Reconstruction of the 1940s-era Spellacy covered bridge—one of America’s largest at 300 ft long and 24 ft wide—had a small price tag of $9.5 million but delivered a big impact. The project adds four trusses, each about 168,000 lb, for new structural support that now extends by at least 125 years the life of a revered and much-visited historic icon in Ohio’s scenic Mohican River corridor.

The project team confronted a number of hurdles, including “use of complex materials, offline bridge construction and overcoming multiple drilling and geotechnical challenges,” says the submission. That included forced redesign of one segment, requiring a quick turnaround to maintain the critical path schedule. Complex logistics in fabrication and treatment of the structure’s glulam members in different states also mandated “meticulous coordination,” says the team. Use of cofferdams enabled the team to manage turbulent river conditions, which had caused excavation site flooding during construction.

The superstructure approach included building the trusses, each more than 150 ft long and nearly 20 ft tall, on a custom-built “table” adjacent to the final structure location. This enabled precise assembly and simultaneous crane lifts of two trusses. With difficult site conditions and truss weight, the contractor designed a work platform that would ultimately support 336,000 lb, the submission says. “The truss setting was a culmination of almost three months of planning,” the submission notes. The project, which was the largest infrastructure project in the history of Holmes County, Ohio, opened to the public five days early. The team credits that to “effective partnering, teamwork and a commitment to safety.”