CHICAGO - Alan Schilke's job is to make people scream.
As a hotshot roller-coaster designer, Schilke promised to build a massive, record-setting wooden coaster at the amusement park in Gurnee, Ill. When he saw how small the construction site was, crammed between a railroad track and other rides, he knew he would have to do back flips to squeeze shrieks out of his customers.
"Necessity is the mother of invention," he said. "We had to make a crazy ride just to get it to fit on the site."
The resulting attraction will set three records for wooden roller coasters. Goliath will be the fastest and steepest wooden coaster in the world, with the longest drop. It will hurtle riders at 72 mph down an 85-degree, 180-foot drop before rocketing them into hairpin curves, two upside-down twists and a zero-gravity stall to make passengers feel momentarily weightless.
Goliath is the latest creation in a revolution in roller-coaster construction, aficionados say. Its patented new construction technique manipulates wooden tracks into shapes never before seen, with inversions, over-banked curves and whip-crack reversals of direction.
The rising coaster structure is still a few weeks from completion. The Goliath is due for its public opening May 31, with a preview for season ticket holders the day before. Roller-coaster lovers are already planning group outings.
"We are definitely excited to ride this thing," said Scott Heck, a spokesman for American Coaster Enthusiasts. "I know a lot of people across the country want to come. I can't wait."
The coaster is being built by an Idaho company that is the upstart innovator in wooden coasters. Rocky Mountain Construction Group, based in Hayden, was started by Fred Grubb and his wife. Grubb was a carpenter and welder building coasters at Silverwood Theme Park in North Idaho. Frequently working to repair old wooden coasters, which often wore out where the wheels made contact, he and his engineers decided there must be a better way.
Traditional wooden coasters, such as the American Eagle at Great America, have simple steel plates lining the track where the wheels go. Rocky Mountain instead built a steel trap that encases the wood track and is much stronger.
The company then developed a method of building new wooden coasters that fabricates computer-designed tracks. Rather than building tracks on-site, as was done in the past, Rocky Mountain cuts, flexes and welds the steel into whatever shape is needed and fastens it to laminated pine in the shop, while curving it to within a sixteenth-of-an-inch margin of error over 40 feet of track.
That technique allows the track to bend in ways traditional wooden rides wouldn't. The company used its new design to retrofit two coasters in Texas, though one site was marred by the death of a person who fell off the ride last summer.
The company wowed riders last year after it built the new Outlaw Run coaster at Silver Dollar City in Branson, Mo. The ride won a Golden Ticket Award from Amusement Today as the best new amusement park ride of 2013.
Using similar techniques as Outlaw Run, Goliath's wheels will ride on a metal covering that is also filled with grout to provide more strength and a quieter run - an important concern to neighbors who live near Great America. In addition, the cars will run not on traditional steel wheels but on nylon wheels in the cold and urethane in the heat.
The construction crew of about 35 men from Idaho included former tradesmen, loggers and rock climbers who had worked in more commonplace forms of commercial and residential construction. But as owner Grubb said, "Square (construction) is much easier than what we're doing but not near as much fun."
The workers are used to winter temperatures in Northern Idaho that often drop below zero, but even they were taken aback by the latest Chicago winter, one of the worst on record, thanks to the polar vortex.
"Our guys are tough," Grubb said. "Even they said this is absolutely brutal."
Since September, they've worked 11-hour days, six days a week through the snow and cold, missing only two full days of work because of weather. But with the wind chill and snow numbing workers' hands and making footing on high structures treacherous, the crew members had to stop frequently to recover in warming shelters, cutting productivity by more than half, supervisors said.
Crews still must finish building the track and installing the mechanicals, such as the chain that lifts the cars and the magnetic brakes that stop it. Then will come hundreds of test runs, featuring water-filled dummies wearing accelerometers to ensure that riders can tolerate forces exceeding three times the pull of gravity.
Park officials wouldn't say exactly how much the coaster will cost but said it is more than $10 million.
Despite the winter work, crew members say building coasters is a lot more rewarding than building an office or a sewage treatment plant.
"It's better," said supervisor Matt Whiteman, an Idaho native who works for the company in Hayden. "When you're done, you get to ride what you're working on."