Los Angeles River Bridges Staff Presentation. Office of Historic Resources September 2007

Transcription

1 Los Angeles River Bridges Staff Presentation Office of Historic Resources September 2007

2 Area of Study

3 Historic Context: What makes the bridges historic? Why were they built? When were they built? Who built them? Why do they look the way they do? What is their relationship to each other?

4 Historic Context: Resources A Context for Common Historic Bridge Types The National Cooperative Highway Research Program (NCHHRP) Parsons Brinckerhoff Engineering and Industrial Heritage October 2005

5 Historic Context: Resources City of Los Angeles Monumental Bridges: Historic Context and Evaluation Guidelines JRP Historical Consulting May 2004

6 Additional Resources Guidelines for Historic Bridge Rehabilitation and Replacement American Association of State Highway and Transportation Officials (AASHTO) Lichtenstein Consulting Engineers Parsons Brinckerhoff Quade & Douglas March, 2007

7 Historic Context I: Monumental LA River Bridges Themes: Los Angeles River Reaction to Metal Truss Bridges City Beautiful Movement Engineering and Technical Innovations Bureau of Engineering City of Los Angeles Municipal Art Commission

8 Historic Context I Los Angeles River 1894 Pierce Map

9 Historic Context I Los Angeles River Natural water feature Need to build across for transportation access Prone to flooding Destroyed bridges throughout its history

10 Historic Context I Metal Truss Bridges First iron and steel bridges built in the 1840s

11 Historic Context I Metal truss bridges thought by some in early 1900s as ugly, sober, and ponderous Economical, standardized parts, ease of installation Built mostly for railroad crossings Products of the Victorian- Industrial Age

12 Historic Context I

13 Historic Context I Last large metal truss bridge survived into the 1990s Replaced with modern bridge for Metro Gold Line

14 Historic Context I City Beautiful Movement to beautify cities through Neo-Classical and Beaux Arts architecture and planning World s Columbian Expostion of 1893

15 Bureau of Engineering Historic Context I Previously, a few steel structures were erected across the river of the truss or girder type, which are inherently unsightly Now the aesthetic side is taken care of by adopting the arch form and by special treatment of the concrete surfaces. Homer Hamlin, City Engineer, Bridge Construction in the City of Los Angeles, (1909)

16 Historic Context I Bureau of Engineering Collection of talented architects, engineers, and builders Work funded by Viaduct Bond Act of 1923 Led for decades by Merril Butler, Engineer of Bridges and Structures

17 Historic Context I City of Los Angeles Municipal Art Commission Founded in 1903 as five member commission to work for the gradual elimination of ugliness from the conspicuous parts of our city. Provided input and recommendations to Bureau of Engineering on bridge design Still exists today as the Cultural Affairs Commission

18 Historic Context I City of Los Angeles Municipal Art Commission Protested use of metal trusses Advocated Beaux-Arts/Classical design For the N. Broadway Bridge (1911) advocated columns for decorative scheme instead of bears, which the Native Sons and Daughters of the Golden West had advocated for Municipal Art Commission, 1950s

19 Historic Context II: WPA Era LA River Bridges Themes: Los Angeles River Funded by Work Projects Administration ( ) Moderne/Art Deco Designs Bureau of Engineering City of Los Angeles Municipal Art Commission

20 Historic Context II Works Progress Administration (WPA) Bridges partly funded through WPA work programs Smaller-scale construction projects

21 Historic Context II Moderne/Art Deco Design Design principles established by construction of the Sixth St. Bridge (1932) and described by bridge architect Loius L. Huot Previous architecture yielded a superficial and incidental mass of gingerbread