Building a better bridge

When Tina Sprague became the St. Joseph Middle School science teacher, she inherited science kits from the Michigan Department of Transportation. Mrs. Sprague liked what she saw, but needed to complete MDOT training to keep the kits.

So, she took the training.

After Christmas, her eighth-graders took on the Bridge Builder kit. This civil engineering project involved physics, geometry, algebra, computer-aided design (CAD), teamwork, and the scientific process.

“The bridge-building one was really cool,” Mrs. Sprague said. “There was a lesson online where the kids can learn about bridge load, what types of bridges are best for what, and the different kinds of bridges.”

After the lesson, Mrs. Sprague gave each student a piece of thin balsa wood and an apparatus that held a bucket. They filled the bucket with sand until the wood broke. Next, they laminated two pieces of balsa wood together, testing it again vertically and horizontally.

Using these results and a basic CAD program, students designed their own box bridges. The computer virtually tested the strength of their digital bridges, after which students improved their designs.

“Then they get to build the bridge that they designed on the computer,” Mrs. Sprague said.

Students had to meet certain criteria using only the materials in the kit. Over the weeks they built, glued, and pinned their box bridges together.

“They all started out on an even playing field,” Mrs. Sprague said. “It all depended on their design. Some of them used all [of the material], some of them ran out because they didn’t think about how much it was going to overlap or the extra cuts that they made that were wrong.”

When the bridges were finished, the eighth grade invited the first grade to watch the testing. Students hung the bucket apparatus on each bridge, filling them with sand until they broke, delighting their young audience.

“[The bridges] held a lot more than I thought they would hold,” Mrs. Sprague said. “The kids were amazed, too. They didn’t think they would be as strong as they were.”

Afterward, students wrote up reports, detailing the scientific principles they used, the challenges they faced, and the conclusions they drew.

“I loved doing the bridge project because we learned how to make a bridge stronger by just changing a few simple things,” eighth-grader Nick Meyers said.

Best of all, Mrs. Sprague successfully supplemented the eighth-grade science curriculum with a hands-on activity, much like the Math and Science Center kits the sixth and seventh grades enjoy.

“This was my guinea pig class,” Mrs. Sprague said.

Next up is the Magnet Levitation kit, where students will build levitating foam vehicles.

“That’s what I’m going to research over Spring Break,” Mrs. Sprague said.