Mile Creek Road Bridge

Information and Findings From Ohio's Historic Bridge Inventory

Setting/Context

The bridge carries a 1 lane, unimproved road over a stream in a rural area of active farms. It is located on a straight section of road and is posted for 6 tons.

Physical Description

The 58'-long pin-connected Pratt pony truss bridge is supported on stone abutments. The upper chords and inclined end posts are traditionally composed, but the lower chords and diagonals are plate. The verticals are rolled I section, and the floor beams, also rolled I section, are located above the lower chords and supported on them. The upper panel points are pinned, but the lower connections as are composed a ingenious cast connecting pieces for both the diagonals and counters with upturned ends and the fittings to hold and stabilize the verticals and floorbeams. Some interior panels have cruciform-shape outriggers that also provide stability. There is some impacted rust on the upper chords and observed impact damage to at least one vertical.

Integrity

The bridge has been underpinned, converting it to a 3-span bridge for inspection reporting purposes, but the trusses themselves are not altered. Impacted rust on upper chords.

Summary of Significance

The cast- and wrought-iron pony truss bridge dates stylistically to ca. 1875, and its details represents the experimentation characteristic of the development of the bridge type. Stylistically it appears to be a very early Wrought Iron Bridge Company (WIBC) bridge. While the upper chords and inclined end posts are built up box sections composed of plates and channels, the lower chords, verticals, and how they are connected reflect the ingenious and idiosyncratic thinking about connections and transfer of stresses that is the hallmark of the pre-standardization era. Many of the details, like using plate for the lower chord and diagonal members, placing the rolled section floor beams above the lower chords, and the cast iron connecting pieces to join the members and accommodate the stress transfers, are commonly seen on bowstring truss bridges. The verticals are also rolled sections, and the cruciform-shape stock used for the outriggers is a feature associated with the WIBC. The bridge, which has been supported from underneath, is remarkably complete and is historically and technologically significant. It may well have significance on the national level given its transitional design, early date of construction, and completeness. This is an important bridge in the evolution of the pin connected metal truss bridge. It was previously typed as stringer bridge because of the underpinning placed in 1975. The WIBCo was established in 1866 by David Hammond, a Stark County carpenter who developed a patented bowstring truss design. WIBCo was noteworthy for its innovation and experimentation with a variety of metal-truss designs. It also built up a very successful network of salesmen and agents to represent the firm to local officials in Ohio and many other states and Canada, eventually becoming one of the largest fabricators in the nation before being absorbed into the American Bridge Co. monopoly in 1901.

Justification

The bridge has high significance as a transition from the technology of the bowstring truss to the Pratt pony truss. It has rare details.

Bridge Considered Historic By Survey: Yes