Mifflinburg, PA, USA
The Hassenplug Covered Bridge in Mifflinburg, PA, is one of the two oldest covered bridges in America open to the public. It was originally built in 1825 in a Burr arch-truss style and spans a length of almost 70 feet. To preserve a large portion of the covered bridge, it was rehabilitated in 1959 to remove the timber deck system and replace it with a steel beam bridge and open steel grid deck. In June of 2021, a $755,000 project was approved to rehabilitate the existing bridge. Upon inspection of the 1959 steel beam bridge, the county decided to remove the open steel grid deck and steel bridge railing, replacing it with a timber deck similar to the 1825 construction. This aesthetically restored the interior of the covered bridge to all its timber components. The construction phase started in March of 2022 and the bridge reopened in August 2022.
When the design was confirmed for the restoration of the Hassenplug Covered Bridge, Portland Bolt was ready to manufacture all the required fasteners for the job. Since Portland Bolt specializes in making fasteners for timber connections and covered bridges, we were the obvious choice to partner with on this project. The project required different types of headed bolts including timber bolts, hex bolts, and lag screws. There were malleable iron washers required with the bolted connections as well. It also required custom templates to bolt onto the timber beams for easy bolt installation. Because the bolted connections were between timber beams, the design also required split rings for each bolted connection. The last fastener requirement for this project was custom tie-rod assemblies. These 20’ long assemblies, with turnbuckles in the center, spanned across the bridge for additional structural support. Because this project had government funding involved, all hardware was required to be 100% USA melted and manufactured with all the proper documentation to verify its origins. Portland Bolt specialize in manufacturing domestic products and was easily up to the task.