Students design, engineer successful bridges

By Siddharth Bharadwaj ‘24

Students in the Engineering Your World course show off their bridge design made of popsicle sticks!

The Bridge Design Challenge was undertaken by the Engineering Your World class led by Dr. Bob Bowman. Students were instructed to create a bridge with a minimum length of 14 inches, using only 200 popsicle sticks. The goal was for the bridge to hold at least 20 pounds. As a result, the team was surprised to learn that, upon testing, the bridge broke that record by almost 1000%, holding a whopping 209 pounds!

The class of 11 was split into two groups, each tasked with creating their own popsicle stick bridge that abided by a set of guidelines. First, the teams engaged in extensive research on different types of bridges and their structural components. Based on this information, they designed numerous bridges in their lab notebooks and finalized the best design. The two teams then began the construction phase, which lasted two weeks. Individuals in both teams maintained an open mindset toward each other’s ideas and worked collaboratively to develop a bridge.

This process, however, was not without its own obstacles. The glue took a long time to dry and teams often would have to carefully remove or reposition glued-on pieces for better fitment. As Jim Zhang ‘23 stated, “Although some members had different proposals, we all actively communicated, cooperated, and discussed our ideas. Through the hard work of each team member, the bridge was ultimately successful and exceeded our expectations.”

The last (and more exciting) aspect of this project was the testing phase, which took place in the fitness center. Two benches were placed parallel to each other, spaced 12 inches apart, with the bridge placed perpendicularly on them. Both teams then strategically placed weights on the bridges, accounting for even weight distribution as well as balance. Both teams placed weights on the bridge and the first team reached a limit of over 130 pounds before their bridge snapped.

The second team placed dumbbells on the bridge and laid the weight plates on top. They then skillfully positioned kettlebells on top of the weight plates, while at the same time, ensuring that the weights did not fall off due to an imbalance. The winning team pushed the limits on testing and their bridge finally managed to break the 200 pounds barrier (209 pounds).

Dr. Bowman, a key mentor in the design process, stated, “It was really exciting to see the students’ bridges hold the first 10, 20, and 30 pounds. Then, I was awestruck as both of the bridges held more than 100 pounds. While I knew the students had chosen excellent designs for their bridges, I had no idea they would be so sturdy. It was really satisfying to see how excited all the students were at the conclusion of the project.”

The surprising part was the fact that 209 pounds was not the bridge’s maximum capacity since it could have definitely held more. However, due to safety considerations, the team was advised to stop going further.

The Bridge Design Challenge enabled students to learn communication and teamwork skills as well as stimulated their understanding of bridges. While the two teams were competing, they also learned about cooperation and patience. All of this was achieved through a popsicle stick bridge activity!