Ironwood Drive Bridge

Bridge Documented: October 2006

This open-spandrel bridge is one of the larger structures in South Bend, featuring a larger vertical clearance that other examples. It is unclear whether the railings on the bridge are original or not. They utilize a design unlike the other South Bend bridges, but this could mean anything. The main arch superstructure however does appear to be intact, and still creates an impressive bridge to look at.

Information and Findings From DHPA Historic Bridge Survey Statement of Significance Indiana's counties and cities built only a couple of open-spandrel bridges in the decage before the Second World War. The rings of this structure are unusually flat and the use of spandrel piers of additional note. While the replacement feck somewhat reduces the architectural integrity of the bridge, it retains all its original structural elements. Architectural Description Open-spandrel arches are more economical than the common solid-spandrel and filled arches only where the distance between the roadway and the stream and the volume which the watercourse carried were both considerable. In such circumstances the amount of concrete and reinforcement needed to compensate for the weight of the required fill and the length of the span sometimes tipped the balance towards open-spandrels. The more graceful appearance of open-spandrels sometimes contributed to their selection, especially in urban settings. This is a three-span, open-spandrel structure flanked by four reinforced concrete approach spans at each end. Consisting of a pair of ribs, each symmetrical, rather segmental arch-ring spans 130' and springs from an inclined bed raised upon modestly decorated spandrel piers. Spandrel columns transfer the loads from the deck to the ribs. Extended about 10' byond the columns and ribs on each side, floor beams carry the 52' concrete-slab roadway and the 5' sidewalks and metal railings. Clyde E. Williams and Associates designed the replacement deck, and the Foundation and Bridge Corporation built it.  County Engineer R. J. Lang prepared plans for a 4-span filled spandrel arch estimated to cost $231,650; National Concrete successfully bid $159,500 to build 3 span open spandrel of Luten design; 478 feet long; 122-130 ft spans; 2 ribs per span; spandrel piers; new cantilevered slab deck (1970), removed balustraded rails and lampposts with cast bronze fixtures.