The Rattler was a 20-year-old wooden roller coaster at Six Flags Fiesta Texas in San Antonio. Schilke helped upgrade its tracks, transforming it into the wood-and-steel Iron Rattler, the first hybrid coaster to include a completely inverted barrel roll. Courtesy of Six Flags Fiesta Texas
Alan Schilke
Alan Schilke Photograph by Dianna Schilke

Structural engineer Alan Schilke specialized in designing supports for buildings and stadiums. Then one day, a roller coaster company asked him to create columns to brace its rides. When Schilke corrected the G-force calculations the company had been using for years, it hired him full time. Now, Schilke designs coasters for Ride Centerline LLC, drawing ideas from a lifetime spent soaring off BMX bike and ski jumps.

How do you begin creating a new roller coaster?

I’m always thinking about what will make a coaster the most fun, which starts at the setup. In the X Games, they build 10 jumps in a row, but they’re not all the same–they avoid repetition. That’s the same thing you do when designing a roller coaster.

How does it feel to ride one of your own creations?

Back in the old days, I was always amazed. But today, we make simulations of everything. There are very few surprises anymore, because I’ve done it all virtually.

What are you working on now?

This year, we’re converting two wooden roller coasters. We take an old, decrepit coaster that has outlived its life and put a steel I-box track on top of it, which upgrades it even beyond most modern coasters.

This article was originally published in the May 2015 issue of Popular Science, under the title “Roller Coaster Designer.”