When creating a bridge competition, it is important to set exact specifications that the bridge must meet in order to qualify, including the distance spanned, the width of the bridge, the maximum weight of the bridge and the materials that can be used in the structure of the bridge. The most common method of constructing a bridge is with balsa, a lightweight wood that is easy to work with. For non-wood shop classes, dried pasta is often used as a substitute.
Technical drawing tools, such as rulers and protractors, should be used in the construction of blueprints for the bridge, as the more accurate the plans are, the more easily the bridge can be accurately fabricated. A winning design can be made with little more than a crafting knife to cut through the soft wood and glue to hold the pieces together. Fasteners such as screws or nails are rarely allowed in competition.
While students learn the basics of cutting and joining wood pieces, bridge competitions also have educational value. Students learn about weight distribution and how bridges are able to suspend such large loads of weight with only a few anchor points touching the ground. They then must apply what they learn about bridges to make a design which best distributes the weight.
The culmination of any lesson on bridge building is the competition to determine which students have created the strongest bridge. Place the bridges across a span of the minimum distance described in the outline for the project and suspend the minimum weight requirement from the bridge. Slowly add more weight to the hanging dish until the bridge cannot support the weight. Repeat for all bridges in the competition and reward the winning entry.