Hanson Bridge - Downieville, CA - Truss Bridges on Waymarking.com

The following information from California State Parks Office of Historic Preservation files:

The Hansen Bridge is a Pratt pony truss steel bridge 80 feet long and 12 feet 4 inches wide, running east-west across the Downie River. The bridge trusses are constructed of steel I-beams secured by riveted steel plates. Steel guardrails extend beyond the edges of the pony truss on either side of the bridge, with a rolled sheet metal safety railing below the steel guardrails. The roadway deck is supported on wooden stringers running the entire length of the bridge, topped with corrugated metal and an asphalt road surface. The bridge is supported by two concrete pilings on each end, resting on concrete footings, with wooden boards between each piling. The boards on the western side appear to have partially collapsed but are still present. Steel struts from the canyon wall to the bridge are located on the eastern side of the bridge behind the pilings. A water pipe runs along the northern edge of the bridge. The remains of a granite retaining wall, possibly from an earlier bridge, are present on the northern side of the western bridge abutment.

The bridge carries automotive and pedestrian traffic over the Downie River connecting Upper Main and Pearl Streets in the community of Downieville. The bridge was constructed and first put into service in 1935. While two bridges downstream were destroyed in a 1937 flood, this bridge sustained major damage to its underpinnings but was repaired and back into service in 1938.

In 1937, Downieville had a total of five bridges. The easternmost (and farthest upstream on the Downie River) was the Hospital Bridge, originally called the Downieville Steel Bridge (due to its status as the town’s first steel truss bridge) constructed in 1908. Next was the Hansen Bridge, a Pratt pony truss bridge completed in 1936. Third was a concrete arch bridge constructed by the State of California to carry traffic on Highway 49. Just downstream of the highway bridge was the Jersey Bridge, a wooden bridge constructed in 1875, and the Durgan Bridge, just downstream of where the Downie River met the Yuba, constructed in 1881. Except for the highway bridge, all were constructed as single-lane bridges by the county government.

On December 10, 1937, major storms sent a torrent of water through Downieville destroying the State Highway bridge, the Jersey Bridge, and the Durgan Bridge. The Sierra County officials replaced the Jersey and Durgan bridges and repaired the Hanson Bridge in 1938.