Hoover Dam, Cable Hoist House, U.S. Highway 93, Boulder City

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

U.S. Highway 93 Vicinity of Boulder City ( puj"' Clark County Nevada USGS Hoover Dam, Nevada-Arizona 7.5 Minute Provisional UTM Coordinates: 1 Date of Construction: Engineer: U.S. Bureau of Reclamation Builder: U.S. Bureau of Reclamation U.S. Highway 93 Vicinity of Boulder City Clark County Nevada USGS Hoover Dam, Nevada-Arizona 7.5 Minute Provisional UTM Coordinates: l Statement of

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

The cable hoist house provided access to control cable tunnels from the power plant to the switchyard relay house, and a transformer in the lower level of the hoist house provided operating electricity to the switchyard complex. An electric hoist in the structure allowed heavy control and power cables to be drawn up from the power plant or lowered to the power plant. The hoist house was therefore a critical element of the Hoover Dam electrical generation and transmission system. Report Prepared by: Associated Cultural Resource Experts (ACRE) Sangre de Cristo Road, STE 202 Littleton, CO Date: April HISTORIC AMERICAN ENGINEERNG RECORD HOOVER DAM, CABLE HOIST HOUSE HAER NO.

(Page 2) The cable hoist house provided access to control cable tunnels from the power plant to the switchyard relay house, and a transformer in the lower level of the hoist house provided operating electricity to the switchyard complex. An electric hoist in the structure allowed heavy control and power cables to be drawn up from the power plant or lowered to the power plant. The hoist house was therefore a critical element of the Hoover Dam electrical generation and transmission system. Description: The cable hoist house is a 16' x 20' poured concrete structure with an extended concrete base/foundation and a flat roof. The building has pilaster-like extrusions at all four comers, stepped-in door and window heads, metal doors, and metal-louvered windows.

The ground floor interior of the hoist house contains a large electric hoist, control equipment, and telephone equipment. A ladder in the west area of the ground floor descends to a concrete tunnel extending to the power plant to the east and to the basement level of the relay house to the west. Extending from the east side of the main structure is a rectangular concrete structure with a steel-hatch roof; this structure is set into the ground and houses a transformer. History: Initial construction of the Hoover Dam switchyard complex included installation of portions of a master control system that would be extended to all six major Hoover Dam switchyards. An underground or semi-underground tunnel system was built to provide a secure venue for control cables and station service power.

From the crest of a topographic saddle between the dam and the future site of the City of Los Angeles Switchyard, a steeply inclined tunnel was driven about to the power plant. Rails for a small hoist car and stairs were installed within the inclined tunnel to facilitate installation and maintenance of control and power cables. A 16' x 20' concrete hoist house was built at the upper end of the inclined tunnel. The hoist house provided access to the tunnel and housed a large electric hoist; an extension of the lower level of the hoist house contained a transformer that provided operating power to the switchyard complex.

A semi-subterranean concrete box conduit was constructed from the lower level of the hoist house southwestward to the lower level of a concrete relay house, which was located just to the east of the City of Los Angeles Switchyard. Construction of the hoist house and the control conduit from the hoist house to the relay house was started in April completed in June Control and service power cables (providing power to switching and other control equipment) connected to relay panels and a transformer in the basement level of the relay house. This underground control conduit system would be extended as switchyards were constructed. The hoist house has remained virtually unchanged, except the hoist cable mechanism was replaced about

Source document Quoted word for word from HAER NV-27-K. 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 HOOVER DAM, CABLE HOIST HOUSE HAER NO.

(Page 3) 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 (NV-27-I); Hoover Dam, Promontory Water Tank Hoover Dam, Control Cable Hoist House Hoover Dam, Transformer Circuits 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 1 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-K. Not written, edited or summarised by this site.

This documentation was prepared for three federal agencies: U.S. Department of Transportation, Federal Highway Administration (FHWA), 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 substantial 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 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 FHWA'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 FHWA. 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; HOOVER DAM, CABLE HOIST HOUSE HAER NO. (Page 4) 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 Westem switchyards at Hoover Dam, an evaluation of the Hoover Dam construction railroads, a National Register nomination for Hoover Dam, and other documents.