Bridge Building Company

Bridge Building Company is a free bridge engineering game that runs in any web browser, including school Chromebooks. It is made for students in grades 4 to 6 and fits a bridge unit in a STEM or makerspace class. Students run a small construction company and take on three job sites. At each site they choose a bridge type, buy supplies, and set crew pay. Then they manage the build through weather, supply, and crew problems. The goal is to finish on time and under budget with a bridge that holds.

What students practice

• Matching a beam, truss, arch, or suspension bridge to a site's span, ground, and traffic.
• Weighing the trade-offs among cost, time, and safety.
• Naming tension and compression, the two forces that decide whether a bridge holds. A glossary is built in.

How to play

1. Read the site card to see the span, ground, traffic, budget, and deadline.
2. Pick a bridge, then buy materials and spare supplies.
3. Set crew pay. Higher pay speeds up the work and keeps the crew happy, but it costs more.
4. Run the build days and make choices when events happen, such as heavy rain or a late shipment.
5. Watch the load test. Each site earns up to four stars: on time, under budget, safe crew, and strong bridge.

Easy mode and Challenge mode

Easy mode shows a risk label for each bridge and never lets a bridge that is too short be picked. The bridge always holds, but a risky design sags and creaks. Challenge mode gives no hints, lets students change crew pay while they build, and a crew that stays unhappy can walk out. A weak design can collapse. After a collapse, a failure report explains the forces and a better choice.

The game has no accounts, no ads, and no tracking. To add hands-on practice, try the Bridge Builder Challenge, a popsicle-stick bridge project for grades 3 to 6. You can also draw and test your own bridge in Bridge Lab, or find more free classroom tools on the Maker404 apps page.