Unsinkable: The 20-Foot Cardboard Boat
A 20-foot cardboard boat that carried five people and over 1,000 pounds across the lake. Stress-tested in Autodesk Inventor before construction; broke the school record for size and payload.
The rules were simple: limited cardboard, limited duct tape, build a boat that floats. I went bigger — the largest one the lake had ever seen, 20 feet long, built to carry five people and over 1,000 pounds.
Testing the design first
Before I cut a single sheet of cardboard, I wanted to know two things: would it hold five people, and was the whole idea even possible? I modeled the boat in Autodesk Inventor, matching the real build as closely as I could, and ran stress tests to see how it would behave under load. The simulations showed where trouble would start: displacement in the side walls once the payload was added.
Design changes
The simulation results shaped the design. I moved tape to strengthen the side walls, and specified thicker cardboard with a stronger flute type for the bottom center of the floor, where the most stress appeared. Each iteration tested safer than the last, until I was comfortable putting my team on the water.
On the water
Then we built it. It carried the whole crew across the lake and broke the Paris High School record for size and payload.
