Hoover Dam, Southern California Edison North & South Lines, U.S. Highway 93, Boulder City

Source document Quoted word for word from HAER NV-27-N. Not written, edited or summarised by this site.

U.S. Highway 93 2 rJ Vicinity of Boulder City Clark County Cpaj "- :L) Nevada USGS Hoover Dam, Nevada-Arizona 7.5 Minute Provisional USGS Boulder Beach, Nevada-Arizona 7.5 Minute UTM Coordinates: SCE North Line: (start) (end) SCE South Line: (start) (end) Date of Construction: Engineer: Southern California Edison Company Builder: Southern California Edison Company U.S. Highway 93 Vicinity of Boulder City Clark County Nevada USGS Hoover Dam, Nevada-Arizona 7.5 Minute Provisional USGS Boulder Beach, Nevada-Arizona 7.5 Minute UTM Coordinates: SCE North Line: (start) (end documented segment) SCE South Line: (start) I I (end documented segment) Statement of

Source document Quoted word for word from HAER NV-27-N. Not written, edited or summarised by this site.

In addition to the direct association of these transmission lines to the early operation of Hoover Dam, the lines were extremely important for providing energy to war industries in California during World War II. Electricity carried on these lines helped to power Douglas, Vultee, and Northrup aircraft plants, the Long Beach Naval Shipyard, military bases, and major steel and aluminum production plants. The lines were also important in the post-war agricultural and municipal development in California. Report Prepared by: Associated Cultural Resource Experts (ACRE) Sangre de Cristo Road, STE 202 Littleton, CO Date: April HISTORIC AMERICAN ENGINEERNG RECORD HOOVER DAM, SOUTHERN CALIFORNIA EDISON NORTH AND SOUTH LINES HAER NO.

(Page 2) In addition to the direct association of these transmission lines to the early operation of Hoover Dam, the lines were extremely important for providing energy to war industries in California during World War II. Electricity carried on these lines helped to power Douglas, Vultee, and Northrup aircraft plants, the Long Beach Naval Shipyard, military bases, and major steel and aluminum production plants. The lines were also important in the post-war agricultural and municipal development in California. Description: The Southern California Edison North and South Transmission Lines are transmission lines that extend from the Southern California Edison Switchyard at Hoover Dam to Chino, California.

The documented segments of these transmission lines originate at the Southern California Edison (SCE) Switchyard near the Nevada rim of Black Canyon, in Section 29, T22S-R65E. The documented segments extend westward to the west section line of Section 29, T22S-R65E. Each segment includes four single-circuit, suspension type steel towers. The lines have identical lattice-steel, wedge A-frame, and metal-waisted towers. Towers are 27' square at base and up to high. Towers consist of a square leg segment up to 25' high, a square vertical panel 25' high, a standard battered segment either 50' or 60' high, a bridge or cross member 5' high and 50' long, and ground wire extensions 20' high.

Towers vary in height and intervening distance to accommodate topography and cultural features crossed by the transmission line. History: Southern California Edison (SCE) began constructing the SCE North or Hoover-Chino No. transmission line from Chino, California to Hoover Dam in The line was completed in May to the SCE switchyard on the south side of Black Canyon Highway (current U.S. Highway Hoover Dam power plant generating units A-6 and A-7 were nearing completion at that time, and SCE began delivering power over the line on June 19, In response to anticipated growth in demand, SCE began construction of a second line before the first line was energized. The second line (SCE South Line or Hoover-Chino No. 2) was completed in November but transformer circuit No.

IO and the switchyard addition to serve the new line were not completed until near the end of The Hoover-Chino No. 2 line may have been energized from the same switchyard system as the No. 1 line as early as November and the No. 2 line was energized from the expanded switchyard facilities by early These two transmission lines were constructed with metal-wedge, A-frame and metal-waisted towers very similar to towers the Southern California Edison (SCE) Company had previously used in innovative, high-voltage transmission lines in California (this basic design was also used for towers on the Metropolitan Water District transmission lines from Hoover Dam). The two SCE HOOVER DAM, SOUTHERN CALIFORNIA EDISON NORTH AND SOUTH LINES HAER NO.

(Page 3) transmission lines take different courses from the SCE Switchyard at Hoover Dam to Hemenway Wash, but the lines then run parallel and llear each other to the north of Boulder City and then to the southwest toward Chino, California. The two transmission lines remain virtually unchanged in the vicinity of Hoover Dam and Boulder City, except for replacement of conductors and installation of bird guards and vibration dampeners. A segment of the South line was relocated near the Hacienda Hotel/Casino about about three miles west of Hoover Dam, including removal or relocation of at least two towers and construction of at least two additional towers.

The SCE lines were tied to Mead Substation, south of Boulder City, in the early by means of tie lines constructed to the west of the substation.

Source document Quoted word for word from HAER NV-27-N. Not written, edited or summarised by this site.

This documentation of features of Hoover Dam and associated structures was accomplished by Associated Cultural Resource Experts (ACRE). ACRE completed documentation of21 features in October Documentation on four linear features was extended and an additional 3 features were newly documented in February Both phases of documentation were conducted as part of the historical/engineering recordation of Hoover Dam-prepared for the Department of Energy, Western Area Power Administration; Bureau of Reclamation; and Federal Highway Administration-that includes a narrative for the Addendum to Hoover Dam and individual documentation of 25 features located at the Hoover Dam facility, photo documentation, and documentation of existing historic photographs and site plans.

The recordation conforms to the standards of the Historic American Engineering Record, U.S. Department of the Interior.

Other reports in the HAER collection completed for these projects are a narrative for the Addendum to Hoover Dam and 24 short forms for individual structures: Hoover Dam, Los Angeles Switchyard (NV-27-A); Hoover Dam, Southern Sierras/CEP/Southern California Edison Switchyard Hoover Dam, Metropolitan Water District Switchyard Hoover Dam, State of Nevada Switchyard Hoover Dam, Southern California Edison Switchyard (NV-27-E); Hoover Dam, Arizona-Nevada Switchyard Hoover Dam, Static Towers and Lines Hoover Dam, Los Angeles Relay Control Building Hoover Dam, Switchyard Fire House Hoover Dam, Promontory Water Tank Hoover Dam, Control Cable Hoist House Hoover Dam, Transformer Circuits I-15 Hoover Dam, Los Angeles BPL Lines 1-3 Hoover Dam, Southern California Edison North and South Lines Hoover Dam, Hoover-Basic Magnesium North and South Lines Hoover Dam, Metropolitan Water District Line I Hoover Dam, United States Construction Railroad Hoover Dam, U.S.

Highway 93 Nevada Segment Hoover Dam, Lower Portal Access Road Hoover Dam, Kingman Switchyard Hoover Dam, U.S. Highway 93 Arizona Segment (NV-27-U); Hoover Dam, Explosives Magazines Hoover Dam, Nevada Downstream Waste Tailings and Hoover Dam, Nevada Spoils Tunnel Hoover Dam, Henderson-Mead Transmission Line 2

Source document Quoted word for word from HAER NV-27-N. Not written, edited or summarised by this site.

This documentation was prepared for three federal agencies: U.S. Department of Transportation, Federal Highway Administration A), Central Federal Lands Highway Division, Lakewood, CO; U.S. Department of Energy, Western Area Power Administration (Western), Desert Southwest Customer Support Region, Phoenix, AZ; and U.S. Department of Interior, Bureau of Reclamation (Reclamation), Lower Colorado Region, Boulder City, NV. This documentation records certain transportation and electrical features associated with Hoover Dam before planned removal or alteration of some structures. FHWA plans to construct a bridge over the Black Canyon of the Colorado River about downstream from Hoover Dam. The Hoover Dam Bypass Project would include realignment of U.S.

Highway 93 on the Nevada and Arizona sides of Black Canyon. The project would include demolition, relocation, or substantiaJ visual impact to a segment of U.S. Highway 93 on the Nevada approach to Hoover Dam, a segment of a former alignment of U.S. Highway 93 in Arizona, electrical transformer circuits in HOOVER DAM, SOUTHERN CALIFORNIA EDISON NORTH AND SOUTH LINES HAER NO. (Page 4) Arizona and Nevada, two electrical switchyards, a segment of the grade of the U.S. Construction Railroad, a stone gate structure for a dam construction and operations road, and six historic transmission lines. This documentation also records certain structures not directly affected by FHW A's Hoover Dam Bypass Project.

Electrical transmission facilities at Hoover Dam are administered by Western, but these facilities are within a federal reservation administered by Reclamation. Documentation of electrical structures is intended to partially fulfill responsibilities of Western and Reclamation under Section 110 of the National Historic Preservation Act (As amended). Some electrical structures addressed by Western and Reclamation would be directly affected by FHWA's Hoover Dam Bypass Project, and all structures addressed by Western and Reclamation are functionally related and geographically near structures addressed by FHW A. Project Manager and historian for the recordation was Kurt P. Schweigert of Associated Cultural Resource Experts. The photographers were Deborah Dobson-Brown and Douglas M.

Edwards of Associated Cultural Resource Experts. This documentation was prepared on the basis of research conducted at Reclamation archives in Denver, CO, and Boulder City, NV; Western archives and files in Denver and Phoenix, AZ; the National Archives and Records Administration in Denver; libraries of the University of Nevada-Las Vegas; and the Western History Collection of the Denver Public Library. This documentation includes information contained in survey reports for the Hoover Dam Bypass Project Environmental Impact Statement, an evaluation of the Western switchyards at Hoover Dam, an evaluation of the Hoover Dam construction railroads, a National Register nomination for Hoover Dam, and other documents.

Source document Quoted word for word from HAER NV-27-N. Not written, edited or summarised by this site.

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