Twin Railroad Bridge

Information and Findings From DHPA Historic Bridge Survey

Statement of Significance

Only a handful of open-spandrel railroad bridges survive, and they are by far the oldest in the state. This is one of three on the New York Central's tracks. In addition to its venerable age and monumental character, it is noteworthy for the coping of its rings.

Architectural Description

Where the distance between the roadway and the stream and the volume of the water carried by the watercourse are both considerable, the weight of the fill and the required side-to-side width of the structure reduces the economic advantages of reinforced concrete arches under fill. The open-spandrel arch, which requires a good bit of formwork is therefore an expensive alternative, may then become the form of choice. In large open-spandrel structures, the arch ring is often composed of two or more longitudinal ribs. A series of columns support the deck and transfer the loads to the ribs or ring. Beams and slabs, in turn, carry the floor below the roadbed. Because of their expense, only a few such rail structures have been built in Indiana. Most resulted from the New York Central's double-tracking and grade separation programs early in the century.

This three-span structure takes the New York Central's tracks over a stream and a county road in Hendricks County. The rings are segmental and coped, about 2' deep at center and 4' at the pier tower and abutment, and raised vertically on the piers as necessary to balance one another (10-12' in the center span). Arched spandrel columns support a 2' concrete slab deck on which the crushed-stone roadbed rides.

Bridge Considered Historic By Survey: Yes