I like this video because it is very systematic and well documented. The video shows a Balsa wood bridge built for a statics project. You can watch the process they went through to design and build their bridge, and at the end they give a little bit of evaluation. The bridge ended up with an efficiency score of 514.
You can see the joints popping and moving around in the video. The joints they used are called mitered joints, which is a fancy end joint. Learn more about bridge joints. They also put a gusset on all their joints.
What do you think about their prediction of where the bridge would fail first? Do you agree with them based on the wood size and the numbers from the John Hopkins Bridge Designer program that they used?
What do you think they could have done to make the bridge stronger?