Richmond LPS students build bridges to support engineering education

Richmond LPS students build bridges to support engineering education
Images courtesy of LPS Richmond.

By Kathy Chouteau

Students in Jeff Grossmann’s Intro to Engineering class at Richmond’s Leadership Public School recently accomplished something that had never been done before in his classroom: They built a bridge out of popsicle sticks, that when tested, withstood weight up to 497 lbs.

Eleventh grade students Henry Salazar and Emiliano Rodriguez Sanchez teamed up with 10th grader Elwynn Cabrera (see him interviewed in this video) to build the competition’s winning truss bridge.

It was all part of a Civil Engineering competition for 10th through 12th graders at the school to construct  strong bridges in class with the highest benefit and cost ratio—ultimately using the fewest number of popsicle sticks possible, according to the school.

During class on Monday and Tuesday, students tested their bridges by hanging a bucket from the middle of their bridge and then adding ten pound bags of sand until the structure collapsed. All the while, students watched, analyzed and predicted how the bridges would perform.

On Dec. 15, the winning bridge withstood a student being placed in the test bucket and 10 lb. sandbags being added to get to 497 lbs. It was constructed with popsicle sticks and glue, weighed 1.1 lbs. and covered a 14 inch span, per, Mr. Grossmann, who has taught at the school five years. He underscored that the winning bridge ended up holding more than 400 times its weight. Watch a video of the test here.

The process leading up to the competition saw the students learning about civil engineering by experimenting with various forces, i.e., tension, compression and bending, and then testing different materials, including popsicle sticks, straws and string, to determine which materials were stronger or weaker, per the school.

Throughout the process, students also researched five different types of bridges—including arch, beam, cable-stayed, suspension and truss—and discussed local bridges and why each were designed and constructed in a particular way.

10th grader Elwynn Cabrera

Mr. Grossmann said that as an engineering major in college, he learned the most from classes where he built things and competed against other teams. He said his students “show that same creativity and problem-solving, which I believe is strong preparation for whatever they do after high school.”

Founded in 2002, Leadership Public Schools operates charter high schools in Richmond, Oakland and Hayward and serves more than 1,700 scholars annually. It aims to create “inclusive, empowering and college-preparatory learning experiences for students that equip them for success in college, career, and community leadership,” per a statement. Learn more about Leadership Public Schools here.