The 2nd Dayton Bridge over the Yamhill River had three design iterations during the time is served as the main crossing of the river.
The first design was a timber through truss main span with long timber trestle approach spans. The bridge was built in 1890 after the first bridge at the site wash away during flooding in February of the same year. The exact layout of the structure is unknown, but the overall length was 1080-feet and the roadway width was 18-feet.
The original timber truss structure collapsed on May 25, 1914. It was determined that the bridge collapsed due to excessive decay in the timber members and the foundation piling.
The bridge was repaired in 1914-15 with a 200-foot long steel Parker through truss on concrete piers replacing the collapsed timber span. The approach trestles were modified, but most of the original spans remained in service following the main span alterations. The timber trestle layout consisted of a 663.5-foot timber approach trestle with 40 spans on the east end and a 215-foot timber approach trestle with 16 spans on the west end. The roadway width remained 18-feet.
The final layout of the bridge was constructed in 1941. During this project the timber trestles were replaced with new timber trestles with the main truss span remaining in place. The final layout following the project consisted on 36 timber trestle spans on the east end and 16 trestle spans on the west end. The roadway width was widened to approximately 21-feet and a 4-foot wide sidewalk was added to the north side of the bridge. The roadway with on the truss span remained 18-feet.
The main highway was rerouted to the north of the city in the late 1950's. It is currently unknown whether this bridge was removed when the new highway bridge was constructed in 1958, was damaged by the 1964 Christmas Flood or was removed at a later date. A pedestrian bridge was constructed in the same location in the mid 1970's.
All I can say is WOW Luke set me up for an adventure by adding this long lost bridge.
I was waiting for some printing and decided I would look this bridge up and add some information on it.
What an interesting history.
We have main spans collapsing, replacements, reconstructions and I never did figure out when the thing was removed.