Year constructed: 1898
Bridge type: Pin-Connected Kingpost Pony Truss
National Register of Historic Places status: Bridge is un-evaluated in its current location
Length: 39 feet
Width: 16 feet
Spans: 1
FHWA: 081330
Jurisdiction: City of Independence
Location: Pedestrian bridge on the SW 6th Street Liberty Trail in a park in Independence, Section 4, T88N-R9W (Sumner Township)
Details
This kingpost pony truss carries 280th Street, a gravel-surfaced county road, across a small stream in southwestern Buchanan County, five miles southwest of Independence. This structure was built in 1898 by D.H. Young of Manchester just prior to the widespread introduction of the Pratt pony truss design in the county. The bridge was part of an eight-bridge contract let to Young for $3,304.70 that year. Young had been active in Buchanan County since 1893 and was the contractor for most of the county bridges built between 1896 and 1899. Supported by a timber substructure and featuring a timber deck with two angle lattice guardrails, this pony truss maintains an excellent degree of physical integrity, as it continues to carry traffic in its rural setting.
With its roots extending to the Middle Ages, the kingpost pony truss is the most rudimentary truss type. Numerous kingposts were built on Iowa's early roads in the late 19th and early 20th centuries, executed first as timber-iron combination structures and later in all-metal configurations. The kingpost as a structural type was limited to relatively short-span applications, however, and as steel beam bridges received widespread acceptance after the turn of the century, erection of kingpost trusses declined rapidly. This bridge in Buchanan County is a typically configured early example of kingpost truss fabrication. Its modern substructure diminishes its physical integrity somewhat, but the structure is nevertheless a well-preserved and noteworthy example of a now-uncommon structural type. Since the site was nominated for the National Register, the bridge has been moved and now lies on a pedestrian trail ion the SW 6th Street Liberty Trail in a park in Independence [adapted from Hybben, Roise, and Fraser 1992].