The Blome Road Bridge in The Village of Indian Hill, Ohio, stands as a rare surviving example of nineteenth-century bridge engineering and one of the last known works of the Queen City Bridge Company.
Designed by William H. Harrison, Cincinnati’s City Engineer from 1872 to 1889 and chief engineer of the Queen City Bridge Company, the one-lane Pratt through truss was completed in 1888. Harrison was a respected figure in Cincinnati’s civil engineering community, having also overseen construction of sections of the Cincinnati & Eastern Railway before his death in 1889.
The Pratt truss design, patented in 1844 by Thomas and Caleb Pratt, became the dominant American truss form during the late nineteenth century. Its success lay in the simplicity of its stress calculations and its adaptability to all-metal construction, making it economical and reliable for spans under 200 feet. Early Pratt trusses varied widely in their construction methods—some using bolts, cast-iron fittings, or pins—but by the 1890s the design had reached a standardized, pin-connected form. This version, exemplified by the Blome Road Bridge, marked the final stage of the Pratt’s technological evolution before it was replaced by riveted trusses such as the Warren in the early twentieth century.
The Blome Road Bridge remained in continuous service for more than a century. Structural deterioration led to a truck ban in 1988, followed by rehabilitation work between 1989 and 1990 that strengthened the bridge with new steel stringers and a lighter metal-grated deck. A more extensive restoration in 2022 replaced key load-bearing components with concrete beams, hot-dip galvanized the steel, and slightly widened the roadway. Designated a local historic landmark in 1991, the bridge today serves as both a testament to the enduring utility of the Pratt truss and a surviving example of William H. Harrison’s engineering legacy.
