Hoover Dam, Hoover-Basic Magnesium North & South Lines, U.S. Highway 93, Boulder City

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

U.S. Highway 93 Vicinity of Boulder City c Clark County Nevada USGS Hoover Dam, Nevada-Arizona 7.5 Minute Provisional USGS Boulder Beach, Nevada-Arizona 7.5 Minute UTM Coordinates: Hoover-Basic North Line: 1 (start) (end) Hoover-Basic South Line: (start) 1 (end) Date of Construction: Engineer: J. M. Montgomery Company Builder: Fritz Ziebarth 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: Hoover-Basic North Line: l l (start) 1 (end) Hoover-Basic South Line: l (start) (end) Statement of

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

The Hoover-Basic Magnesium North and South transmission lines served a vital function during World War II by providing electricity generated at Hoover Dam to the Basic Magnesium plant to the south of Las Vegas. After the war, these transmission lines continued to provide power to the Basic Magnesium plant, which was converted to a number of industrial uses and provided an industrial economic base for the Las Vegas Valley. Through interconnection with Nevada Power Company substations and distribution networks, these lines supported the rapid expansion in gaming and residential development of Las Vegas in the post-war period.

Report Prepared by: Associated Cultural Resource Experts (ACRE) Sangre de Cristo Road, STE 202 Littleton, CO Date: April HISTORIC AMERICAN ENGINEERNG RECORD HOOVER DAM, HOOVER-BASIC MAGNESIUM NORTH AND SOUTH LINES HAER NO. (Page 2) The Hoover-Basic Magnesium North and South transmission lines served a vital function during World War II by providing electricity generated at Hoover Dam to the Basic Magnesium plant to the south of Las Vegas. After the war, these transmission lines continued to provide power to the Basic Magnesium plant, which was converted to a number of industrial uses and provided an industrial economic base for the Las Vegas Valley.

Through interconnection with Nevada Power Company substations and distribution networks, these lines supported the rapid expansion in gaming and residential development of Las Vegas in the post-war period. Description: The Hoover-Basic North and South transmission lines consist primarily of A-frame, metal-wedge towers that support conductors carrying current from the Arizona-Nevada and Metropolitan Water District switchyards at Hoover Dam to substations in Henderson, Nevada and to Mead Substation near Boulder City, Nevada. 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 according to topography and cultural features crossed by the transmission line. The documented segment of the Hoover-Basic North line originates at the Metropolitan Water District Switchyard near the Nevada rim of Black Canyon, in Section 29, T.22S-R65E and extends westward to the west section line of Section 29, T.22S-R65E. This segment includes 4 steel towers, all of which are single-circuit, suspension structures. The documented segment of the Hoover-Basic South line originates in the Arizona-Nevada Switchyard in Section 29, T.22S-R65E and extends southwestward to the south section line of Section 30, T.22S-R65E. The recorded segment includes 6 steel towers, all of which are single-circuit, suspension structures.

History: On August 1, the Defense Plant Corporation, a corporation created by the Reconstruction Finance Corporation, entered into an agreement with Basic Magnesium, Inc., a private Nevada corporation, for the construction and operation of a magnesium plant near Las Vegas. Magnesium was a critical war material, used for strengthening alloys and as a component in incendiary bombs and anti-tank weapons. The Basic Magnesium plant was planned to be the largest magnesium production plant in the world. Magnesium production would require very large amounts of electricity, estimated at 1.2 million kilowatt-hours in the first year ending May 31, and 1.5 million kilowatt-hours for each of the two succeeding years.

Two transmission lines were constructed in to carry power from the switchyard of the Metropolitan Water District of Southern California at Hoover Dam to the magnesium plant at Henderson, Nevada. Under subcontract to Basic Magnesium Inc., the Montgomery Company designed the transmission lines, and Fritz Ziebarth of Long Beach, California, built the lines in and early The lines were designated Basic Magnesium 1 HOOVER DAM, HOOVER-BASIC MAGNESIUM NORTH AND SOUTH LINES HAER NO. (Page 3) and 2; by the lines had become known as Hoover-Basic North and Hoover-Basic South, respectively. The Basic North line ran approximately 16 miles west from the Metropolitan Water District of Southern California switchyard at Hoover Dam to the substation at the plant.

The Basic South line began at the Metropolitan Water District rack and ran southwest eight miles and then about miles northwest to the BMI plant substation. The two lines converged about 1.5 miles southeast of the BMI plant and then ran parallel, but on separate towers, to the plant site. The lines were constructed with circular mil. copper conductors and metal-wedge, A-frame-type towers, similar to those previously used in Southern California Edison and Metropolitan Water District transmission lines from Hoover Dam. The two transmission lines were probably constructed to rigid standards of the Bureau of Reclamation, as were other transmission lines terminating at Hoover Dam. Tower specifications for the lines were apparently drawn by Basic Magnesium, Inc.

in October but the format of the specifications is identical to that of Bureau of Reclamation tower specifications. On May 9, an agreement was reached among the United States, Basic Magnesium, Inc., and the City of Los Angeles, under which the City of Los Angeles would generate energy for the magnesium plant for the duration of the war. Other recipients of Hoover Dam power, particularly the Metropolitan Water District of Southern California, would also relinquish part of their power allotments to Basic Magnesium. To accommodate the Basic Magnesium lines, the existing Metropolitan Water District line connection was moved from the No. 2 bay to a temporary direct bus connection in May In August the MWD line was moved "permanently" to the No. 4 bay of the MWD Switchyard.

The Basic Magnesium North line was tied into the former location of the MWD line in bay No. 2, and after testing this line was energized on June 14, The Basic Magnesium South line was tied into the MWD Switchyard No. 3 bay on August 30, The Basic South line probably began service to the magnesium plant in the fall of but installation of circuit breakers and other equipment in the Metropolitan Water District Switchyard at Hoover Dam continued well into Construction of the lines, Basic Substation, and alterations and additions to the Metropolitan Water District Switchyard cost more than $6 million, apparently far more than was originally estimated. At the height of BMI plant operation in the BMI electrical system transmitted one-fourth of the power generated at Hoover Dam.

The magnesium plant began to curtail operations by mid-1944, and it ceased all magnesium processing by the end of that year. The Basic North and South lines continued to provide electricity for the remaining industrial functions at the Basic Magnesium complex and for the town of Henderson, and the lines provided a connection between Hoover Dam and the Parker Dam power plant, which also had provided electricity for the Basic Magnesium plant. The Basic South line also provided electricity to Boulder City through the Basic Tap Substation, which is now known as the Boulder City Tap Substation.

The two power lines were included in the purchase of the BMI facility by the State of Nevada in subject to a right of the Bureau of Reclamation to negotiate purchase of the lines from the War Assets Administration. In the Bureau of Reclamation purchased the lines for million. In Reclamation assumed control and operation of the transmission lines and Basic Substation from the Colorado River Commission of Nevada, which had leased the entire water and electrical system for BMI since September Reclamation purchased the lines with funds that were a line item of a Congressional appropriation for the Davis Dam Project, and therefore the Basic North and South lines were administered as part of the Davis Dam Project and later the Parker-Davis Project, rather than the Boulder Canyon Project.

HOOVER DAM, HOOVER-BASIC MAGNESIUM NORTH AND SOUTH LINES HAER NO. (Page 4) The State of Nevada was allotted kilowatts of power from Davis Dam, of which the state could begin taking delivery on June 1, at Basic Substation. In early the Basic South line was connected at Basic Tap near Boulder City with a 230-kilovolt line to Davis Dam, thus providing the means for Nevada to obtain its Davis Dam power. In the Metropolitan Water District reclaimed its excess Hoover Dam power that had been going to the State of Nevada, and thereafter the Basic South line primarily conducted power from Davis Dam to BMI.

About a portion of the Basic South line southeast of Boulder City was altered so that the line would pass through Mead Substation; thereafter the line was known as the Basic-Mead or Mead-Basic line between the two substations. The Basic North line is known as the Basic-Hoover or Hoover-Basic line. The Basic-Mead or Mead-Basic has been further segmented into the Mead-Amargosa line, between Mead Substation and the Amargosa Substation in Henderson; the Amargosa-Henderson line, between those substations in Henderson; and the very short Henderson-Basic line, between the Henderson Substation and the old Basic Substation at the BMI complex in Henderson. In January the Basic South line was relocated from the MWD switchyard to the Arizona- Nevada (A-N) Switchyard.

The line segment from the second tower on the outgoing side of the MWD Switchyard (OS2) to the third tower was removed. A new connection was established between a new tower on the outgoing side of the Arizona-Nevada Switchyard and the third tower of the original Basic South line. The original OS2 tower was replaced with an angled-steel tower, which became part of the permanent tie between the MWD and A-N switchyards. The original Basic South line was abandoned and removed for a distance of about four miles southwestward from the Basic/Boulder City Tap Substation after the first phase of the Mead Substation was completed in The Davis Dam line (built in was rebuilt near Mead Substation to connect the Basic/Boulder City Tap Substation with Mead Substation.

A connecting line about 1.5 miles long was built to connect Mead Substation to the southern end of the remaining original Basic South line running northwestward to Railroad Pass and eventually to Basic Substation. Several alterations have occurred to the Basic-Mead (Mead-Basic) line near the BMI site in Henderson. In a 0.7-mile segment of the line was relocated and rebuilt to allow construction of an automobile mall. This relocation included construction of one lattice steel tower and replacement of at least one lattice steel tower with four double-circuit steel poles. The relocated segment was strung with three 1,272,000-circular mil, aluminum cable steel-reinforced (ACSR), conductors and two 1/2-inch, seven-strand-steel, overhead ground wires.

A 0.5-mile segment of the line was rebuilt in to allow relocation of Nevada Highway. This alteration included relocation of Structure 7/5 and replacement of an original tower with a single steel pole structure. Alterations in other areas have included installation of at least three wood-pole, H-frame structures in intermediary locations between steel lattice towers.

Source document Quoted word for word from HAER NV-27-O. 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 HOOVER DAM, HOOVER-BASIC MAGNESIUM NORTH AND SOUTH LINES HAER NO.

(Page 5) reports in the HAER collection completed for these projects are a narrative for the Addendum to Hoover Dam and 24 short fonns 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-O. 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; 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 HOOVER DAM, HOOVER-BASIC MAGNESIUM NORTH AND SOUTH LINES HAER NO. (Page 6) Register nomination for Hoover Dam, and other documents.