1922: (same location as today's bridge)1967: (Bridge Hunter; Historic Bridges; 3D Satellite)
Construction of a bridge at Piper Road (now Ridgeland Avenue) over the under-construction Cal-Sag Channel in Worth, Illinois, on July 24, 1917. The 16-mile Cal-Sag Channel was completed 100 years ago this year, with construction beginning in 1911 and ending in 1922.
This plan shows that the Cal Sag was still just 60' in the 1960s. As HistoricBridges explains, the bridge was designed so that lift towers could be added if more clearance was needed. Instead, towboats in the Chicagoland area have a retractable pilothouse so that the waterway bridges starting with the Lemont Santa Fe Bridge don't have to move.
As HistoricBridges explains, these Cal Sag trusses were the twilight of truss bridges. They represent a transition between historic and modern construction methods. Using plates instead of lattice and v-lacing is modern. Using rivets on the built-up beams is historic.
Connecting the beams with bolts instead of rivets is modern.
Using a truss instead of a concrete slab on steel girders is historic. Having pedestrian sidewalks is modern. Not having any shoulders is historic. (Although shoulders are not as critical when there are two lanes in each direction. I wonder if those are 12' lanes. Today's standard of 12' lanes plus a big shoulder borders on overkill.)
|2012 Photo by Steve Conro via BridgeHunter|