Year constructed: 1953
Bridge type: Concrete Stringer, Multi-Beam or Girder
National Register of Historic Places status: Eligible
Length: 68 feet
Width: 20.2 feet
Spans: 1
FHWA: 336201
Jurisdiction: Washington County
Location: Underwood Avenue over the North Fork of Long Creek north of Ainsworth, Sections 16 & 17, T75N-R6W (Oregon Township)
Details
The Underwood Avenue Bridge is eligible for inclusion in the NRHP as it meets one of the registration requirements outlined in the MPD simple span bridges in excess of 50' in length. The bridge is a concrete girder structure (Type 102) that is 68' in length, which is at the 95th percentile for its type. The bridge has integrity of design, workmanship, feeling, association, setting, materials, and location.
The Concrete Stringer, Multi-beam or Girder bridge (Type 102), consists of a series of parallel reinforced concrete beams (meaning stringers, beams or girders), spanning between supports (abutments and piers), and spaced sufficiently close to one another to allow a concrete slab deck to span the distance between them while carrying the intended load. The terms stringer, beam and girder commonly refer to the relative size of the beams, girders being the largest. Since stringers, beams and girders all function structurally as beams; these types are generally all called beam bridges. The concrete beam bridge is also cast-in-place in either pre-made steel or wood forms or custom formwork made on site, which allows the size of the beams to be completely variable by the engineer for a given span.