Emerald Brown wanted to be a veterinarian when she was in high school, but that’s not why she was at the Hutchinson Zoo Tuesday afternoon.

The Hutchinson Community College sophomore studies automation engineering technology. “I like it a lot better,” she said, than her earlier goal.

And that’s why she was at the zoo.

This is the fourth year for HCC students to spend their free time voluntarily for weeks, applying their engineering skills to create a holiday scene for zoo visitors.

Sensors and timers and generators - and the students’ know-how - will treat nightly train riders as the Prairie Thunder Railroad triggers lights to flash as it rolls along the track. Elsewhere at the zoo in Carey Park, an animated display is timed to music.

The students have to figure out among themselves how to tackle some challenges, and they must take into consideration the setting - “like the type of lights in the nocturnal area,” Brown said.

They also are not supposed to ask HCC Automation Engineer Technology Trainer/Coordinator Robert Blume for time out of class to work at the zoo.

Squirrels chewed up some wiring and they had to repair it, said HCC student Braxtyn Felty, but otherwise animals at the zoo don’t pose a problem for the workers.

“You come out here and actually put the skills you learn in the classroom to the real-world test,” Felty said.

They troubleshoot the timers and calculate how much power is available to feed lights strung along or above the train track. When a generator proved balky Tuesday, students took turns pulling the cord - over and over and over again. Finally, the generator kicked on. A Santa Claus with lights was attached, and HCC student Guthrie Turner cupped his hands around a light to create enough darkness to see if it was lit.

“We got it,” Turner said.

By Thursday, they must be done, said HCC student Victor Martinez, because train rides begin Friday.

“It’s a race,” Turner said.

This is the fourth year for the annual “Nights Before Christmas” at the Hutchinson Zoo when the HCC students’ light show will be on display.