From above, you can see all the girders recently set over the northern section of the trench. Meanwhile, workers continue excavating the crossing under State Route 180 (SR 180) outside of downtown Fresno. As they dig down five feet, they add to the retaining wall with a rebar mesh and sprayed concrete (also known as shotcrete). Once they reach the bottom of the trench, they’ll construct a concrete box that will carry the trains under SR 180, a rail spur and the Dry Creek Canal.