Harvard Model Bridge Testing! Trusses and Beams

Learning by Doing!

When I was teaching Structures II at Harvard's GSD, we decided to do a bridge competition where the students design and build bridges with limited materials to span approx 10ft (3m).

We gave three prizes (all of equal value):
1) Best looking bridge as voted by the whole class (before testing took place).
2) The bridge that could carry the heaviest load.
3) The bridge that could carry the heaviest load per self-weight of bridge itself.

Each team loaded their own bridge until failure. They also had a related report assignment which was in two parts:
1) Before testing: Why this design, how they expected it would fail, and under how much load.
2) After testing: How their bridge actually failed, how and why (if) that was different to what they expected, and what they would do differently to improve it.

Thanks to Andrew Gipe for pushing the concept, to the TAs Andrew Gipe, Alex Karadjian, Dimitris Venizelos, and Wen Wen. Also to the GSD Fab Lab Burton LeGeyt and Rachel Vroman and to Juhun Lee for video editing. Most of all thank you to the students for an awesome set of work!

I'm Paul Kassabian. I'm a structural engineer and a Principal at SGH in Boston, MA. I taught graduate students at MIT for nine years and currently teach on/off at Harvard's Graduate School of Design (GSD). These are videos based on my structural design projects and years of teaching structures to students.

[joeqiu]

Dear Mr. Paul Kassabian, I had the privilege of being part of this class, which to me, has been one of the most rewarding experiences provided by GSD. I express my gratitude for your efforts in creating such an engaging and productive learning process. Thank you.

[TimothyR.Heistand]

I don't know what I love more... how excited the students get or how excited the teacher gets. This is how education should be done!!

[jimhabsfan]

An educator who makes learning interesting AND fun. Well done, sir.

[isar]

Paul my father was a bridge engineer and worked his whole life building and maintaining structures. Your passion, enthusiasm and attention to detail reminds me very much of him. Wonderful teaching and great to see some engineering passion. Thank you.

[zorbl]

This would be super interesting to see students try at the first class and again at the last class to see their progress :)

[bobrikerik]

The Poly Bridge 4 graphics look insane. And the replay comes with a custom commentary so you know what to improve.

[markharrisllb]

YouTube amazes me how it shows me things I never knew I was interested in. A phenomenal teacher and I imagine every student is proud to have studied under you.

[btsmochimi]

Classes like these are life changing. It changes your perspective about learning mechanics. I wish i had u as a teacher sir😢

[bsavagestudios]

I remember doing this in high school in my architectural engineering and design class. My little balsa wood bridge held 176lbs before giving out! Great fun and an awesome learning experience!

[GERALD_Featureworx]

I participated in one of these exercises back in college (35 years ago). Our span was to be roughly 18”. Material efficiency was the goal, so I made mine very light. The weight being used were bricks. Knowing the size the brick, my design used the first brick as a structural element. We ran out of bricks and the bridge never broke. A fun memory. Nice video. 👍🏻

[SoloRenegade]

there is NO substitute for hands-on application and learning. Engineering colleges are failing miserably at this of late. This is a perfect example of how learning should be done. Hands-on application, with a little trial and error. Let them test their ideas, take notes, and try again. Couple this with classroom learning and you have a winning combination.

So much wasted opportunity in engineering colleges to really give students a truly great education with little extra effort.

[ReeveProductions]

It would be amazing to start a class with a two week build like this, then finish it with another two week build to let the students demonstrate what they’ve learned.

[oneperspective]

I am an undergrad Structural student. Your students are so lucky. I wish I could have you as a teacher

[ceerstar]

I love how he's just as excited as I am watching the video, yet he was already for it. That's real passion right there.

[Fubeman]

Just an outside admirer here. I have to say, professor Kassabian reminds me so much of my physics professor. Someone who truly cares about the subject, his students and their overall engagement with the material and makes it all fun at the same time. Well done! Even though I am a graphic designer, I am always interested in all engineering subjects. And I f I had someone like YOU back in the day, I really think I would have become an engineer just because of the way you teach. Well done sire! Well done.

[NightInParisOfficial]

This is how teachers should be. Allowing the students to express their curosity in the field, outside of writing notes.

[sabrekai]

Now that reminds me of the college I went to between 1973-1976. It was ALL hands on. 2 years of forestry, we were in the bush just as much as in the class, learning by doing. 1 year of welding and fabricating, skills I've used my entire working life. Keep doing it this way, we need people who THINK instead of parroting the party line they are being indoctrinated with. Those young people are having a blast, putting what they learned into actual use.

[gbsbill]

That was amazing to watch as a spectator, I can only imagine the problem solving and learning plus team building that took place to get to the test of all 13 bridges. Thank you for taking the time to record this and let all of us participate.

[robsalvv]

We did something similar in my civil eng class 35yrs ago, with a fixed amount of balsa wood for each team to span a 400mm gap. Fascinating to see the much more elaborate designs in the video.

[FutureEon]

🎓✨ Mr. Paul Cassabian, I want to express my sincere appreciation for the incredible learning experience you provided through this class. It was truly a privilege to be a part of it. Your dedication and effort in creating an engaging and productive learning process are commendable. Thank you for enriching our knowledge and inspiring us to reach new heights. Grateful for this opportunity! 🙏🏼🌟📚