Pick a job site

You are the engineer. Design a bridge for each site, test it with a real vehicle, and fix what breaks. Stay on budget!

How to play

Pick a site. Read the goal and the budget. The drawing shows how wide the gap is.
Pick a material. Start at an orange anchor plate and draw a beam to another dot. Add beams to make triangles.
Press Test the bridge. A vehicle drives across. Beams glow from blue to rose as they work harder.
If something breaks, the drawing points to the beam that snapped first. Fix it and test again. Engineers do this over and over.

Want to run a construction company instead?

In Bridge Building Company you pick a bridge type, buy supplies, set crew pay, and handle weather and supply problems.

Open Bridge Building Company

About Bridge Lab

Bridge Lab is a free bridge engineering game that runs in any web browser, including school Chromebooks. Students design their own bridge for eight job sites, from a footbridge over a creek to a harbor crossing. Then they test it with a real vehicle and watch which beams squeeze and which stretch. The bridge either holds or it breaks, so every test teaches something.

What students practice

The engineering design process: ask, plan, build, test, and improve.
Compression and tension, the two forces in every beam. A view shows squeezed beams in blue and stretched beams in orange.
Why triangles keep their shape and make a strong truss.
Materials and money: deck, timber, steel, and cable each have a price per foot, a strength, and a longest length.

How it works

Each beam is a stiff spring between two joints. The game works out the force in every beam as the vehicle drives over. A beam snaps when it is pushed or pulled past its limit. A road that sags too far also fails. Nothing is random, so the same bridge always gets the same result.

The game has no accounts, no ads, and no tracking. Your bridges are saved only on your own device. Teachers can pair it with the Bridge Builder Challenge, a popsicle-stick bridge project, and play the Bridge Building Company game to practice choosing the right bridge for a site. Find more free classroom tools on the Maker404 apps page.