Video: There's a lot of moving parts when it comes to the construction of a bridge. Like, how do you build a bridge without the help of a bridge? The easiest way? This SLJ900 machine. It moves in coordinated parts to deftly erect a bridge or viaduct, balancing its weight on the beams before laying out the groundwork. It's really cool to see it slide across and pop out.
And an animation detailing how it works: