This is one of a very rare surviving group of Phoenix column pony trusses all in a single county.
Information and Findings From Pennsylvania's Historic Bridge Inventory
Discussion of Bridge
The 5 panel, 69'-long Pratt pony truss bridge is supported on stone abutments. The pin-connected truss tension diagonals are rods, with eyebar bottom chords and Phoenix column top chords. Metal pipe rails are fixed to the trusses. The bridge has been determined eligible by the PHMC.
The one span, 70'-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 deck roadway width is 15'-8" 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. The diagonals are eyebars, and the counters are bar stock and Dean & Westbrook’s cast open loop heads. The original pipe railings have been lost, replaced by beam guiderail railings set inside the truss lines. The deck is timber planks, and the abutments with wingwalls are fieldstone.
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 Chester 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), the Phoenix section truss members, the truss to floorbeam connection details (deep, built up floorbeams are framed into the bottom portion of the verticals above the eyebar lower chords).
Discussion of Surrounding Area
The single lane bridge carries an unimproved road over a stream in a sparsely developed, forested setting with open, undeveloped areas as well.
The bridge is located on a one lane unimproved road south of SR 4006 in a rural setting with woodlands, active agriculture and scattered houses. The 15'-8" 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
This bridge is tagged with the following special condition(s): Phoenix Columns
Coordinates (Latitude, Longitude):
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