The Neawanna Creek Bridge is significant as an intact example of a 1930s continuous concrete, multi-span highway bridge, utilizing Hardy Cross's moment distribution theory, and for its association with C.B. McCullough, Oregon's premier bridge engineer. The configuration of continuous concrete T-Beam construction utilized in the design of the 1930 Neawanna Creek Bridge represents a significant change in structural engineering theory and reinforced concrete technology by applying the moment distribution technique of distributing loads on girder structures. The moment distribution theory for continuous concrete frames was developed in the late 1920s by Hardy Cross, a civil engineer and professor of structural engineering at the University of Illinois. Hardy Cross was regarded by his contemporaries as a leader in a new school of thought in the field of structural analysis, and his theory is regarded by many architects and engineers to be one of the more significant structural theories developed during the 20th century.
Information from HAER Neawanna Creek Bridge Page
Length of largest span: 52.5 ft.
Total length: 210.0 ft.
Deck width: 26.9 ft.
Approximate latitude, longitude
+46.01056, -123.91139(decimal degrees) 46°00'38" N, 123°54'41" W (degrees°minutes'seconds")
Approximate UTM coordinates
USGS topographic map
OR 01305 (Oregon Dept. of Transportation structure number)
BH 37384 (Bridgehunter.com ID)
Inspection (as of 09/2011)
Deck condition rating: Satisfactory(6 out of 9) Superstructure condition rating: Fair(5 out of 9) Substructure condition rating: Fair(5 out of 9) Appraisal: Functionally obsolete
Sufficiency rating: 54.8 (out of 100)
Average daily traffic (as of 2010)
April 24, 2011: New photos from K. A. Erickson
April 27, 2010: New Street View added by Michael Goff
April 20, 2009: Posted HAER photos
October 29, 2008: Updated by Michael Goff: Edited Builders
October 7, 2008: Updated by Michael Goff: Added design description and builder
September 8, 2008: Added by Michael Goff
Mike Goff - michael [dot] goff [at] hotmail [dot] com
HAER OR-129 - Neawanna Creek Bridge, Spanning Neawanna Creek at Milepoint 19.72 on U.S. 101 (Oregon Coast Highway), Seaside vicinity, Clatsop County, OR