Arch bridge

Test your engineering skills in this amusing physics-based construction game.

Build an arch bridge out of angled blocks.

Because the structure is completely unstable until the two spans meet in the middle, you have to use a centering falsework. The centering is a temporary wooden form supporting both spans until they locked together at the top

The keystone is the center stone at the apex of an arch.

This app provides also pictures of famous arch structures.