Suspension and Cable-stayed Bridges, and Building a Suspension Bridge Model

We talked about our favorite suspension bridges including the Brooklyn Bridge, the Golden Gate Bridge, and the Tacoma Narrows Bridge. We also talked about the (relatively) new technique of the cable-stayed bridge and looked at pictures of the magnificent Millau Viaduct. I LOVE this bridge and want to see it someday!

We watched this documentary about a cable-stayed bridge in the United States.

We discussed, of course, "Galloping Gertie" and the role of torsion in her collapse. You can watch a video here and read more here, if you are interested, which who would not be? We compared the effects of a strong wind (simulated by the hair dryer) on a thin bridge span versus a thicker bridge span, and watched the way wind shear (from the side) creates torsion waves in the thinner span.

We used thread to mimic how suspension bridge cable is spun. You pull the cables around again and again until they are many strands thick. The strands are then bound together (we used tape) into larger bundles.

Trying out some traffic on our suspension bridge. It held the live load!