Engineering Students Take Part in Hands-on Design Competition

With final exams looming, many students are looking for last-minute ways to boost their grades. Three students in Rockhurst’s engineering, computing and information technology program did just this by taking advantage of a hands-on extra credit opportunity – a Balsa Truss Engineering Design Competition.

“Students were asked to design and build a load-bearing bridge out of balsa wood materials,” said Kris Schumacher, adjunct professor who offered the extra credit opportunity in his statics class. “They were responsible for creating a design that would be able to hold at least 25 pounds. The student with the lightest bridge to hold the specified load would be the winner.”

Sophomores Nick Engler, Simon Clark and Jeff Clayton jumped at the opportunity, working long hours developing preliminary sketches, performing detailed engineering calculations, writing a design report, and putting together their finished products.

On Wednesday, Dec. 5, it was time to unveil their creations. Schumacher measured the mass of each bridge before each student took their turn in the hot seat. A large group of students, faculty and staff gathered in the Science Center lobby to watch as the three students tested their bridges, adding weight in small increments.

Clark was first up, with his bridge holding a solid 25-27.5 pounds. Next was Clayton who constructed a bridge that withstood a whopping 30.5-33 pounds. Engler’s creation held 5.5-10.5 pounds before collapsing.

“All three students put in a lot of effort, exceeding my highest expectations,” said Schumacher. “The crowd was on pins and needles as each student added weight to their bridge.”

Although Engler’s bridge held the least amount of weight, this outcome was the most interesting to Schumacher.

“His truss broke in a very unexpected way – the sides held up fine, but the bridge split straight down the center span, which is a mode of failure we didn't consider,” he said.

In the end, Clayton walked away with two awards for his bridge, one for the most economical design and the other for the highest load-to-weight ratio design.

“I think Jeff’s secret weapon was in the custom balsa wood joints he created to connect each piece of wood,” added Schumacher. “They were solid and, after inspecting his collapsed bridge, we noticed the bridge didn’t break at the joints – it buckled in the middle of one of the balsa sticks making it an issue with the material, not so much with his construction technique.”

To learn more about Rockhurst’s engineering program, visit www.rockhurst.edu/ecit.