, 2009 - Page: 4B

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After a countdown Wednesday morning, the superstructure of the 77-year-old U.S. 190 Bridge over the Amite River fell straight down and was enveloped in a cloud of dust.

The roar of 125 pounds of explosives going off reached onlookers more than 1,000 feet away.

The crowd watched as some 20 shaped charges sliced the span into five pieces that now must be plucked from the river.

The rusting, steel truss bridge had to be demolished because it was in the path of a new bridge for eastbound traffic being built across the river, said Dustin Annison of the state Department of Transportation and Development.

Westbound traffic, which previously used the bridge demolished Wednesday, is already using a new span that is part of a $29.5 million project to replace both of the old bridges.

“It was a nice shot,” Patrick Carney said of the explosive demolition project he had carried out in a way that would avoid damage to construction on the replacement span 20 feet away.

Carney simultaneously used dynamite to bring down the bridge piers and “linear shaped charges” covered in copper to cut the steelwork.

One of the difficult parts of this job was blowing both the piers and the superstructure at the same time, so that there would have to be only one road closure.

The other main problem was working with explosive charges near the new construction without damaging it, Carney said.

“Every job has its particular challenges,” he added.

The job by Chicago Explosive Services appeared to go flawlessly except for a last-minute delay when authorities found two people slipping through the woods to the river in order to get a closer view, said Lt. Doug Cain of State Police.

The bridge broke apart in the intended places and wound up sitting in a position to be picked up by a crane and removed, he said.

“We’ll pitch it out and cut it up” for scrap, said Mike Young, the job superintendent for James Construction Group.