How the Grainger Generating Station smokestacks will fall

Here’s how the Grainger smokestacks will fall.

At the bases of the two concrete towers, demolition crews have drilled a combined 330 holes and packed them with 120 pounds of dynamite.

Around 8 a.m. Sunday, a series of controlled explosions will weaken the base of each 300-foot tower. If the work goes as planned, the towers should fall about 10-12 seconds after detonation.

“It’s very similar to felling a tree,” said Thom Doud, project manager with Controlled Demolition Inc., the Maryland-based contractor taking the smokestacks down. “You take out that notch, it starts to lean, and, once gravity takes over, it should continue.”

Shortly before the explosion, a warning siren will sound and there will be an audible 10-second countdown.

Anyone who would like to watch the stacks fall is encouraged to arrive at Lake Busbee, which is across from the site, before 7 a.m.

U.S. 501 will be closed from about five minutes before the explosion until about 10 minutes afterwards. Once an explosives technician has determined everything is safe, traffic will reopen.

Marina Drive will also be closed between Third Avenue Extension and Elm Street from 6 a.m. until around 10 a.m.

Doud said the sensation of the towers falling won’t be as powerful as some might think.

“People, they get a little amped up, they hear it and they think that they feel it,” he said. “It’s really no more than the effect of a tractor trailer rolling past your home.”

This story was originally published February 6, 2016 at 1:00 AM with the headline "How the Grainger Generating Station smokestacks will fall."