Bridges, Part 2

So, now that we have experienced building different types of bridges, it is time to apply that knowledge!

To focus on the Portland bridges, I gave the kids diagrams of different Portland area bridges, and their truss structure.  The kids were put into groups, and challenged to build a bridge using popsicle sticks.  At the end, there will be a load test to determine the strength of each structure....to see how many books each bridge could hold.

To prep for this, we watched a few NOVA specials on bridge building.  We discovered that if just one truss fails on a bridge, the whole thing will go down.  We learned about stress points, and how engineers are using cutting edge technology to determine the strength of bridges.

As a result, we really focused on making our joints and connections secure.  The kids also talked about how to reinforce areas of the structure that could be stress points.  We tried to anticipate the weaknesses of the bridge in advance and then how to deal with it.

 Once the bridges were assembled with a deck and top bracing, we moved on to load testing.

This was our winning bridge, it held 12 books before collapsing.  It was our all-girl engineering team.

 

 Here it is at 10 books!  By the way, those things are heavy!  That stack is at least 30 pounds.