St. Paul teen’s model roller coaster sets world record


Austin Granger loves roller coasters. Not to ride, mind you. He’s interested in how they work: height, design, speed. That interest inspired him to build the tallest K’NEX roller coaster in the world, a 32-foot-eight-inch structure that soars above the roof line of his St. Anthony Park home.

Austin, who will be a sophomore at Central High School in the fall, started building his roller coaster last winter and finished it in early July. He’s been acquiring sets of K’NEX, plastic building materials, since preschool, amassing a collection of 30,000 pieces.

The roller coaster uses about half of those, some of which were donated by Austin’s friends Walker Leonard and Paul Davis. Austin and his friend Sam Ihlenfeldt assembled it in sections.

With the help of other friends, Nehemiah Nesheim and Stephen Walker, they combined the sections and installed the structure behind Austin’s house, taking over the spot where his father, Adam Granger, was planning to build a fire ring. Those plans are on hold.

When the roller coaster was first erected, the wind blew it over twice before Austin figured out a system of guy wires to support it. Now it’s stable enough to withstand most anything short of a tornado.

The roller coaster is powered by 53 rubber bands and the train achieves a speed of 40 mph. It might have ended up even taller if Austin hadn’t run out of the right pieces.

“My original plan was for 36 feet,” he said. “I would have added a third tower for stability.”

He got the idea after noticing on the K’NEX Web site that someone else had built a 28-foot-eight-inch roller coaster. That structure is free-standing but is located indoors, where the designer, Brandon Davis, didn’t have to contend with wind.

Austin had built other tall structures for his own amusement, but now he had a goal. “This is the only thing I’ve built with the intention of setting a world record,” he said.

To make his roller coaster, Austin started with 3-D software created for designing real roller coasters, then modified things to reflect the fact that he was working with plastic modeling pieces.

His design uses a vertical launch, which gives the structure a fairly compact footprint. Brandon Davis’ roller coaster, on the other hand, uses a horizontal launch, so that structure takes up considerably more floor space.

Austin’s claim for the world record may be short-lived. Brandon is working on a 40-foot tower. Austin describes their rivalry as friendly, but he notes that Brandon, who lives near K’NEX headquarters in New Jersey, got a donation of 8,000 pieces from the company, as well as a $500 grant from a nearby amusement park. So there may be some grant writing in Austin’s future.

On the immediate horizon, though, is a world record for speed. By adapting and reinstalling his roller coaster on the ground, Austin figures he can make it go much faster. Brandon’s roller coaster does 60 mph.

“I’m sure I can top that,” Austin said.