CRI Vertical Lift Bridge

This bridge carries the former Chicago, Rock Island & Pacific railroad over the Des Plaines River at Joliet, Illinois. As the river is also a barge channel at this point, a movable bridge was required to allow maximum vertical clearance. With this type of bridge, the movable span is lifted vertically between the towers (it is shown in the raised position) by steel cables that run over pulleys atop the towers and are attached on the other end to concrete-filled iron counterweight boxes that move vertically within the tower frames. When opened, the bridge has a clear span of 302' and vertical clearance 59.5' The lifting span itself weighs approximately three million pounds, and takes about two minutes to open or close. I particularly liked this shot, as it seems the bridge and its towers have sprouted from the pine grove in the foreground.
Camera: Canon AE-1 Program SLR
Lens: Canon type FD (fixed, 50mm)
Film: Ilford XP-2 Monochrome (ASA 400)
Exposure: f16 at 1/250.
Paper: Ilford MultiGrade IV RC (8"x10")
Location shot.
For more information on this bridge, and access to other interesting works of engineering, visit the Historical American Engineering Record, NPS, US Dept. of Int. [link]