Structural Engineering: Bridges of the Japanese Garden

This spring, Dawn Straith, Innovation & Technology Specialist at the Vlasic Early Childhood Center & Cranbrook Kingswood Lower School Brookside, used the bridges in the Japanese Garden as a tool in her Design Thinking Unit with the Senior Kindergarteners. I asked Mrs. Straith to explain the project.

The Senior Kindergarteners exploring the Cranbrook Japanese Bridge (aka Red Wood Bridge) in the Japanese Garden, 2025.

DS: In our design thinking and engineering unit, the Senior Kindergarten students became bridge investigators! They explored six different bridges in the Japanese Garden to see how safe and strong they are. While investigating, they discovered that bridges with beams and columns are much stronger than those without. They considered what goes over and under the bridges, who and what use the bridges, the materials the bridges are made from, and whether they had handrails. Some bridges didn’t have handrails at all, which we determined made them feel a bit less safe. They also noticed that the ground near a few of the bridges was eroding, which isn’t as safe either.

Side view of the Japanese Garden Round Island Footbridge.

DS: The bridge to “Round Island” (a small island the children have affectionately named for themselves as “SK Island”) got the lowest safety score—it’s tilted, there are no support beams, the ground is eroding, the materials used aren’t the strongest and there are no handrails to hold onto!

Japanese Garden Round Island Footbridge from the eastern shore of the Lily Pond. Photo by Saida Malarney.

DS: After analyzing all this, the students got to work designing a safer bridge for “SK Island”. They learned that triangles are super strong shapes and that engineers use them all the time when building bridges. With their users in mind, the students carefully designed and built models of brand-new, safer bridges. Their final step is to share their ideas with the garden’s groundskeepers.

Round Island Bridge design, incorportating safety features like “rallens” and “sport beams.”

Enter the Center, the aforementioned “garden’s groundskeepers”!

I am the “Proud Museum Person” with some of our Japanese Garden volunteers working in the garden in April 2025.

As the Associate Registrar, and once-a-month “Gardener” in the Japanese Garden, I was invited to visit the SK classes as they presented their bridge models.

Most of my friends in SK had already helped cover garden sculptures for a number of seasons, so I knew they understood taking care of objects on the campus, but I was once again impressed by our students. They carefully considered what changes could be made to make our bridge safer for all visitors — kids, parents, guests with limitied mobility, and furry friends.

A very big THANKS! to our SK engineers.

Some of the students’ ideas even aligned with designs by our garden designer Sadafumi (Sada) Uchiyama, a third-generation Japanese gardener, registered landscape architect, and Curator Emeritus of Portland Japanese Garden.

Design for Round Island Bridge by Sadafumi Uchiyama.
Design for Round Island Bridge by Gretchen and Liam.

As we start the construction of the new Welcome Garden in the Japanese Garden this summer, we hope our future structural engineers will return in the fall to see how we are progressing.

Leslie Mio, Associate Registrar, Cranbrook Center for Collections and Research

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