Suspension Bridges, Part 1

Moving on in our Bridge unit, we started talking about suspension bridges.  The 3rd Grade engineers are becoming very savvy about how to build a sturdy and stable bridge.  I told the kids I wanted them to build a suspension bridge, but I would only give them on piece of string, one 5 inch section of tape, and 2 reading textbooks.  Their bridge would be tested in the end.

First, the engineers developed a plan.

Then, they started putting their ideas into action.   There were some different approaches.

These bridges all were 'suspension' bridges, but they wouldn't hold any weight.  The books would topple right over.

Finally, the engineers realized the string needed to be anchored to something other than the books.  This puts tension on the string which gives it the strength to hold weight.

A good first step into building suspension bridges.   Watch out for Part 2!