Fairmount Boulevard Bridge

Information and Findings From Ohio's Historic Bridge Inventory

Setting/Context

The bridge carries a two-lane road over a river in a sparsely developed, wooded setting.

Physical Description

The 3-span, girder-floorbeam bridge composed of built up girders is supported on concrete abutments and column bents. Interior span lengths are defined with extensions of the pilasters added to the fascias of the bents. Pipe railings are attached to the top flanges of the girders.

Integrity

Was rehabilitated in 1976.

Summary of Significance

The thru girder-floorbeam bridge was built in 1941 by the county. It has no unusual or distinctive features being an example of a bridge type that was introduced by railroads in the mid 19th century and used extensively through the middle of the 20th century. Earlier and more distinguished examples better represent the significance of the technology to the development of Ohio's roads and bridges.

The inventory includes 240 examples of pre-1961 girder-floorbeam highway bridges (Phase 1A, 2008). The technologically significant examples tend to be those unaltered examples that date to the early period of use in the 19th century and standardization during the first decades of the 20th century. Later examples may represent important refinements, particularly the application of continuous-design principles in the 1930s.

Girder-floorbeam bridges have two or more longitudinal beams (i.e., girders) supporting transverse floorbeams and a deck. The longitudinal girders are typically built-up to achieve a greater depth than economically available from rolled sections. The technique of building up the girders has historically been riveting. Welding became a more common alternative after 1945 with the advancement of welding technology.

Girder-floorbeam bridges may be either through or deck designs, but the difference is not historically significant, merely reflecting a choice in where to connect the floorbeams. The thru girder is where the floorbeams are placed in line with the bottom flanges of the girders with the roadway passing between the paired girders. The deck girder is where the floorbeams are placed near the top flanges of the girders and the roadway located at the top of the girders. All things being equal, the thru girder has the advantage over the deck girder of increasing the available vertical clearance under the bridge.

The girder-floorbeam was developed in the late 1840s and was first used by railroads. In fact, it was the only serious competitor to metal truss railroad bridges during the mid to late 19th century. Railroads continued to be the leading builders of girder-floorbeam bridges in Ohio through the early decades of the 20th century. Not only did railroad engineers develop the bridge type, but they also had the heavy equipment (flat cars and cranes) to move and place the girders. The oldest and most technologically significant girder-floorbeam bridges in Ohio are likely to be rail-carrying or highway over rail. The rail-carrying examples are outside the scope of this survey.

The Ohio Department of Highways issued its first set of standard drawings for steel thru girder bridges in 1911-15. The bridges measured 50', 60', and 70' long, and their details were similar to and based on more than 50 years of railroad experience with the bridge type. State specifications covered such details as the thickness of plates and flange sections, placement of rivets, and the spacing of web stiffeners.

The department used thru girder bridges into the 1930s, but as longer and deeper rolled wide-flange beams became economically available, the steel stringer gained cost advantage over girder-floorbeams and they gradually fell from use. Girder-floorbeam bridges had also proven to be impractical to widen. After 1930, the department built continuous deck girder bridges of about 90' to 150' span. One of the most commonly used early continuous standard designs had three or more lines of built-up girders supporting rolled floorbeams and an intermediate line of steel stringers. This design offered savings in steel, and thus cost, over other available steel bridge types.

Bridge Considered Historic By Survey: No