Daro Road Bridge

Information and Findings From Pennsylvania's Historic Bridge Inventory

Discussion of Bridge

The 5 panel, 80'-long Pratt pony truss bridge is supported on a stone and a concrete abutment. The pin-connected truss diagonals are rods, with eyebar bottom chords and Phoenix column top chords. Built-up floorbeams and rolled stringers support the timber deck. Pipe railings are fixed to each truss. The bridge has been determined eligible by the PHMC.

The one span, 80'-long, wrought iron, pin-connected, Pratt pony truss bridge was built by Dean & Westbrook using Phoenix sections for the upper chords and inclined end posts and standard design Phoenix Company connecting pieces and bearings along with details that are particular to Dean & Westbrook. The roadway width is 15'-4" and the overall deck width is 16'. This is not a standardized design Pratt pony truss bridge, and it represents Dean & Westbrook’s innovative thinking about features intended to provide a stronger bridge with the most economical use of material. The verticals are composed of angles with lacing. Pin plates are used to make their connection at the cast iron upper chord connecting pieces. The deep, built up floorbeams are framed into the bottom portion of the verticals above the eyebar lower chords. There are punched pin holes in each vertical for the lower panel point connection. Placing floorbeams above the lower chords is not common in Pratt pony truss bridges. A triangle-shaped plate riveted to both ends of each floorbeam accommodates connection of an outrigger that meets the vertical at about its midpoint. The diagonals and counters are bar stock and Dean & Westbrook’s cast open loop head. The bridge is finished with two lines of pipe railings set in their original U shaped brackets and a wood plank deck. It is supported on one stone abutment that has open joints and collapsing wingwalls and one modern concrete abutment. There are minor welded repairs to at least one cast iron connecting piece. Although there is no plaque on the pin connected Pratt pony truss bridge with Phoenix section upper chords and inclined end posts, it has the same distinctive details and design variations as 40 7217 0482 6006 that has a plaque identifying it as built in 1889 by Dean & Westbrook, Engineers and Contractors. Dean & Westbrook were the agents for marketing and building highway bridges for the Phoenix Iron Company. They are also noted for innovative designs, including at least five remaining examples of this one in Luzerne and Montgomery counties and the English Center (Lycoming County) hybrid design placed in 1891. The bridge has high technological significance because of its distinctive details representing the era of experimentation in metal truss bridge design and the use of Phoenix sections, which did as much as any detail to prove the value of metal truss bridges during the last half of the 19th century. The cast- and wrought-iron bridge provides an important snapshot of thinking about bridge design and fabrication prior to steel and standardization. All bridges with Phoenix sections have cultural value. The character-defining features include the truss form and method of truss member end connection (pinned Pratt pony truss) and the floorbeam connection details (floorbeams are above the lower chords, punched pin holes in each vertical for the lower panel point connection), and Phoenix section truss members.

Discussion of Surrounding Area

The single lane bridge carries an unimproved road over a stream in a sparsely developed, forested setting.

The bridge is located on a one lane unimproved road just east of its T intersection with Hunlock-Harveyville Road (SR 4016) in a rural setting with woodlands, active agriculture and scattered houses. The 15'-4" wide bridge roadway is as wide if not wider than the maintained travelway. The bridge and road have a very low reported traffic volume.

Bridge Considered Historic By Survey: Yes