Clarks Mills Bridge

Key Facts

Technical Facts

Information and Findings From Pennsylvania's Historic Bridge Inventory

Discussion of Bridge

The 1885, single span, 82'-long, Pratt thru truss bridge is supported on ashlar abutments with flared wingwalls. The traditionally composed trusses have built up box section upper chords, channels with lacing verticals, and eye bar lower chords and diagonals. The bridge is historically and technologically significant as a complete, early example of a pin connected, metal thru truss bridge. The bridge is one of the two oldest surviving truss bridges in the county. Adding to its significance is its association with the Penn Bridge Company, a prolific regional fabricator of metal truss bridges.

Discussion of Surrounding Area

The bridge carries a 1 lane unimproved road over a stream in a sparsely developed, rural area with scattered, undistinguished early and mid 20th century houses. The area does not have historic district potential.

Bridge Considered Historic By Survey: Yes

Information From www.mercercotrussbridges.com Demolition Mitigation Website

The bridge, constructed in 1885, is a relatively early example of a standard-design, pin-connected, Pratt Through Truss bridge. It was fabricated by the Penn Bridge Company of Beaver County, a prolific regional fabricator of both wood and metal truss bridges.

The Penn Bridge Company of Beaver Falls, Pennsylvania, was organized in 1868 as T.B. White & Sons. At the time, the firm constructed wooden bridges. The plant was initially established in New Brighton; it was moved across the Beaver River to Beaver Falls in 1878. In 1887, the firm reorganized and incorporated as the Penn Bridge Company, producers of wrought iron, steel, and combination bridges; iron substructures, buildings, and roof trusses; and plate, box, and lattice girders and architectural ironwork. In the 1890s, the Penn Bridge Company's output averaged 5,000 long tons, ranking it as a small bridge fabricator. The Penn Bridge Company remained independent of the American Bridge Company, and continued to grow over the first two decades of the twentieth century, producing large and small structures and structural steel work. The company added new physical plant in 1902, reincorporated in 1905, and employed more than 500 workers in 1908. The Penn Bridge Company built bridges and structures in nearly all U.S. states and territories. It was particularly prominent in Pittsburgh, the City of Bridges. By 1908, the company had built four bridges over the Ohio River, five over the Monongahela River, and two over the Allegheny River, as well as the original Ohio River Dam Nos. 2, 4, 5, and 6.