How do those fireworks work?
• At Riverfest Express: Learn how experts make it happen
August 19, 2007
By DAVE GATHMAN STAFF WRITER
suburbanchicagonews.com
SOUTH ELGIN -- So you, like many local aficionados of the bursting blues and the streaking reds and the just-kabooming "salutes," think the annual fireworks shows at Riverfest Express are snazzier than the Fourth of July shows in other towns? Maybe there's something to the idea that "made in the USA" is best.
"Our company tries to use some American-made shells in every show," says John Weitekamp, foreman of the five-man crew from Central States Fireworks that shot off the opening-night show Thursday. They will return to repeat that show, but with about 30 percent more shells and "cakes" (more about that later) as the festival climaxes its 2007 run at 9:30 p.m. Sunday.
"You can't do an all-American show, because fireworks made in America cost 10 or 20 times as much as those made in China," Weitekamp says.
Central States Fireworks employees Andy Ocampo (clockwise
from bottom left), Dave Hlavin, Jeremy Janis and Dave Borchers work to
prepare the firework barge for the Thursday night firework display at
Riverfest Express in South Elgin. SCOTT M. BORT / STAFF PHOTOGRAPHER
"But the colors of an American shell are more pure. An experienced eye can see one explode and know right away, 'That was an American one.' "
Preparation for Thursday began when the crew rolled into South Elgin about eight hours before the show with a box truck full of boats and a van pulling a trailer bearing a "Danger -- Explosives" banner. Entering the Fox River about a half-mile upstream from Panton Mill Park, the men pulled out four 20- by 8-foot pontoon rafts, which they lashed together into one giant floating barge. On this they erected about 450 blue fiberglass tubes, held in place by wooden racks slanted at a nearly vertical angle. This they would adjust at show time based on wind speed and direction.
Erected at the end of the raft was a little wooden shelter not unlike a North Woods fish-cleaning stand, from which the man shooting off the fireworks would press buttons to send an electric current into the "lift charge" of each shell.
Then the crew began placing the shells into the tubes -- one tube for each shell to be shot off.
"Electrical firing is safer, but it takes a lot longer to set up, because every tube has to be wired, and you need a separate tube for every shell," Weitekamp says. "A lot of companies, especially ones just starting out that can't afford spending $30,000 on an electric firing system, still shoot them by hand. A guy goes down the line of tubes with a lit road flare, touching it to each shell. Another guy will reload each tube with another shell."
A look at the fireworks
His crew comes packing four kinds of ammo:
• Shells: Actually looking l ike a little paper pouch, they come in 3-inch and 4-inch diameters. The bottom half, called "the lift charge," is full of gunpowder and explodes when hit by the electrical charge. That explosion inside the fiberglass tube propels the top half of the shell into the air -- 300 feet for a 3-incher, 400 feet for a 4-incher. It also sets on fire a fuse that makes the shell's top half blow up when it reaches altitude.
The explosion in the air consists of either gunpowder or more intense, noisy flash powder, mixed with powdered metals. The color for the flowery explosion depends on the type of metal powder. Titanium creates white streaks, magnesium yellow, etc.
• Finale: How can so many shells blow up almost at once at the big climax? For the finale, clumps of 10 shells are tied together at the top, flying into the air together.
• Cakes: Clusters of 49 or 100 small, low-flying shells that explode all at once, somewhat like the finale shells.
• Salutes: Those tooth-rattling bombs that make a lot of noise but little light as they set off every car alarm for blocks.
By early evening, the shells were all loaded into their tubes. Doyle Ware, a South Elgin man who lends his motorized fishing boat to the effort each year, tied his boat to the quadruple barge and towed it slowly out into the middle of the river. Safety rules call for a separation between launch site and crowd of at least 70 feet for each inch that a shell is in diameter; since this show would involve some 4-inch shells, the barge must be at least 280 feet from the park, although Weitekamp added more distance "just in case the wind shifts."
The men dropped two anchors, then tied the barge even more tightly in place by securing ropes to trees on each riverbank. As much as Weitekamp and company do not want to face an explosion on board, they also don't want to be washed over one of the Fox River's "drowning machine" dams, just a few hundred feet downstream. But Weitekamp says he did end up in the Fox last year.
"I dropped my cell phone into the water, so I dived in to get it. The way we finally found it was that I got somebody else to call it and I could hear it ringing underwater. The phone still works, too."
He said he has never seen any of his men hurt by a fireworks accident.
"What really scares me is to see a 6-year-old holding a sparkler, with metal burning at 1,200 degrees just an inch from his finger," says the meister of the mortars. |
