Bridges are taken for granted everyday. They cross obstacles such as rivers and valleys for drivers and pedestrians alike. In the United States alone, there are more than half a million bridges in use. Since antiquity, engineers have built three major types of bridges, the beam, the truss and the arch. Another bridge type is the modern suspension bridge, like the Golden Gate. To fully learn about the engineering process of bridges, create a bridge challenge for kids using only plastic drinking straws and tape.
Pass out boxes of plastic drinking straws and tape to the students. For a large group, divide the students into teams of three or four. This challenge works best after a lesson on bridge engineering.
Announce the rules of the challenge. The children can only use the materials provided and sketch out a design before they begin. The kids are allowed to use scissors to cut the straws up. Once complete the bridge should be able to hold at least 100 pennies in a small plastic cup, while placed across two desks.
Review and comment on design sketches. Ask other students if they think that the bridge design will work or fail. Once the plans are finalised, each group may start building their bridges.
Place the bridges between two desks of equal height to test them out. Place the cup with pennies on top of each bridge to see if they are strong enough to support the weight.
Add more weight to the bridges to see which bridge design holds the most weight. Scissors may be used to cut excess parts of each straw bridge to find out which parts are necessary and which are not.
Children may use other simple materials for a bridge challenge such as paper or cardboard. Be sure to limit the amount of materials used for each challenge. Be sure to give kids enough time to plan their designs. Create new engineering challenges such as building a skyscraper or dome.
Adult supervision is needed when children are using sharp tools such as scissors. This challenge is best for children 7 and older.